Altered cortical visual processing in PD with hallucinations: an fMRI study.

Published

Journal Article

OBJECTIVE:To compare fMRI activation during two visual stimulation paradigms in Parkinson disease (PD) subjects with chronic visual hallucinations vs PD patients who had never hallucinated. METHODS:Twelve pairs of PD subjects, matched for age, PD duration, and dopaminergic drug exposure duration, participated in this study. The authors examined group differences in activation during stroboscopic (flashing) vs no visual stimulation and kinematic (apparent motion) vs stationary visual stimulation. RESULTS:During stroboscopic stimulation, non-hallucinating PD subjects showed significantly greater activation in the parietal lobe and cingulate gyrus compared to hallucinating PD subjects. In contrast, the hallucinating subjects showed significantly greater activation in the inferior frontal gyrus and the caudate nucleus. During kinematic stimulation, non-hallucinating PD subjects showed significantly greater activation in area V5/MT, parietal lobe, and cingulate gyrus compared to hallucinating PD subjects. Hallucinating PD subjects showed significantly greater activation in the superior frontal gyrus. CONCLUSIONS:PD patients with chronic visual hallucinations respond to visual stimuli with greater frontal and subcortical activation and less visual cortical activation than non-hallucinating PD subjects. Shifting visual circuitry from posterior to anterior regions associated primarily with attention processes suggests altered network organization may play a role in the pathophysiology of visual hallucinations in PD.

Full Text

Cited Authors

  • Stebbins, GT; Goetz, CG; Carrillo, MC; Bangen, KJ; Turner, DA; Glover, GH; Gabrieli, JDE

Published Date

  • October 2004

Published In

Volume / Issue

  • 63 / 8

Start / End Page

  • 1409 - 1416

PubMed ID

  • 15505157

Pubmed Central ID

  • 15505157

Electronic International Standard Serial Number (EISSN)

  • 1526-632X

International Standard Serial Number (ISSN)

  • 0028-3878

Digital Object Identifier (DOI)

  • 10.1212/01.wnl.0000141853.27081.bd

Language

  • eng