Impaired visual processing preceding image recognition in Parkinson's disease patients with visual hallucinations

作者：Anne Marthe Meppelink, Bauke M. de Jong, Remco J. Renken, Klaus L. Leenders, Frans W. Cornelissen, Teus van Laar · 发表于：Brain · 年份：2009 · DOI：10.1093/brain/awp223 · 被引用次数：186 · 研究领域：Hallucinations in medical conditions、Neurology and Historical Studies、Spatial Neglect and Hemispheric Dysfunction

Impaired visual processing may play a role in the pathophysiology of visual hallucinations in Parkinson's disease. In order to study involved neuronal circuitry, we assessed cerebral activation patterns both before and during recognition of gradually revealed images in Parkinson's disease patients with visual hallucinations (PDwithVHs), Parkinson's disease patients without visual hallucinations (PDnonVHs) and healthy controls. We hypothesized that, before image recognition, PDwithVHs would show reduced bottom-up visual activation in occipital-temporal areas and increased (pre)frontal activation, reflecting increased top-down demand. Overshoot of the latter has been proposed to play a role in generating visual hallucinations. Nine non-demented PDwithVHs, 14 PDnonVHs and 13 healthy controls were scanned on a 3 Tesla magnetic resonance imaging scanner. Static images of animals and objects gradually appearing out of random visual noise were used in an event-related design paradigm. Analyses were time-locked on the moment of image recognition, indicated by the subjects' button-press. Subjects were asked to press an additional button on a colour-changing fixation dot, to keep attention and motor action constant and to assess reaction times. Data pre-processing and statistical analysis were performed with statistical parametric mapping-5 software. Bilateral activation of the fusiform and lingual gyri was seen during image recognition in all groups (P < 0.001). Several seconds before...