THALAMIC EXPERIENTIAL HALLUCINOSIS

Two patients with an infarct limited to the thalamus developed auditor y and visual experiential hallucinations. Neuropathological studies in one patient showed a small cavity in the right intralaminar nuclei su rrounded by focal spongiform change, partly involving the right dorsom edial nucleus. Neuroradiological data in another patient indicated tha t the same nuclei in the left thalamus were also affected. It was conc luded that a unilateral thalamic lesion could cause experiential hallu cinations and the intralaminar and dorsomedial nuclei might be importa nt structures to explain the phenomenon.