Pergolide for levodopa-induced complications in Parkinson's disease.

OBJECTIVES: To compare the efficacy and safety of adjunct pergolide therapy versus placebo in patients with Parkinson's disease suffering from the complications of levodopa therapy. SEARCH STRATEGY: Electronic searches of MEDLINE, EMBASE and the Cochrane Controlled Trials Register. Handsearching of the neurology literature as part of the Cochrane Movement Disorders Group's strategy. Examination of the reference lists of identified studies and other reviews. Contact with Eli Lilly and Company Limited. SELECTION CRITERIA: Randomised controlled trials of pergolide versus placebo in patients with a clinical diagnosis of idiopathic Parkinson's disease and long-term complications of levodopa therapy. DATA COLLECTION AND ANALYSIS: Data was abstracted independently by each author and differences settled by discussion. The outcome measures used included Parkinson's disease rating scales, levodopa dosage, 'off' time measurements and the frequency of drop outs and adverse events. MAIN RESULTS: A large number of small RCTs were identified, but these were part of a large multicentre trial which was eventually published in full. The final publication was used as the only subject for this review. The time patients spent 'off' was reduced by 1.8 hours with pergolide compared with 0.2 hours with placebo (p < 0.001). Dyskinesia developed or deteriorated in 62% of pergolide-treated compared with 25% placebo-treated patients (p < 0. 05). The excess in dyskinesia prevalence and severity resolved by the end of the study with levodopa reduction. Levodopa dose was reduced more in those receiving pergolide (235 mg v 51 mg; p < 0. 001). Pergolide produced significant improvement in Hoehn and Yahr stage (p < 0.05) and both the motor and activities of daily living parts of a modified Columbia rating scale (both p < 0.001). Significantly more patients suffered nausea (24% v 13%; p < 0.001) and hallucinations (14% v 3%; p < 0.01) on pergolide. No difference was found in the numbers remaining on treatment at the end of the study (pergolide 84% v placebo 82%) but withdrawals due to adverse events were greater in those taking pergolide (10% v 4%). REVIEWER'S CONCLUSIONS: Based on this single large multicentre study, pergolide reduces 'off' time and improves impairment and disability due to Parkinson's disease whilst allowing a reduction in levodopa dose. This is at the expense of dopaminergic adverse events. Further trials are required to compare pergolide with the newer dopamine agonists.

Pergolide versus bromocriptine for levodopa-induced motor complications in Parkinson's disease.

OBJECTIVES: To compare the efficacy and safety of adjunct pergolide therapy versus bromocriptine in patients with Parkinson's disease, already established on levodopa and suffering the long-term complications of therapy. SEARCH STRATEGY: Electronic searches of MEDLINE, EMBASE and the Cochrane Controlled Trials Register. Handsearching of the neurology literature as part of the Cochrane Movement Disorders Group's strategy. Examination of the reference lists of identified studies and other reviews. Contact with Eli Lilly Company and Sandoz Limited. SELECTION CRITERIA: Randomised controlled trials of pergolide versus bromocriptine in patients with a clinical diagnosis of idiopathic Parkinson's disease and long-term complications of levodopa therapy. DATA COLLECTION AND ANALYSIS: Data was abstracted independently by each author and differences settled by discussion. MAIN RESULTS: Three short-term trials fulfilled the inclusion criteria for the review. Pergolide was superior to bromocriptine regarding UPDRS and NYPDS motor and NYPDS ADL scores in two trials. More patients recorded a 'marked' or 'moderate improvement' in clinician's global impression score with pergolide than bromocriptine in two studies. Insufficient evidence on fluctuations and dyskinesia was available to draw any conclusions. No significant differences between the agonists were seen in levodopa dose reduction, drop outs or adverse events. REVIEWER'S CONCLUSIONS: Although pergolide is superior to bromocriptine in reducing motor impairments and disability, no firm conclusions regarding levodopa-induced motor complications can be reached. Levodopa dose reduction, adverse events and withdrawals from treatment are similar for the two agonists. The small advantage of pergolide in efficacy does not take into account its additional cost compared with bromocriptine.

Lisuride versus bromocriptine for levodopa-induced complications in Parkinson's disease.

OBJECTIVES: To compare the efficacy and safety of adjunct lisuride therapy versus bromocriptine in patients with Parkinson's disease, already established on levodopa and suffering the long-term complications of therapy. SEARCH STRATEGY: Electronic searches of MEDLINE, EMBASE and the Cochrane Controlled Trials Register. Handsearching of the neurology literature as part of the Cochrane Movement Disorders Group's strategy. Examination of the reference lists of identified studies and other reviews. Contact with Cambridge Laboratories, Roche Products Limited and Sandoz Limited. SELECTION CRITERIA: Randomised controlled trials of lisuride versus bromocriptine in patients with a clinical diagnosis of idiopathic Parkinson's disease and long-term complications of levodopa therapy. DATA COLLECTION AND ANALYSIS: Data was abstracted independently by each author and differences settled by discussion. MAIN RESULTS: Only one randomised cross-over trial including 20 patients has compared lisuride with bromocriptine as adjunct therapy in Parkinson's disease. Both lisuride and bromocriptine improved motor fluctuations with no significant differences between the agonists. However, this conclusion is based on an unvalidated 4 point rating scale which could only record positive outcomes. This, combined with the small size of the trial, suggests that firm conclusions on motor fluctuations should not be drawn. Lisuride and bromocriptine produced similar benefits in parkinsonian impairments according to the Columbia Rating Scale. Adverse events were similar with the two agonists and no withdrawals were reported from either drug. REVIEWER'S CONCLUSIONS: The small size of this study and other methodological problems do not allow any firm conclusions to be drawn regarding the efficacy and safety of lisuride compared with bromocriptine in advanced Parkinson's disease with motor complications.

Lisuride for levodopa-induced complications in Parkinson's disease.

OBJECTIVES: To compare the efficacy and safety of adjuvant lisuride therapy versus placebo in patients with Parkinson's disease, already established on levodopa and suffering from motor complications. SEARCH STRATEGY: Electronic searches of MEDLINE, EMBASE and the Cochrane Controlled Trials Register. Handsearching of the neurology literature as part of the Cochrane Movement Disorders Group's strategy. Examination of the reference lists of identified studies and other reviews. Contact with Cambridge Laboratories and Roche Products Limited. SELECTION CRITERIA: Randomised controlled trials of lisuride versus placebo in patients with a clinical diagnosis of idiopathic Parkinson's disease and long-term complications of levodopa therapy. DATA COLLECTION AND ANALYSIS: Data was to be abstracted independently by each author and differences settled by discussion. MAIN RESULTS: No randomised controlled trials comparing lisuride with placebo in advanced Parkinson's disease with motor complications were found. REVIEWER'S CONCLUSIONS: Well designed randomised controlled trials demonstrating efficacy and safety are required before the use of lisuride in later Parkinson's disease can be supported.

Pramipexole versus bromocriptine for levodopa-induced complications in Parkinson's disease.

OBJECTIVES: To compare the efficacy and safety of adjuvant pramipexole versus bromocriptine therapy in patients with Parkinson's disease, already established on levodopa and suffering from motor complications. SEARCH STRATEGY: Electronic searches of MEDLINE, EMBASE and the Cochrane Controlled Trials Register. Handsearching of the neurology literature as part of the Cochrane Movement Disorders Group's strategy. Examination of the reference lists of identified studies and other reviews. Contact with Pharmacia Upjohn and Boehringer Ingelheim. SELECTION CRITERIA: Randomised controlled trials of pramipexole versus bromocriptine in patients with a clinical diagnosis of idiopathic Parkinson's disease and long-term complications of levodopa therapy. DATA COLLECTION AND ANALYSIS: Data was abstracted independently by the authors and differences settled by discussion. The outcome measures used included Parkinson's disease rating scales, levodopa dosage, 'off' time measurements and the frequency of drop outs and adverse events. MAIN RESULTS: One randomised controlled trial has compared pramipexole with bromocriptine using a double-blind, parallel group, multicentre design. It was not powered to examine differences between active treatment arms. There was a larger reduction in off time with pramipexole therapy compared with bromocriptine (weighted mean difference 1.4 hours; 0, 2.8, 95% CI). No differences occurred in dyskinesia rating scale, dyskinesia as an adverse event or UPDRS complication score. The UPDRS ADL and motor scores showed similar improvements compared to placebo with both agonists. Levodopa dose reduction was similar with both agonists. Subscales of the Functional Status Questionnaire showed significant improvements compared to placebo with both agonists. The finding that the EuroQol improved significantly compared with placebo with pramipexole but not bromocriptine should be treated with caution. Dopaminergic adverse events were similar with each agonist, as was the all cause withdrawal rate. REVIEWER'S CONCLUSIONS: Although pramipexole and bromocriptine improved off time and reduced parkinsonian motor impairments and disability compared with placebo, no conclusions regarding their comparative effectiveness and safety can be drawn as this single trial did not have adequate power to assess such differences. Further larger trials are required to examine this issue in the future.

Pramipexole for levodopa-induced complications in Parkinson's disease.

OBJECTIVES: To compare the efficacy and safety of adjuvant pramipexole therapy versus inactive placebo in patients with Parkinson's disease, already established on levodopa. SEARCH STRATEGY: Electronic searches of MEDLINE, EMBASE and the Cochrane Controlled Trials Register. Handsearching of the neurology literature as part of the Cochrane Movement Disorders Group's strategy. Examination of the reference lists of identified studies and other reviews. Contact with Pharmacia Upjohn and Boehringer Ingelheim. SELECTION CRITERIA: Randomised controlled trials of pramipexole versus placebo in patients with a clinical diagnosis of idiopathic Parkinson's disease and long-term complications of levodopa therapy. DATA COLLECTION AND ANALYSIS: Data was abstracted independently by the authors and differences settled by discussion. The outcome measures used included Parkinson's disease rating scales, levodopa dosage, 'off' time measurements and the frequency of drop outs and adverse events. MAIN RESULTS: Four randomised controlled trials have compared pramipexole with placebo in 669 patients with later Parkinson's disease. Two phase III studies were medium term (24 weeks maintenance period) and 2 phase II studies were short term (4 weeks maintenance period). The reduction in off time was significantly greater with pramipexole compared with placebo (weighted mean difference 1.8 hours; 1.2, 2.3 95% CI). No significant changes were noted in a dyskinesia rating scale in any of the 4 studies, but dyskinesia as an adverse event was reported more frequently with pramipexole. A significant improvement occurred in UPDRS complication score (part IV) in 2 studies but not in the remaining trials. Statistically significant improvements in UPDRS ADL score occurred with pramipexole in all studies. Significant improvements in UPDRS motor scores in the on state were reported in 3 of the 4 studies. Levodopa dose reduction was allowed in 3 studies and meta-analysis shows a significant difference in favour of pramipexole (weighted mean difference 115 mg; 87, 143 95% CI). Trends toward a higher incidence of dopaminergic adverse events with pramipexole only reached statistical significance regarding hallucinations. There were significantly fewer withdrawals from pramipexole. REVIEWER'S CONCLUSIONS: Pramipexole can be used to reduce off time, improve motor impairments and disability and reduce levodopa dose at the expense of increased dyskinetic adverse events. This conclusion is based on short and medium term trials (up to 24 weeks). Further trials are required to directly compare the newer with the older dopamine agonists.

Bicuculline-induced circling from the rat superior colliculus is blocked by GABA microinjection into the deep cerebellar nuclei.

In a recent electrophysiological experiment, we showed the deep cerebellar nuclei to be a major source of excitatory input to the superior colliculus. Furthermore, target neurons in the colliculus were found, in every case, to receive convergent tonic inhibitory input from the substantia nigra pars reticulata. In the present study, we investigated these effects in the awake rat. We asked whether circling behaviour, induced by unilateral injection of a GABA antagonist into the lateral colliculus, could be suppressed by concurrent cerebellar inactivation. Rats were chronically implanted with bilateral guide cannulae located above the superior colliculus and deep cerebellar nuclei. Bicuculline methiodide (25 pmol) was microinjected unilaterally into intermediate layers of the colliculus at increasing depths until an optimal contralateral circling response was elicited. This behaviour was taken as the "baseline response" and was the first of three treatments. The second was an identical manipulation of the colliculus with a concurrent 200-nl microinjection of 1 M GABA into the contralateral deep cerebellar nuclei. The third was a repeat of BIC alone into the colliculus or, if rotation had been suppressed by more than 50% on test 2, the treatment was collicular BIC plus deep cerebellar saline. This latter treatment was used as a control for possible non-pharmacological injection effects. The effect of cerebellar GABA at 26 sites (17 within cerebellar nuclei and 9 outside) on BIC-induced rotation at 15 collicular sites was studied in ten animals. Only GABA injections at sites that fell within the cerebellar nuclei significantly reduced turning (P < 0.0001). A full behavioural analysis showed that this was a specific suppression of turning, not the result of general motor impairment. These results provide clear behavioral evidence that opposing, convergent influences from the basal ganglia and cerebellum interact in the lateral superior colliculus to control head and body movements. They furthermore suggest that the tonic deep cerebellar excitation of the superior colliculus could be the driving force in the expression of rotation induced by manipulations of the basal ganglia.