A 69-year-old man presented to the neurology department with progressed cognitive impairment for two years. He had medical history of diabetes but without remarkable family history of dementia. On initial neurological examination, only ataxia was observed and his Mini-Mental State Examination score was 16/30. Acute computed tomography showed ventriculomegaly and electroencephalogram suggested no obvious abnormalities. Subsequently, magnetic resonance imaging (MRI) of the brain revealed moderate cerebral atrophy and high-intensity areas in bilateral cerebral white matter on T2-FLAIR sequence(Fig.
