[Parkinson's disease: some physiopathologic aspects and clinical practice].

The lesions of Parkinson's disease chiefly involve the dopaminergic nigrostriatal tract and the great subcortical-cortical dopaminergic, noradrenergic, serotoninergic and cholinergic neuron systems. On the basis of these data, one may suggest a mechanism for some motor and mental disorders, as well as the rationale for treatment with L-dopa, the origin of its main side-effects and the classical escape phenomenon observed with this drug.