Département de Médecine Service de Neurologie ACUTE APHASIA AFTER RIGHT HEMISPHERE STROKE THESE

Right hemispheric stroke aphasia (RHSA) rarely occurs in rightor left-handed patients with their language representation in right hemisphere (RH). For right-handers, the term crossed aphasia is used. Single cases, multiple cases reports, and reviews suggest more variable anatomo-clinical correlations. We included retrospectively from our stroke data bank 16 patients (rightand left-handed, and ambidextrous) with aphasia after a single first-ever ischemic RH stroke. A contrai group was composed of 25 successive patients with left hemispheric stroke and aphasia (LHSA). For each patient, we analyzed four modalities of language (spontaneous ftuency, naming, repetition, and comprehension) and recorded eventual impairment: (1) on admission (hyperacute) and (2) between day 3 and 14 (acute). Lesion volume and location as measured on computed tomography (CT) and magnetic resonance imaging (MRI) were transformed into Talairach stereotaxic space. Nonparametric statistics were used to compare impaired/nonimpaired patients. Comprehension and repetition were less frequently impaired after RHSA (respectively, 56% and 50%) than after LHSA (respectively, 84% and 80%, P = 0.05 and 0.04) only at hyperacute phase. G. M. Dewarrat (12l) · J.-M. Annoni · A. Carota Department of Neurology, Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne, Rue du Bugnon, 46, 1011 Lausanne, Switzerland e-mail: [email protected] E. Fomari ·P. Maeder Department of Radiology, Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne, Lausanne, Switzerland J. Bogousslavsky Genolier Swiss Medical Network, Clinique Valmont-Genolier, Glion-sur-Montreux, Switzerland Among RHSA, fewer left-handers/ambidextrous than righthanders had comprehension disorders at second evaluation (P = 0.013). Mean infarct size was similar in RHSA and LHSA with less posterior RHSA lesions (caudal to the posterior commissure). Comprehension and repetition impairments were more often associated with anterior lesions in RHSA (Fisher's exact test, P < 0.05). Despite the small size of the cohort, our findings suggest increased atypical anatomo-functional correlations of RH language representation, particularly in non-right-handed patients.