[Fatigue syndrome in chronic neurological disorders]

Fatigue without coincident depression may accompany many neurological disorders, including multiple sclerosis, Parkinson's disease, motor neuron disease, stroke and post-polio syndrome, and is frequently reported by patients as a predominant complaint. The pathophysiology of fatigue is unknown. The role of various mechanisms has been suggested, including the effect of proinflammatory cytokines (TNF-alpha, IL-1beta and IL-6) on glutaminergic transmission, hypothalamo-pituitary-adrenal (HPA) axis dysfunction, disturbances of astroglia metabolism and decreased levels of the neurotransmitters noradrenaline and serotonin. The diagnosis of fatigue syndrome is based on exclusion of depression and additional organic conditions (anaemia, cardiovascular disorders, kidney diseases or hypothyroidism). The treatment of fatigue syndrome is complex. Physical activity, rehabilitation, psychotherapy and avoidance of factors which may increase fatigue, such as fever, anxiety, depression, pain, sleep disturbances, as well as some drugs like opioids and benzodiazepines, are important. Pharmacological treatment leads to slight improvement. Amantadine, modafinil and pemoline are administered to such patients.