Article Text

Download PDFPDF
Detecting fasciculations in amyotrophic lateral sclerosis: duration of observation required
  1. Kerry R Mills
  1. Department of Clinical Neurophysiology, King's College Hospital, London, UK
  1. Correspondence to Professor Kerry R Mills, Department of Clinical Neurssophysiology, King's College Hospital, London SE5 9RS, UK; Prof.krmills{at}


A practical issue in the diagnosis of amyotrophic lateral sclerosis (ALS) is how long the EMG must be observed before a muscle can be declared free of fasciculations with some degree of certainty. To answer this question, the intervals between fasciculation potentials (FPs) were recorded from 53 muscles of 19 ALS patients. The distribution of the FP intervals found across the sample showed that to record a single fasciculation with a probability approaching unity, observation for up to 90 s may be required.

  • Amyotrophic lateral sclerosis
  • fasciculation
  • EMG
  • ALS

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.


  • Competing interests None.

  • Patient consent Obtained.

  • Provenance and peer review Not commissioned; externally peer reviewed.