To review a rarely identified acute presentation of right middle cerebral artery (MCA) ischemic stroke causing receptive amusia.
Historically, receptive amusia refers to a pathologic inability to distinguish melodies, timbre, and pitch, which may result in ensembles of acoustic sounds being perceived as discordant. Though rarely appreciated in clinical evaluation of stroke patients, voxel-based symptom lesion mapping (VSLM) studies show that acquired amusia in stroke is specifically associated with infarcts in the superior temporal gyrus, Heschl's gyrus, insula, and striatum of the right hemisphere.
A 62-year-old male with right bundle branch block and moderate mitral valve regurgitation presented to the emergency department with a vague transient binocular visual disturbance, followed by two days of difficulty with the auditory processing of music, first noticed while playing the drums. There was no difficulty with physically playing the drums, coordinating his movements, or reading sheet music, however he could not process harmonies or stay synchronized with his bandmates. No deficits on neurologic exam. MRI brain without contrast showed a late acute right inferior division MCA territory infarct involving the parietal, temporal, and posterior insular regions. Vessel imaging showed no significant stenosis or large vessel occlusion. Further workup revealed a large patent foramen ovale (PFO) and an episode of atrial fibrillation. One month later, the patient still had difficulty processing music and also endorsed that environmental sounds were bothersome to him.
We report a case of a musician presenting with isolated receptive amusia in the setting of an acute embolic right MCA stroke. We suggest that this subtle sign is under-recognized as a possible presentation of cortical infarct in this territory, especially in non-musically inclined patients, and careful assessment for amusia could facilitate the appropriate diagnosis and management of stroke patients with infarcts in the right hemisphere.