Author(s) :

Colin Chien.

Volume/Issue :

Abstract :

This systematic review evaluates the extent to which different hypotheses drive visual hallucinations in Charles Bonnet Syndrome (CBS) patients. CBS is a rare condition characterized by complex, persistent visual hallucinations (VH) in patients with normal cognitive function and vision impairment. At present, the cause of CBS remains unclear; there is evidence that deafferentation, hallucinations caused by a deprivation of visual stimuli, which propagates neural hyperactivity through cortical excitability, is considered a putative mechanism by which CBS arises. Through Google Scholar and PubMed, 18 studies were included to support evidence. This emerging research posits that the condition stems from changes in sensory and control neural networks. Studies have shown reorganization of functional connectivity among different systems, including the default mode network (DMN), salience network (SN), and visual network (VN) in CBS patients, modeling alterations in brain activity. Therefore, we propose a multi-stage process which systematically combines the two hypotheses in order to clarify the underlying mechanisms behind CBS. High-order network dysregulation causes gating failures, leading hallucinations from visual deafferentation to be conceptualized.