[Balint's syndrome--visual disorientation].

The three major components of the Balint's syndrome are described: 1) visual disorientation or simultanagnosia, i.e. the inability to perceive the visual field as a whole, 2) ocular apraxia, a deficit of visual scanning and 3) optic ataxia, an impairment of pointing and reaching under visual guidance. Our description of the syndrome is illustrated by three case histories. The complete syndrome is rare, and partial syndromes have been reported more frequently. Sudden and severe hypotension resulting in bilateral borderzone infarction in the occipito-parietal region is reported to be the most frequent cause of complete Balint's syndrome. Lack of awareness of the syndrome may lead to misdiagnosis such as blindness, psychosis, or dementia.