Faculty Bibliography

We report a case of radiation necrosis occurring 47 years after resection and radiotherapy for a juvenile pilocystic cerebellar astrocytoma, the longest yet reported. The patient presented with progressive lower cranial nerve dysfunction, and eventually died from cardiopulmonary arrest secondary to aspiration. The presentation, diagnosis, pathological features, and management of radiation necrosis are discussed

Pediatric meningiomas are uncommon. Those presenting in the third ventricle are rare; there are only 15 cases reported in the literature. We report an additional third ventricular meningioma in a 6-year-old boy. The tumor was resected via an anterior transcallosal interfornicial approach. Postoperatively, the patient exhibited a transient episode of mutism. Unlike previous reports, the pathological diagnosis of this lesion was an atypical meningioma. The presentation, management, pathological features, and postoperative course of our case are discussed and compared with previous reports

OBJECTIVE: The association of human immunodeficiency virus with a clinical picture of motor neuron disease is uncommon, with three cases reported to date. This case represents an additional case of a human immunodeficiency virus-infected patient with apparent motor neuron disease. DESIGN: Single patient case report. SETTING: Large urban public hospital. PATIENT: A 45-year-old human immunodeficiency virus-positive Hispanic man who presented with muscle wasting, fasciculations, areflexia, cranial nerve deficits, and weakness progressing to a complete quadriplegia. RESULTS: Electrophysiologic data showed evidence of diffuse denervation with normal sensory and motor nerve conductions and no evidence of demyelination. Electromyography showed diffuse sharp waves and fibrillation. CONCLUSIONS: This case demonstrates a progressive motor neuron dysfunction in a patient positive for the human immunodeficiency virus and provides additional evidence that infection with the human immunodeficiency virus should be considered in the differential diagnosis of apparent motor neuron disease

Intramedullary spinal cord abscesses are relatively uncommon. We report the first case of an intramedullary spinal cord abscess in a preexisting spinal cord ependymoma. The clinical features and pathogenesis are discussed. Salient features of the management of intramedullary spinal cord abscesses are outlined

Oligodendrocyte transplantation into the retina enables us to investigate the early events in myelin formation in a new in vivo system. The axons of rat retinal ganglion cells are unmyelinated in the eye but should express a myelination initiation signal since they acquire myelin posterior to the globe. The lamina cribrosa may block the migration of oligodendrocytes from the optic nerve into the retina. Animals that lack a lamina cribosa such as the rabbit have myelinated retinas. We have bypassed the lamina cribrosa by using transplantation techniques and inserted freshly isolated syngeneic 3-week-old rat oligodendrocytes into the unmyelinated 4-day-old rat retina during the period of active optic nerve myelination. The animals are sacrificed at 1-week intervals for 8 weeks. The retinas are examined immunocytochemically for myelin with an antibody to myelin basic protein (MBP). MBP-positive cells are seen extending processes at 1 and 2 weeks. Three and four week retinas show the formation of thicker and longer myelin sheaths oriented along the same radial path as the retinal ganglion axons with maximal MBP staining intensity seen by 5 weeks. Transplanted retinas are negative when stained for P0, a Schwann cell antigen, ruling out Schwann cell myelination of our retinas. We have shown that rat cerebral oligodendrocytes survive, mature, and express a myelin-specific protein in the retinal environment in a pattern consistent with myelination of ganglion cell axons. Retinal transplantation provides a new in vivo model to study oligodendrocyte development and axonal-glial interactions, free from the difficulties inherent in culture systems