Multimodality evoked potentials in patients and carriers with adrenoleukodystrophy and adrenomyeloneuropathy

A combination of brain-stem auditory evoked potentials (BAEPs), short latency somatosensory evoked potentials (SEPs) and pattern reversal visual evoked potentials (VEPs), were studied in two patients with adrenoleukodystrophy (ALD) and one patient with adrenomyeloneuropathy (AMN), as well as in one female carrier of each of the respective diseases. Abnormalities in at least 1 of the 3 evoked potentials were found in every case, including the carriers of ALD and AMN. The two most common findings were prolongation of the I-V interval of the BAEP and the N13-N20 interval of the SEP. These abnormalities were recorded either alone or in combination in all 5 cases. This finding suggests delayed conduction time in the central sensory pathways in both diseases, probably due to demyelination. The remarkable result, which distinguished AMN from ALD, even in their respective carriers, was delay of the N9 latency of the SEP, indicating slowing in conduction velocity of the peripheral nerve. Multimodality evoked potentials are useful not only in raising the detection rate for abnormal findings, but also in providing additional information about the functional state of separate afferent pathways. It is also of value in detecting and differentiating the carriers of ALD and AMN.