Neurosurgery
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We have used a recently introduced cerebral blood flow tracer, technetium-99-DL-hexamethylpropylene amine oxime, to map regional cerebral blood flow simultaneously with measurements of glucose metabolism ([14C]-2-deoxyglucose technique) using autoradiography. The technique was used to compare the acute effects of middle cerebral artery occlusion with the more complex events that occur after induction of an acute subdural hematoma (SDH) in the rat. Previous studies with this SDH model have shown that an infarction is induced in the cortex under the hematoma. ⋯ Global blood flow after the SDH was reduced by 14%, but remained unchanged after middle cerebral artery occlusion. In the hippocampus, a massive increase in metabolism (up to 157%) after SDH was accompanied by a paradoxical decrease in blood flow (32%). This discrepancy between blood flow and metabolism indicates loss of flow-metabolism coupling and provides a mechanism for infarct recruitment and delayed hippocampal damage after SDH.
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Case Reports
En bloc resection of an ethmoid carcinoma involving the orbit and medial wall of the cavernous sinus.
The involvement of the cavernous sinus by malignant tumors has limited their surgical treatment. We report here a successful en bloc resection of an invasive ethmoid carcinoma involving the cavernous sinus in a 46-year-old man. To prepare for surgery on this patient, a cadaver study was performed to investigate the feasibility of en bloc cavernous sinus resection and reconstruction. The preoperative evaluation, operative approach, and postoperative management are presented.
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In the management of patients with acute cerebral disturbances, it is essential to determine precisely the degree of impaired consciousness. In order to secure the accuracy of observations, one must use a reliable coma scale. We have evaluated the Edinburgh 2 coma scale (E2CS) and explored the relationship between levels of the E2CS and the final outcome. ⋯ It was shown at the same time that each level has different prognostic significance and that the distance between each level is not identical. The recommendation is made to separate the levels on a chart not by an ordinal number but by the distance calculated on the basis of either mortality or morbidity rates. This will make it possible to get a rough estimate of the patients' prognoses by simply looking at a daily clinical chart.
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We report a series of 84 consecutive patients (41 women) with 92 distal anterior cerebral artery aneurysms (DACAA). All aneurysms were saccular. Four different locations of DACAAs were found: proximal, 5 aneurysms; frontobasal, 8; genu corporis callosi, 72; and distal, 7. ⋯ All of the poor surgical results were obtained in patients with severe preoperative deficits. Exact measurements of DACAA sizes and necks were smaller than those of cerebral aneurysms in other locations. Aside from localization, microsurgery of these aneurysms presented no special difficulties, as compared with surgery of aneurysms in other locations.
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Comparative Study
Total intravenous anesthesia for improvement of intraoperative monitoring of somatosensory evoked potentials during aneurysm surgery.
Two anesthetic regimens for monitoring somatosensory evoked potentials (SEPs) during intracranial aneurysm surgery were compared. Eighty-four sequential cases of intracranial aneurysms were operated on employing SEP monitoring. The first group of 22 cases was anesthetized with "balanced anesthesia" and the second group of 62 cases received total intravenous anesthesia (TIVA) consisting of propofol and alfentanil. ⋯ The higher amplitude of posterior tibial nerve SEPs recorded with TIVA made monitoring during surgery for anterior communicating artery aneurysms possible in all cases. This was not always the case with balanced anesthesia. The late deflection of median nerve SEPs (N30) was more frequently observed with TIVA.(ABSTRACT TRUNCATED AT 250 WORDS)