Faculty Bibliography

Intrinsic focal tumor of the medulla oblongata is an uncommon entity. Of the 51 cases presenting for treatment of a brainstem glioma between 1984 and 1990, only 7 were confined to the medulla. Radical excision was performed on each patient. Four of the first 5 patients who were extubated in the recovery room had CO2 retention, with associated respiratory arrest and hypoxia. Three suffered permanent cranial nerve deficits as a result. It is the purpose of this report to describe the serious complications of medullary surgery and to make recommendations as to how they may be avoided

Two cases of aplasia cutis congenita with associated bony defects are presented to highlight the dangers of delayed coverage of exposed dura. Management of one case was complicated by repeated local and systemic sepsis and the other by repeated, life-threatening hemorrhage. Early, definitive coverage of these defects using full thickness skin flaps avoids the risks of hemorrhage and should, if the recipient bed is clean, lessen the incidence of complicating sepsis

Sixteen children underwent 18 operations for radical resection of chiasmatic-hypothalamic tumors. The clinical presentation correlated with age: infants under 1 year of age presented with macrocephaly, failure to thrive, and severe visual failure; children aged 1 to 5 years predominantly had precocious puberty with mild visual deficits; and older children (greater than 5 years old) had slowly progressive loss of vision. All three infants had biologically aggressive tumors in spite of low-grade histology, and died from progressive tumor growth. Eleven of the 13 children aged 1 year or over are alive and well, without clinical or radiographic evidence of disease progression, 4 months to 4 1/2 years following surgery. Six of these patients, with a follow-up period of 10 months to 4 1/2 years (mean 27 months), have had no adjuvant therapy following radical surgical resection. The authors conclude that: 1) radical surgical resection of chiasmatic-hypothalamic tumors can be performed with minimal morbidity; 2) radical resection may delay the time to disease progression in older children and postpone the need for irradiation; 3) resection of postirradiation recurrent tumors may provide neurological improvement and long-lasting clinical remission; and 4) chiasmatic-hypothalamic tumors of infancy are aggressive neoplasms that require multimodality therapy

171 patients with intramedullary spinal cord tumors were operated on, of which 25 patients (15%), mostly children, developed symptomatic hydrocephalus. Twenty patients (12%) had malignant tumors, with 13 of the 20 cases (63%) complicated by increased intracranial pressure and ventriculomegaly. Of the remaining 151 patients with benign tumors (89%), only 12 (8%) developed symptomatic hydrocephalus. In an effort to understand the relationship between hydrocephalus and intramedullary spinal cord tumor, the authors analyze the level and histology of the neoplasm, as well as its association with spinal cysts. A review of the neurosurgical literature reveals that 34 similar cases of hydrocephalus associated with intramedullary spinal cord tumors have been reported to date. The authors note that the presence of hydrocephalus in patients with malignant intramedullary astrocytomas is associated with a shorter rate of survival than in those patients with high-grade lesions but without hydrocephalus, apparently due to rapid tumor progression. The ventriculomegaly seen with benign spinal cord gliomas has no statistically significant effect upon long-term prognosis

Intrinsic brain stem tumors are a heterogeneous group of neoplasms that may be classified according to clinical and neurodiagnostic criteria. We have described simple anatomic categories that include focal, diffuse, cystic, and cervicomedullary tumors. Although there is no surgical option for the common diffuse brain stem neoplasms, the other tumors may be operated on if the clinical and neurodiagnostic assessment suggests the possibility of a benign neoplasm. It is important to emphasize that although all tumors that were covered by intact ependyma or pia were considered intrinsic tumors in this series, most of these tumors created a 'bulge' that was obvious on visual inspection of the external surface of the brain stem. In all of the tumors that were benefitted by surgery, the neoplasms tended to 'bulge' from the brain stem rather than infiltrate it, which was the case with the diffuse neoplasms. It seems likely that many of the focal, cystic, and cervicomedullary tumors are similar to the dorsal exophytic brain stem tumors, which are characteristically low-grade astrocytomas that disrupt the ependymal lining and grow posteriorly into the fourth ventricle. Although surgery has been well tolerated and beneficial in many patients, it would be premature to comment on the duration of remission or the possibility of permanent cure