Effects of the traditional Chinese herbal medicine Yi-Gan San for cholinesterase inhibitor-resistant visual hallucinations and neuropsychiatric symptoms in patients with dementia with Lewy bodies.

Sir: Dementia with Lewy bodies (DLB) is characterized clinically by progressive and fluctuating cognitive decline, visual hallucinations, and parkinsonism. Some studies have reported that cholinesterase inhibitors are at least partially beneficial for treating patients with DLB. However, Shea et al. reported that cholinesterase inhibitors occasionally caused deterioration of parkinsonian symptoms in patients with DLB. Use of neuroleptics is also considered, but patients with DLB are particularly sensitive to neuroleptics and occasionally experience fatal extrapyramidal symptoms. Recently, we reported that the traditional Chinese medicine Yi-Gan San (YGS) reduced behavioral and psychological symptoms and improved activities of daily living (ADL) in dementia patients. In that study, YGS was successfully used to treat visual hallucinations in 6 patients with DLB. In the study described here, we expanded on our earlier observations on more generalized neuropsychiatric symptoms by using the Neuropsychiatric Inventory (NPI) and individual interviews to assess YGS treatment in a sample of patients who had cholinesterase inhibitor–resistant visual hallucinations and other symptoms of DLB.