Epidemiological and clinical features of amyotrophic lateral sclerosis in a Tunisian cohort

Objective: To describe the phenotypic heterogeneity of amyotrophic lateral sclerosis (ALS) in Tunisian patients, and to define the sociodemographic features, treatments, and survival rate with ALS. Methodology: The study included 210 patients with ALS diagnosed between 2003 and 2019 in The Neurology department, Razi Hospital Tunisia. ALS patients were phenotyped and followed until their death. Results: median age of ALS onset was 54.93 +/- 14.08 years (men = 56.21 +/- 12.58, women = 52.36 +/- 16.49). The sex-ratio was 2.0 with obvious male predominance. Juvenile ALS form was found in 5.71% of our cohort and 94, 76% of the patients had the classic ALS form. In the latter, 76.3% had spinal onset whereas bulbar onset was seen in 20.1% of patients. Spinal onset was most frequent in Juvenile ALS patients. Approximately half of the ALS patients used Riluzole (58.5%). Median survival rate was 60 months (5 years). According to univariate analysis, the factors related to survival rate of ALS patient were: age at onset, diagnostic delay, site of onset, phenotype and treatment use. The multivariate analysis revealed that age at onset, gender, diagnostic delay, superior muscles atrophy, treatment use, consanguinity, cognitive signs, dysautonomia, and ALSFRS-R score were independent prognostic factors of survival among ALS patients. Conclusion: Our Tunisian cohort was characterized by a slower disease progression and a better prognosis. Juvenile ALS patients were more common. Initial ALSFRS-R scores were higher in our population. Age at onset of Bulbar ALS was younger. Our study highlights the possible presence of genetic and environmental factors that may influence the clinical phenotype of ALS in Tunisia.