[Neuropsychology of dementia].

As cognitive dysfunction is the core symptom of dementia, the assessment of it is essential for the clinical practice. The role of "neuropsychology" is none other than analysis and interpretation of the central symptoms of brain damaged including dementing illnesses. "Neuropsychology" in this sense does not refer only to the neuropsychological tests that psychologists employ, but certainly implies mental status examination as a part of the neurological examination, which enables us to make focal diagnosis and differential diagnosis, to evaluate the disability, to predict the problems in living, and to measure disease severity, rate of progression, and response to treatment are essential. This paper, citing aphasia due to degenerative diseases, behavioral neurological signs, and the relationship between visuoperceptive impairments and visual hallucinations as examples, discussed the clinical roles and scientific potentials of neuropsychology in dementia.