Investigation of auditory dysfunction in Leber hereditary optic neuropathy

Purpose: To investigate the possibility of auditory dysfunction in patients with Leber hereditary optic neuropathy (LHON). Methods: We prospectively recruited 10 affected patients from the north-east of England harbouring one of the three primary mitochondrial LHON mutations (3460G > A n = 3, 11778G > A n = 5 and 14484T > C n = 2). A detailed auditory history was taken and they were asked to complete a validated hearing questionnaire. Each patient then underwent a comprehensive topographic neuroauditory assessment to evaluate both middle- and inner-ear functions and the integrity of the brainstem auditory pathways. Results: We found no evidence of cochlear nerve dysfunction or abnormalities of the central brainstem auditory pathways in our LHON cohort and five patients had completely normal hearing tests. The remainder had mild conductive hearing loss from childhood ear infections and/or high-frequency sensorineural hearing loss from previous noise injury. Conclusion: Although further studies are required to confirm our findings, auditory dysfunction as a result of a primary LHON mutation is probably uncommon.