Apraxia of speech from a right frontal lesion

Apraxia of speech (AOS) is a potentially severe motor speech disorder. In right handers, AOS is almost always associated with lesions of the dominant, left frontal region. Here we describe a patient with familial sinistrality who suffered a severe AOS from a hemorrhage in the right frontal lobe. AOS had the same clinical characteristics as in customary, left hemisphere cases, and was accompanied by deficits of phonological and short term memory processing. It is concluded that neural functions subserving motor speech programming, as well as other networks incorporating the dominant frontal lobe can be lateralized to the right hemisphere in subjects with abnormal, genetically determined handedness.