Donepezil‐induced sleep spindle in a patient with dementia with Lewy bodies: a case report

Here, we report a case of rapid eye movement sleep behavioural disorder in an elderly patient with dementia with Lewy bodies. Pretreatment polysomnography revealed atonia during rapid eye movement sleep, absence of sleep spindles and loss of slow‐wave sleep. Administration of donepezil, an acetylcholinesterase inhibitor, markedly improved delusional symptoms and cognitive function. Pretreatment polysomnography performed after donepezil administration revealed a considerable number of sleep spindles. The effects of cholinergic modulation induced by donepezil seemed to cause remarkable improvement in mental status, incorporating associated with sleep spindles generated by the thalamocortical circuit involved in this patient.