Denervation findings on EMG in amyotrophic lateral sclerosis and correlation with prognostic milestones: Data from a retrospective study

Clin Neurophysiol. 2020 Aug;131(8):2017-2022. doi: 10.1016/j.clinph.2020.04.161. Epub 2020 May 21.

Abstract

Objective: To verify whether the finding of denervation activity on EMG at the time of diagnosis has a prognostic value in amyotrophic lateral sclerosis (ALS).

Methods: We retrospectively studied all the patients discharged with a diagnosis of ALS between January 2009 and January 2017. 92 patients met the inclusion criteria. We mainly verified three prognostic targets:All EMG examinations were reviewed and a denervation score (DS) was calculated. The association of DS with clinical milestones was analysed, adjusting for disease duration, age , sex, and clinical phenotype.

Results: We found a significant association between bulbar DS and time to NIV/tracheostomy (HR: 3.34, 95% CI: 1.49 to 7.48, p = 0.002) and with survival (HR 3.633, 95% CI 1.681-7.848, p = 0.001), regardless of the clinical phenotype. Furthermore, we found a significant influence of a general DS on survival (HR: 2.62, 95% CI 1.335-5.160, p = 0.005).

Conclusion: EMG assessment could be of value not just for ALS diagnosis but also for its intrinsic prognostic value.

Significance: EMG could provide additional information about the rate of progression of ALS as early as the diagnosis is made.

Keywords: ALS; Amyotrophic lateral sclerosis; Denervation; EMG; Motor neuron disease; Prognosis.

Publication types

  • Evaluation Study

MeSH terms

  • Aged
  • Amyotrophic Lateral Sclerosis / diagnosis*
  • Electromyography / methods*
  • Electromyography / standards
  • Female
  • Hand Strength
  • Humans
  • Male
  • Middle Aged
  • Motor Neurons / physiology
  • Muscle, Skeletal / innervation
  • Muscle, Skeletal / physiology
  • Phenotype
  • Pulmonary Ventilation
  • Sensitivity and Specificity