Single-fiber electromyography in amyotrophic lateral sclerosis and cervical spondylosis

Muscle Nerve. 2013 Jul;48(1):137-9. doi: 10.1002/mus.23767. Epub 2013 May 22.

Abstract

Introduction: Cervical spondylosis (CS) is a common disease in adults and may coexist with amyotrophic lateral sclerosis (ALS). It is important to detect ALS coexisting with CS (ALS-cs) at an early stage, especially when surgical treatment of CS is planned.

Methods: Single-fiber electromyography was performed in 26 patients with ALS, 19 with ALS-cs, and 22 with CS.

Results: Mean jitter, percentage of jitter >55 μs, and percentage of impulse blocking were not statistically different between ALS and ALS-cs cases, but they were significantly lower in CS. Mean fiber density was not statistically different among the 3 groups. The percentage of pairs with jitter >55 μs exceeding 40% and mean jitter exceeding 55 μs had high sensitivity and specificity in the diagnosis of ALS.

Conclusions: Single-fiber electromyography can supply valuable information in helping to differentiate ALS from CS.

MeSH terms

  • Amyotrophic Lateral Sclerosis / diagnosis*
  • Amyotrophic Lateral Sclerosis / physiopathology*
  • Electromyography / methods*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Muscle Fibers, Skeletal / physiology*
  • Spondylosis / diagnosis*
  • Spondylosis / physiopathology*