Background and purpose: Complex, well-formed, and detailed visual hallucinations (VHs) are among the core clinical features of dementia with Lewy bodies (DLB). We investigated the diagnostic value of VHs in different types of very mild degenerative dementia.
Methods: Participants were required to complete a structured interview form recording their basic data, clinical history, neuropsychological tests, and neuropsychiatric symptoms. Basic demographic characteristics of the participants were summarized and compared. The frequency and association factors of VHs were compared among three major degenerative dementia groups, namely, Alzheimer's disease (AD), Parkinson's disease dementia (PDD), and DLB.
Results: A total of 197 patients with dementia and a clinical dementia rating of 0.5 were investigated, comprising 124 with AD, 35 with PDD, and 38 with DLB. A significantly higher frequency of VHs was found in the DLB group compared with the other groups (DLB, PDD, and AD = 31.6%, 11.4%, and 4.0%; p < 0.001). A multivariable logistic regression test for associations of positive VHs revealed that DLB was the only independently predictive factor (odds ratio: 13.62; p < 0.001).
Conclusion: Our findings revealed a high diagnostic value of VHs in very mild degenerative dementia. VHs in this stage of dementia were significantly associated with DLB, and more than 30% of patients with very mild dementia caused by DLB presented with VHs.