Verbal and musical memory: Selectivity of auditory disorders after stroke

Abstract

Neuropsychological consequences of stroke have important social, professional, and private life impacts. Deficits affecting language processing are well documented unlike musical disorders. Yet, according to Sarkamo et al. (Neuropsychologia, 2009), the incidence of acquired amusia after stroke is 60% after a delay of one week and 42% after 3 months. The goal of this study is to compare verbal and musical auditory memory in patients with stroke history, using a short-term memory paradigm. The goal is to evaluate the interest of testing non-verbal memory in neuropsychological assessment after stroke, as it could guide the choice of reeducation methods. Patients included in the study have been hospitalized in the stroke unit of the neurological hospital in Lyon for a stroke in the MCA (middle cerebral artery) territory. Several months after stroke, they were assessed with a test battery including cognitive evaluation, speech evaluation and audiometry. Acquired amusia was diagnosed with the MBEA (Montreal Battery of Evaluation of Amusia, Peretz et al., Ann N Y Acad Sci, 2003). The auditory musical and verbal short-term memory was tested with a paradigm involving a comparison of short word sequences or tone sequences, separated by a delay of 1000 ms. Performance in the auditory short-term memory task were significantly decreased for the verbal task in patients with left hemisphere lesions, and for the musical task in patients with right hemisphere lesions, in comparison with controls. These results suggest separated cerebral networks for speech and music, for auditory short-term memory, with a preference of the left hemisphere for speech and the right hemisphere for music. To correlate behavioral results and cerebral lesions, analyses of cerebral imaging data will be conducted using voxel based lesion symptom mapping and DTI.