[Crossed aphasia disclosed by central auditory disorder]

A 80-year-old woman, right-handed, suddenly felt the impression to be deaf. Besides, she presented language disorders of aphasic type relating to a sensorial transcortical aphasia. The case meets the diagnostic criteria for crossed aphasia. The magnetic resonance imaging showed a right temporo-parietal infarct. There was no sensorial or peripheral auditive disorder and no auditory agnosia of non verbal modality. During the evolution, the aphasic symptoms diminished partially and the subjective auditory deficit of the left ear continued. The integrated auditory evaluation (neuroacoustic test, study of auditory gnosia, dichotic listening test, evoked cortical auditory potentials) allowed the evidence of the characteristic disturbances of a right hemianacousia: loss of left hear in dichotic audition, decrease of amplitude of evoked right cortical auditory potentials. In the light of theories concerning auditory integration, one can explain this evolution. The initial aphasic comprehension disturbance expresses the alteration of the linguistic treatment of auditory information of the dominant hemisphere, here the right hemisphere. Subsequently, the linguistic disturbance regresses largely, letting persist the change of general auditory treatment. The representation of this general auditory treatment is hemispheric bilateral, the only right hemispheric damage shall result in hemianacousia.