[A patient with probable dementia with Lewy bodies, who showed catatonia induced by donepezil: a case report].

We report a 75-year-old Japanese woman with probable dementia with Lewy bodies (DLB). At the age of 64, she showed left hand resting tremor, and gradually developed bradykinesia, and rigidity. She was diagnosed as having parkinsonism and took medication. At the age of 70, she showed hallucination and dementia. As she had developing cognitive dysfunction and hallucination and parkinsonism, she was diagnosed to have probable DLB. At the age of 75, after administration of donepezil, she showed severe psychosis and worsened parkinsonism, and was admitted to hospital. On neurological examination, she showed severe rigidity and akinesia, and behavioral immobility like "waxy flexibility" or motiveless resistance to maintenance of rigid posture against attempts to be moved. The phenomena, she presented as motor abnormalities, were thought to be catatonia. In consideration of clinical course, her catatonia and worsened parkinsonism was thought to be induced by donepezil and she was stopped the administration of donepezil. After treatment with trihexiphenizil, she had improvement of motor abnormalities and worsened parkinsonism. It is important to recognize that donepezil may induce catatonia on the patients of parkinsonism with severe dementia.