[Motor complications of treatment with levodopa in Parkinson's disease]

Motor complications of treatment with levodopa affect more than 50% of patients after several years' treatment. This has a marked effect on patients with Parkinson's disease since these side effects are undesirable, affect the natural course of the disorder and complicate treatment.

In this review we describe the main epidemiological, physiopathological and therapeutic aspects of the motor complications of levodopa. According to most epidemiological studies, starting treatment at an early age and more severe degree of the disorder are the main risk factors. The physiopathology of motor complications is varied. It has been thought to be due to loss of the buffer effect of the brain on plasma levels of levodopa, alterations in the functional state of the postsynaptic receptors and chronic intermittent use of levodopa. Management includes division and/or reduction of the dose of levodopa, use of slow-release preparations and association of dopaminergic agonists with COMT inhibitors which are the latest drugs to be tried. Various surgical possibilities in specialist centres may also be considered for serious cases of motor complications which do not respond to medical treatment.

Recent advances in understanding the physiopathology and in the medical and surgical treatment permit improved control of the motor complications of chronic treatment with levodopa.