Bilateral symmetrical softening of the thalamus.

The clinical and pathological data of a 48 year old patient who survived 40 days are reported. Her disturbance of consciousness corresponded to an apallic syndrome, which 12 days later bacame akinetic mutism. Symmetrical softening involving the medial thalamic nuclei from the plane of the corpora mamillaria to the red nuclei was found. The ischemic lesion might be explained by transient circulatory collapse combined with hypoplasia of the vertebrobasialr arteries. On the EEG slight irregular alpha activity was recorded (alpha coma) and external stimuli elicited theta-delta waves (paradox activation). A survey of the literature of akinetic mutism is included and the correlation between non-hypnoid unconsciousness and EEG is discussed.