Possible impact of dopamine SPECT on decision-making for drug treatment in Parkinsonian syndrome.

Single-photon emission computed tomography (SPECT) markers allow measuring the integrity of the brain dopaminergic system in vivo. We used dopamine transporter (DAT) SPECT with [(123)I]FP-CIT and dopamine D(2)/D(3) receptor SPECT with [(123)I]IBZM to evaluate whether there is a reduction of DAT and/or D(2)/D(3) receptor SPECT in treated and untreated patients with Parkinsonian syndrome (PS). We found that almost a quarter of our patients treated with anti-Parkinsonian medication prior to SPECT imaging did not show evidence of a presynaptic dopaminergic deficit while 37% of untreated patients were diagnosed as having Parkinson's disease. 17% of treated patients had additional loss of D(2)/D(3) receptor binding capacity in concordance with the clinical follow-up diagnoses of multiple system atrophy, progressive nuclear palsy, and vascular Parkinsonism. Apart from 38% clinically uncertain cases, SPECT was in concordance with 75% of initial clinical diagnoses. 25% were reclassified as indicated by SPECT findings and confirmed by a 1.5-year clinical follow-up. We conclude that dopamine SPECT may support establishing or refuting the clinical diagnosis and, therefore, help to make the decision for or against dopaminomimetic treatment in cases with PS.

Efficacy and safety of high-dose cabergoline in Parkinson's disease.

OBJECTIVES: To assess the efficacy and safety of high-dose (up to 20 mg/day) cabergoline in Parkinson's disease (PD) patients with motor fluctuations and/or dyskinesias. MATERIALS AND METHODS: Thirty-four PD patients had cabergoline up-titrated and their levodopa (L-dopa) reduced over a maximum of 20 weeks, followed by at least 6 weeks steady cabergoline dosing. Primary endpoint was change in mean hyperkinesia intensity at the final visit (week 26). RESULTS: Mean (+/- SD) cabergoline was increased from 6.43 +/- 2.66 to 12.78 +/- 5.67 mg/day and mean L-dopa reduced from 606.6 +/- 263.9 to 370.6 +/- 192.5 mg/day. A significant reduction (P < 0.001) in mean hyperkinesia intensity occurred from baseline (day 0) to week 26. Improvements in 'on with dyskinesias', mean dystonia intensity (P < 0.05), time spent in 'severe off' condition, severity of 'off' periods as well as clinical/patient global impression, and health-related quality of life were observed. Twenty-four drug-related adverse events were recorded of which four were regarded as serious. CONCLUSION: High-dose cabergoline was well tolerated and provided significant improvements in the Parkinson symptomatology and a reduced requirement for L-dopa.