Charles Bonnet Syndrome: Resting-State Functional Connectivity, Morphology, Neurochemical, and Psychosocial Correlates

Abstract

Charles Bonnet Syndrome (CBS) is a debilitating phenomenon characterized by a triad of visual hallucinations, an absence of cognitive impairment, and vision loss that usually affects the ageing population secondary to age-related visual impairment. CBS mechanisms continue to be explored, and it is unknown whether the etiology, timing (early vs. late onset), and locus (central vs. peripheral) of vision loss drive different neurophysiological mechanisms that cause CBS hallucinations. Evidence also suggests that there may be an association between psychosocial health factors and change in CBS hallucinations during the COVID-19 pandemic. My dissertation describes three experiments that examine functional connectivity, morphology, neurochemical, and psychosocial correlates in CBS. My findings expand our understanding on the compensatory neuroplastic changes that occur in the visual cortex secondary to vision loss. Chapter II examines functional connectivity in resting state networks and global morphological changes in the brain. Chapter III examines the concentrations of excitatory and inhibitory neurometabolites in the visual cortex. Chapter IV explores psychosocial health measures such as anxiety, loneliness, social isolation, quality of life, and physical activity to examine whether they are associated with changes in the nature and frequency of CBS hallucinations during the COVID-19 pandemic. This information contributes to a better understanding of the neural correlates of CBS which affects the vulnerable ageing population.