Amyotrophic Lateral Sclerosis in Northern Spain 40 Years Later: What Has Changed?

BACKGROUND: In the last years different studies have reported an increase of amyotrophic lateral sclerosis (ALS) incidence, highlighting the role of the environment in this disease. This prompted us to review ALS cases diagnosed at our hospital in the last decade and to compare them with a previous ALS series reported in our region 30 years ago. METHODS: We reviewed those ALS cases diagnosed at our centre between 2004 and 2013. Subsequently, we compared them with the previous series regarding clinical and epidemiological features. RESULTS: A total of 53 patients (30 males, 23 females) were included. The annual incidence was 1.7 cases per 100,000 inhabitants (2.2 and 1.2 per 100,000 in males and females, respectively), which was significantly higher than in the previous series (1 case per 100,000 inhabitants). Otherwise, the clinical and epidemiological features were similar in both series. The median age at symptom onset was 67 years, with a median diagnosis delay of 6 months. About two thirds of the patients presented with systemic ALS, whereas the remaining had a bulbar onset. Weakness, dysphagia, and dysarthria were the most common clinical symptoms at diagnosis. The median survival from symptom onset was 22 months. CONCLUSION: After 3 decades, the annual incidence of ALS has almost doubled in our region. We did not find significant differences regarding other clinical or epidemiological features.