Prognostic value of clinical and electrodiagnostic parameters at time of diagnosis in patients with amyotrophic lateral sclerosis

Abstract

Objective: To assess the added prognostic value of the aggregated clinical and electrodiagnostic data, which define a given diagnostic category according to the Awaji or revised El Escorial criteria at time of diagnosis in patients with amyotrophic lateral sclerosis (ALS). Methods: Clinical signs and electrodiagnostic test results were collected at time of diagnosis in 396 patients with ALS between January 2009 and January 2016. Significant predictors of prognosis were identified using a univariate model, and later combined in a multivariate Cox regression model. Results: Known factors associated with reduced survival included older age at onset, shorter diagnostic delay, higher ALSFRS-R slope and presence of C9orf72 mutation (all p < 0.05). Diagnostic category according to Awaji (p < 0.0001) or to revised El Escorial (p = 0.0177) criteria, definite ALS according to Awaji (p < 0.0001) or to revised El Escorial (p = 0.0343) and number of regions with LMN involvement (p < 0.0001) were all associated with shorter survival. Discussion: Clinical and electrodiagnostic data at time of diagnosis provide additional prognostic information compared to other known prognostic factors. Diagnostic category according to Awaji and the extensiveness of LMN involvement contain the most additional value.

Keywords:

• Prognosis, electromyography, electrodiagnostic testing, Awaji, revised El Escorial

Acknowledgements

PVD is a senior clinical investigator of the Flemish Fund for Scientific Research (FWO-Vlaanderen, Fonds voor Wetenschappelijk Onderzoek Vlaanderen, Belgium). This work was supported by the Interuniversity Attraction Poles (IUAP) programme P7/16 of the Belgian Federal Science Policy Office, by the FWO-Vlaanderen under the frame of E-RARE-2, the ERA-Net for Research on Rare Diseases (PYRAMID) and by a EU Joint Programme - Neurodegenerative Disease Research (JPND) project (STRENGTH). PVD is supported by the Belgian ALS Liga. The funding institutions had no influence on the design, analysis or publication of the study.

Declaration of interest

The authors report no financial conflict of interest.

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Funding

This work was supported by the Interuniversity Attraction Poles (IUAP) programme P7/16 of the Belgian Federal Science Policy Office, by the FWO-Vlaanderen under the frame of E-RARE-2, the ERA-Net for Research on Rare Diseases (PYRAMID) and by a EU Joint Programme - Neurodegenerative Disease Research (JPND) project (STRENGTH). PVD is supported by the Belgian ALS Liga. The funding institutions had no influence on the design, analysis or publication of the study.