[Paraneoplastic Neurological Syndrome with Dementia].

Paraneoplastic neurological syndrome with limbic encephalopathy tends to progress rapidly, presenting with physical symptoms such as ataxia or sensory disturbance. However, some affected patients demonstrate amnesia, inactivity, or abnormal behavior, which lead to the diagnosis of dementia. It is important to perform an extensive differential diagnosis with autoantibody-examination and tumor survey, so as not to overlook potentially treatable dementia.