Dementia in an elderly patient associated with extreme dilatation of the perivascular space

The authors present a 91-year-old woman with the clinical picture of slowly progressive dementia, initially with slight paresis on the right side. Mag netic resonance imaging (MRI) revealed symmetrical periventricular white ma tter abnormalities and extreme dilatation of perivascular spaces, predomina ntly in the left hemisphere. They were accompanied with periodic lateralize d epileptiform discharges (PLEDs). Dementia is possibly caused in this case through functional impairment of the left hemisphere.