Faculty Bibliography

PURPOSE: In a previous randomized trial, the addition of adjuvant chemotherapy to postoperative radiotherapy proved beneficial in the treatment of childhood high-grade astrocytomas. The present study tests the hypothesis that an eight-drug adjuvant chemotherapy regimen would improve survival in such children compared with the three-drug regimen of the prior study. PATIENTS AND METHODS: Between April 1985 and May 1990, patients between the ages of 18 months and 21 years with newly diagnosed high-grade astrocytomas were eligible for this study, as determined by the treating institution's histopathologic diagnosis. Treatment consisted of postoperative local-field radiotherapy and adjuvant chemotherapy, either lomustine (CCNU), vincristine, and prednisone (control regimen) or eight-drugs-in-1-day chemotherapy (experimental regimen). Two cycles of postoperative preirradiation chemotherapy were administered in the experimental regimen. Patients were evaluated radiographically every 3 months after irradiation. RESULTS: Eighty-five eligible patients were randomized to the control regimen and 87 to the experimental regimen. The progression-free survival (PFS) and overall survival (OS) at 5 years were 33% (SE = 5%) and 36% (SE = 6%), respectively. There was no statistical difference in outcome between the two chemotherapy regimens. In patients with confirmed diagnoses of anaplastic astrocytoma (AA) or glioblastoma multiforme (GBM), anaplastic astrocytoma, greater than 90% resection, and nonmidline tumor location were characteristics predictive of an improved PFS. There was a difference in toxicity between the two chemotherapeutic regimens, with greater myelosuppression and hearing loss in the experimental regimen. Tumor recurrence occurred primarily within the primary tumor site. CONCLUSIONS: There is no benefit to the treatment of high-grade astrocytomas in children with eight-drugs-in-1-day chemotherapy compared with CCNU, vincristine, and prednisone. Extent of tumor resection and histopathologic diagnosis are significant prognostic variables. The overall outcome for children with high-grade astrocytomas remains poor

Hydromyelia, or hydrosyringomyelia is frequently associated with the Chiari I malformation of the cerebellar tonsils. Descent of the cerebellar tonsils is considered a congenital anomaly with a few reports of 'acquired' Chiari I malformation. We report a patient with a giant craniopharyngioma and hydrocephalus who at presentation had a concomitant Chiari I malformation and hydromyelia. The patient underwent gross total resection of the tumor and, with no further treatment, demonstrated spontaneous resolution of the Chiari I malformation and hydromyelia during the postoperative period. This suggests that the Chiari I malformation and the resulting hydromyelia were 'acquired', and were caused by an intracranial mass effect. This provides further evidence for an associative mechanism of cerebellar tonsillar descent and the development of hydromyelia

Fourth-ventricular shunting is commonly used to treat symptomatic posterior fossa cysts of the Dandy-Walker malformation and trapped fourth ventricle. Although the benefits of this procedure have been widely reported, there is a paucity of data on the pitfalls of posterior fossa shunting in the neurosurgical literature. During the 4-year period from July 1989 to June 1993, we placed fourth-ventricular shunts in 12 patients. Remarkably, 5 patients suffered complications related to posterior fossa catheter placement (42% rate). Three of these patients developed new cranial nerve dysfunction caused by direct injury to the floor of the fourth ventricle, 1 patient suffered an intracystic hemorrhage and acute shunt malfunction, and 1 patient had the catheter tip in the brainstem on postoperative studies without new neurological deficit. We conclude that placement of fourth-ventricular shunts can be fraught with complications which we believe is related to technique. We propose that altering the trajectory of the ventricular catheter from our usual midline technique to a more lateral position will lessen the chances for injury to the floor of the fourth ventricle. In this manner we hope to decrease our incidence of complications for this procedure

Supratentorial primitive neuroectodermal tumors (S-PNETs), which have also been called cerebral neuroblastomas, have been considered to be the hemispheric equivalent of posterior fossa medulloblastomas. Twenty-seven children with S-PNETs (excluding pineoblastomas) which were confirmed by central pathology review were treated on the CCG-921 protocol from 1986 to 1992. After operation, all patients were staged with CSF cytology and spinal myelography or magnetic resonance scans and were treated with craniospinal irradiation and chemotherapy. Data from these 27 patients have been reviewed to evaluate neurosurgical treatment, survival, and prognostic variables that correlate with survival. Overall survival at 5 years was 34% (SE 20%) and progression-free survival (PFS) was 31% (SE 18%), which is lower than the survival of patients with posterior fossa PNETs (medulloblastomas). PFS was significantly worse in children 1.5-3 years of age at diagnosis and in those with evidence of tumor dissemination at the time of diagnosis. Large preoperative tumors were more likely to be associated with greater than 1.5 cm2 residual tumor postoperatively. Neurosurgeons estimated that less than 1.5 cm2 of residual tumor was present in 52% of the cases; postoperative scans confirmed that in 58%. For children with less than 1.5 cm2 residual tumor, postoperative survival at 4.0 years was 40% (SE 22%); for those with greater than 1.5 cm2 residual tumor, survival was 13% (SE 8%). The difference did not reach statistical significance, due to small numbers in this series, though a trend did exist (p = 0.19). Large series will be required to clarify the effects of extent of resection on survival

The Pallister-Hall syndrome (PHS) was initially described as the congenital hypothalamic 'hamartoblastoma' syndrome in 1980. Cardinal manifestations of the syndrome consist of a hypothalamic hamartoma and extracranial abnormalities, initially thought to be fatal in the perinatal period. The original pathologic description of these hypothalamic lesions were from infants who died in the perinatal period and revealed small cells of variable density which resembled primitive undifferentiated germinal cells and appeared to invade the hypothalamic nuclei, suggesting a neoplastic potential. Hypothalamic lesions have now been removed from older infants and children with this syndrome and reveal a more mature histologic appearance typical of a hypothalamic hamartoma. We present 2 new cases of PHS who underwent surgery and demonstrate the maturational nature of the hypothalamic lesion and the phenotypic variability of the syndrome

Pathological and clinical data from 56 patients operated on for craniopharyngioma since 1981 were analyzed to determine the utility of dividing patients with this tumor into distinct clinical groups based on recognized pathological type and to determine the prognostic import of brain invasion. Of the tumors in the 30 adult patients, 66% were adamantinomatous, 28% were squamous papillary, and the remainder were mixed. However, of the tumors in the 26 children, 96% were adamantinomatous and none were pure squamous papillary (P < 0.01). Forty-six percent of the children compared with 17% of the adults had brain invasion (P < 0.01). Brain invasion was present in 37% of the adamantinomatous but in only 13% of the squamous papillary tumors. Seventy-seven percent of the children underwent gross total resection (GTR) compared with 27% of the adults (P < 0.01). Sixty-three percent of the squamous papillary tumors underwent GTR compared with 54% of the adamantinomatous and mixed tumors. Follow-up ranged from 7 to 187 months (mean, 49 mo). After subtotal resection, with or without radiation therapy, 58% of the tumors recurred compared with 17% recurrence after GTR (P < 0.01), with a mean time to recurrence of 34 months. In both tumor histological types, subtotal resection was associated with a higher rate of tumor recurrence compared with gross total resection. Among the subtotally resected craniopharyngiomas, 2 of the 3 (67%) squamous papillary and 11 of the 21 (52%) adamantinomatous and mixed tumors recurred. In contrast, among the totally resected tumors, none of the 5 squamous papillary and only 5 of the 25 (20%) adamantinomatous and mixed tumors recurred. There were no significant differences in Karnofsky performance status score, mortality rate, or visual and endocrine outcomes when comparing patients based on histological tumor type. When controlling for age and extent of resection, we found that brain invasion had no significant effect on recurrence rate in totally resected tumors. Based on the limited number of patients in this series, we conclude as follows. 1) Contrary to previous reports, squamous papillary craniopharyngiomas, like adamantinomatous tumors, may recur when subtotally resected. 2) For both tumor variants, the most significant factor associated with craniopharyngioma recurrence is the extent of surgical resection rather than histopathological subtype. 3) Contrary to prior hypotheses, brain invasion in totally resected tumors does not predict higher recurrence. 4) GTR is associated with a significantly lower recurrence rate and can be achieved without sacrificing functional outcome

We conducted a retrospective analysis of the cases of 122 children operated on for various brain tumors, to determine the incidence and natural history of postoperative diabetes insipidus (DI), and the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). Abnormalities of water homeostasis were observed in 15 patients (12%). DI, with or without SIADH, was observed in 10 patients (8%), while SIADH alone was seen in five (4%). DI was permanent in five subjects (50%), whereas SIADH resolved completely in all affected individuals. Parenteral desmopressin (dDAVP) was an effective mode of therapy in the postoperative period. The effect did not correlate with a dosage strictly based on body weight

Moyamoya disease is a cerebrovascular disease characterized radiologically by progressive narrowing and occlusion of the arteries contributing to the circle of Willis and its branches. There is formation of an exuberant collateral network of blood vessels at the base of the brain, which is thought to arise in response to chronic ischemia. Clinically, the course is variable, with patients having repeated transient ischemic attacks, strokes, migraine, and seizures. Effective treatment is not available. The etiology and pathophysiology of moyamoya disease are largely unknown. Two patients with arteriographically proven moyamoya disease were identified. Both patients were symptomatic before age 5 years. Despite successful encephaloduroarteriosynangiosis revascularization procedures, they continued to experience an inexorable downhill course. A calcium channel blocker (nicardipine HCl) was introduced in order to prevent further symptoms. After the introduction of nicardipine, no further strokes occurred in either patient. There were no further episodes of transient ischemic attacks, seizures, or headache in one patient and decreased frequency in the other. In patients with moyamoya disease, nicardipine may have a beneficial effect on cerebral hemodynamics and may prevent ischemic sequelae by optimizing existing collateral circulation