A progressive neurodegenerative disorder involving motor neurons in the cerebral cortex, brainstem, and spinal cord.

Characterized by findings of the following in an ever-widening distribution over time:

Usually a “pure” motor disorder without significant sensory impairment or bowel or bladder dysfunction.

No single diagnostic test though consensus diagnostic criteria exist, which are based on clinical observations and electrodiagnostic testing.

Peak incidence 55-70yo, only 5-10% familial (autosomal dominant).

Average survival after dx is approx. 3y but about 10% have > 10y survival after dx.