Neurobiology and treatment of Parkinson's disease.

Parkinson's disease (PD) is the second most common neurodegenerative disorder after Alzheimer's disease and is an important cause of chronic disability. Numerous important advances have been made in our understanding of the aetiopathogenesis, pathology and clinical phenomenology of this disease, and these have underpinned advances in symptomatic treatment and the prospect that these might be extended into interventions that will slow progression. It is notable that the continuing characterisation of the downstream biochemical consequences of the genetic causes of PD serves only to reinforce this notion. Progress in the management of PD has continued, particularly in timing of drug initiation and the sequence and combinations in which drugs are used to improve long-term outcome and reduce drug-induced complications. Particular progress has been made in the field of neuroprotection, where novel therapies and clinical trial designs are being tested. This review will focus particularly upon this area.