[Dystypia after ischemic stroke: a disturbance of linguistic processing for Romaji (Romanized Japanese)?]

"Dystypia", characterized by an impairment of typing on a keyboard, is a unique neurobehavioral syndrome. A 77-year-old right-handed woman developed a relatively selective impairment of typing after ischemic stroke. The MRI documented new scattered ischemic lesions in the middle cerebral artery territory of the left hemisphere and an old infarct lesion in the frontal area of the right hemisphere. The standard neuropsychological tests showed no aphasia, normal praxis, intact visuospatial ability, and a mild visual memory disturbance. The detailed analysis documented severe impairment of writing and reading abilities for Romaji (Romanized Japanese), spelled by alphabet letters and the most common way to input Japanese into computers. The writing and reading abilities for other Japanese linguistic modalities such as kanji (morphogram: Chinese character), kana (syllabogram: Japanese proper character), and alphabet letters, were not or minimally impaired. A disturbance of linguistic processing for Romaji may be the main underlying neural mechanism for dystypia in this patient.