We are currently investigating the underlying causes of fatigue in neurological conditions that affect the central and peripheral nervous systems and recently assessed the role of autonomic nervous system dysfunction in causing fatigue in Guillain Barr� Syndrome. Our results indicate that orthostatic hypotension secondary to persistent autonomic dysfunction may underlie the disabling fatigue in GBS survivors. This observation provides a potential avenue for ameliorating a symptom for which no therapy is currently available. We now hope to study and understand factors underlying the persistent and intractable fatigue that occurs in multiple sclerosis - a condition which commonly affects young to middle aged women in this part of the world. It is possible that dysfunction of central pathways leading to autonomic deregulation in these patients may underlie fatigue.