A patient with probable dementia with Lewy bodies, who showed improvement of dementia and parkinsonism by the administratim of donepezil

We present a 73-year-old man with probable dementia with Lewy bodies (DLB). At 65 years of age, he gradually developed bradykinesia, gait disturbance and mild amnesia. At 71 years of age, he noted resting tremor in bilateral hands, and amnesia and disorientation were exacerbated. He was diagnosed as having parkinsonism and took L-dopa/carbidopa at 100mg/day. Since he developed hallucination and abnormal behavior 2 days after the initiation of the drug, he stopped taking L-dopa and was admitted to our hospital. A neurological examination on admission revealed moderate amnesia, disorientation, finger agnosia, constitutional apraxia, mask-like face, cog-wheel rigidity, resting tremor in bilateral hands, and bradykinesia. Brain MRI showed mild brain atrophy, and single photon emission computerized tomography (SPECT) showed diffuse moderate hypoperfusion in bilateral cerebral cortex. As he had fluctuating cognitive dysfunction and parkinsonism, he was diagnosed to have probable DLB. As his dementia was exacerbated by trihexyphenidyl, an anti-cholinergic agent, at 2mg/day, we treated him with donepezil, an anti-choline esterase agent, at 3∼5mg/day. His parkinsonism, including rigidity and bradykinesia, was markedly improved his dementia, consisting of amnesia and disorientation. Electroencephalography (EEG) improved in the organization of the dominant rhythm. The SPECT improved in the blood perfusion of the bilateral frontal lobe as well as cognitive function and parkinsonism were maintained by donepezil for 6 months after discharge. A therapeutic efficacy of donepezil for DLB has recently been reported. It is notable that donepezil was beneficial not only for cognitive dysfunction but also for parkinsonism in the present case with probable DLB.