Amyotrophic lateral sclerosis: what role does environment play?

The cause of sporadic amyotrophic lateral sclerosis (ALS) is not known. Studies associate toxic, dietary, infectious, neoplastic, and physical factors as underlying, predisposing, or pathogenic influences. Historical, conventional, and novel disease mechanisms, acting solely or in concert, convert previously healthy individuals into terminally ill patients. Despite intensive investigations in the previous decades, the underlying cause and effective treatments elude researchers. Discovering causative mechanisms in sporadic ALS will facilitate effective treatments and cures for this disorder. After a brief review of the disease process itself, this article discusses potential environmental influences on the development of ALS.