Cerebral blood flow and metabolism in an amnestic patient with left thalamic infarction--a positron emission tomographic study.

A 30-year-old man with left thalamic infarction developed severe amnesia. The positron emission tomography showed a decrease in cerebral blood flow and oxygen metabolism in the left thalamus and the ipsilateral frontal cortex (-20% to -12% of asymmetry index) both at day 11 and at 5 months after onset, although amnestic symptoms certainly improved during that period. The selective hypometabolism of the cerebral cortex suggested the remote effects of neuronal fiber disconnection between the left thalamus and the ipsilateral frontal cortex, which did not parallel the clinical course.