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Ninety-three patients with idiopathic Parkinson's disease (PD) entered a 12 week open-label, baseline controlled, multicentre study. The study was designed to determine the levodopa sparing effect of pramipexole as add-on treatment in PD while maintaining an optimal clinical improvement in motor performance. The overall reduction in adjusted levodopa dose was the primary endpoint. Unified Parkinson's Disease Rating Scale (UPDRS) subscores as well as motor fluctuations, frequency and severity of dyskinesia (assessed by patient diaries) were secondary endpoints. Pramipexole permitted a median reduction of adjusted levodopa by 40% while maintaining or improving the UPDRS scores in 61 patients (per protocol [PP] analysis). The intent-to-treat (ITT) analysis (90 patients) similarly revealed a median reduction of 40%. An anticipated short-term levodopa dose reduction as substantiated by 95% confidence interval calculations lies within a range of 35% to 50%. If unadjusted levodopa doses were considered, a median reduction of 42% (PP) or 43% (ITT) was achieved. 47% patients (ITT) had a levodopa dose reduction (adjusted) of more than 40% while maintaining or improving their level of efficacy, and 72.2% had a reduction of at least 20%. Motor fluctuations improved compared to baseline according to patient diaries and UPDRS part IV. These findings suggest that pramipexole can markedly reduce the daily levodopa dosage without deterioration of motor response and support that this new selective D2/D3 receptor agonist also improves later levodopa-associated motor complications.

The effects of voluntary adaptations of the walking pattern were studied in 10 healthy subjects. These subjects had to adapt their walking pattern to external cues that resulted in either temporal or spatial constraints on walking. The results show that whereas the normal walking pattern in each subject was characterized by a stable linear relationship between step frequency and step length, the adaptation of walking to external cues resulted in two different modes of walking: frequency modulation with a constant amplitude of leg movements in rhythmic walking, and amplitude modulation with a constant frequency of leg movements in walking with visually guided step length. The relative timing of support, swing, and double-support phases was remarkably different between the two conditions; only with changes in step length a change in the relative timing of these phases could be observed. The different modes of walking could not be explained by the nature of the constraints imposed by the instruction to adapt the walking pattern to the external cues. It can be concluded that the way step frequency and step length are controlled involuntarily varies with the employed voluntary strategies. The different modes of walking suggest the existence of specific supraspinal influences on lower level pattern generating mechanisms. The involuntary adaptation of the relative timing within the stride cycle may result from the interaction between (low level) central processes and the dynamics of the movement.

Neurological complications after cardiac operations with the aid of cardiopulmonary bypass and hypothermia are well known. A 6 months-old child is described with severe neurological complications after cardiac surgery for Fallot's tetralogy. On the CT scan cortical calcification was seen to vanish. Such calcification has not been reported in similar patients. Possible causes are discussed but the precise pathophysiology of this phenomenon remains unclear.