Abnormal brainstem auditory evoked responses in mitochondrial neurogastrointestinal encephalomyopathy (MNGIE): evidence of delayed central conduction time.

OBJECTIVE: To assess the usefulness of brain auditory evoked potentials (BAEPs) in the study of asymptomatic white matter alterations in brain MRI observed in mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) patients.
METHODS: The authors studied the neurophysiological characteristics of the BAEPs in four genetically confirmed MNGIE patients who presented varying degrees of leukoencephalopathy in brain MRI.
RESULTS: Prolonged I-III and I-V interpeak latencies were the most common abnormalities found, with a correlation between the extent of brain MRI lesions and BAEPs.
CONCLUSIONS: The findings suggest a delayed central conduction time along the brainstem. BAEPs may be useful in the neurophysiological evaluation of central white matter lesions in MNGIE. Similar neurophysiological findings have been reported in other myelin disorders in the central nervous system. SIGNIFICANCE: The BAEPs abnormalities identified should be interpreted as an indirect sign of CNS involvement in MNGIE patients and provide comprehensive and integrated information concerning brainstem dysfunction. Further studies are necessary in order to identify whether there is a correlation between BAEPs and the clinical progression of the disease.