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Sci final with author
Monday, April 27, 1998
6:45 AM – 9:30 AM
6:45 AM – 7:30 AM
7:30 AM – 9:30 AM
ANEURYSM CLIPPING: ADVANCED TECHNIQUES
Ralph Dacey, MD (Saint Louis, MO)
Philip E. Stieg, MD, PhD (Boston, MA)
Robert Solomon, MD (New York, NY)
Robert Spetzler, MD (Phoenix, AZ)
H. Hunt Batjer, MD (Chicago, IL)
John Tew, MD (Cincinnati, OH)*
Peter Jannetta, MD (Pittsburgh, PA)
Takanori Fukushima, MD (Pittsburgh, PA)
Albert Rhoton, Jr., MD (Gainesville, FL)
NEUROSURGICAL MANAGEMENT OF
Richard North, MD (Baltimore, MD)*
Robert Levy, MD (Chicago, IL)*
Kim Burchiel, MD (Portland, OR)*
Samuel Hassenbusch, MD (Houston, TX)*
Yucel Kanpolat, MD (Ankara, Turkey)
Robert Maxwell, MD (Minneapolis, MN)
Glenn Morrison, MD (Miami, FL)
Paul Kanev, MD (Detroit, MI)
Anne-Christine Duhaime, MD (Philadelphia, PA)
Philip Villanueva, MD (Miami, FL)
Gordon Baltuch, MD (Philadelphia, PA)
CONTROVERSIES IN PEDIATRIC
Gordon McComb, MD (Los Angeles, CA)
Mark Dias, MD (Buffalo, NY)
David Jimenez, MD (Columbia, MO)
James Goodrich, MD (Bronx, NY)
Derek Bruce, MD (Dallas, TX)
SURGERY OF THE CRANIOCERVICAL
JUNCTION IN PEDIATRIC PATIENTS
Arnold Menezes, MD (Iowa City, IA)
David Gordon McLone (Chicago, IL)
Gerald Tuite, MD (Saint Petersburg, FL)*
Benjamin Carson, MD (Baltimore, MD)
J. Parker Mickle, MD (Gainesville, FL)
STEREOTACTIC SURGERY FOR MOVEMENT
M. Peter Heilbrun, MD (Salt Lake City, UT)*
Robert Grossman, MD (Houston, TX)
Andres Lozano, MD (Toronto, ON)*
Roy A.E. Bakay, MD (Atlanta, GA)*
Alim Benabid, MD (New York, NY)*
SURGICAL OPTIONS IN EPILEPSY
George Ojemann, MD (Seattle, WA)
Guy Clifton, MD (Houston, TX)
Robert Goodman, MD (New York, NY)Webster Pilcher, MD (Rochester, NY)Steven Roper, MD (Gainesville, FL)
EVALUATION AND MANAGEMENT OF
TRAUMATIC C1–C2 INSTABILITY
Ronald Apfelbaum, MD (Salt Lake City, UT)*
Volker K.H. Sonntag, MD (Phoenix, AZ)*
Nevan Baldwin, MD (Albuquerque, NM)
Michael Fehlings, MD (Toronto, ON)
R. Patrick Jacob, MD (Gainesville, FL)
PERIPHERAL NERVE INJURY AND
ENTRAPMENT: EVALUATION AND MANAGEMENT
David Kline, MD (New Orleans, LA)
James Campbell, MD (Baltimore, MD)*
Allan Friedman, MD (Durham, NC)
Eric Zager, MD (Philadelphia, PA)
Allan Belzberg, MD (Baltimore, MD)
MANAGEMENT OF SPINAL CORD TUMORS
Paul Cooper, MD (New York, NY)
Fred Epstein, MD (New York, NY)
Jacques Brotchi, MD (Brussels, Belgium)
Michael Ebersold, MD (Rochester, MN)
Ian McCutcheon, MD (Houston, TX)
MINIMALLY INVASIVE SURGERY OF THE
Richard G. Fessler, MD (Gainesville, FL)*
Kevin T. Foley, MD (Memphis, TN)*
Paul Young, MD (Saint Louis, MO)
Parvin Kambin, MD (Philadelphia, PA)*
Manucher Javid, MD (Madison, WI)
CERVICAL SPONDYLOTIC MYELOPATHY:
SURGICAL MANAGEMENT AND LONG-TERM
Ulrich Batzdorf, MD (Los Angeles, CA)
Gary Rea, MD (Columbus, OH)
Richard Saunders, MD (Lebanon, NH)
Barth Green, MD (Miami, FL)
George Sypert, MD (Fort Myers, FL)
SPINAL STABILIZATION: STATE OF THE ART
PRINCIPLES OF SELECTION, APPLICATION,
AND CONSTRUCTION DESIGN
Edward C. Benzel, MD (Albuquerque, NM)*
Vincent C. Traynelis, MD (Iowa City, IA)*
Dennis Maiman, MD (Milwaukee, WI)*
Regis Haid, Jr., MD (Atlanta, GA)*
Eric Woodard, MD (Boston, MA)
NEUROLOGICAL INJURIES AND THE ATHLETE
Michael L.J. Apuzzo, MD (Los Angeles, CA)
Charles Tator, MD (Toronto, ON)Joseph Maroon, MD (Pittsburgh, PA)Robert Cantu, MD (Concord, MA)Arthur L. Day, MD (Gainesville, FL)Ronald Barnes, MD (East Rutherford, NJ)
CAVERNOUS SINUS SURGERY: TECHNIQUES,
PITFALLS, AND COMPLICATIONS
Ossama Al-Mefty, MD (Little Rock, AR)
Laligam Sekhar, MD (Washington, DC)
Harry Van Loveren, MD (Cincinnati, OH)
J. Diaz Day, MD (Boston, MA)
Wolfgang Koos, MD (Vienna, Austria)
LOW-GRADE GLIOMAS: CURRENT TREATMENT
Mitchel Berger, MD (San Francisco, CA)
Michael Salcman, MD (Baltimore, MD)
James Rutka, MD (Toronto, ON)
Kevin Judy, MD (Philadelphia, PA)
Jeffrey Wisoff, MD (New York, NY)
CRANIAL BASE APPROACHES TO THE
Steven Giannotta, MD (Los Angeles, CA)*
Johnny B. Delashaw, MD (Portland, OR)
Donald Wright, MD (Washington, DC)
Jack Rock, MD (Detroit, MI)
Chandranath Sen, MD (New York, NY)
ESTABLISHING STROKE CENTERS AND
Marc Mayberg, MD (Seattle, WA)
Issam Awad, MD (New Haven, CT)
Julian Bailes, MD (Pittsburgh, PA)
Lee Guterman, MD (Buffalo, NY)
FROM LABORATORY TO THE OPERATING
ROOM: TECHNOLOGY TRANSFER IN
Forcht Dagi, MD (Atlanta, GA)
George Dohrman, MD (Chicago, IL)
Theodore Roberts, MD (Seattle, WA)
CONSULTANTS CORNER: CEREBROVASCULAR
David Piepgras, MD (Rochester, MN)
Roberto Heros, MD (Miami, FL)
Duke Samson, MD (Dallas, TX)
Daniel Barrow, MD (Atlanta, GA)
Robert Rosenwasser, MD (Philadelphia, PA)
3-D VIDEO SEMINAR—8TH NERVE TUMORS
Ken Smith, MD (Saint Louis, MO)
9:00 AM – 4:30 PM
Exhibit Hall A/B/C
479 posters have been chosen for presentation. All will be ondisplay Monday through Wednesday. Presentations will be givenbetween 1:45 PM and 2:45 PM on Wednesday, April 29, 1998,for uninterrupted viewing.
(See Poster Program for complete listing of papers.)
PLENARY SESSION I
9:45 AM – 11:40 AM (Ballroom A/B)
J. Charles Rich, MD (Salt Lake City, UT)
Randomized Trial of Pallidotomy for Parkinson’s Disease
Roy A.E. BakayJerrold L. VitekAlan FreemanMarian L. EvattJoanne GreenWilliam McDonaldMichael HabarHiuman BarnhartShirley TricheKlaus MewesVijay ChockkanJian-Yu ZhangNatalie WahlayMahlon R. DeLong (Atlanta, GA)
KEY WORDS: pallidotomy, Parkinson’s disease
The effect of posterolateral “sensorimotor” pallidotomy on parkinso-
nian motor signs as well as neuropsychological and psychiatric function wasexamined.
The beneficial effects of pallidotomy on parkinsonian motor signs have
been reported in uncontrolled studies by several centers. Based on the suc-cess of these studies, we designed a randomized trial comparing best medi-cal therapy to pallidotomy.
Patients with idiopathic Parkinson’s disease (PD) were assessed pre-
and postoperatively using the Unified Parkinson’s Disease Rating Scale(UPDRS), timed tests of motor function, Schwab and England measure offunctional independence, as well as a detailed neuropsychological battery andpsychiatric evaluation. Following the second of three baseline evaluations,patients were randomized to surgical or medical management. Pallidotomywas performed using electrophysiological guidance. Lesion locations werereconstructed using high-resolution MR images.
Of the 44 patients enrolled, 27 have completed 6-month follow up in
surgical (14) and medical control arms (13) of the study. The study was closedafter the third interim analysis. Following surgery, there was a statistically sig-nificant reduction in the total UPDRS score, from 77 to 51 (p < 0.0001). Themedical control arm showed a slight worsening, from 73 to 77. The surgicalgroup also showed significant (p, 0.0001) improvement in the “off” motor and
ADL subscores, improving from 42 to 28, and 23 to 17, respectively. The Schwaband England score improved from 51 to 71% when “off” and from 81 to 89%when “on.” In addition, drug-induced dyskinesias were significantly reduced (p= 0.0019). In the “off” state, improvement in overall motor function was re-flected by a substantial reduction in contralateral tremor (p = 0.0012), rigidity(p < 0.001), and bradykinesia (time test 2-point movement [p < 0.0001]). Sig-nificant (p < 0.0001) ipsilateral benefit in bradykinesia and rigidity was alsoobserved and sustained over the 6-month follow-up period. Statistical com-parisons did not suggest a difference in neuropsychological or psychiatric func-tion between the two groups.
This randomized prospective clinical trial demonstrates significant im-
provement in the cardinal motor features of PD following unilateral GPIpallidotomy. (Supported by NIH grant #NS-32047.)
MONDAY, 10:00-10:15 AM
Gamma Knife Radiosurgery for Cerebral Arteriovenous
Malformations: A Multi-Institutional Study in Japan
Masaaki Yamamoto (Tokyo, Japan)Tatsuya Kobayashi (Sendai, Japan)Hidefumi Jokura (Komak, Japan)Seiji Fukuoka (Sapporo, Japan)Hiromichi Hosoda (Chigasaki, Japan)
KEY WORDS: radiosurgery, arteriovenous malformation
No multi-institutional studies on radiosurgery for cerebral AVMs have been
published. The results of greater than 3 years’ follow-up data in 885 patientswith AVMs who underwent gamma knife radiosurgery between May, 1991, andMarch, 1994, at one of the 11 gamma knife centers in Japan are analyzed.
Postradiosurgically, 681 (77%) of the 885 patients were periodically ex-
amined by means of angiography. Complete nidus obliteration wasangiographically confirmed in 443 patients (50%), subtotal obliteration in 114(13%), shrinkage in 99 (11%), and no significant change in the remaining 25(3%); these rates correspond to 65%, 17%, 15%, and 4%, respectively, of the681 patients who had follow-up angiography. Hemorrhages occurred duringthe postradiosurgical latency period, ranging from 1 to 48 months, in 41 pa-tients (4.6%); annual rates were 2.4% during the first postradiosurgical year,0.9% during the second, 0.8% during the third, and 0.3% during the fourth.
Although 14 (34%) of the 41 patients showed full recovery, 13 (32%) died andthe other 14 (34%) have persistent deficits. Radiation-related aggravation ofclinical symptoms was seen in 24 (2.7%) of the 885 patients at between 5 and36 postradiosurgical months. Steroid treatment was required in all 24 patients,16 of whom recovered completely while the other 8 had persistent deficits.
The overall obliteration rate reported here seems relatively low as com-
pared with those reported previously. However, the annual incidence of (re-)bleeding during the latency period was low as compared with those reportedfor untreated AVMs.
Monday, 10:15–10:18 AM
Distinguished Service Award Presentation—
Mark J. Kubala
(To be introduced by Russell L. Travis, MD)
MONDAY, 10:18-10:33 AM
Posterior C1-2 Transarticular Screw Fixation for Atlantoaxial
Curtis A. DickmanVolker K.H. Sonntag (Phoenix, AZ)
KEY WORDS: atlantoaxial instability, arthrodesis, screw fixation
One hundred twenty-one patients were treated for atlantoaxial instability
with posterior C1-2 transarticular screws and an autologous wired posterior C1-2 interposition bone strut. Atlantoaxial instability was due to rheumatoid arthritis(n = 48), fractures of C-1 or C-2 (n = 45), transverse atlantal ligament disruption(n = 11), os odontoideum (n = 9), tumors (n = 6), or infection (n = 2). In all, 226screws were placed. Bilateral C1-2 transarticular screws were placed in 105patients; 16 patients had only one transarticular screw placed because of ananomalous course of the vertebral artery (n = 13), tumor (n = 1), joint erosion (n= 1), or C-1 fracture (n = 1). All screws were placed under lateral fluoroscopicguidance. All patients had postoperative radiographs and CT scans to assessscrew positioning, stability, and osseous union.
Two hundred twenty-one (98%) of the 226 screws were positioned satis-
factorily; five were malpositioned (2% malpositioning), none had clinical se-quelae. Four of the five malpositioned screws were reoperated on (1 screwwas repositioned, 3 screws were removed). There were no neurological com-plications, strokes, or TIAs associated with the surgical procedures. Long-term follow up was achieved in 114 patients (mean follow-up duration 22months). One hundred twelve (98%) of the patients achieved fusion. Therewere two nonunions (1.9%) associated with delayed screw fractures and re-current C1-2 hypermobility which required occipitocervical fusion. In compari-son, our prior C1-2 fixations for similar pathology with C1-2 wires and au-tograft (n = 89) had an 86% union rate. C1-2 transarticular screw fixation rigidlyfixes the unstable motion segments resulting in a significantly higher fusionrate (98% vs 86%) than wiring and grafts alone.
The risk of screw malpositioning and catastrophic vascular or neural
injury is small and can be minimized by assessing the position of the foramentransversarium on preoperative CT scans, by using intraoperative fluoroscopy,and by using frameless stereotaxis to guide the screw trajectory.
MONDAY, 10:33-10:48 AM
Results and Expectations From Trigeminal Neuralgia
Douglas Kondziolka*L. Dade LunsfordBernardo PerezJohn C. Flickinger (Pittsburgh, PA)
KEY WORDS: radiosurgery, trigeminal neuralgia, pain relief
Over the last 5 years, stereotactic radiosurgery has been performed for
the management of patients with trigeminal neuralgia (TGN). Initially, radio-surgery was used for patients with recurrent pain after prior surgeries. Morerecently radiosurgery has been advocated as a minimally invasive surgicalstrategy for TGN. Our hypothesis was that radiosurgery could provide painrelief with low risk for facial sensory loss and no other morbidity. We reviewedour 5-year experience in patients and evaluated the factors of age, prior surgi-cal history, radiosurgery dose, multiple sclerosis, imaging appearance of thenerve, and need for further treatment.
One hundred twenty-one patients underwent gamma knife radiosurgery
with a 4-mm isocenter (3 patients had a 2-isocenter plan). A maximum dose of70 Gy (n = 54), 80 Gy (n = 60), 85 Gy (n = 5), or 90 Gy (n = 2) was adminis-tered. Prior operations included microvascular decompression (n = 42), glyc-erol rhizotomy (n = 57), and radiofrequency rhizotomy (n = 19). Mean patientage was 67 years (32–92 years), and the mean duration of pain was 11 months.
Seventy-nine patients had radiosurgery with the Model U gamma knife and 42with the Model B.
Median follow up after radiosurgery was 18 months. Initial improvement
was noted in 106 patients (88.3%). Degree of pain relief was coded as total(100% relief off medications) in 64 patients (60.4%); 50 to 90% relief in 18patients (17%); 10 to 50% relief in 9 patients (9%); and no relief in 15 patients(14%). Significant pain relief was noted by 77% of patients at last follow up.
There was no difference in the spectrum of pain relief according to radiosur-gery dose, patient age, imaging identification of the nerve, or whether priorsurgery had been performed. Patients with multiple sclerosis-related TGN fairedworse (p = 0.04). Postradiosurgery paresthesias (numbness) was describedby 12 patients (10%). Relapse of pain was noted in only 6 (10%) of 64 patientswho attained complete relief. There was no other morbidity after radiosurgery.
Radiosurgery is a minimally invasive surgical approach for the manage-
ment of trigeminal neuralgia that is associated with a low rate of facial pares-thesia and no other morbidity. At the current range of dose and nerve lengthirradiated, significant and lasting pain relief was noted in 77% of patients.
Radiosurgery should be considered part of the armamentarium for TGN, es-pecially in patients with concomitant medical illness or in whom other surgicalprocedures have failed.
Monday, 10:48–10:51 AM
THINK FIRST Announcement
Thomas G. Saul, MD (Cincinnati, OH)
MONDAY, 10:51-11:06 AM
Transplantation of Fetal Pig Cells for Parkinson’s Disease:
James M. Schumacher (Sarasota, FL)*Prather PalmerSamuel A. Ellias (Burlington, MA)Steven Fink (Boston, MA)Ole Isacson (Belmont, MA)
KEY WORDS: Parkinson’s disease, pig cell transplantation, outcome
This series includes 12 patients with moderate to severe Parkinson’s
disease for an average of 13.9 years (5–24 years), age 61 years (48–70 years),Hoen and Yahr stage of 3.7 off, 2.2 on. The patients underwent unilateral trans-plantation of pig ventral mesencephalic cell suspensions into the striatum inan open-label study. Six patients were immunosuppressed with cyclosporinand six received cells treated with a F(ab)’2 antibody directed to MHC1. Tenpatients were tested both presurgically and at 3-month intervals postsurgeryusing a modified CAPIT protocol including the Unified Parkinsonís DiseaseRating Scale (UPDRS), timed tests, neuropsychological testing, and homediaries. F-DOPA PET scans were performed.
Specific patients in both treated groups showed clinical improvement.
One patient improved 81 points on the UPDRS from 9 months to 21 monthsafter surgery. Two patients showed sustained improvement on the UPDRS at15 months. Ten patients had an average improvement of 13.2 UPDRS points
at 6 months (p < 0.05). Seven of 10 patients showed improvement on theUPDRS, UPDRS motor, and UPDRS activities of daily living. There were nomajor side effects or decrement in neuropsychological scores. One patientdied 7 months after surgery of a pulmonary embolism unrelated to the proce-dure. Autopsy revealed surviving pig dopaminergic grafts in the patient’s stria-tum. Xenotransplantation of pig neural cells is possible in Parkinson’s diseaseand has shown clinical efficacy in some patients.
Monday, 11:06–11:21 AM
Special Presentation—Philadelphia Art
Michael Salcman, MD (Baltimore, MD)
MONDAY, 11:21-11:36 AM
Gamma Knife Radiosurgery of Cavernous Sinus Meningiomas:
Results of a Two-Institution, 10-Year Experience
Christopher M. Duma (Los Angeles, CA)L. Dade LunsfordDouglas KondziolkaBrian R. Subach (Pittsburgh, PA)Deane B. Jacques (Los Angeles, CA)
KEY WORDS: radiosurgery, cavernous sinus, meningioma
To evaluate the response of cavernous sinus meningiomas to stereotac-
tic radiosurgery we reviewed the combined 10-year experience, from two in-stitutions, of 92 patients. This review included long-term data in 34 patients(median follow up 5.8 years) from a previously reported series. All patientsunderwent radiosurgery using a cobalt-60 gamma knife. Fifty-four patients(59%) had histological confirmation of meningiomas (1–5 skull base cranioto-mies per patient, average 2.6); 38 (41%) were treated on the basis ofneuroimaging criteria alone. The single-fraction radiation tumor margin dose(5-20 Gy, median 14 Gy) was designed to conform to the irregular tumor vol-umes and required an average of 6.9 isocenters.
None of the 92 patients had tumor growth (100% tumor control) during
the follow-up interval (median 3.1 years, range 0.3–9.5 years). Tumor regres-sion was observed in 39% of patients imaged at an average of 18 months.
Thirteen patients (14%) improved clinically. Three patients (3%) had new orworsened visual field deficits with varying improvement during the follow-upinterval. One patient developed deterioration of a previously present 6th nerveparesis. Three patients developed a partial-complex seizure disorder. Twopatients died in the follow-up interval of unrelated causes. The overall perma-nent complication rate was 7.6%. In the initial 34-patient series, followed up to9.5 years (median 5.8 years), the tumor control rate remained 100%. Nine-teen patients (56%) showed tumor regression. The overall complication ratewas 8.8%.
Gamma knife radiosurgery is an accurate, safe, and effective adjunct or
alternative to craniotomy to prevent growth of tumors involving the cavernoussinus. The long-term results show safety and efficacy. Conformal radiosurgeryshould be considered the treatment of choice for residual or recurrent menin-giomas as well as selected tumors discovered de novo.
SPECIAL LECTURE I
DECADE OF THE BRAIN MEDALIST
11:40 AM – 12:15 PM (Ballroom A/B)
FROM STEM CELLS TO CIRCUITS, EARLY STEPS IN
(To be introduced by William F. Chandler, MD)
12:15 PM – 1:00 PM (Ballroom A/B)
(To be introduced by William Shucart, MD)
SCIENTIFIC SESSION I
2:45 PM – 5:15 PM (Room 113A/B/C)
Russell Travis, MD (Lexington, KY)
MONDAY, 2:45-3:00 PM
Management of Cerebral Vasospasm: Timing of Endovascular
Robert H. RosenwasserJeffrey E. ThomasPatricia GannonRodney BellDara Jamieson (Philadelphia, PA)
KEY WORDS: vasospasm, endovascular surgery
This series includes a total of 367 patients with SAH treated between
July, 1993, and March, 1997. Ninety-two percent of all patients admitted wereoperated on within the first 24 hours of admission to our institution, regardlessof the day of the original hemorrhage. The remainder were operated on withina 48-hour window pending medical stabilization. Postoperatively, all patientswere managed in the routine fashion, with prophylactic hypervolemichemodilutional therapy, and twice-daily transcranial Doppler ultrasound evalu-ation. Treatment protocol was extremely aggressive, in that if a patient’s neu-rological deficit from cerebral vasospasm did not reverse within a 60-minuteperiod, the patient was then taken to the interventional suite for angioplastyand papaverine infusion.
Eighty patients (22%) underwent endovascular management during this
period of time. Angioplasty protocol involved placement of a No. 9 French femo-ral sheath, full heparinization, continuation of dextran infusion (40 cc/hr), andgeneral anesthesia. Materials utilized included the ITC silicone balloon, as wellas the Stealth system, with inflations of approximately 0.5 to 1 atmosphere for1- to 5-second inflation periods. Balloon angioplasty was followed by papaver-ine infusion, administering 300 mg total over a 30- to 45-minute period.
Analysis of the data indicated that there appears to be a 2-hour window
in which angioplasty is most successful in reversing the deficit and maintain-ing a sustained clinical improvement. Forty-nine patients (61%) were treatedin < 2 hours. The remainder were treated in a > 2-hour period, but no longerthan an 8-hour interval. In those patients treated in < 2 hours, there was a90% rate of angiographic improvement after treatment, with a 70% rate ofimmediate and sustained clinical improvement. At > 2 hours, there was 88%angiographic improvement with only a 40% sustained clinical improvement; inthis group, asymptomatic salt and pepper reperfusion hemorrhages were noted.
No patients developed intracranial hematomas necessitating surgical evacua-tion or elevating ICP to dangerous levels. Eight patients required retreatment;all were in Fisher Grade III or above, with sustained transcranial Doppler flowvelocities > 200 cm/sec. There were no dissections and no surgical hemato-mas for the entire group treated with angioplasty.
Aggressive and early intervention should be undertaken in patients who
are refractory to medical measures to reverse the symptoms of cerebral va-sospasm. It appears in this preliminary series that the 2-hour window may beimportant. Rationales and details of treatment will be discussed.
MONDAY, 3:00-3:15 PM
Mercury Water and Cauterizing Stones: Nicolaus André and Tic
Jeffrey A. Brown (Toledo, OH)Catherine SimonDevedutta G. Sangvai (Groton, MA)Mark C. Preul (Detroit, MI)
KEY WORDS: tic douloureux, Nicolaus André, cautery, neurosurgical
In his 1756 publication, Observations Pratiques sur les Maladies de
l’Urethre et sur Plusiers Faits Convulsifs, Nicolaus André included a series of5 case reports wherein he coined the term “tic douloureux” and described anovel treatment for the disease known before as “spasme cynique.” This paperrepresents the first translation of this aspect of his work into English and re-views André’s understanding of the etiology and treatment of trigeminal neu-ralgia two centuries ago. André hypothesized that tic douloureux occurs be-cause of peripheral compression of the inferior maxillary or orbital nerves. Inhis first case there was a traumatic origin to the pain and associated infection,presumably osteomyelitis. The other cases had no known cause. André treatedthe pain with cauterizing stones and mercury water to bloodlessly expose theperipheral nerve branches over the periosteum of the maxilla. He first com-pressed and squeezed the associated nerve branches with tweezers, thenleft the wound open to decompress it.
Testimonies confirm the success of his pain relief, but in two cases there
was a recurrence of pain about 6 months after treatment which was treatedsuccessfully again with the same technique. His patients were followed for sev-eral years and often had had pain for a decade or longer before reaching hisattention. André believed in a peripheral etiology and he treated pain both bynerve compression and decompression. He was able to identify a specific trigemi-nal branch which mediated the triggering sensation and suggested in his obser-vation that the nerve was injured, observing a probable neuroma. By graduallyapproaching the nerves with cautery he limited the blood loss. He suggestedthat the clot which formed after direct surgical approach continued to compressthe sensitive nerve branch and trigger pain. André’s treatment was successfulbecause he used the modern medical model of clinical and surgical observa-tion, applied anatomy, careful hemostasis, and innovative technique.
MONDAY, 3:15-3:30 PM
The Value of Clinical Symptoms and Signs in Predicting Shunt
Hugh Garton*John Kestle (Vancouver, BC, Canada)James Drake (Toronto, ON, Canada)
KEY WORDS: shunt failure, grading system, prognosis
Shunt malfunctions are a common occurrence in neurosurgical practice.
Predictive values for signs and symptoms are important in deciding whichpatients need an imaging study and/or transfer to regional care facility. Like-wise, symptoms or lack thereof that correlate with a low probability of shunt
failure could simplify management. Data from the recently completed ShuntDesign Trial were analyzed. Predictive values were calculated for the signsand symptoms of shunt failure. To refine predictive capability, a Symptom Score,based on a cluster of signs and symptoms, was then developed and assessed.
A total of 570 encounters from 344 patients (median age at entry 71 days)
were analyzed. For patients with recent shunt insertion (< 5 months), the follow-ing factors were most useful in predicting shunt failure: bulging fontanelle (posi-tive predictive value [PPV] = 94.3%, likelihood ratio [LR] = 37.0), CSF leak (PPV= 87.5%, LR = 16.31), decreased level of consciousness (LOC) (PPV = 85.7%,LR = 13.9), fluid tracking around shunt (PPV = 82.8%, LR = 11.2), and nauseaand vomiting (PPV = 81.4%, LR = 10.3). For patients further out from shuntinsertion (> 9 months), fewer factors were predictive: decreased LOC (PPV =77.8%, LR = 27.5) and nausea and vomiting (PPV = 60%, LR = 11.8). No fac-tors were independently successful in predicting the lack of malfunction in ei-ther group. Using the Symptom Score, in the recent insertion group, the lowestLR obtained was 0.2, while in the late group the lowest LR was 0.6.
Effectively ruling out a shunt malfunction based on symptoms alone re-
mained a problem, particularly in the late group. Based on the prevalence of shuntfailure of 30% and 10% for the two groupings, with a minimum Symptom Score,the likelihood of malfunction could be decreased to 7% and 6%, respectively.
MONDAY, 3:30-3:45 PM
Outcome Analysis of Patients With Isolated Neck Pain in the United
States: Results of the Cervical Spine Research Society Study
John DavisPrakash SampathMohammed Bendebba (Baltimore, MD)Thomas Ducker (Annapolis, MD)
KEY WORDS: neck pain, multicenter study, pain treatment
The impact of medical and surgical treatment on neck pain is poorly
understood. The Cervical Spine Research Society (CSRS) Study is amulticenter study of a large heterogeneous group of patients who were re-ferred to a specialist for the evaluation and treatment of subacute or chronicrecognized cervical spine pain problems. In this study, we focus on patientswho have neck pain; patients with radiculopathy or myelopathy were studiedseparately. The goals of the study are to characterize these patients, assesstheir outcome with respect to the treatment received, treatment prescribed,and expected outcome, identify the most effective forms of treatment, andexamine factors that influence outcome.
A total of 503 patients were enrolled in the study. Of these, 195 (39%)
presented with neck pain as the predominant complaint with no associatedradiculopathy or myelopathy. Forty-one CSRS surgeons participated in thestudy. Each study patient completed a CSRS questionnaire on initial presen-tation and at follow-up appointment after receiving a treatment. The physicianthen completed a form. Statistical analysis was performed by a blinded thirdparty using the SAS program.
Of 195 patients who presented with neck pain as the predominant clinical
feature, 122 (63%) returned for follow up and completed the questionnaire. Theprescribed treatment was medical treatment for 101 patients (83%), surgical treat-ment for 10 (8%), and no treatment for 11 (9%). In actuality, 107 (88%) receivedmedical treatment and 14 (12%) received surgical treatment. In the patients whowere prescribed and received surgical treatment (with or without fusion), 11 (79%)still had significant neck pain, with only 21% reporting improvement. The patientsreceiving medical treatment fared better with 60% improvement. Complete dataon medical and surgical treatments, pain scales, social activity, work status, litiga-tion, workers’ compensation, and patient satisfaction will be presented. Factorsthat influence outcomes in all patients will be discussed in detail.
Currently, it appears there are minimal benefits of surgery for patients
with isolated neck pain without signs of myelopathy or radiculopathy, evenwith fusion. This is the first prospective, multisurgeon study that examines thisimportant issue and correlates with present clinical opinion.
MONDAY, 3:45-4:00 PM
Thoracoscopic Microsurgical Excision of Herniated Thoracic Discs
Curtis A. Dickman (Phoenix, AZ)Daniel Rosenthal (Frankfurt, Germany)Luiz MadallozoVolker K.H. Sonntag (Phoenix, AZ)
KEY WORDS: intervertebral disc, thoracoscopy, discectomy
From 1992 through 1996, 55 patients were treated with thoracoscopy to
resect herniated thoracic discs. Thirty-six patients presented with myelopa-thies and 19 had incapacitating thoracic radicular pain. Forty-three patientshad a single-level discectomy, 11 had two-level discectomies, and one had athree-level discectomy. The mean operative time for thoracoscopicmicrodiscectomy was 3 hours 25 minutes (range 80–542 minutes), and theaverage blood loss was 327 cc (range 124–1500 cc).
Compared to a cohort treated with thoracotomy (n = 18), thoracoscopy
involved an average of 1 hour less operative time and less than half the bloodloss, chest tube drainage, pain medication usage, and hospital stay. Com-pared to costotransversectomy for thoracic discs (n = 15), thoracoscopy pro-vided more complete resection of calcified and midline discs because it pro-vided a direct view of the entire anterior surface of the dura. Thoracotomy wasassociated with significantly greater incidence of prolonged, disabling inter-costal neuralgia compared to the mild transient episodes of intercostal neural-gia associated with thoracoscopy (50% vs 16%). Thoracotomy was also asso-ciated with a higher incidence of postoperative atelectasis and pulmonarydysfunction than thoracoscopy (30% vs 14%).
Excellent clinical and neurological outcomes were achieved (mean fol-
low up 15 months). Among the 36 myelopathic patients, 22 completely recov-ered neurologically, 5 had functional improvement with some residual myelo-pathic symptoms, and 9 had stabilization of their myelopathy. Among the 19patients with isolated thoracic radiculopathies, 15 completely recovered, and4 had moderate improvement; none had worsened radicular pain. Thoraco-scopic microdiscectomy is a reliable surgical technique that can be performedsafely with excellent clinical and neurological results.
MONDAY, 4:00-4:15 PM
Predictive Value of Temporary External Drainage in Normal-
Dimitris ZevgaridisJulian KrottAdolf SeichertIngo UttnerHans-Juergen Reulen (Munich, Germany)
KEY WORDS: normal-pressure hydrocephalus, lumbar drainage, shunt
The clinical triad of gait disturbance, dementia, and urinary incontinence
is often incomplete in normal-pressure hydrocephalus (NPH). Furthermore,the radiological picture is not pathognomonic for the disease. In many patientsthe effect of shunting becomes manifest only after a few days. Therefore, we
decided to use external lumbar drainage for 3 consecutive days to establish aprecise predictive tool in the diagnosis of NPH.
Twenty-two patients admitted in our clinic underwent surgery on the ba-
sis of well-established clinical and radiological criteria suggestive of NPH. All22 patients were studied before operation with measurement of the resorptivecapacity of CSF using the constant-rate infusion test (CRIT) and by means ofexternal lumbar drainage (120 ml/d) for 3 days. Gait evaluation with apparativegait-analysis and complete neurological and psychometric investigations wereperformed before and after drainage and 6 months after operation.
Twenty patients (90.9%) had shown improvement in gait and 12 (54.5%)
in cognitive properties in the preoperative evaluation; 19 of them showed im-provement after operation. Two patients showed neither preoperative (by meansof lumbar drainage) nor postoperative improvement. Only 14 patients (63.6%)had a decreased resorptive capacity of CSF. We conclude that external lum-bar drainage is a safe and precise (19/20, 95%) test for predicting the out-come of definitive shunt procedures in patients with NPH. The CRIT showed asensitivity of 63.6% (14/22).
MONDAY, 4:15-4:30 PM
Microendoscopic Discectomy: Surgical Technique and Initial
KEY WORDS: discectomy, endoscopy, lumbar disc disease, radiculopathy
Percutaneous endoscopic approaches to lumbar discectomy remain con-
troversial. In general, they have not proven to be as efficacious as conventionalopen surgery. We have developed a new endoscopic technique which allows thesurgeon to address free fragment disc and bone pathology while providing easyaccess to the entire lumbar spine. The purpose of this study was to determine thefeasibility and efficacy of this novel endoscopic approach to lumbar disc disease.
Forty-one patients with single-level radiculopathy secondary to lumbar disc
herniation were treated with microendoscopic discectomy (MED). The patient popu-lation consisted of 28 males and 13 females with ages ranging from 23 to 67 years.
Disc levels included L2-3 (2 patients), L3-4 (3 patients), L4-5 (11 patients), and L5-S1 (25 patients). Five patients had far-lateral discs; the remaining disc herniationswere within the spinal canal. Twenty-five (61%) of 41 cases had free fragment pa-thology. The surgery was performed under epidural anesthesia on an outpatientbasis. A 16-mm tubular retractor was inserted via a small paramedian stab wound.
An adjustable endoscope was attached to the retractor. Under direct endoscopicvision, a hemilaminotomy, medial facetectomy, resection of ligamentum flavum, re-traction of nerve root, and removal of disc were performed as necessary. Concomi-tant lateral recess stenosis (12% of cases) was addressed with a specially modifiedhigh-speed drill. Follow up ranged from 7 to 18 months, with a mean of 13 months.
All patients had substantial relief of their radiculopathy. Under modified
Macnab criteria, all patients had good to excellent results. All patients weredischarged home within 6 hours of surgery except our first patient, who sus-tained a dural tear and was admitted for 48 hours. There were no other com-plications. Return to work ranged from 2 to 40 days in the non-workers’ com-pensation population (mean 14 days) and 14 to 107 days in the workersícompensation population (15% of cases, mean 58 days).
The MED procedure combines standard lumbar microsurgical technique
with endoscopy, enabling the surgeon to successfully address free fragmentdisc pathology and lateral recess stenosis. The endoscopic approach allowsfor a smaller incision and less tissue trauma than standard openmicrodiscectomy. Routine outpatient application and the avoidance of general
anesthesia lower hospital stays and costs. We conclude that MED is bothfeasible and efficacious for the management of lumbar disc disease.
MONDAY, 4:30-4:45 PM
Results of Long-Term Follow-Up of 405 Temporal Lobectomies
Over a 20-Year Period
Michael O’ConnorMichael SperlingJoyce LiporaceJoseph Sirven (Philadelphia, PA)Elizabeth Barry (Baltimore, MD)
KEY WORDS: temporal lobectomy, epilepsy, outcome
Temporal lobectomy has been the standard for treating intractable tempo-
ral lobe epilepsy for more than the last 50 years. The senior surgeon (MOC) hasperformed 405 of these operations over the last 20 years, and during that timethere has been a gradual change in the evaluation and surgical performance ofthis procedure. In general, the more recent patients have had a more extensivemesial resection and less extensive lateral resection, and have benefited frompre- and postoperative evaluation that included MRI. Depth electrode implanta-tion has been used more commonly in the last 10 years. All patients undergoingtemporal lobectomy performed by MOC between 1974 and 1996 for whom fol-low up was available were included in this study. As a result, fewer than 10% ofthe patients operated on in that period have been excluded.
Of the 48 patients followed from our surgical series in the first 12 years
(1974-1986), 65% are seizure free and 8% have less than three seizures a year,whereas 27% remain in a higher classification and were therefore judged to haveno significant improvement. This category included 8% who had an 80% reduc-tion in their seizure frequency. In the last 10 years of the study (1986-1996), thecurrent classification reveals that 249 (70%) of 357 patients remained seizurefree during the year when their status was last evaluated, whereas 28 (8%) of the357 were Class II (rare seizures, < 3 per year) during that year. In 1986 to 1996,26 patients were Class III, with an 80% reduction, whereas 21 were Class IV, 2were Class V, and 10 had died; 21 patients had no classification recorded. Otherthan one hemiplegia in 1977, there was no significant morbidity or mortality. Therewere occasionally mild and rarely moderate changes in memory.
Of the patients with temporal lobectomies performed in the last 10 years
who have been followed to date, the current classification revealed 78% seizurefree or with rare seizures (< 3 per year). This compares with 73% of those withsurgery from 1976 to 1986 (p < 0.05). The seizure-free category was slightlyhigher in the more recent series, being 70% compared to 65% (p = 0.05). Theramifications of these findings and the updated figures will be discussed.
MONDAY, 4:45-5:00 PM
Deep-Brain Stimulation in Parkinsonís Disease: Indications and Results
Giovanni BroggiDomenico ServelloAngelo FranziniIvano DonesFloriano Girotti (Via Celoria, Italy)
KEY WORDS: brain stimulation, Parkinson’s disease, electrode implantation
The efficacy of chronic deep-brain stimulation in the treatment of move-
ment disorders led to renewed interest in surgical therapy for Parkinson’s dis-
ease (PD). From 1991 to 1997, 41 patients (pts) underwent this surgery. In thesame period, 15 pts underwent lesioning surgery (thalamotomy). We are re-porting on 36 pts affected by PD implanted with a deep-brain electrode (ActivaMedtronic system mod. 3837) at the INNCB in Milan from January, 1996, toJune, 1997. In 29 pts (age 35–75 years, mean 62 years) with disabling lateral-ized and drug-resistant tremor, the chosen target for electrode implant wasthe nucleus ventralis intermedius of the thalamus (Vim). One pt underwentbilateral Vim neurostimulation. In 7 pts (age 39–60 years, mean 45 years)affected by dopa-induced on-off phenomena and diskinesias (2 with bilateralsymptoms), the target was the ventroposterolateral part of the palliduminternum. In all pts a postoperative MRI control was performed during the testperiod (1–3 days). A stereotactic electrode implant procedure by means offused CT and MR images compared to a stereotactic atlas was performed inall cases. In 2 cases a target error was presumed from the absence of effectand ascertained by postoperative MRI, leading to an immediate repositioningof the electrode. The tremor disappeared in 28 pts (96%) while failure of treat-ment occurred just in 1 case, due to a severe psychic side effects (unbearablefear and illusions). All pts who underwent pallidal implantation showed a markedreduction or disappearance of dyskinesias and rigidity. There were no deaths.
In spite of the short follow up of these series, the results strongly sup-
port the use of this procedure in the treatment of drug-resistant or drug-in-duced tremor, dyskinesias, and rigidity in selected parkinsonian pts. The ad-vantages and limits of these surgical techniques, as well as the clinical indicationto perform neurostimulation or lesioning surgery, will be discussed.
WEDNESDAY, 5:00-5:15 PM
Prolongation of Survival in Mice With Intracerebral Glioma Treated
With Semi-Allogeneic/Syngeneic Fibroblasts
Roberta P. GlickTerry LichtorEdwin DeZoetenEdward P. Cohen (Chicago, IL)
KEY WORDS: glioma, fibroblast, immunotherapy
The current prognosis for patients with malignant brain tumors remains poor.
We have previously shown that prolongation of survival can be achieved in C57BL/6 mice (H-2b) with a syngeneic intracerebral or subcutaneous glioma if treatedwith allogeneic mouse fibroblasts (H-2k) genetically engineered to secreteinterleukin-2 (IL-2). Like other antigens, tumor-associated antigens are recog-nized by cytotoxic T lymphocytes in the context of determinants specified by themajor histocompatibility complex (MHC) class I locus. Since the rejection of allo-geneic MHC determinants has the property of an immune adjuvant, immuno-therapy of glioma with a cellular immunogen that combines the expression of bothsyngeneic class I determinants and allogeneic antigens could have advantagesover an immunogen that expresses syngeneic or allogeneic determinants alone.
To investigate this question in a mouse glioma model, we further modi-
fied allogeneic mouse fibroblasts (H-2k) not only for IL-2 secretion but also forthe expression of H-2Kb class I determinants. We tested the immunothera-peutic properties of these semi-allogeneic/syngeneic cells in C57BL/6 micewith G1261 glioma in both subcutaneous and intracerebral models.
The results indicate that C57BL/6 mice with either a subcutaneous or
intracerebral glioma treated solely by injection of these IL-2-secreting semi-allogeneic/syngeneic cells significantly prolonged survival compared to un-treated mice or mice treated with cells secreting IL-2 or cells lacking H-2Kbdeterminants. In addition, in some instances the mice treated with the semi-allogeneic/syngeneic cells survived indefinitely, suggesting total eradicationof the glioma. Thus, the augmented immune response against glioma in micetreated with the semi-allogeneic/syngeneic IL-2-secreting cells points towarda new form of immunotherapy for patients with malignant intracerebral glioma.
SCIENTIFIC SESSION II
2:45 PM – 5:15 PM (Room 103A/B/C)
William Shucart, MD (Boston, MA)
MONDAY, 2:45-3:00 PM
Endoscopic Endonasal Transsphenoidal Surgery in 94 Patients
KEY WORDS: endoscopy, chordoma, craniopharyngioma, pituitary
adenoma, transsphenoidal surgery, skull base surgery
Endoscopic transsphenoidal surgery via a natural nasal cavity can now
be performed without the use of a nasal speculum or a transsphenoidal retrac-tor. Endoscopic surgical techniques have evolved into standardized simple andeasy ones. The average operation time is now 1 to 2 hours for a pituitary ad-enoma. Endoscopic transsphenoidal surgery has been performed in 94 patientswith pituitary and other skull base lesions at the University of Pittsburgh MedicalCenter during the period from September 1993 through July 1997. Our patientsincluded 54 females and 40 males (age range 14–88 years; median 38 years).
Eighty-one patients had pituitary adenomas and 13 had other skull base le-sions. Among 81 patients with pituitar y adenomas, 25 patients hadmicroadenomas, 22 had intrasellar macroadenomas, 21 had macroadenomaswith suprasellar extension, and 13 had invasive macroadenomas involving thecavernous sinus with suprasellar extension. Forty-one adenomas were hormone-secreting (12 associated with Cushing’s disease, 25 prolactinomas and fouracromegaly). Two patients underwent surgery as outpatients and 63 patientsstayed in the hospital one postoperative night. No nasal packing was requiredand postoperative discomfort was minimal.
Ten patients with Cushing’s disease were improved clinically with nor-
mal ACTH and urinary cortisol levels. Two patients with incompletely treatedCushing’s disease were treated by gamma knife surgery. Among 25 patientswith prolactinomas, 16 were improved clinically with normal prolactin level,four were improved clinically with mildly elevated prolactin levels, and five hadresidual tumors in the cavernous sinuses. Two patients with residualprolactinomas in the cavernous sinuses were treated with gamma knife sur-gery and three patients were treated with bromocriptine. Among 40 patientswith nonsecreting adenomas, 32 underwent total resection and eight had re-sidual tumors in the cavernous sinuses. Two patients had residual tumors: onewas treated with conventional radiation therapy and oe was treated by gammaknife surgery. The remaining six patients were observed. Three patients devel-oped CSF leakage postoperatively, which was repaired with endoscopic ab-dominal fat graft immediately.
Endoscopic transsphenoidal surgery has been performed via a nostril in
94 patients; these patients have experienced a fast recovery, short hospitalstay, and minimal morbidities. Evolved surgical techniques and improved sur-gical tools will be presented with patient outcome.
MONDAY, 3:00-3:15 PM
Treatment of Essential Tremor by Gamma Knife Thalamotomy
Ronald F. Young*Arthur GinsbergSandra S. VermeulenAllen Posewitz (Seattle, WA)
KEY WORDS: essential tremor, thalamotomy, radiosurgery, tremor
Fourteen patients (9 male, 5 female, mean age 67 years) underwent
ventral intermediate nucleus (Vim) thalamotomy using the Leksell gamma knifebetween February, 1994, and May, 1997, for treatment of medically refractory,disabling essential tremor. The lesions were performed contralateral to thedominant hand in all patients. The target was localized by stereotactic MRIand the lesions were made with a single isocenter, the 4-mm secondary colli-mator helmet and radiosurgical dose maximum levels between 120 and 140Gy. Pre- and postoperative assessments were carried out by trained but disin-terested observors using the clinical rating scale (CRS) for tremor developedby Fahn, Tolosa, and Marin.
Coincidental with the appearance of lesions on MR images and within 2 to
3 months of treatment all but one patient began to experience a clinically observ-able progressive decline in tremor and by 6 months after treatment 12 (85.7%) of14 patients were tremor free or nearly so. Of the other two patients, one hadsignificant improvement in tremor and the other showed no change in tremor witha follow-up period over 1 year. Both the mean global examiners scores and themean global subjects scores on the CRS showed statistically significant improve-ments (p < 0.001). Ten of the 14 patients had illegible handwriting and could notdrink from a cup preoperatively and 9 (90%) of these 10 were able to write legiblyand drink from a cup without spilling the contents by 6 months posttreatment. Nocomplications of any kind were experienced by any of the patients.
We conclude that Vim thalamotomy is a safe and very effective treat-
ment for essential tremor. It is minimally invasive, probably safer thanradiofrequency thalamotomy, and probably safer and less expensive than theplacement of thalamic stimulators.
MONDAY, 3:15-3:30 PM
Effects of Surgical Revascularization on Outcome of Patients
With Pediatric Moyamoya Disease
Tatsuya IshikawaKiyohiro HoukinHiroshi Abe (Sapporo, Japan)
KEY WORDS: moyamoya disease, revascularization, outcome
We reviewed surgically treated patients with pediatric moyamoya dis-
ease to examine whether vasoreconstructive surgeries reduced the risk ofrecurrent ischemic attacks and changed the overall outcomes in terms of thepatientsí performance and intellectual status. Sixty-four hemispheres in 34pediatric moyamoya disease patients who received surgical treatment wereexamined. We performed a superficial temporal artery to middle cerebral ar-tery (STA-MCA) bypass and encephaloduroarteriomyosynangiosis (EDAMS)on 48 sides (combined group) and indirect bypass surgery such as EDAMSon 16 sides (indirect group). These 34 patients were observed postoperativelyfrom 1 to 14 years (mean ± SD: 6.6 ± 3.8 years) and were examined for theincidence of recurrent ischemic attack. Of the 34 patients, 23 were followedfor more than 5 postoperative years, and their overall outcomes in terms oftheir performance and intellectual status were determined.
Perioperative ischemic events (within 2 weeks after surgery) occurred in
5 surgeries (31%) in the indirect group and in 6 (13%) in the combined group(p = not significant). The incidence of postoperative ischemic events (morethan 2 weeks after surgery) was significantly reduced in the combined group(10%) compared to the indirect group (56%, p < 0.01). Of the 23 patientsobserved for more than 5 years, 7 (30%) were mentally retarded and regardedas having a fair outcome.
Combined surgery (STA-MCA bypass with EDAMS) for pediatric moyamoya
disease was more effective in reducing the risk of postoperative ischemic at-tacks compared to indirect surgery. Surgical revascularization may be effectiveto prevent intellectual deterioration and improve the overall outcome.
MONDAY, 3:30-3:45 PM
Genetically Engineered Cytotoxic T Cells Targeted Against
Angiogenesis: A Novel Antitumor Strategy
Zoher GhogawalaRichard C. Mulligan (Boston, MA)
KEY WORDS: angiogenesis, T cell receptor, gene therapy
The growth of solid tumors including malignant glioma is dependent on
angiogenesis. The characterization of the basic molecular mediators of angio-genesis has established a critical interaction between a specific endothelialmitogen called vascular endothelial growth factor (VEGF), which is secretedby many tumors including glioblastoma, and an endothelial receptor calledFlk-1, which is upregulated in angiogenic endothelium and is not present inquiescent endothelium. Interruption of the VEGF/Flk-1 interaction has shownpromise as an antitumor strategy in several animal models. The objective ofthis work is to modify T cells genetically so that the cells specifically bindendothelial Flk-1 and cause the lysis of angiogenic endothelial cells.
We have constructed a murine chimeric T cell receptor (TCR) that con-
tains VEGF as its extracellular domain with the hypothesis that the receptorwould confer upon T cells the ability to bind and kill Flk-1-expressing cells.
This chimeric TCR gene was cloned into a retroviral vector (CMMP), andretroviral particles were produced by transient transfection of the 293 GPG(VSV G) packaging cell line. Primary mouse T cells were isolated from C57/B6mouse spleens using CD8+ immunoselection columns.
Transient transfection of 293 GPG cells reproducibly yielded a titer of 5 x
106 cfu/ml as determined by Southern blotting and by FACS analysis of in-fected 3T3 cells. Successful retroviral gene transfer into primary T cells wasshown by demonstrating cell surface expression of this chimeric TCR on pri-mary T cells (FACS analysis). Finally, chromium-51 release assays showedthat primary T cells transduced with this chimeric TCR are capable of potentand specific cytotoxic activity against Flk-1-expressing cells. At effector/targetratios of 12/1, the cytotoxicity approached 100% as measured by cytotoxicityassays in vitro (p < 0.001, one-way ANOVA).
This work raises the novel concept of directing T cells against angiogen-
esis as a tumor therapy. Such cells, in principle, would be capable of inhibitingmany types of tumors. The next step, which is in progress, is to adoptivelytransfer anti-angiogenic T cells into glioblastoma-bearing mice in order to as-sess the antitumor potential of these genetically modified T cells. In anticipa-tion of its use in human T cells, we have constructed a human VEGF-chimericTCR, which is currently under in vitro evaluation in the laboratory.
MONDAY, 3:45-4:00 PM
Results of Phase I Trials of 131I-Labeled Anti-Tenascin Monoclonal
Antibody Injected via Surgically Created Resection Cavities in
Patients With Recurrent Malignant Brain Tumors
John H. SampsonAllan H. FriedmanHerbert E. FuchsDarell D. BignerHenry S. Friedman (Durham, NC)
KEY WORDS: radiolabeled monoclonal antibody, tenascin, recurrent tumor
The murine immunoglobulin G monoclonal antibody 81C6 is reactive
against the extracellular matrix protein, tenascin, present in gliomas and somecarcinomas but not in normal adult brain. A Phase I trial of a single injection of131I-radiolabeled 81C6 (131I-81C6) into surgically created resection cavities(SCRCs) was conducted in patients with recurrent malignant brain tumors.
Escalating doses of 131I on a fixed dose of 81C6 were used.
In 34 patients with prior external beam radiation therapy, dose-limiting neu-
rological and hematological toxicity was reached at a 131I dose of 120 mCi. Noneof the patients treated with less than 120 mCi developed serious neurologicaltoxicity, and only one other patient developed hematological toxicity. The esti-mated average absorbed radiation dose to the SCRC interface at the 100 mCiadministered activity level was 36,800 cGy. Median time to progression for thesepatients from the time of 131I-81C6 treatment was 5.1 weeks (4.1–12.1 weeks,95% confidence index [CI]). Although there have been no complete or partialresponses to date, 14 of 33 evaluable patients had stabilized disease, and themedian estimated survival for these patients with recurrent malignant brain tu-mors was 62 weeks (50.3 weeks-infinity, 95% CI). In 23 patients without priorradiation therapy, the maximum tolerated dose has not been reached with 131Idosages of 140 mCi. Fifteen of these patients remain alive. Survival times haveranged between 30 and 186 weeks with a median survival time of 82 weeks.
The high levels of radiation that can be delivered by this technique with
acceptable toxicity are encouraging and suggest that radiolabeled antibodiesspecific for tumor-associated antigens may improve current therapy for malig-nant brain tumors.
MONDAY, 4:00-4:15 PM
Endovascular Cervical Carotid Revascularization
Lee R. GutermanAjay K. WakhlooL.N. Hopkins (Buffalo, NY)
KEY WORDS: carotid stenosis, angioplasty, stent, revascularization
To evaluate the safety and efficacy of endovascular revascularization for
cervical carotid stenosis in a high-risk surgical population, we studied 96 pa-tients. These were designated for endovascular revascularization of the ca-rotid artery for one or more of the following reasons: multiple medicalcomorbidities, unstable angina, restenosis after carotid endarterectomy, ra-diation-induced stenosis, high cervical bifurcation, and long segment steno-sis. A No. 9 French guide catheter was placed into the common carotid artery.
Angioplasty was performed at 8 to 12 atm for 30 to 60 seconds. In 62 patients,angioplasty was followed by stent placement. In some cases, transvenousatrial or ventricular pacers were used. In the 62 stented patients, heparin wasnot used postoperatively unless a new neurological deficit occurred.
In the group that was treated with angioplasty and stent, there were no
major and two minor strokes. There were two deaths, one from cardiac arrestin a patient awaiting bypass surgery and one immediately after four-vesselcoronary artery bypass grafting and two valve replacements. There was onereversible ischemic neurological deficit in a patient whose fine motor deficitscleared within 30 days. Another patient developed minor fine motor deficits,and MRI revealed a small capsular infarction. One patient suffered from iliacocclusion requiring axillobifemoral bypass. He subsequently developed acuterenal failure requiring dialysis. He is neurologically intact. Patients have beenfollowed with carotid Doppler ultrasound at 1, 3, 6, and 12 months after stentplacement. One patient developed significant restenosis distal to the stentand required retreatment and an additional stent placement.
Endovascular revascularization of the cervical carotid artery using
angioplasty and stent placement is a safe and efficacious procedure in pa-tients considered at high risk for surgical carotid revascularization.
MONDAY, 4:15-4:30 PM
Mortality After Epilepsy Surgery
Michael SperlingHarold FeldmanJudith KinmanMichael O’Connor (Phildelphia, PA)
KEY WORDS: epilepsy surgery, mortality risk, seizure relief
The mortality rate is increased in people with epilepsy, particularly those
with uncontrolled seizures. Since epilepsy surgery eliminates seizures in somepeople, we used an epilepsy surgery population to examine how seizure con-trol influences mortality. We tested the hypothesis that patients with completeseizure relief after surgery would have a lower mortality rate than those whohad persistent seizures.
We followed 393 patients who had epilepsy surgery between January,
1986, and January, 1996. Of these, 347 had focal resection or transection, and46 had anterior or complete corpus callosotomy. Survival analysis using a timevariable technique was performed, contrasting those who had seizure recur-rence with those who remained seizure free. Analyses were adjusted for type ofsurgery, age at seizure onset, preoperative seizure frequency, and age at sur-gery, since these variables potentially affect the likelihood of seizure relief.
For the entire cohort, seizure-free patients had a lower mortality rate
than those with persistent seizures (p = 0.0117), after adjusting for the abovevariables. This was true as well for the subset of patients with localized resec-tion or transection (p = 0.0352). Of 194 patients with seizure recurrence, 11died, whereas no patients died among 199 with no seizure recurrence. Sixdeaths were sudden and unexplained, 3 others were probably epilepsy re-lated, and 2 were non-neurological. Most patients who died had seizure re-duction after surgery, and 6 had less than monthly seizures. Standardizedmortality ratio in patients with recurrent seizures was 4.69, and the risk ofdeath in these patients was 1 in 73 person-years.
Patients who have complete seizure relief after epilepsy surgery have a
lower mortality rate than those with persistent seizures. This suggests thatepilepsy surgery may reduce the risk of death. In contrast, recurrent seizures,even relatively infrequent ones, carry a high mortality risk.
MONDAY, 4:30-4:45 PM
Factors Associated With Surgical Complications for Basilar
Bifurcation Aneurysms: An Analysis of 101 Patients
Peter LeRouxRajiv SethiJ. Paul Elliott (New York, NY)Gerald GrantH. Richard Winn (Seattle, WA)
KEY WORDS: aneurysm, basilar bifurcation, surgical complication
We retrospectively analyzed 101 patients admitted to Harborview Medical
Center to determine the incidence and impact of surgical complications duringoperative treatment of basilar bifurcation aneurysms. Median aneurysm sizewas 10 mm (range 3–40 mm). There were 26 unruptured aneurysms and 53patients in good and 22 in poor clinical grade after aneurysm rupture. Fifty-two(70%) of the 75 patients underwent surgery within 3 days of SAH. Postopera-tively all 101 patients underwent head CT and 94 underwent angiography.
The incidence of surgical complications including intraoperative cere-
bral swelling (4%), aneurysm rupture (16%), or vessel injury (2%) and postop-erative radiographic evidence for perforator injury (26%), retraction contusions(4%), aneurysm remnants (6%), or vessel occlusion (6%) was similar to thatobserved in 434 anterior circulation aneurysms treated during the review pe-riod. Intraoperative rupture (p = 0.001), vessel occlusion (p = 0.01), and perfo-rator injury (p = 0.0001) were associated with poor outcome. Surgical compli-cations, however, did not prolong hospital stay. Bivariate analysis was performedto determine what preoperative clinical, CT, and angiographic factors wereassociated with surgical complications. Intraoperative rupture was more fre-quent during ruptured aneurysm repair (p = 0.06), particularly during earlysurgery (p = 0.008). No clinical or radiographic factors were associated withvessel occlusion or aneurysm remnants. Perforator injury was significantlyassociated with large aneurysm size (p = 0.002) and posterior orientation (p =0.0001). Among 20 patients who underwent posterior-oriented aneurysm re-pair, 14 (70%) suffered perforator injury and 15 (75%) had a poor outcome.
We conclude that, overall, patients undergoing surgical repair of basilar
bifurcation aneurysms are at no greater risk for surgical complications thanpatients undergoing anterior circulation aneurysm repair. However, direct sur-gical repair of posterior-oriented aneurysms may not always be warranted.
MONDAY, 4:45-5:00 PM
Development and Impact of a Craniotomy for Tumor Critical
Gregory P. LicholaiPeter McL. BlackSharon P. Kleefield (Boston, MA)
KEY WORDS: craniotomy, brain tumor, cost/efficiency
Much interest has been focused on health expenditures, but few studies
examining the benefits of specific cost-control methods have been reported inpeer-reviewed literature. In 1994, a craniotomy for tumor critical pathway wasdeveloped at the Brigham and Women’s Hospital to determine if length of stay(LOS) and costs could be reduced while not increasing readmission rates, mor-bidity, mortality, or dissatisfaction. All patients with brain tumors admitted from1994 to 1996 at our hospital were included. Variables examined were LOS,direct cost per case, hospital charges per case, in-house morbidity and mortal-
ity, 30-day readmission rates, and degree of patient satisfaction. There were764 subjects enrolled, including 461 pathway and 303 non-pathway patients.
Pathway and non-pathway patients had similar demographics and aver-
age age of 49.3 years. It was found that LOS for patients in the critical pathwaygroup was 5.7 days compared to 7.3 days for non-pathway patients. This wasstatistically significant when adjusted for age, sex, and comorbid factors. Chargesper case were $22,299 for pathway and $25,366 for non-pathway patients, adifference of $3,067. Direct cost per case was $12,206 for pathway and $14,812for non-pathway patients, a difference of $2,606. Readmission rates were 9.8%in pathway and 18.4% in non-pathway patients. In-house morbidity and mortal-ity rates were similar and patient satisfaction, based on follow-up questionnaires,was above 95% in both groups. It was also determined that the only significantvariable to affect LOS was presentation through the emergency ward.
A postoperative critical pathway for brain tumor patients is a safe and
effective method of controlling costs and reducing LOS without increasingreadmission rates, morbidity and mortality, or decreasing satisfaction.
MONDAY, 5:00-5:15 PM
The Opportunity Costs of Training to Become a Neurosurgeon:
Relevance for the Expectation of Appropriate Compensation
Frederick SimeoneAndrew Freese (Philadelphia, PA)
KEY WORDS: neurosurgical training, compensation, opportunity cost
As reimbursements for neurosurgical procedures continue to decline,
salaries for neurosurgeons are likely to decrease significantly over the nextdecade. Although neurosurgeons appear to receive high compensation fortheir work when compared to the general populace, such a comparison fails toaccount for the extraordinarily high opportunity costs associated with trainingto become a neurosurgeon. We have calculated opportunity costs of training,including 4 years of college, 4 years of medical school, and 6 or 7 years ofresidency training. We have also compared these costs to the training costsrequired for four other careers: lawyer, MBA executive, stockbroker, and truckdriver. In deciding career paths, college and medical students often becomeaware of such considerations, explaining in part the current precipitous de-cline in applications for anesthesiology residencies. At some point in the de-cline of compensation for neurosurgical procedures, the effect on the appli-cant pool for highly qualified neurosurgical residents may become significant.
Economic parameters (salary, tuition costs, costs of living, and debt) were
calculated using information obtained from federal sources, trade unions, and pro-fessional schools and organizations. Conservative estimates of salary incomes wereused and investment income was estimated using the annualized return from fivewell-established mutual funds for the past 15 years. The cost of living was normal-ized to the standard of living first of a medical student for 4 years, and thereafter fora resident. For all careers except the truck driver, the analysis of opportunity costsbegan at the end of college, whereas the truck driver received credit for income andsavings associated with working rather than attending college.
If a college senior were to consider starting medical school in 1998 and
thereafter enter a 7-year neurosurgery program, by his completion of trainingin 2009 his indebtedness would approximate $200,000, assuming no parentalfinancial support throughout the training period. In contrast, a truck driver whobegan work after graduating high school in 1994 would, by 2009, have almost$1 million in savings if he maintained the same standard of living during thisentire time period as the neurosurgeon-in-training. Similarly, the savings dif-ferential between the neurosurgeon and a moderately successful stockbrokerwho started at the end of college is also in excess of $1 million. The savingsdifferential between the neurosurgeon and a moderately successful lawyer or
midlevel MBA executive would exceed $700,000. It is impossible to predict thefuture earning potential of a neurosurgeon in 2009.
As our society continues to permit payors to devalue surgical special-
ists, in particular neurosurgeons, the implicit and fragile balance of opportu-nity costs and earnings potential for neurosurgeons becomes threatened. Atsome point, the many sacrifices, both economic and personal, of becoming aneurosurgeon may no longer be adequately compensated by our society.
SCIENTIFIC SESSION III
2:45 PM – 5:15 PM (Room 114)
Stanley Pelofsky, MD (Oklahoma City, OK)
William A. Friedman, MD (Gainesville, FL)
MONDAY, 2:45-3:00 PM
Results of Transsphenoidal Microsurgery for Growth Hormone-
Secreting Pituitary Adenomas
Aviva AboschJ. Blake TyrrellLisa HanneganKathleen LambornCharles B. Wilson (San Francisco, CA)
KEY WORDS: pituitary adenoma, acromegaly, growth hormone level
We performed a retrospective review of 254 patients with acromegaly who
underwent transsphenoidal microsurgical resection of a pituitary adenoma atUCSF, between 1974 and 1992. The purpose of this review was to assess pa-tient outcome following surgical treatment of acromegaly. Of these patients, 173(68%) had growth hormone (GH) levels below 5 µg/L within 30 days after sur-gery and were considered to be in remission. An additional 20 patients (8%)were deemed to have technical persistence of disease, defined as a singleelevated GH level within the first 30 postoperative days, and subsequent normalGH levels with clinical remission of acromegalic symptoms in the absence offurther therapy. True disease persistence was found in 61 cases (24%). Overallinitial success rate was thus 76%. Univariate analysis revealed larger tumorsize, higher tumor stage and grade, and higher preoperative GH levels all to bepredictive of disease persistence (p < 0.01). Younger age and earlier surgerywere marginally predictive of disease persistence (p = 0.05 and p = 0.08, re-spectively). No relationship was found between disease persistence and gen-der, prior irradiation, prior medical therapy, or symptom duration.
Of the original 173 patients demonstrating initial remission, 130 could
be contacted for long-term follow up. Of these, 9 (7%) had suffered diseaserecurrence. Five of these patients underwent further therapy, 4 of whom arecurrently in remission. Median time to recurrence was 3.3 years. Technicalrecurrences, defined as a single elevated GH level unaccompanied by clinicalsymptoms, and followed by subsequent normal GH levels without further treat-ment, occurred in 11 cases (9%). In contrast to disease persistence, no vari-ables were found to be predictive of disease recurrence. The total postopera-tive complication rate among the 254 patients was 13%, including 6%hyponatremia, 2% CSF leaks, 2% meningitis, and 2% hypopituitarism. Therewere no known cases of postoperative hemorrhage and no postoperativedeaths linked to surgery. In contrast to the 2- to-5-fold increased mortality rateamong untreated acromegalics, the mortality rate among patients withpostsurgery GH levels of < 5 µg/L was equivalent to that predicted by age-adjusted mortality statistics. Aggressive therapy to reduce GH levels shouldtherefore be instituted at the time of diagnosis.
MONDAY, 3:00-3:15 PM
Predictive Value of Immediate Serum Prolactin Levels Following
Arun P. AmarWilliam T. CouldwellMartin H. Weiss (Los Angeles, CA)
KEY WORDS: prolactin level, prolactinoma, pituitary adenoma
The ability to immediately predict long-ter m outcome following
transsphenoidal resection of prolactin-secreting pituitary adenomas is impor-tant in determining the vigilance with which residual or recurrent tumor is soughtand in allaying the concerns of patients who want to know whether their tumorhas been cured. Therefore, we retrospectively reviewed our experience withprolactinomas followed for at least 5 years after surgery in order to assess theprognostic value of serum prolactin levels drawn on the first postoperative day.
Between 1979 and 1991, 241 patients underwent transsphenoidal sur-
gery for prolactinomas. Nineteen were lost to follow up, while the remaining222 had fasting AM prolactin levels drawn on postoperative day (POD) 1 andrandom serum levels taken at 6 weeks, 12 weeks, and then every 6 months fora minimum of 5 years.
Of the 222 patients, 176 had normal serum prolactin levels (< 20 ng/ml in
our lab) on the morning after surgery; 133 of these were < 10 ng/ml (Group 1)and 43 were between 10 and 20 ng/ml (Group 2). At 12 weeks postoperatively,132 patients (99%) in Group 1 had normal prolactin levels, compared with only32 (74%) of those in Group 2. By 5 years, 130 patients (98%) in Group 1 still hadnormal levels, compared with only 5 patients (12%) in Group 2. No patient whohad a prolactin level < 3 ng/ml on POD 1 had an elevated prolactin at 5 years.
Prolactin levels < 10 ng/ml drawn the morning after surgery predict cure,
whereas patients with normal levels between 10 and 20 ng/ml on POD 1 arestill at high risk for treatment failure. Reported recurrences at 5 years thusmost likely represent persistent tumor that was not originally removed, andpatients with immediate prolactin levels > 10 ng/ml should undergo early post-operative imaging to determine if resectable residual tumor exists.
MONDAY, 3:15-3:30 PM
Endocrine-Inactive Pituitary Adenomas: Clinicopathological
Features and Long-Term Outcome Following Transsphenoidal
Gordon Tang (Barstow, CA)Ming-Ming NingMarielle H. NyugenBrooke SwearingenNicholas T. Zervas (Boston, MA)
KEY WORDS: pituitary adenoma, hormone level, endocrine
Endocrine-inactive adenomas (EIA) account for 30% of pituitary tumors
but are infrequently studied. We aim to characterize their clinical presentation,identify endocrinological and radiographic features, study pathological char-acteristics, and determine long-term outcome. We have therefore retrospec-tively reviewed the cases of 357 patients who underwent resections of EIAfrom 1978 to 1996 with an average follow up of 8.4 years.
The group ranged in age from 16 to 82 years with a mean age of 52.6
years. Symptoms of mass effect, such as visual field deficits (70%), headaches
(48%), and ophthalmoplegia (7%), prompted diagnosis in most cases. Sevenpercent presented with apoplexy. Symptoms consistent with hypopituitarism werereported by a third of patients. Endocrine workup disclosed pituitary insuffi-ciency in half of the patients, with deficits of ACTH (35%) and gonadotropins(33%) being the most frequent. Seven patients exhibited alpha-subunit hyper-secretion. Nearly all tumors were macroadenomas (93%), with a median size of2.3 cm. Immunostaining revealed that truly null tumors were less common thanpreviously supposed (23.4%) with immunoreactivity for FSH (47%), LH (43%),and alpha-subunit (50.6%) higher than expected. Immunoreactivity to other hor-mones suggests that EIA include a significant subpopulation of clinically silentendocrine tumors (ACTH, 15%; TSH, 16%; GH, 7.9%; prolactin, 12.8%). Al-though total resection was reported in 80% of cases, only 29% were free oftumor on follow-up imaging. Only 16% developed symptomatic recurrencesdespite the high incidence of residual tumor. Patients undergoing postoperativeradiotherapy (RR = 2.8, p < 0.01) and those receiving complete resections (RR= 5.5, p < 0.01) were less likely to develop recurrences. Surgery improved head-aches (92%) and visual field deficits (90%) in most patients. Thyroid insuffi-ciency (35%) appeared to increase following surgery while steroid dependency(28%) decreased. Surgery infrequently reversed hypogonadism.
Based on these data we conclude that: 1) postoperative radiotherapy
likely reduces the recurrence rate; 2) surgeon impression of resection under-estimates residual tumor; 3) a complete resection lowers the recurrence risk;4) surgery alleviates symptoms of mass effect but is less successful for treat-ing hypopituitarism; and 5) most EIA are immunoreactive to LH, FSH, or al-pha-subunit with a significant portion being clinically silent endocrine tumors.
MONDAY, 3:30-3:45 PM
Pallidotomy in Advanced Parkinson’s Disease: Two-Year
Andrés M. Lozano*Anthony E. LangErwin B. MontgomeryJan DuffRonald R. Tasker (Toronto, ON, Canada)
KEY WORDS: pallidotomy, Parkinson’s disease, outcome
Recent claims that posteroventromedial (PVM) pallidotomy has striking
ameliorative effects in Parkinson’s disease come from studies involving smallnumbers of patients, short follow up, or nonvalidated rating methods. We stud-ied 40 patients with detailed assessment of parkinsonism using validated rat-ing scales after drug withdrawal (OFF) and under optimal drug response (ON).
Scores 6 months after surgery were compared to baseline scores in the fullcohort (n = 39), and stability of response was assessed in patients reaching 1year (n = 27) and 2 years (n = 11) of follow up.
At 6 months total motor and daily activities (ADL) OFF scores had im-
proved by 30% and contralateral limb scores by 40 to 55%. At the same time,ADL ON scores had improved by 30% and levodopa-induced dyskinesias by83% in the contralateral limbs and 50% in the ipsilateral limbs. Improvement inthe scores for total parkinsonism, contralateral bradykinesia, rigidity, anddyskinesias were sustained for the 2-year follow-up period. Benefit to ipsilat-eral dyskinesias was lost after 1 year and postural stability and gait improve-ments lasted only 3 to 6 months. PVM pallidotomy had a major impact onfunctional capacity with approximately 50% of patients dependent in mea-sures of ADL in the OFF state before surgery becoming independent aftersurgery. Medication changes were not significant.
We conclude that PVM pallidotomy significantly reduces levodopa-in-
duced dyskinesias and the disability experienced in OFF periods in later-stageParkinson’s disease. The benefit from this procedure is largely sustained for
at least 2 years although certain features, such as improvements on the ipsi-lateral side and in axial symptoms, wane within the first year. ON period symp-toms resistant to dopaminergic therapy do not benefit from surgery.
MONDAY, 3:45-4:00 PM
Improved Outcome and Reduced Cost in Cervical Spinal Cord
Injury Using Emergency MRI and Surgical Decompression
Nathan R. SeldenNayna PatelSusan GrubeStephen Papadopoulos (Ann Arbor, MI)
KEY WORDS: spinal cord compression, cervical spine, magnetic
Ninety-one consecutive patients with acute traumatic cervical spinal cord
injury (1991–1996) initially received conventional treatment with cervical trac-tion, as needed, and steroids. Sixty-six patients then underwent emergencyMRI to determine the presence of persistent spinal cord compression, fol-lowed, if indicated, by immediate operative decompression and stabilization(protocol group). Twenty-five patients were managed outside the protocol be-cause of contraindication to MRI, need for other emergency surgical proce-dure, or surgeon preference (reference group). The protocol and referencegroups had similar sex and age distributions, admitting Frankel scores, levelsof neurological injury, and injury severity scores.
Protocol patients improved an average of 0.7 Frankel grades more than
reference patients between admission and most recent follow up (p < 0.01). Fiftypercent of protocol patients but only 24% of reference patients improved fromtheir admitting Frankel grade. Eight protocol patients (12%) but no reference pa-tients improved from complete motor quadriplegia (Frankel A or B) to indepen-dent ambulation (Frankel D or E). Protocol patients required significantly shorterICU, general care, rehabilitation hospital stays and fewer days of ventilator sup-port than reference patients (p < 0.01), representing an average savings per caseof approximately $50,000. MR images obtained during protocol treatment alsoprovided useful prognostic information regarding neurological outcome.
We conclude that immediate MRI to determine the need for emergency
operative decompression and definitive stabilization significantly improvesneurological outcome and reduces cost in the management of acute trau-matic cervical spinal cord injury.
MONDAY, 4:00-4:15 PM
Results of Linear Accelerator-Based Radiosurgery for Intracranial
Peter McL. BlackRodolfo HakimEben Alexander, IIIJay S. LoefflerDennis Shrieve (Boston, MA)
KEY WORDS: radiosurgery, meningioma, linear accelarator
We report the outcome of the patients treated with LINAC radiosurgery
for intracranial meningiomas at our institution. We reviewed 127 patients with155 meningiomas treated with stereotactic radiosurgery (SRS) at the studyinstitutions between October, 1988, and December, 1995.
There were 86 females and 41 males (median age 61.5 years, range 19.9–
87.9 years). Median follow up was 31 months (range 1.2–79.8 months). The mediantumor volume was 4.1 cc (range, 16–51.2 cc) and the median marginal dose was15 Gy (range 9–20 Gy). The tumor locations were: 31 convexity, 39 parasagittal/falcine, 82 skull base, and 3 ventricular/pineal. There were 106 benign meningio-mas, 26 atypical, 18 malignant, and 5 meningiomatosis. SRS was given to 48 le-sions as initial treatment and to 107 lesions as adjunct therapy. Twenty patients haddisease progression (16 marginal and 4 local) at a median time of 19.6 months(range 4.1–69.3 months); 6 patients (4.7%) had permanent complications attribut-able to SRS (median time months; range 4.3–18.0 months); 13 patients died ofcauses related to the meningioma (median 17.5 months; range 4.3–37.3 months).
The 1-, 2-, 3-, 4-, and 5-year survival rates in benign meningiomas, excluding deathfrom intercurrent disease, were 97.6%, 94.8%, 91%, and 91%, respectively.
Even though complications from SRS are more probable with larger tu-
mors and with those near critical structures, it offers a safe and effective meansof treating selected meningiomas.
MONDAY, 4:15-4:30 PM
Anterior Cervical Surgery Without Plate Instrumentation in 245
KEY WORDS: cervical spine, instrumentation, plating
To examine the efficacy of anterior cervical surgery without plate instru-
mentation, 248 patients with anterior cervical discectomy (ADF) or corpectomy(ACF) and fusion performed by the author over a 7.5-year period were re-viewed. Only three were plated. Of the other 245 patients, 179 had ADF aver-aging 1.6 levels, 56 had ACF averaging 1.6 vertebrae, while 10 had ADF/ACFaveraging 1.1 levels. Fusion was assessed with flexion/extension x-ray, and/or3D-CT studies, performed at 2 months and repeated every month for a mini-mum of 6 months, or longer if fusion had not occurred. Based on White andPanjabiís definition of clinical instability, patients were placed into one of threecategories: 1) fused; 2) clinically stable but with radiographic lucency; or 3)clinically unstable. The mean follow up was 52 months.
Fusion was demonstrated in 210 patients, clinical stability with radio-
graphic lucidity in 25, and clinical instability in 10 patients. There was no rela-tionship between the type and severity of the original operation and clinicalinstability. In 4 of these 10 patients, a secondary posterior wiring and fusionwas performed within 4 to 22 months of the original surgery. The other 6 pa-tients are being followed conservatively. Postoperative vertebral fractures ledto graft extrusions/complications and reoperations in another 7 patients.
The frequencies of clinical instability (4.1%) and secondary surgery due
to clinical instability (1.6%) or fractures/graft extrusions (2.9%) compare fa-vorably with the frequencies of complications (up to 15%) and reoperations(up to 12.5%) reported in plated series.
MONDAY, 4:30-4:45 PM
Current Patterns of Inflicted Head Injury in Children
Shervin RahimdashtiDebra DeckerAshfaq RazzaqAlan Cohen (Cleveland, OH)
KEY WORDS: head injury, child abuse, subdural hematoma
Although inflicted trauma is a major cause of serious head injury in young
children, it has received little systematic examination. To define current patternsof child abuse associated with head trauma, we analyzed the clinical presenta-tion, socioeconomic status, mechanism of injury, and outcome in patients carry-ing this diagnosis. We reviewed 353 consecutive cases of head trauma admit-ted to Rainbow Babies and Childrens Hospital between January, 1995, andJuly, 1997, and identified 30 children with deliberately inflicted injuries. Therewere 18 boys and 12 girls (median age 5 months). All but 3 children were lessthan 2 years old. Of the patientsí families, 67% lived in the inner city, 75% wereon welfare, and 20% had a history of drug or alcohol abuse.
In most cases, the mechanism of injury was unknown or the history was
insufficient to explain the injury. Median Glasgow Coma score was 7. Retinalhemorrhages were present in 11 patients (37%). There were 7 skull fractures(23%). Seventeen patients (57%) had acute subdural hematomas, 6 (20%)had subarachnoid hemorrhage, and 4 (13%) had epidural hematomas. Mostpatients (24) had isolated head injuries. In those sustaining multiple trauma,associated injuries included human bite (2), rib fracture (2), facial fracture (1),liver contusion (1), and pancreatic contusion (1). No patient had a long bonefracture. Four patients died, 3 from acute subdural hematoma. Of the survi-vors, 9 were placed in foster care, 3 were left in the custody of other familymembers, and 14 were returned to a safe caregiver in the home.
We stratified the patients by age and identified 86 children under 2 years
old admitted for head trauma. Of these, the head injury was inflicted in 27(31%) and accidental in 59 (69%). Acute subdural hematoma occurred in 16(59%) of the 27 children with inflicted trauma but only 5 (8%) of the 59 withaccidental trauma. Four (80%) of the 5 accidental subdural hematomas werecaused by motor-vehicle accidents.
Deliberately inflicted injury remains exceedingly common. In our series,
inflicted injury accounted for almost a third of all hospital admissions for headtrauma in children under 2 years old. Child abuse was strongly correlated withlow socioeconomic status. Inflicted head injuries occurred most often as iso-lated wounds. No patient in this series had an extremity fracture, calling intoquestion the routine use of skeletal surveys. Acute subdural hematomas oc-curring in children under the age of 2 years, in the absence of a motor-vehicleaccident, are most likely related to abuse.
MONDAY, 4:45-5:00 PM
Head Injury in Abused Children
Javad Hekmat-Panah (Chicago, IL)Linda CallansPia Pannaraj (Philadelphia, PA)
We reviewed the clinical and social findings of abused children with head
injury admitted to our hospital over the past 30 years. We selected the files of190 children in whom head injury was severe enough to require hospitaliza-tion. There were 119 (63%) male and 71 (37%) female infants. The age distri-bution was 63% below 1 year, 36% below 6 months, and 23% below 3 months.
There were 88% Blacks, 9% Caucasian, and 3% Hispanic. Of the parents,26% were married and 72% were unmarried; 7% of mothers were alcoholabusers and 19% drug abusers.
There was a depressed level of consciousness in 79 (42%) of the chil-
dren, respiratory depression in 61 (32%), seizures in 60 (32%), and vomitingin 43 (23%). Suppressed level of consciousness varied in its degree; 20 (10.5%)arrived comatose. The respiratory distress also varied in intensity; 50% hadapnea. The alteration of the pupils was recorded in 172 patients, and fundus-copic examination was recorded in 143. Thirty-two (19%) had dilatation of
pupils, bilateral in 25 (14.5%); 58 (41%) suffered retinal hemorrhage and 52%had associated injuries. Information about the fontanel was available in 149patients; the fontanel was open in 101 (68%); in 44 (43%) it was bulging ortense. There were 78 (41%) skull fractures, 11 (6%) cerebral contusion, 10(5%) SAH, 54 (29%) subdural hematoma, and 7 (3%) epidural hematoma; 9%required craniotomy or other operations. At discharge, 29 (15%) had physical,8% mental, and 2% both impairments. There were 22 (12%) deaths.
Of all abused children, 67% are below the age of 9 years, while 80% of
head injury victims are under 2 years old when the condition could mimicother diseases of infancy. This is especially true when a history of trauma isminimized or denied. This study reveals that the clinical symptoms are so dis-tinct that a history of trauma is not necessary for diagnosis.
MONDAY, 5:00-5:15 PM
Failed Radiosurgery and the Role of Microsurgery for Acoustic
L. Dade Lunsford (Pittsburgh, PA)*Bruce E. Pollock (Rochester, MN)Douglas KondziolkaRaymond SekulaBrian Subach (Pittsburgh, PA)
KEY WORDS: acoustic neuroma, radiosurgery, microsurgery
The indications, operative findings, and outcomes of acoustic neuroma
microsurgery are controversial when it is performed after a patient has under-gone stereotactic radiosurgery. We reviewed our experience at two academicmedical centers during a 10-year interval in which 523 patients underwentstereotactic gamma knife radiosurgery. Ten patients with unilateral tumors (2%,three men, seven women, age range 35–79) underwent delayed microsurgery6–49 months (mean 29.9 months) after radiosurgery. Six patients had under-gone microsurgery before radiosurgery. The mean marginal dose to the tumormargin was 16 Gy, and an average of 6.2 isocenters were used for each tu-mor. The indications for surgery were tumor growth in four patients (substan-tiated in one), increased symptoms in seven, persistent symptoms in two, andcystic enlargement in two. Microsurgery consisted of suboccipital removal ineight patients, translabyrinthine in one, and a combined approach in one. Gross-total removal was possible in seven patients. Tumor consistency was describedas cystic in two patients, adherent to normal structures in five (three had un-dergone prior microsurgery), fibrous in two, and normal in five. Histopatho-logical examination revealed a typical Schwann cell neoplasm in all cases;three tumors showed suggesting radiation effects. Postoperative complica-tions included hydrocephalus in two patients, meningitis in two, CSF leak intwo, new onset deafness in two, worsened facial nerve function in five, diplo-pia in one, and ninth and tenth cranial nerve palsies in two. At last follow upseven patients had House-Brackmann Grade 6 facial palsies, two had Grade 4,and one had Grade 3. All patients were deaf. Two patients remained bedridden.
The goal of radiosurgery is the prevention of further growth. Failed radiosur-
gery was rare at our two institutions, occurring in less than 2% of patients, andfailure occurred before 5 years had elapsed since radiosurgery. Failed microsur-gery was more common in patients in whom prior microsurgery had already failed,and for whom radiosurgery was performed as a microsurgical alternative. Clinicalworsening appears to be common after microsurgery performed after radiosur-gery, and patient outcomes are usually worse. No clear relationship could bedetected between the use of radiosurgery and the subsequent ease or difficulty ofdelayed microsurgery. The indications for microsurgery after radiosurgery shouldreflect definitive, sustained tumor volume increase in association with progres-sive, new neurological symptoms. Because 1 to 2% of patients have slight tumorgrowth before subsequent growth arrest, the need for delayed microsurgical re-section should be reviewed with the surgeon who performed radiosurgery.
SCIENTIFIC SESSION IV
2:45 PM – 5:15 PM (Room 108A/B)
Stewart Dunsker, MD (Cincinnati, OH)
MONDAY, 2:45-3:00 PM
Hearing Preservation in 75 Acoustic Neuroma Surgeries
Catalino D. DurezaTakanori FukushimaMoises Arriaga (Pittsburgh, PA)
KEY WORDS: hearing preservation, acoustic neuroma, facial nerve function
In this series of patients selected for hearing preservation in acoustic
neuroma surgery the emphasis was placed on a meticulous microsurgicalskull base technique which was tailored to fit each patient. In the hands of ahighly skilled microsurgical team with appropriate selection criteria, the ma-jority of acoustic neuromas can be removed safely with excellent facial nervefunction and as nearly successful rate of hearing preservation. This study re-views 75 consecutive hearing preservation acoustic neuroma surgeries in atotal series of 360 acoustic neuromas performed over an 8-year period. Pa-tients with speech reception threshold (SRT) of 50 dB and at least a 60%speech discrimination score (SDS) were preferred candidates for hearing pres-ervation. We have attempted hearing preservation in patients with 50 dB SRTand 50% SDS if other factors were favorable.
Patients with largely intracanalicular tumors underwent a middle fossa
approach, whereas tumors located predominantly in the cerebellopontine anglewere excised via a retrosigmoid transmeatal approach. Postoperatively 80%of the patients in this series had some form of hearing preserved. Of the totalnumber of patients undergoing surgery for hearing preservation, 69% hadusable hearing based on the American Academy of Otolaryngology hearingclassification. Of the 33 retrosigmoid cases, 73% had hearing preserved; 64%had usable hearing; and 9% measurable hearing. Of 42 middle fossa opera-tions, 86% had hearing preserved; 74% had usable hearing; and 12% hadmeasurable hearing. No significant complications were encountered. Excel-lent immediate postoperative facial nerve function was present in 90% of thecases. There were no cases of complete facial nerve paralysis. Details of ourcurrent operative techniques and sophisticated microinstrumentation will bediscussed using illustrative cases.
MONDAY, 3:00-3:15 PM
Late Angiographic Follow Up of Surgically Treated Aneurysms:
Recurrence, De Novo Formation, and the Fate of Residuals
Carlos David (Phoenix, AZ)A. Giancarlo VishtehMichael LemoleMichael Lawton (San Francisco, CA)Shahram PartoviRobert F. Spetzler (Phoenix, AZ)
KEY WORDS: aneurysm recurrence, angiography, residual aneurysm
The long-term angiographic follow up of surgically treated aneurysms is
unknown. This study was undertaken to evaluate the long-term angiographicoutcome of surgically treated aneurysms, specifically, to determine the inci-dence of recurrent aneurysms, the fate of residual necks, and the de novoformation of aneurysms. Ninety surgically treated aneurysm patients under-went late follow-up angiography. There were 70 females and 20 males with amean age of 48.5 years (range 12 to 78 years) and a total of 155 aneurysms.
One hundred forty-eight aneurysms were surgically treated. Late angiographicfollow up was obtained at a mean of 4.4 ± 1.6 years (range 2.6–9.2 years).
Total patient follow-up time was 393 years.
There were 2 (1.3%) recurrent aneurysms, yielding a recurrence rate of
0.50%/yr. Sixteen aneurysms had known residuals of which 3 (18.7%) enlargedin size and 13 (81%) remained unchanged. Two residuals (12.5%) ruptured yield-ing a yearly hemorrhage risk of 2.4%/yr. Eight de novo aneurysms were found insix patients for a yearly risk of 2.0%/yr. A previous history of multiple aneurysmswas associated with de novo aneurysm formation (p = 0.031, Fisher’s exact test).
This study confirms the long-term efficacy of aneurysmal clip ligation. In
addition, there is a small but significant risk of de novo aneurysm formation, par-ticularly in multiple-aneurysm patients. Most residual aneurysmal rests appear toremain stable, although a subset may enlarge or rupture. These findings supportthe use of late angiographic follow-up evaluation in aneurysm patients.
MONDAY, 3:15-3:30 PM
Failed Microsurgery and the Role of Radiosurgery for Acoustic
Bruce E. Pollock (Rochester, MN)L. Dade LunsfordDouglas S. KondziolkaBrent C. ClydeJohn C. Flickinger (Pittsburgh, PA)
KEY WORDS: radiosurgery, microsurgery, acoustic neuroma, outcome
To assess the outcomes of stereotactic radiosurgery (SR) for acoustic neu-
roma in patients who have failed prior microsurgical resection, we reviewed ourexperience in 72 consecutive patients referred during a 9-year interval. The 72patients (74 tumors) had a minimum of 1 year follow up after SR using the gammaknife. Multiple isocenter dose planning was used in all patients (doses rangedfrom 12–20 Gy at the tumor margin, depending on tumor volume). All tumors wereeither recurrent after total resection (34%) or persistent after subtotal resection(66%). Twenty-eight patients (38%) had undergone multiple resections. Forty-onepatients (55%) had significant impairment of facial nerve function (House-BrackmanGrade III–VI) after their microsurgical procedure; 50% had trigeminal sensoryloss, and 96% had unserviceable hearing (PTA > 50, SDS < 50%). Median followup after radiosurgery was 40 months (range 12–97 months).
In-hospital stay varied from 6 to 24 hours after radiosurgery. Patients
returned to their preradiosurgical functional status the next day. Tumor controlafter radiosurgery was achieved in 69 patients (93%). Six patients requiredadditional resection despite radiosurgery (median of 32 months afterwards)and one patient had repeated radiosurgery for tumor progression outside thepreviously irradiated volume. Nine (20%) of 45 patients with Grade I to IIIfacial function prior to radiosurgery developed increased facial weakness af-ter radiosurgery. Ten patients (14%) developed new trigeminal symptoms.
Effect of Rosiglitazone on the Risk of Myocardial Infarction Steven E. Nissen, M.D., and Kathy Wolski, M.P.H. Background Rosiglitazone is widely used to treat patients with type 2 diabetes mellitus, but its From the Cleveland Clinic, Cleveland. Ad effect on cardiovascular morbidity and mortality has not been determined. the Department of Cardiovascular Medicine, Cleveland Clinic, 9500 Eu
Maplewood Oral and Maxillofacial Surgery, P.A. Patient Name ____________________________________________________ Date of Birth _________________ M □ F □ Dentist __________________________________________ Orthodontist (if applicable) _____________________________________ And Relationship _________________________________________________________ Phone_____________________________ If patient