Restoration of brain stem auditory-evoked potential in maple syrup urine disease.

OBJECTIVE

The purpose of this study was to report a unique case of reversible brain stem auditory-evoked potential (BAEP) involving wave I in maple syrup urine disease (MSUD). The possible mechanism of the hearing loss and reversibility of wave I is proposed.

PATIENTS: Single case report.

INTERVENTION: Treatment of MSUD with dialysis and diet devoid in branched-chain amino acids.

MAIN OUTCOME MEASURE: BAEPs.

RESULTS

Initial presentation of MSUD in a 14-week-old child included failure to thrive, present otoacoustic emissions, and absent BAEPs. After treatment with dialysis and an MSUD-appropriate diet, the BAEPs gradually recovered.

CONCLUSION

Appropriate and timely treatment of MSUD can reverse the central neuropathy leading to hearing loss. Because patients with MSUD have elevated levels of glutamate, we propose that the auditory dysfunction in these patients may be related to glutamate excitotoxicity, and with appropriate treatment, these effects may be reversible.