Ann Rehabil Med.  2012 Dec;36(6):866-870.

A Case of Generalized Auditory Agnosia with Unilateral Subcortical Brain Lesion

• Suh H
• Shin YI
• Kim SY
• Kim SH
• Chang JH
• Shin YB
• Ko HY

Abstract

The mechanisms and functional anatomy underlying the early stages of speech perception are still not well understood. Auditory agnosia is a deficit of auditory object processing defined as a disability to recognize spoken languages and/or nonverbal environmental sounds and music despite adequate hearing while spontaneous speech, reading and writing are preserved. Usually, either the bilateral or unilateral temporal lobe, especially the transverse gyral lesions, are responsible for auditory agnosia. Subcortical lesions without cortical damage rarely causes auditory agnosia. We present a 73-year-old right-handed male with generalized auditory agnosia caused by a unilateral subcortical lesion. He was not able to repeat or dictate but to perform fluent and comprehensible speech. He could understand and read written words and phrases. His auditory brainstem evoked potential and audiometry were intact. This case suggested that the subcortical lesion involving unilateral acoustic radiation could cause generalized auditory agnosia.

Keyword

Auditory agnosia; Unilateral subcortical lesion

MeSH Terms

Acoustics
Agnosia
Audiometry
Brain
Brain Stem
Evoked Potentials
Hearing
Humans
Male
Music
Speech Perception
Temporal Lobe
Writing

Figure

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  Fig. 1 (A) A computed tomography image that shows acute intracranial hemorrhage at the left striatocapsular area with mild perihematoma edema. (B) The MRI T2-weighted axial images showed a large subacute hematoma in the left basal ganglia, internal capsule and temporal white matter with mild mass effect. The cerebral white matter including left auditory radiation was severely damaged, whereas the auditory cortexes were intact. (C) The brain SECT image showed a severe perfusion decrease and an impaired vascular reserve in the left temporal lobe. Also a moderate perfusion decrease and preserved vascular reserve in the left basal ganglia were shown.

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  Fig. 2 Pure tone audiometry that showed nearly normal bilateral findings that were considered for his age.

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  Fig. 3 Brainstem auditory-evoked potentials (BAEP) of the patient 3 weeks after stroke onset showed normal bilateral latencies and amplitudes.

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