Biological markers in amyotrophic lateral sclerosis: help or hindrance?

Biological markers play an important role in the development of the understanding of a disease, its diagnosis and treatment. This is particularly true of amyotrophic lateral sclerosis (ALS) at this time. We need better biological markers for the diagnosis, for improved understanding of the underlying pathogenetic mechanisms, and for assistance in new drug development. This review of currently available biological and surrogate markers in ALS discusses novel approaches to the use of such markers, and new drugs for the treatment of ALS.