Visual cortical excitability in dementia with Lewy bodies.
Where this comes from
- Record sourced from PubMed, PMID 26541688.
- Also identified by DOI 10.1192/bjp.bp.114.152736 and PMC identifier 4853644.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Alterations in the visual system may underlie visual hallucinations in dementia with Lewy bodies (DLB). However, cortical excitability as measured by transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI) activation of lower visual areas (V1-3) to visual stimuli appear normal in DLB. We explored the relationship between TMS-determined phosphene threshold and fMRI-related visual activation and found a positive relationship between the two in controls but a negative one in DLB. This double dissociation suggests a loss of inhibition in the visual system in DLB, which may predispose individuals to visual dysfunction and visual hallucinations.
Medical subject headings
- Cortical Excitability
- Hallucinations
- Lewy Body Disease
- Magnetic Resonance Imaging
- Phosphenes
- Transcranial Magnetic Stimulation
- Visual Cortex
- Visual Perception