RISK-FACTORS FOR PEAK DOSE DYSKINESIA IN 100 LEVODOPA-TREATED PARKINSONIAN-PATIENTS

Background: No clinical parameter other than ''sufficient'' dopamine d enervation and exposure to exogenous levodopa has been unquestionably linked to dyskinesia in levodopa-treated Parkinson's disease patients, Methods: We retrospectively analyzed data on 100 consecutive patients treated with levodopa for 1 to 18 years to identify clinical risk fac tors for dyskinesia. The cumulative dyskinesia-free survival probabili ty in relation to levodopa therapy was assessed using the Kaplan-Meier method, Results: Overall, 56% of patients developed dyskinesia after a mean of 2.9 years, a figure similar to the average duration of levod opa treatment in the non-dyskinetic group, Dyskinetic patients were si gnificantly younger at disease onset, but their mean latency to dyskin esia induction after levodopa initiation was not different from older dyskinetic individuals and the overall dyskinesia-free survival of you nger subjects was not worse either. Dyskinetic patients were on a high er daily levodopa dose than non-dyskinetic subjects when dyskinesia em erged, but the cumulative levodopa dose used prior to dyskinesia did n ot discriminate dyskinetic from non-dyskinetic patients. A delay in in itiating levodopa therapy of more than three years after disease onset and levodopa treatment initiation in Hoehn-Yahr stage II compared to stage I patients did not increase the probability of developing dyskin esia over time, Conclusions: Since withholding levodopa therapy did no t increase the risk for dyskinesia in our patients and can delay the e mergence of dyskinesia after onset of parkinsonian symptom, a trial wi th a dopaminomimetic agonist as initial treatment appears logical.