Thalamic experiential hallucinosis.

Two patients with an infarct limited to the thalamus developed auditory and visual experiential hallucinations. Neuropathological studies in one patient showed a small cavity in the right intralaminar nuclei surrounded by focal spongiform change, partly involving the right dorsomedial nucleus. Neuroradiological data in another patient indicated that the same nuclei in the left thalamus were also affected. It was concluded that a unilateral thalamic lesion could cause experiential hallucinations and the intralaminar and dorsomedial nuclei might be important structures to explain the phenomenon.