Mitchel S. Berger and Charles B. Wilson
✓ Epidermoid cysts originating in the paramedian basal cisterns of the posterior fossa are congenital lesions that grow to a large size through slow accumulation of desquamated epithelium. These lesions grow between and ultimately displace cranial nerves, vascular structures, and the brain stem, causing a long course of progressive neurological deficits. The onset of symptoms usually occurs during the fourth decade of life. Epidermoid cysts are easily diagnosed with computerized tomography scans, which characteristically show a low-density extra-axial pattern. The primary surgical objective is to decompress the mass by evacuating the cyst contents and removing nonadherent portions of the tumor capsule; portions of the capsule adherent to vital structures should be left undisturbed. Aseptic meningitis is the most common cause of postoperative morbidity, and its incidence may be minimized by intraoperative irrigation with steroids followed by systemic therapy with dexamethasone. Symptomatic recurrences that occur many years after surgery should be managed with conservative reoperation.
Victor A. Levin, Michael S. B. Edwards, Philip H. Gutin, Pamela Vestnys, Dorcas Fulton, Margaret Seager and Charles B. Wilson
✓ The authors have conducted a Phase II trial to evaluate orally administered dibromodulcitol in the treatment of 40 evaluable patients with recurrent medulloblastoma, ependymoma, and malignant astrocytoma. Ten of 20 patients harboring medulloblastoma responded to therapy with a median time to tumor progression (MTP) of 40 weeks, and four of 20 patients had no sign of progression of disease 4 years after treatment was begun. The MTP for all 12 patients with ependymoma was 30 weeks. Nine of these 12 patients had stabilization of their disease with an MTP of 67 weeks; three of these 12 patients had no signs of progression for 1 to 3 years after treatment was begun. Of six patients harboring supratentorial gliomas, none responded to dibromodulcitol. Two patients, one with a primitive neuroectodermal tumor and the other with a metastatic carcinoma of the breast, had stabilization of disease for more than 4 and 2 years, respectively.
The Herbert Olivecrona Lecture
Charles B. Wilson
✓ The author reviews his experience with surgical treatment of 1000 pituitary tumors, the majority of which were endocrine-active. The criteria of grading, the microsurgical technique used, and the postoperative results are presented. The mortality rate was 0.2% overall, with no deaths in the group of 774 patients with endocrine-active adenomas.
Report of six cases and review of the literature
Mitchel S. Berger and Charles B. Wilson
✓ Dissecting aneurysms of the intracranial posterior circulation are unusual lesions that affect otherwise healthy young adults, are difficult to diagnose and manage, and carry a high morbidity and mortality rate. Headache in the suboccipital-posterior cervical region is the most common presenting symptom. The dissection usually occurs between the intima or internal elastic lamina and the media; subadventitial dissection does occur and accounts for the infrequent finding of subarachnoid hemorrhage. A deficit in the inner layers of the vessel is the proposed source of dissection. The angiographic features are inconsistent, although an irregularly narrowed arterial segment with proximal and/or distal dilatation are typical findings. Depending on the location of the dissection, the surgical options are: ligation, trapping, or reinforcement of exposed abnormal portions of the vessel. Anticoagulation therapy is not indicated in the management of this lesion.
Favorable results with syringoperitoneal shunting
Nicholas M. Barbaro, Charles B. Wilson, Philip H. Gutin and Michael S. B. Edwards
✓ The authors reviewed the clinical findings, radiological evaluation, and operative therapy of 39 patients with syringomyelia. Syringoperitoneal (SP) shunting was used in 15 patients and other procedures were used in 24 patients. Follow-up periods ranged from 1½ to 12 years. During the period of this study, metrizamide myelography in conjunction with early and delayed computerized tomography scanning replaced all other diagnostic procedures in patients with syringomyelia. Preoperative accuracy for the two procedures was 87%.
The most common symptoms were weakness (79%), sensory loss (67%), pain (38%), and leg stiffness (28%). Surgery was most effective in stabilizing or alleviating pain (100%), sensory loss (81%), and weakness (74%); spasticity, headache, and bowel or bladder dysfunction were less likely to be reversed. Approximately 80% of patients with idiopathic and posttraumatic syringomyelia and 70% of those with arachnoiditis improved or stabilized. Better results were obtained in patients with less severe neurological deficits, suggesting the need for early operative intervention. A higher percentage of patients had neurological improvement with SP shunting than with any other procedure, especially when SP shunting was the first operation performed. Patients treated with SP shunts also had the highest complication rate, most often shunt malfunction. These results indicate that SP shunting is effective in reversing or arresting neurological deterioration in patients with syringomyelia.
Griffith R. Harsh IV and Charles B. Wilson
✓ Local recurrence developed 6 years after the initial resection of an intraspinal meningeal tumor that originally was thought to be an angioblastic meningioma. Histological review of the pathology led to a change of that diagnosis to one of mesenchymal chondrosarcoma. The recurrent vascular tumor was embolized, then totally excised. Because this tumor had malignant features, the patient received irradiation and chemotherapy. No evidence of regrowth has been observed during a period of more than 4 years. Mesenchymal chondrosarcomas of the central nervous system and their treatment are reviewed.
Results of treatment with radiation therapy and chemotherapy
Surasak Phuphanich, Michael S. B. Edwards, Victor A. Levin, Pamela S. Vestnys, William M. Wara, Richard L. Davis and Charles B. Wilson
✓ Twenty-seven patients aged 1 to 18 years harboring supratentorial (20 in the cerebrum and seven in the thalamus) malignant gliomas were treated between 1975 and 1982. There were four glioblastomas multiforme, 14 anaplastic astrocytomas, and nine malignant gliomas. All patients had a subtotal resection or biopsy as the initial procedure and received postoperative radiation therapy (RT). Fifteen of 27 patients were treated by RT alone; 14 had tumor progression with a median time to tumor progression (MTP) of 65 weeks. Twelve patients were treated with chemotherapy as an adjuvant to RT; only seven had tumor recurrence, with an MTP of 130 weeks. Of the 21 patients with recurrent tumors in both groups, 18 were treated with chemotherapy alone, or chemotherapy with a second surgical procedure or second course of RT.
For all histological grades of tumor, the MTP for first recurrence was 75 weeks and the median survival time was 180 weeks. Age at initial diagnosis was found to be a statistically significant prognostic factor, with patients younger than 10 years of age surviving longer than patients aged over 10 years (p = 0.02).
Stephen K. Powers, Michael S. B. Edwards, James E. Boggan, Lawrence H. Pitts, Philip H. Gutin, Yoshio Hosobuchi, John E. Adams and Charles B. Wilson
✓ The argon surgical laser has been used in 68 neurosurgical procedures that included the removal of intracranial and intraspinal tumors, spinal cord fenestration for syringomyelia, and the production of dorsal root entry zone lesions. Characteristics that make the argon surgical laser a useful microneurosurgical instrument include the availability of a fiberoptic delivery system, a laser spot size that can be varied continuously between 0.15 and 1.5 mm, a single laser-aiming and treatment beam, the transmission of argon laser light through aqueous media such as irrigating or cerebrospinal fluids, and improved hemostasis compared to conventional techniques. The argon laser is limited primarily by its relatively low power output (less than 16 W), which makes the excision of large tumors difficult. However, even with these limitations, which can be used to advantage in the proper setting, the authors' laboratory and clinical experience suggests that the argon surgical laser may be useful in certain microneurosurgical operations.