Aetiology : unknown (genetic and environmental)
Prevalence : 1/20 000 inhabitants (mainly between 50 and 70 years old)
Genetic risk factor : SOD1, C9ORF72, TARDBP, FUS/TLS... (with 10% of hereditary cases)
Main clinical forms :
Limb onset (most typical form – 70%) : Characterized by weakness in limbs, muscles atrophy, slowness, cramps,
Bulbar onset (25%) : Characterized by speech and swallowing difficulties : dysphagia, dysarthria, facial and jaw weakness.
Less common presentations : truncal-abdominal (axial) involvement at onset, respiratory involvement at onset, weight loss, fasciculations and cramps
à Most of the time, paralysis begins to affect respiratory muscles, leading to death within three to five years after diagnosis.
Currently, the available treatments are only symptomatic or palliative but not curative : extend survival by only 3-6 months after 18 months of treatment
Riluzole is the only treatment of reference in Europe.