Programs

The American Association of
Neurological Surgeons 1998 Annual Meeting
The American Association of Neurological Surgeons (AANS) held its 66th Annual Meeting April 25 - 30, 1998 at the Pennsylvania Convention Center in Philadelphia, Pennsylvania. NOTICE: The AANS meeting program information is available from the AANS. Users are responsible for complying with all copyright and licensing restrictions associated with the program information. Copyright © 1998; The American Association of Neurological Surgeons / Congress of Neurological Surgeons

Scientific program in PDF format
Poster program in PDF format

PAPER #729
Endocrine-Inactive Pituitary Adenomas: Clinicopathological Features and Long-Term Outcome Following Transsphenoidal Resection

Gordon Tang (Barstow, CA)
Ming-Ming Ning
Marielle H. Nyugen
Brooke Swearingen
Nicholas T. Zervas (Boston, MA)

Discussant: Kalmon Post

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 EIA from 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. Seven percent presented with apoplexy. Symptoms consistent with hypopituitarism were reported 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 of 2.3 cm. Immunostaining revealed that truly null tumors were less common than previously 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 silent endocrine 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 of tumor on follow-up imaging. Only 16% developed symptomatic recurrences despite the high incidence of residual tumor. Patients undergoing postoperative radiotherapy (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.

PAPER #762
Clinical Outcome of Patients With Subarachnoid Hemorrhage With Vasospasm Is the Same as in Patients Without Vasospasm Using Aggressive ICU Management

Christopher Ogilvy
Oscar Szentirmai
Deidre Buckley
Nicholas Zervas (Boston, MA)

Discussant: Neil Kassell

KEY WORDS: subarachnoid hemorrhage, vasospasm, outcome

Following treatment of an intracranial aneurysm after SAH, there is po-tential for significant morbidity and mortality as a result of cerebral vasospasm. We reviewed 411 patients with SAH admitted to Massachusetts Gen-eral Hospital between 1992 and 1997 and compared outcome in patients with and without clinical vasospasm. The patients’ clinical conditions at time of treat-ment were as follows: Hunt and Hess (HH) Grade 1, 120 patients (30%); HH Grade 2, 38 patients (9.5%); HH Grade 3, 147 patients (37%); HH Grade 4, 73 patients (18%); and HH Grade 5, 22 patients (5.5%). Patients treated ranged in age from 7 to 95 years. The majority of aneurysms were obliterated within 24 to 48 hours of initial ictus. Within the total group of patients, clinical vasos-pasm developed in 177 patients. Vasospasm was managed with hypertensive, hemodilutional, and hypervolemic therapy in an ICU setting, with endovascular treatment used in 39 patients. Outcome was evaluated from 3 months to 5 years after treatment (average follow up of 2.2 years).

Outcome was assigned as Excellent: normal neurological function; Good: slight neurological deficit with return to work; Fair: unable to return to previous level of employment; Poor: full-time nursing care. Of the group of 177 patients with vasospasm, 128 (72%) had excellent or good outcome, 19 (11%) had fair outcome, and 6 (3%) had poor outcome, with 24 deaths (14%). In 234 patients without spasm, 181 (77%) had an excellent or good outcome, 8 (3%) fair, 4 (2%) poor, and 44 (19%) died. There was no significant difference in outcome between the two groups. Therefore, patients with vasospasm managed ag-gressively in a neurological ICU do as well as patients without vasospasm after SAH.

DONAGHY LECTURE
AANS/CNS Section on Cerebrovascular Neurosurgery
EVOLUTION IN THE UNDERSTANDING AND MANAGEMENT OF CAVERNOUS MALFORMATIONS

Robert Ojemann, MD (Boston, MA)
(To be introduced by Joshua B. Bederson, MD)

SPECIAL SYMPOSIUM
AANS/CNS Section on Cerebrovascular Surgery
COMPLICATIONS OF INTRACRANIAL ANEURSYM TREATMENT

Moderator:
Joshua B. Bederson, MD (New York, NY)

Panelists:
David Piepgras, MD (Rochester, MN)
Fernando Vinuela, MD (Los Angeles, CA)
Robert Ojemann, MD (Boston, MA)

Seminar #217
SURGICAL APPROACHES TO LATERAL SKULL BASE

Moderator:
Albert Rhoton, Jr., MD (Gainesville, FL)

Panelists:
Laligam Sekhar, MD (Washington, DC)
Madjid Samii, MD (Hannover, Germany)
J. Diaz Day, MD (Boston, MA)
Griffith Harsh IV, MD (Boston, MA)

Seminar #412
TUMORS OF THE CLIVUS AND FORAMEN MAGNUM

Moderator:
Jon H. Robertson, MD (Memphis, TN)

Panelists:
Ossama Al-Mefty, MD (Little Rock, AR)
Chandranath Sen, MD (New York, NY)
Jeffrey Bruce, MD (New York, NY)
Paul Chapman, MD (Boston, MA)

Seminar #303
PERIOPERATIVE MANAGEMENT OF SUBARACHNOID HEMORRHAGE

Moderator:
Ralph Dacey, MD (Saint Louis, MO)

Panelists:
Neil Martin, MD (Los Angeles, CA)
Neal Kassell, MD (Charlottesville, VA)
Christopher Ogilvy, MD (Boston, MA)
Philip Stieg, MD (Boston, MA)

PAPER #775
A Modification of the Fisher Grading System to Predict Vasospasm Based on CT Scans After Aneurysmal Subarachnoid Hemorrhage

Oscar Szentirmai
Deidre Buckley
Christopher Ogilvy (Boston, MA)

Discussant:
Ralph G. Dacey, Jr.

KEY WORDS: grading system, vasospasm, subarachnoid hemorrhage

C. M. Fisher published a landmark paper in 1980 which related the den-sity of SAH to the chance of developing vasospasm. However, the scale tends to group patients into those with a low risk (Grades 1 and 2) and high risk (Grades 3 and 4) of developing vasospasm. We present a modified Fisher scale which more accurately predicts the chance of developing vasospasm based on location of blood.

We performed a retrospective blinded review of 83 preoperative CT scans using the original Fisher scale and the proposed modified Fisher scale. The modified grading scale is as follows: Grade 0 -- No blood or intraventricular hemorrhage alone or intraparenchymal hemorrhage alone; Grade 1 -- Only basal cistern blood; Grade 2 -- Only peripheral fissure blood; Grade 3 -- Diffuse SAH with intraparenchymal hematoma; Grade 4 -- Dense blood in basal cisterns and peripheral fissures. The CT grade was then correlated to the presence and severity of vasospasm diagnosed with transcranial Doppler ultrasound (TCD) postoperatively. Using the modified grading system, the in-cidence of vasospasm was found to increase with each grade: Grade 0: 1/10 patients (10%) had TCD vasospasm; Grade 1: 1/7 (14%); Grade 2: 3/8 (38%); Grade 3: 14/28 (50%); and Grade 4: 18/30 (60%). The results using the origi-nal Fisher scale were as follows: Grade 1: 2/11 (18.2%) patients had TCD vasospasm; in Grade 2: 10/24 (41.6%); Grade 3: 21/34 (61.7%); and Grade 4: 4/11 (36.4%).

The results obtained using the modified system are linear, with a corre-lation coefficient of r = 0.98, while the original Fisher scale was nonlinear (r = 0.75). There is a significant difference in the probability of developing vasos-pasm between grades using the new system (p = 0.0032 between each grade). Using this modified Fisher system, the chance of developing vasospasm can be more accurately predicted.