A patient suffers a destructive lesion confined to the left auditory cortex and medial geniculate body. Pure-tone audiometry is performed. What hearing result is expected?
- A Little or no measurable hearing loss in either ear ✓
- B Complete deafness of the right ear
- C Bilateral high-frequency hearing loss only
- D Complete deafness of the left ear
Correct answer: A. Little or no measurable hearing loss in either ear
Explanation
From the cochlear nuclei onward, auditory fibres ascend bilaterally through the lateral lemniscus, inferior colliculus and medial geniculate body, so each cortex receives input from both ears. D strictly unilateral lesion of the central auditory pathway therefore causes little or no measurable hearing loss, though sound localisation on the opposite side is impaired. Unilateral sensorineural deafness requires a lesion peripheral to the cochlear nuclei, such as the cochlea or vestibulocochlear nerve.
Reference: Ganong's Review of Medical Physiology, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.