Regional distribution of cerebral arteriovenous malformations. Interactions with sex and handedness.

On the basis of clinical observation and a developmental theory of cerebral laterality, Geschwind and Galaburda suggested that cerebral arteriovenous malformations (AVMs) are more common in the left hemispheres of male patients. We tested this hypothesis by examining interactions among sex, handedness, and location of lateralized, supratentorial AVMs. Data from 112 cases were analyzed by log-linear procedures. We found that (1) females had a greater proportion of left-hemisphere AVMs, whereas males showed an opposite trend; (2) there were no interactions between sex and handedness; and (3) nondextrals showed a higher proportion of AVMs located in frontal regions, regardless of the hemispheric side of the lesion. Although these findings appear to be inconsistent with the Geschwind-Galaburda hypothesis, the inconsistency may be attributable to the embryonic stage at which this developmental abnormality occurs. In addition, the unexpected findings may also reflect our use of multivariate statistical procedures, which control for interaction effects.

Computed tomography of the sacrum: 2. Pathology.

Fifteen cases of primary sacral pathology were analyzed. High-resolution computed tomography was found to be the most accurate means of studying these cases. Certain anatomic changes involving the central canal and sacral foramina were found to be helpful in determining the type of pathology. Although conventional plain films, radionuclide bone scans, and myelography were useful in certain cases, computed tomography was found to be the procedure of choice in the workup of sacral problems.

CT of subarachnoid hemorrhage due to ruptured aneurysm.

Computed tomographic scans in 81 consecutive patients wih subarachnoid hemorrhage due to ruptured aneurysm were analyzed for patterns of hemorrhage and lucency and correlated with the development of spasm and hydrocephalus. The circulation time was measured angiographically in representative cases of spasm. Hemorrhage corresponded in a general way to the fossa of aneurysm origin and, when there was parenchymal or ventricular hemorrhage, in more specific ways to anterior communicating, middle cerebral, and posterior inferior cerebellar artery aneurysms. Basal ganglionic hemorrhages due to aneurysm ruptures occurred in two cases and could not be distinguished by appearance from hypertensive hemorrhage. Regions of low attenuation (lucencies) were often persistent and had lateralizing value; they showed a high correlation with arterial spasm. Conversely, spasm, particularly of a distal type, showed a significant correlation with increased circulation time and the occurrence of brain lucency. In cases of multiple aneurysms arising from different vessels in which there was hemorrhage or lucency, CT scans correctly predicted the site of aneurysm in 77% of cases. Periventricular lucency was a weak predictor of progressive hydrocephalus, while an intraventricular hemorrhage was a strong predictor of moderate to severe hydrocephalus.

The embolization of vascular malformations of the spinal cord with low-viscosity silicone rubber.

Development of the low-viscosity silicone rubber has made possible the successful embolization and complete obliteration of 9 out of 11 vascular malformations of the spinal cord treated with this material. The procedure is particularly useful in patients where the malformation is fed by a limited number of posterior radicular feeders without any supply from the anterior spinal artery. One patient with a supply from the anterior spinal artery. One patient with a supply from both anterior and posterior feeders was successfully embolized after a temporary occlusion of the anterior spinal radicular feeder. Seven patients out of 11 embolized with silicone rubber showed a clinical improvement of their signs and symptoms.