[A 68 year-old man presenting ideomotor apraxia and incomplete Gerstmann syndrome with multiple cystic lesions in the left hemisphere].

A 68-year-old man was referred to our hospital with tension-type headaches and a 1-year history of dementia. On neurologic examination, he had ideomotor apraxia and incomplete Gerstmann syndrome that was characterized by acalculia, agraphia, and finger agnosia. On imaging, multiple cystic lesions reported as "unusually dilated perivascular spaces" were observed along the medullary arteries in the left hemisphere; some of them had adjacent hyperintense areas in fluid attenuated inversion recovery images.