Somatosensory evoked potentials in adrenomyeloneuropathy

Adrenomyeloneuropathy (AMN) is an X-linked metabolic disorder causing accumulation of very-long-chain fatty acids with multifocal nervous system demyelination of the peripheral nerves, spinal cord, and cerebrum. The extent to which the disorder affects upper versus lower limbs or peripheral versus CNS has not been electrophysiologically defined in a large population nor differentiated in men and women. To determine patterns of nervous system demyelination and define gender differences, we studied 83 AMN patients with short latency median and posterior tibial nerve somatosensory evoked potentials (SSEPs). Most women (10/16) had abnormal median SSEPs all involving central pathways, whereas most men (59/67) had abnormal median SSEPs involving both peripheral and central pathways. Tibial SSEPs were abnormal in both sexes (14/15 women, 67/67 men), with either peripheral or central pathway involvement. This study demonstrates the frequent widespread involvement of both peripheral nerve and central somatosensory pathways in men with AMN and the predominantly central involvement in women.