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Published on: April 23, 2021
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Cognitive impairment and Charles Bonnet syndrome: a prospective study
Gregor Russell1, Robert Harper2, Harry Allen3
1Horton Park Centre, Horton Park Avenue, Bradford District Care NHS Foundation Trust, Bradford, UK.
International Journal of Geriatric Psychiatry
|January 25, 2017
Summary
Charles Bonnet syndrome (CBS) may not be benign, as some patients develop dementia. Early signs like partial insight and mild cognitive impairment in CBS patients may indicate a higher risk for subsequent dementia.
Area of Science:
- Ophthalmology
- Geriatrics
- Neurology
Background:
- Charles Bonnet syndrome (CBS) causes visual hallucinations in the elderly.
- The link between CBS and cognitive decline, including dementia, is not well understood.
- Anecdotal evidence suggests dementia can develop in individuals with CBS.
Purpose of the Study:
- To investigate the incidence and severity of cognitive impairment in CBS patients compared to controls.
- To determine if CBS is associated with an increased risk of developing dementia.
Main Methods:
- A cohort of individuals over 65 with CBS (from low-vision and glaucoma clinics) and age-matched controls were recruited.
- Participants underwent psychiatric assessments at baseline and a one-year follow-up.
- Cognitive function was assessed using the ACE-R.
Main Results:
- Mild cognitive impairment was observed in 2/12 CBS participants and 2/10 controls.
- Two CBS participants, but no controls, developed dementia at follow-up.
- Dementia development in CBS patients was associated with partial insight and hallucinations of familiar figures at diagnosis, with one also having mild cognitive impairment.
Conclusions:
- The assumption that CBS is always benign may be incorrect.
- Certain factors at CBS diagnosis, including partial insight, mild cognitive impairment, and specific hallucination types, may predict subsequent dementia.
- Current cognitive testing at diagnosis may not reliably identify individuals at risk for dementia.
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