Neurosurgery
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Pineal cysts are being described with increasing frequency since the advent of magnetic resonance imaging. Although pineal cysts are incidental findings in as many as 4% of magnetic resonance imaging studies, symptomatic pineal cysts are quite rare. We present a case of pineal cyst causing aqueductal obstruction with symptomatic hydrocephalus and resultant headache and syncope, which was treated by surgical resection. A review of the relevant literature and discussion follow.
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Case Reports Comparative Study
The frequency-dependent behavior of cerebral autoregulation.
Cerebral autoregulation is a complex physiological process composed of both fast and slow components that may respond differently to different rates and patterns of blood pressure variation. To assess the temporal nature of autoregulation, transcranial Doppler velocity recordings of the middle cerebral artery obtained over prolonged periods were compared with blood pressure recordings in 5 patients without cerebral disease and in 13 patients with intracranial pathological changes. Correlations between the velocity and pressure wave forms at various frequencies of variation were measured with systems analysis techniques. ⋯ Patients without cerebral disease had significantly lower correlations (P less than 0.01), indicating intact autoregulation. Examples of increasing correlations and correlations at new frequencies emerging as the clinical condition worsened are given. These preliminary examples suggest that the application of systems analysis techniques to velocity and pressure data allow measurement of the temporal nature of cerebral autoregulation.
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Multiple intracranial tumors of different cell types are rare. We report nine patients with multiple intracranial tumors, who did not have a history of trauma, irradiation, or phacomatosis. The clinical, radiological, and histopathological findings as well as indications for operations in patients with asymptomatic second tumors are discussed.
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Case Reports
The effect of arteriovenous malformation resection on cerebrovascular reactivity to carbon dioxide.
To investigate the cerebral hemodynamic changes associated with obliteration of arteriovenous malformations (AVMs), we studied 26 patients undergoing total microsurgical AVM resection during isoflurane and N2/O2 anesthesia. Detectors were placed 5 to 6 cm from the margin of the lesion and in a homologous contralateral position. Cerebral blood flow (CBF) was measured using the intravenous xenon-133 technique before and after AVM resection, during both hypocapnia and normocapnia at each stage. ⋯ One patient suffered postoperative intracerebral hemorrhage, attributable to technical problems, and had no increase in CBF. We conclude that, with an acute increase in the arteriovenous pressure gradient (and cerebral perfusion pressure) that results from shunt obliteration, there is an immediate global effect of AVM resection to increase CBF. Cerebrovascular reactivity to CO2 remains intact both before and after excision.
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Case Reports
Acute spinal intradural extramedullary hematoma: a nonsurgical approach for spinal cord decompression.
The authors present the case of a 60-year old man with a spontaneous spinal intradural hematoma in the thoracic and lumbar region, which was caused by anticoagulant therapy and led to a severe progressive transverse lesion. After substitution of coagulation factors, a small catheter was inserted into the subarachnoid space via a lumbar puncture. By alternating irrigation and suction removal of the blood clot, restoration of the cerebrospinal fluid passage was possible along with a marked improvement in the neurological deficits. At 8 months' follow-up, the patient had completely recovered from the severe paraparesis and bladder dysfunction.