An 85-year-old woman who had been living alone and eating an unbalanced diet suddenly entered a neighbour's house. Her house was hot and humid due to lack of air conditioning caused by a loss of electrical power. After arrival, the patient exhibited disorientation, paresis of the right upper extremity, a tendency towards right conjugated deviation and perseveration. Electrocardiogram showed ST segment elevation and prolongation of the QT interval. Echocardiography suggested Takotsubo cardiomyopathy. The cardiac wall motion and neurological abnormalities improved after admission. The serum thiamine level was found to be low, which was compatible with a diagnosis of Wernicke's encephalopathy. Hasegawa dementia score was 10 points and the patient was suspected to have frontotemporal dementia. She was transferred to a nursing home with continuing dementia. In this case, psychological stress trigged by poor living circumstances induced by dementia and Wernicke's encephalopathy may result in the occurrence of Takotsubo cardiomyopathy.