Amyotrophic Lateral Sclerosis: An Aging-Related Disease
Résumé
Amyotrophic lateral sclerosis (ALS) is a rapidly progressive disorder characterized primarily by selective neurodegeneration of the motor neurons. The basis of diagnosis is the presence of signs of both upper and lower motor neuron involvement in more than one body region. ALS was considered until a few years ago a disease of young adults but recently population-based studies have consistently shown that ALS is an age-related disease with age incidence curve similar to other age-dependent neurodegenerative diseases like Parkinson’s disease and Alzheimer’s disease. The peak of incidence is in the eighth decade and declines thereafter, first in men and then in women. In the majority of cases, ALS is sporadic while 5–10 % of the disease is familiar. After the identification of C9ORF72, it is now recognized that the definition of familial ALS can be enlarged to include family members with frontotemporal dementia considering the tight link between the two nosological entities.