Agrammatic primary progressive aphasia in two dextral patients with right hemispheric involvement.

Agrammatic primary progressive aphasia (PPA-G) has been known to be associated with focal brain atrophy involving the left posterior frontal and anterior insular regions. However, aphasia can also rarely result from right hemispheric lesions in right-handed patients, so-called crossed aphasia in dextrals (CAD). We report two right-handed patients with PPA-G whose 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) showed hypometabolism predominantly in the right hemisphere, implicating "crossed PPA-G."