Stimulus-Driven Cortical Hyperexcitability in Individuals with Charles Bonnet Hallucinations.

Stimulus-Driven Cortical Hyperexcitability in Individuals with Charles Bonnet Hallucinations. Curr Biol. 2018 Nov 05;28(21):3475-3480.e3 Authors: Painter DR, Dwyer MF, Kamke MR, Mattingley JB Abstract Throughout the lifespan, the cerebral cortex adapts its structure and function in response to changing sensory input [1, 2]. Whilst such changes are typically adaptive, they can be maladaptive when they follow damage to the peripheral nervous system, including phantom limb pain and tinnitus [3, 4]. An intriguing example occurs in individuals with acquired ocular pathologies-most commonly age-related macular degeneration (MD) [5]-who lose their foveal vision but retain intact acuity in the peripheral visual field. Up to 40% of ocular pathology patients develop long-term hallucinations involving flashes of light, shapes, or geometric patterns and/or complex hallucinations, including faces, animals, or entire scenes, a condition known as Charles Bonnet Syndrome (CBS) [6, 7, 8]. Though CBS was first described over 250 years ago [9, 10], the neural basis for the hallucinations remains unclear, with no satisfactory explanation as to why some individuals develop hallucinations, while many do not. An influential but untested hypothesis for the visual hallucinations in CBS is that retinal deafferentation causes hyperexcitability in early visual cortex. To assess this, we investigated electrophysiological responses to peripheral visual field stim...
Source: Current Biology - Category: Biology Authors: Tags: Curr Biol Source Type: research