[Long-term syndrome in the treatment of parkinsonism with L-dopa].

A group of 71 patients with Parkinson's disease were treated with L-Dopa and benserazide during periods ranging from 27 to 60 months. In 28% of cases a decline in therapeutic effects and or delayed appearance or increase of secondary actions were observed constituting a long-term syndrome. Its most complex and dramatic expression, the on-off effect, was present in 11% of cases. Those patients with more severe symptoms were studied by means of continuous clinical observation enabling the design of daytime follow-up curves. Observations were repeated with varying dosage patterns, showing variations but no substantial changes or disappearance of the symptoms described. Electromyographic recordings and films were taken in certain cases defining the characteristics of on and off effects. Several procedures were implemented in an attempt to control Long-Term Syndrome manifestations: Change of dosage, variation of L-dopa/decarboxilase inhibitor ratio, association of anticholinergic agents with antidepressants, hypoprotein diets. Improvement was moderate and/or transient, with the exception of Nortriptilline which permitted total or partial control of certain symptoms, especially hypokinetic periods, bouts of tremor and dystonic attitudes. It was occasionally necessary to interrupt administration of L-Dopa, readministering it later with recovery of the therapeutic effect and/or avoidance of undesirable effects for varying periods of time. Loss than optimal doses proved beneficial in reducing or postponing Long-Term Syndrome manifestations. Although L-Dopa does not detain the course of the disease, the persistence of favourable results in most patients for prolonged periods of treatment confirms the long-term therapeutic value of this drug.