Degeneration of the thalamus and inferior olives associated with spongiform encephalopathy of the cerebral cortex.

We describe a 37-year-old man with a 30-month history of progressive dementia, myoclonus and prominent ataxia with the additional clinical features of dysautonomia and delirious psychomotor excitement and with relatively preserved verbal responses. The pathological changes include 1) severe neuronal loss and gliosis without spongiform change of the thalamus and inferior olives associated with gliosis of the midbrain tegmentum, and demyelination and gliosis of the central tegmental tract, olivo-cerebellar fibers and spino-olivary tract, and 2) mild spongiform encephalopathy of the cerebral cortex. Although the latter implies that the present case may be an example of the rare thalamic form of Creutzfeld-Jakob disease, the preferential and severe involvement of the thalamus and inferior olives without spongiform change as well as the clinical features are quite reminiscent of primary thalamic degeneration [Stern 1939]. This case draws further attention to the relationship between spongiform encephalopathy and degeneration without spongiform change of the thalamus and olivary system.