EMG and evoked potentials in adrenomyeloneuropathy

: In a 31 year old patient with adrenocortical gland insufficiency and minor clinical signs of involvement of peripheral and central nervous system an adrenoleucodystrophy was diagnosed, based upon the characteristic elevation of hexacosanoic acid in plasma. The motor and sensory nerve conduction velocities in upper and lower extremities were markedly reduced; in accordance, the somatosensory evoked potentials showed distinct reduction in the peripheral part. In contrast, the interpeak latencies N 20 - NSEP 3 (median nerve) and N 22 - P 40 (tibial nerve) were in the upper normal range, so that a damage of the central sensory system could not be evaluated. The visual and brainstem acoustic evoked potentials were a little prolonged. The problems in differential diagnosis of this form of adrenoleucodystrophy, which especially involves the peripheral nervous system, are discussed.