Mecahism of hallucination in Parkinson’s disease

Keita Matsuura, Hidekazu Tomimoto

Department of Neurology, Graduate School of Medicine, Mie University

The frequency of hallucinations in patients with Parkinson’s disease (PD) has been reported to be 14-40%.　The mechanism of hallucination in PD involves, first of all, the pathway from the eye to the occipital and temporal lobes.　If there is a problem with this system, the input information will be disturbed, and as a result, their brain will make the wrong visual information.　True visual hallucinations are strongly associated with the temporal lobe based on Lewy pathology.　A study in our DBS patients reported that the hypointensity of pulvinar nuclei in SWI was associated with the appearance of hallucinations.　The pulvinar nucleus itself has a very strong connection to the occipital lobe, so the effects of projection fibers may affect visual information.　On the other hand, the pulvinar nucleus is a system involved in blindsight through the superior colliculus.　Therefore, the disorder here may affect the visual input information.　The appearance of visual hallucinations is basically due to the pathological development of PD.　In addition, problems with visual information, alteration of consciousness, and drugs are thought to trigger the appearance of visual hallucinations.

Address correspondence to Dr. Keita Matsuura, Department of Neurology, Graduate School of Medicine, Mie University （2-174 Edobashi, Tsu, Mie 514-8507, Japan）