BACKGROUND To determine and compare lesion patterns and structural dysconnectivity underlying post-stroke aprosodia and amusia, using a data-driven multimodal neuroimaging approach. METHODS Thirty-nine patients with right or left hemisphere stroke were enrolled in a cohort study and tested for linguistic and affective prosody perception and musical pitch and rhythm perception at subacute and 3-month post-stroke stages. Participants listened to words spoken with different prosodic stress that changed their meaning, and to words spoken with six different emotions, and chose which meaning or emotion was expressed. In the music tasks, participants judged pairs of short melodies as same or different in terms of pitch or rhythm. Structural MRI data was acquired at both stages, and machine learning-based lesion-symptom mapping and deterministic tractography were used to identify lesion patterns and damaged white matter pathways giving rise to aprosodia and amusia. RESULTS Both aprosodia and amusia were behaviorally strongly correlated and associated with similar lesion patterns in right fronto-insular and striatal areas. In multiple regression models, reduced fractional anisotropy (FA) and lower tract volume of the right inferior fronto-occipital fasciculus were the strongest predictors for both disorders, over time. CONCLUSIONS These results highlight a common origin of aprosodia and amusia, both arising from damage and disconnection of the right ventral auditory stream integrating rhythmic-melodic acoustic information in prosody and music. Comorbidity of these disabilities may worsen the prognosis and affect rehabilitation success.
Right ventral stream damage underlies both post-stroke aprosodia and amusia.