Peduncular hallucinosis according to Jean Lhermitte.

Peduncular hallucinosis (PH) is a rare clinical syndrome with dream-like visual hallucinations intruding normal consciousness. It was initially reported in a 72-year-old woman by Jean Lhermitte in 1992. We uncovered the medical file of this patient with handwritten notes by Lhermitte and commented on it in the light of neurological knowledge that was common at that time. All along his career, Lhermitte has always been fascinated by consciousness disturbances, dreams and hallucinations. He had here the brilliant intuition of linking PH to awareness mechanisms located in the mesencephalic area. This PH case represented a good opportunity to him to emphasize the close relationships between neurology and psychiatry.