Left non-dominant hand mirror writing

Abstract

A 38-year-old right-handed woman, who had suffered a left cerebral hemisphere infarction, was studied. She developed right hemiparesis, motor and sensory aphasia, and left hand mirror writing. All possible brain mechanisms involved in writing, either perceptual or motor, were investigated in search of the one responsible for her mirror writing; however, no abnormality was detected. On examination of the left handwriting, in the directionality of writing tracings as related to the body midline, we detected a lack of inversion of the right handwriting motor patterns--at the moment they are transmitted from the left to the right cerebral hemisphere--implicating a motor rather than a perceptual mechanism.