ALS

Amyotrophic lateral sclerosis, widely known as ALS or Lou Gehrig's disease, is a rare terminal neurodegenerative disease and the most common form of motor neuron disease. It causes progressive destruction of the motor neurons that control voluntary muscle movement, producing muscle stiffness, involuntary twitches, weakness and wasting that worsen over time. In later stages patients face severe difficulty speaking, swallowing and breathing, and at least half develop cognitive or behavioral changes, with about fifteen percent developing frontotemporal dementia. Onset is usually between ages forty five and seventy five, classified as limb onset or bulbar onset by where symptoms begin. Ninety to ninety five percent of cases are sporadic with no identifiable cause; the remainder are inherited, most often tied to a mutation in the C9orf72 gene. Average survival after diagnosis is two to four years, with death usually caused by respiratory failure, though roughly one in ten patients survive more than a decade.