Article Text

Download PDFPDF
Patterns of conduction impairment in experimental allergic neuritis. An electrophysiological and histological study.
  1. G K Harvey,
  2. J D Pollard
  1. Department of Medicine, University of Sydney, Australia, NSW.


    Electrophysiological and histological studies of peripheral nerve were performed in 24 Lewis rats with experimental allergic neuritis (EAN) in which disease had been induced by a single myelin and adjuvant inoculation in one footpad. Demyelination was demonstrated in transverse nerve sections from ventral roots, proximal sciatic nerves and also in distal plantar nerves. Histological and electrophysiological assessments showed that injected limbs were more affected than uninjected limbs. Neurophysiological studies demonstrated two distinct patterns of conduction failure based upon proximal/distal compound muscle action potential (CMAP) amplitude ratios in both uninjected and injected limbs. Slightly more than half of all nerve trunks showed a mildly reduced distal CMAP amplitude irrespective of stimulus origin. The rest displayed a more severe reduction of distal amplitude that was length-dependent, becoming smaller with proximal stimulation. Histological lesions in plantar nerves were often more severe than those in proximal sciatic nerves or ventral roots. Axonal degeneration was an uncommon finding. This study has demonstrated patterns of peripheral nerve conduction impairment similar to those reported in patients with inflammatory demyelinating neuropathy. Moreover, it has shown that a low distal CMAP amplitude may result from demyelination of distal motor nerve segments and not necessarily from axonal degeneration.

    Statistics from

    Request Permissions

    If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.