Prognostic value of time to generalization in 71 Chinese patients with sporadic amyotrophic lateral sclerosis

BACKGROUND: It is important to determine prognostic factors for the outcome of amyotrophic lateral sclerosis (ALS) at an early stage. The time taken for symptoms to spread from spinal or bulbar regions to both (time to generalization; TTG) is considered a strong predictor of survival; however, this has rarely been studied in Asian populations. The aim of this retrospective study was to evaluate potential factors affecting prognosis in Chinese patients with sporadic ALS, with a focus on the association between TTG and overall survival. METHODS: Seventy-one patients with sporadic ALS who were hospitalized at Chinese PLA General Hospital from 2009 to 2016 were followed up until December 2017. Survival analysis was performed using univariate Kaplan-Meier log-rank and multivariate Cox proportional hazards models. The clinical data of the patients were recorded and analyzed. Variables studied were age at symptom onset, sex, site of symptom onset, diagnostic latency, TTG, diagnostic category, ALS Functional Rating Scale-revised score, percent predicted forced vital capacity (FVC%), and disease progression rate (DPR) at diagnosis. RESULTS: The mean age at onset was 54 (SD = 10.2) years, and the median survival time from symptom onset was 41 months (95% confidence interval: 34–47). By univariate analysis, factors independently affecting survival were age at symptom onset (Log rank = 15.652, P < 0.0001), TTG (Log rank = 14.728, P < 0.0001), diagnostic latency (Log rank = 11.997, P = 0.001), and DPR (Log rank = 6.50, P = 0.011). In the Cox multivariate model, TTG had the strongest impact on survival time (hazard ratio = 0.926, P = 0.01). CONCLUSIONS: TTG can be used as an effective indicator of prognosis in patients with sporadic ALS.