Mechanisms of early and late recovery in acute motor axonal neuropathy

Motor unit number estimate (MUNE) of the abductor pollicis brevis (APB) was sequentially performed in seven patients with acute motor axonal neuropath y (AMAN). The MUNE markedly decreased (mean, 11)at the peak of the illness. Clinical recovery of APE strength began during week 4, with an increase in amplitude of distal compound muscle action potentials. The MUNE did not ch ange significantly in this early recovery phase and increased slowly with t ime. The main mechanism for early recovery in AMAN may be collateral reinne rvation, with nerve regeneration developing later. (C) 2001 John Wiley & So ns. Inc.