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

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.