Clinical features and incidence trends of amyotrophic lateral sclerosis in Navarre, Spain, 2007-2018: a population-based study

Objective: Amyotrophic Lateral Sclerosis (ALS) is a heterogeneous neurodegenerative disorder with a median survival of 3 years. The aim of our study is to analyze the incidence, age-related phenotype and clinical onset, geographical distribution, survival and diagnostic delay of ALS in Navarre. Methods: This is a population-based observational retrospective study, including all residents of Navarre (a northern Spanish region) from 2007 to 2018, who were followed until 30th September 2020. Results: We observed a global incidence 2.47/100,000 person-years, with an upward trend throughout the study, with the highest being in the age group of 70¿74 years old. Point prevalence in December 2018 was 6.64/100,000 inhabitants (95%CI: 4.52¿8.45). Upper limbs weakness onset was the most frequent in young people (<60 years), and bulbar, lower limbs weakness, generalized and respiratory associated with older age. Bulbar phenotype is the most frequent in women and in 80+ group. The median survival from clinical onset was 27.7 months (95%CI: 24.0¿31.4), higher in spinal phenotype and younger onset age, and the diagnosis delay was 10.0 months (95%CI: 8.9¿11.2) from clinical onset. Conclusions: We have observed a trend of increasing incidence in older people where the bulbar phenotype and female predominance. © 2021 World Federation of Neurology on behalf of the Research Group on Motor Neuron Diseases.