[Case of cortical deafness sparing the music area]. / Un cas de surdité corticale épargnant en partie la musique.

ABSTRACT

A 33-year-old woman had developed cortical deafness with profound initial deafness lasting for eleven months after pneumococcal meningitis ten years previously. CT scan demonstrated bilateral temporal lobe lesions, predominantly on the left side where it extended into the adjacent parietal and frontal lobes. Audiometry suggested integrity of the internal ear and brain stem. Early auditory evoked potentials were present, while potentials of moderate latency and delayed potentials were abolished. Neuropsychological investigations demonstrated total absence of spoken language, contrasting with conservation of written language, though with agrammatism and an impossibility of identifying non-verbal noises, spoken language, and music. The patient could not identify rhythms, pitch, melodies or the different types of music. The musical quality of sound stimuli and musical pleasure were, however spared as shown by recognition of tape recorded sound stimuli with written denomination and designation of images in multiple choice tests. The relations between auditory agnosia, "pure" verbal deafness and cortical deafness are discussed. Reported cases are reviewed and an attempt is made to demonstrate the existence of several levels in the integration of musical stimuli, the most elementary of which could be the perception of the musical quality of sounds, as was the case in the present patient.