Computed tomography and cerebral blood flow correlations of mental changes in chronic subdural hematoma.

To elucidate the pathophysiology of mental disturbances associated with chronic subdural hematoma, we performed quantitative and three-dimensional measurements of cerebral blood flow (CBF) on xenon-enhanced computed tomographic scans in 12 patients who had chronic subdural hematomas and manifested mental disturbances. In 2 patients who had no headache or hemiparesis, minimal mass effect, and severe multiple infarctions on computed tomographic scan, mentation did not improve after surgery. The CBF reduction was severe, and it further deteriorated after surgery. On the other hand, mentation improved to a varied extent in the other 10 patients, who had headache and/or hemiparesis and minimal, moderate, or severe mass effect and minimal or moderate multiple infarctions on computed tomographic scan. The CBF reduction was diffuse on both sides, but was more marked in the thalamus and putamen than it was in the cortex and subcortex. It was restored after surgery, but insufficiently. The restoration rate was statistically significant only in the thalamus, on both sides (with and without hematoma) (P less than 0.05). Dementia scores and CBF values after surgery were correlated on the side with the hematoma in the frontal cortex and thalamus (P less than 0.01) and in the hemisphere and temporoparietal cortex (P less than 0.05). There was no correlation on the side with the hematoma in the occipital cortex, putamen, and frontal and temporoparieto-occipital subcortices or on the side without the hematoma. The thalamus undergoes displacement and distortion by the hematoma, which in turn leads to changes in consciousness. Postoperative residual mental deficits consist primarily of dementia related to preexisting multiple infarctions.(ABSTRACT TRUNCATED AT 250 WORDS)