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

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.