Primary Sjögren's syndrome with subcortical dementia.

A 48-year-old man with primary Sjögren's syndrome (P-SS) developed subcortical dementia, characterized by forgetfulness, poor attention and concentration, slowness of thought process, difficulty to manipulate acquired knowledge, introversive and hostile personality change and inactivity. These were improved by corticosteroid treatment. Magnetic resonance imaging (MRI) revealed small lesions in the subcortical and periventricular white matter. An electroencephalogram (EEG) revealed short runs of theta activities in bilateral parietal areas. Latency of P300 shortened in accordance with clinical improvement. These findings suggest that the cognitive and neuropsychiatric manifestations in P-SS are included in a spectrum of organic brain dysfunction and are treatable.