Incidence and Clinical Features of Amyotrophic Lateral Sclerosis in Møre and Romsdal County, Norway

Abstract

BACKGROUND: To determine the annual incidence rate and clinical features of amyotrophic lateral sclerosis (ALS) in Møre and Romsdal County, Norway, in the 20-year period from 1988 to 2007. METHODS: We recruited ALS patients retrospectively from the patient database of the two neurological departments in Møre and Romsdal County, Norway. The patients were identified by use of the international classification code for diseases. We recorded gender, age, municipality, symptoms, clinical signs, time from onset to diagnosis and death. RESULTS: 105 patients met the inclusion criteria. The crude annual incidence was 2.17 per 100,000 for the period 1988-2007. Gender-specific incidence for men was 2.32 per 100,000, and for women 2.03 per 100,000. Mean age at symptom onset was 66.8 ± 10.5 years. Mean interval from onset of symptoms to diagnosis was 13.5 ± 11.0 months, and mean survival time from diagnosis was 18.0 ± 22.0 months. Prevalence rate estimated on December 31, 2007 was 4.06 per 100,000. CONCLUSION: The present study shows an annual incidence of ALS of similar magnitude to the previous studies from the Nordic countries during the past years. The short survival time corroborates prior studies, and is stable throughout the two studied decades.