From the Research
Association with Alzheimer's
- There is limited evidence to suggest a direct association between Charles Bonnet syndrome (CBS) and Alzheimer's disease 1, 2.
- A systematic review found that existing studies on the link between CBS and cognitive impairment are of limited methodological quality and allow no conclusion to be reached regarding a relationship between cognitive impairment and CBS 1.
- However, some case reports suggest that patients with CBS may be at risk of developing dementia, including Alzheimer's disease 1, 2.
- A prospective study found that two participants with CBS developed dementia at follow-up, and that partial insight, mild cognitive impairment, and hallucinations of familiar figures at diagnosis of CBS may confer an increased risk of subsequent dementia diagnosis 2.
- Another study reported a case of atypical CBS in a patient with dementia, highlighting the need for clearer guidelines for the diagnosis of atypical CBS and greater attention to the disorder 3.
Cognitive Impairment
- Cognitive impairment is not a diagnostic criterion for CBS, but some studies suggest that patients with CBS may be at risk of developing cognitive decline 1, 2.
- A study found that mild cognitive impairment was present in 2/12 CBS participants and 2/10 controls, and that no significant differences in performance on the ACE-R were found between the groups 2.
- The use of donepezil, a cholinesterase inhibitor, has been reported to be effective in treating CBS, suggesting that the visual hallucinations may be related to dysfunction of cholinergic neurons 4.