Electrophysiological diagnosis of motor neuron disease and pure motor neuropathy

J Neurol. 1999 Jul;246(7):520-5. doi: 10.1007/s004150050397.


Motor neuron disease (MND) is a group of disorders in which there is degeneration of upper and lower motor neurons to a variable degree. Amyotrophic lateral sclerosis is the most frequent form of the disease, presenting with both upper and lower motor neuron involvement. Frequently, especially in the early stages of the disease, only lower motor neuron signs are present. In these conditions, some pure motor neuropathies may resemble MND. The diagnosis is of importance because some of these motor neuropathies are "dysimmune" disorders and may respond to immune therapies. In such diseases the multifocal motor neuropathy with conduction block appears to be the more frequent. In MND and pure motor neuropathies, the electrophysiological examination is the most decisive test. In MND, it is of diagnostic importance. In addition, it is useful in the assessment of disease severity and progression, in the evaluation of therapeutic trials and in the understanding of etiopathogenesis of the disease. In pure motor neuropathies, the presence of conduction block leads to immune treatment with good response in more than 50% of the cases.

Publication types

  • Review

MeSH terms

  • Diagnosis, Differential
  • Disease Progression
  • Electromyography
  • Humans
  • Motor Neuron Disease / diagnosis*
  • Motor Neuron Disease / physiopathology
  • Motor Neurons / physiology*
  • Neural Conduction
  • Peripheral Nervous System Diseases / diagnosis
  • Peripheral Nervous System Diseases / physiopathology
  • Severity of Illness Index