Electrodiagnostic criteria for diagnosis of ALS

Clin Neurophysiol. 2008 Mar;119(3):497-503. doi: 10.1016/j.clinph.2007.09.143. Epub 2007 Dec 27.


A consensus meeting was held to determine the best use and interpretation of electrophysiological data in the diagnosis of ALS. The utility of needle EMG and nerve conduction studies was affirmed. It is recommended that electrophysiological evidence for chronic neurogenic change should be taken as equivalent to clinical information in the recognition of involvement of individual muscles in a limb. In addition, in the context of a suspected clinical diagnosis of ALS, fasciculation potentials should be taken as equivalent to fibrillation potentials and positive sharp waves in recognising denervation. The importance of searching for instability in fasciculation potentials and in motor unit potentials in ALS is stressed. These changes in the interpretation of electrophysiological data render obsolete the category Probable Laboratory-Supported ALS in the modified El Escorial diagnostic criteria for ALS. Methods for detection of upper motor neuron abnormality appear sensitive but require further study, particularly regarding their value when clinical signs of upper motor neuron lesion are uncertain.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Amyotrophic Lateral Sclerosis / diagnosis*
  • Electrodiagnosis / methods*
  • Electrodiagnosis / standards*