Peduncular Hallucinosis - History

History

The first documented case of peduncular hallucinosis was by French neurologist and neuropsychiatrist Jean Lhermitte which described a 72-year-old woman’s visual hallucinations of colorfully dressed people and children which occurred at dusk. The hallucinations occurred during normal conscious state and the patient’s neurological signs were associated with those characteristic of an infarct to the midbrain and pons. Von Bogaert, Lhermitte’s colleague, named this type of hallucination “peduncular,” in reference to the cerebral peduncles, as well as to the midbrain and its surroundings. In 1925, Von Bogaert was the first to describe the pathophysiology of peduncular hallucinosis through an autopsy of a patient. His autopsy revealed the infarction of many areas of the brain including the inferolateral red nucleus, superior colliculus, periaqueductal gray, third nerve nucleus, superior cerebellar peduncle, substantia nigra, and pulvinar. Later in 1932, Lhermitte, Levy, and Trelles discovered an association between peduncular hallucinosis and “pigmentary degeneration of the periaqueductal gray and the degeneration of the occulomotor nucleus.” Posterior thalamic lesions were also found to be linked to peduncular hallucinosis by De Morsier. More recently, magnetic resonance imaging (MRI) has been used to localize lesions in the brain characteristic of peduncular hallucinosis. In 1987, the first case of peduncular hallucinosis was reported in which MRI was used to locate a midbrain lesion.