New strategies for the treatment of Parkinson's disease hold considerable promise for the future management of neurodegenerative disorders

Neurodegenerative diseases are often consideredincurable with no efficient therapies to modifyor halt the progress of disease, and ultimatelylead to reduced quality of life and to death.Our knowledge of the nervous system in healthand disease has, however, increasedconsiderably during the last fifty years andtoday, neuroscience reveals promising newstrategies to deal with disorders of thenervous system.Some of these results have been implementedwith success in the treatment of Parkinson'sdisease, a common neurodegenerative illnessaffecting approximately 1% of the populationaged seventy or more. Parkinson's disease ischaracterized by a massive loss of dopaminergicneurons in the substantia nigra, leading tosevere functional disturbance of the neuronalcircuitry in the basal ganglia. A thoroughdescription of basal ganglia circuitry inhealth and disease is presented. We describehow the functional disturbances seen inParkinson's disease may be corrected atspecific sites in this circuitry by medicaltreatment or, in advanced stages of Parkinson'sdisease, by neurosurgical methods. The latterinclude lesional surgery, neuraltransplantation and deep brain stimulation,together with future treatment strategies usingdirect or indirect implantation of geneticallymodified cell-lines capable of secretingneurotrophic factors or neurotransmitters.Advantages and disadvantages are brieflymentioned for each strategy and theimplications for the future and the possibleuse of these interventions in otherneurodegenerative diseases are discussed, withspecial emphasis on deep brain stimulation.