62. MANAGING VISUAL RELEASE HALLUCINATIONS: A SYSTEMATIC REVIEW

Abstract

Introduction

Visual release hallucinations (described as Charles Bonnet Syndrome or CBS) are thought to result from disinhibition of visual cortical neurons following acquired blindness. While visual release hallucinations are often non-distressing and present with retained insight, a portion of patients with continuous or thematically upsetting visual hallucinations report distress and quality of life impairment. Few systematic investigations into management options for individuals with CBS have been conducted.

Methods

Pubmed, Embase, and Cochrane were searched from inception until 09/30/24 according to guidelines from PRISMA. The input “visual release hallucinations” OR “Charles Bonnet Syndrome” AND “treatment” OR “management” were used to generate search queries. Observational and experimental studies involving behavioral, environmental, or medication management options in humans were eligible for inclusion. Studies reporting resolution of acute-onset CBS following discontinuation of iatrogenic medication or other acute reversible causes were excluded from analysis.

Results

13 studies meeting pre-specified inclusion criteria were found. One double-blind RCT found significant improvement in visual hallucinations with minimal tolerability issues from the use of tDCS. An open-label investigation of a Japanese herbal preparation (Yi-gi san) found improvement in visual hallucinations after a 4 week period of treatment. The remainder of data described individual cases and case series, with individual reports describing successful treatment of CBS with agents including anti-epileptic medication, antipsychotics, and cholinesterase inhibitors. Case reports noting successful use of supportive treatments such as psychoeducation, eye-training exercises, and social support were also found.

Conclusions

Though classically described as non-distressing and with preserved insight, Charles Bonnet Syndrome can meet the threshold for treatment. Pharmacologic options appear to be effective in single case reports (and may be attractive based on theoretical etiological considerations) but may carry the potential for adverse effects. Results from a single RCT investigating tDCS argue in favor of the use of neuromodulation in some patients. Evidence to strongly support any treatment option for Charles Bonnet Syndrome is limited at this time, though psychosocial and environmental interventions appear attractive based on their lack of iatrogenic effects. Data from high quality prospective studies is needed to make further conclusions about management options in Charles Bonnet Syndrome.