The response of "de novo" Parkinson's disease patients to bromocriptine in a "low and slow" regimen is predictive for prognosis.

It is possible that Bromocriptine only determines a complete antiparkinson effect in a subset of P.D. patients that have a good dopaminergic reserve. Our study intent to demonstrate that a good short-term response to Bromocriptine used in a "low and slow" regimen is a marker of long term good prognosis. We studied a series of 36 sequential "de novo" P.D. patients treated with Bromocriptine in a "low and slow" regimen. The principal end-point was the introduction of Levodopa. "Good prognosis" was defined as no need of Levodopa until five years of follow-up. An improvement greater than 33% in the Columbia rating scale, at the 6th month of treatment, was the cut-off point to decide that a patient had a good short term response to Bromocriptine. Nine patients fulfilled the criteria for being good short term responders. Multiple regression analysis showed that this outcome could not be predicted by the clinical characteristics of the patients at admission. The sensitivity and the specificity of the short term response to Bromocriptine to predict a good prognosis were 70% and 90.5% respectively. We conclude that Bromocriptine in monotherapy is an efficient antiparkinson agent in 1/3 of "de novo" P.D. patients and good short term response to Bromocriptine is an acceptable marker for a good prognosis. Therefore it is possible that the response to Bromocriptine is a discriminator for a subset of P.D. patients in the early phases of the disease.