[Cognitive disorders and amyotrophic lateral sclerosis. Beyond motor impairment].

Amyotrophic lateral sclerosis (ALS) is a predominantly motor disease that can be associated in half the patients with a cognitive and/or behavioral impairment. Cognitive/behavioral disorders are subclinical in most cases and need specific testing to be diagnosed. They can meet the diagnostic criteria of FTLD in 10-15 % of patients. The occurrence of cognitive/behavioral changes in patients with ALS is taken as evidence of a continuum between ALS and fronto-temporal dementias. The cognitive changes mostly involve executive functions, language and social cognition. Behavioral changes include apathy, disinhibition, lack of empathy and impulsivity. Cognitive/behavioral changes in the course of ALS are related to a shorter survival. Cognitive/behavioral changes may interfere with decision making, particularly end-of-life decisions, and they increase the burden of carers. Cognitive/behavioral changes should be recognized and assessed so as to tailor therapeutic interventions.