PURE THALAMIC DEMENTIA WITH A SINGLE FOCUS OF SPONGIFORM CHANGE IN CEREBRAL-CORTEX

An absence of spongiform change differentiates the pure thalamic degen eration (PTD) from the thalamic form of Creutzfeldt Jakob Disease (CJD ). This report describes a case which in addition to the neuropatholog ical changes typical of primary thalamic degeneration showed a single small focus of spongiform change in the cerebral cortex. The exception al instances of thalamic degeneration associated with limited spongifo rm change among which this case is unique by virtue of the size of the single focus of vacuolation probably represent a variant of the thala mic form of CJD. In the context of potential infectious etiology the f act that the patient had a blood transfusion five months before the on set of neurological illness is of interest.