[Parkinson's disease: the disease concept, etiology and diagnostic bases]

Parkinson's disease (PD) is caused by degeneration of nigral dopaminergic neurons. This results in dysfunction of the basal ganglia, thereby exhibiting movement disorders. The four cardinal signs of PD include bradykinesia, rigidity, resting tremor and postural instability. In the majority of patients with PD, the four cardinal signs are ameliorated by levodopa. In addition to anti-parkinson medication, surgery of the basal ganglia for PD has been applied. Local electrical stimulation of particular nuclei of the basal ganglia (deep brain stimulation) for PD has also proved to give satisfactory outcome. Both genetic and environment factors are considered to contribute to the initiation of PD. Some mutations of particular genes (e.g., alpha-synuclein) are found to link to parkinsonian families.