[Autotopagnosia ameliorated by looking at the image reflected in a mirror]

A 52-year-old right-handed man presented progressive dystonia and apraxia of his right hand of five years' duration. He also suffered from parkinsonian features such as rigidity or impaired postural reflexes. Serial investigation of brain MRI revealed progressive cerebral atrophy, which started in the left parietal lobe, and subsequently extended to both hemispheres. He was clinically diagnosed as corticobasal degeneration. He could not point at any part of his own body in response to verbal or visual commands. On the other hand, he could point at every part of the examiner's body or of the illustrated body image. Deep sensations and linguistic functions were not involved. This cognitive impairment was regarded as autotopagnosia. In contrast with inability to recognize any part of the own body in response to the commands, he could name every part of his body as soon as the examiner touched there. Moreover, his symptoms of autotopagnosia were ameliorated by looking at himself in a mirror; he could point at any part of his own body. Disconnection between primary proprioceptive sensory area and the center of body schema was thought to be the mechanism of autotopagnosia in this patient, because the impairment improved with the aid of visual or tactile informations. We speculated the lesion was the left parietal lobe.