Pathophysiology of akinetic movement disorders: a paradigm for studies in fibromyalgia?

Patients with fibromyalgia sometimes have sign of a movement disorder in ad dition to sensory disturbances sometimes similar as those found in akinetic syndromes. Akinesia is due to disturbances in the functions of the cortico -thalamonigro-striatal system and associated areas. The reason of this dysf unction in Parkinson's disease is a decreased nigral dopaminergic efferent innervation due to a neuronal degeneration in the pars compacta of the subs tantia nigra. Changes in other neurotransmitters, like GABA or serotonin, a nd in receptors and second messengers also occur, with additional modulatio n due to therapy. The aetiology of nigral malfunction is in only rarely kno wn. Drugs and mutations of some genes are examples which give much insight in the pathogenesis of movement disorders in general. In other akinetic dis orders, Like multisystem atrophy, corticobasal ganglionic degeneration, and progressive supranuclear palsy, more complex patterns of degeneration have been found. This pathological anatomical disturbances have typical clinica l effects which can be studied physiologically and with imaging in vivo. Si nce basal ganglia play also a role in pain, a comparative study of their in volvement in movement disorders and nociception seems to be fruitful, espec ially in devising new therapeutic strategies.