Dopamine D4 receptor polymorphism and idiopathic Parkinson's disease

Patients with idiopathic Parkinson's disease (IPD) are described as having markedly decreased novelty seeking characteristics. Since recent publications suggest an association between the dopamine D4 receptor polymorphism and novelty seeking, we investigated this polymorphism in a group of 122 patients with IPD and 127 healthy control subjects. We found similar allele and genotype frequencies in both groups and no association with the age of onset of symptoms. Therefore, the dopamine D4 receptor polymorphism does not confer genetic susceptibility to IPD and cannot explain the decreased novelty seeking in IPD patients.     

Utility of the WHO‐five well‐being index as a screening tool for depression in Parkinson's disease

Beck depression inventory (BDI‐1A) is the gold standard screening tool for Parkinson's disease (PD) depression, but as a result of its complexity, it is of limited suitability as a quick and easy screening device. We, therefore, validate the 5‐item WHO‐Five Well‐being Index (WHO‐5) as a screening tool for PD depression. Two hundred thirteen of 215 recruited PD patients (99.1%) completed the WHO‐5. Receiver operating characteristic plots were used to calculate sensitivity/specificity for all cut‐off scores for the detection of depression and combined depression/dysthymia as assessed by an independent investigator using the Mini International Neuropsychiatric Interview (MINI). Internal consistency of the WHO‐5 was good (Cronbach's α = 0.83). WHO‐5 showed high validity with adequate detection of depression without differences in the validity indices compared to BDI‐1A (P = 0.234). The optimal cut‐off value for detection of depression was 12 of 13 points. WHO‐5 is a useful, brief, and easy instrument for identifying PD subjects with depression in daily practice. © 2010 Movement Disorder Society     

Tolcapone improves sleep in patients with advanced Parkinson's disease (PD)

Efficacy of the long-acting catechol-O-methyltransferase (COMT)-inhibitor, tolcapone on sleep quality was studied in 61 patients with advanced PD in a prospective open-label multicenter non-interventional trial. Main outcome measures were the PD sleep scale (PDSS). Further outcome measures were global clinical impression of change (GCI-C), daily off-time, activities of daily living (UPDRS part II), quality of life (EuroQoL-5D), Epworth sleepiness scale (ESS) and adverse events reports. All efficiency and safety parameters were assessed 4 weeks after the switch to tolcapone and compared to baseline. The mean ± S.D. daily dose of tolcapone was 294.2 ± 36.9 mg/day at the final assessment. The mean PDSS scores significantly improved from 21.6 ± 8.1 at baseline to 16.3 ± 7.7 at final assessment (p < 0.0001). Consistently, daytime sleepiness was significantly reduced as reflected by lower scores on the ESS (p = 0.0057). Further efficacy parameters including GCI-C, daily off-time, activities of daily living, and quality of life were also significantly improved. Tolcapone was in general well tolerated and safe. This observational study provides first evidence that tolcapone improves sleep quality and reduces daytime sleepiness in patients suffering from advanced PD.     

Gleichgewichtsstörungen bei idiopathischer Parkinson-Erkrankung Der Einfluss zerebrovaskulärer Komorbidität

Disturbance of balance in idiopathic Parkinson's disease (IPD) has a significant effect on disability. Yet the underlying mechanisms and the contribution of age-associated comorbidity to dysequilibrium are unclear. In this study, static posturography was performed in 30 healthy controls and 40 patients with IPD. Comparison of sway during quiet stance did not show significant differences between patients and controls. Multiple linear regression analysis was used to identify factors responsible for the considerable interindividual variance in patients. Results of the pull test, CT-verified cerebral microangiopathy, dementia, and age were assessed, but only cerebrovascular comorbidity contributed significantly to variance. Apart from increased sway, patients with coinciding cerebral microangiopathy (n = 20) more frequently had a history of falls or pathological responses in the pull test. The present results suggest that cerebrovascular comorbidity enhances dysequilibrium in IPD. Pathological sway in IPD can indicate comorbidity and may have implications for further diagnostics.     

Fully enzymic method of plasma triglyceride determination using an immobilized glycerol dehydrogenase nylon-tube reactor

A new, enzymic method of triglyceride determination in serum and plasma by use of an immobilized glycerol dehydrogenase nylon-tube reactor, integrated into the flow system of an AutoAnalyzer II (Technicon) is described. The combination of this reactor, stable for 1500–2000 tests, with the lipolytic enzymes which are added in solution yields a reliable and reproducible assay, which correlates well with the commonly used fully enzymic triglyceride determination. Using this new method, the cost can be reduced to about one-third of that of the other method.     

Involvement of motor pathways in corticobasal syndrome detected by diffusion tensor tractography

Corticobasal syndrome (CBS) is a progressive parkinsonian disease characterized by cortical and subcortical neuronal loss. Although motor disabilities are a core feature of CBS, the involvement of motor pathways in this condition has not been completely clarified. We used magnetic resonance diffusion tensor imaging (DTI) to study corticospinal and transcallosal motor projections in CBS, and applied fiber tractography to analyze the axonal integrity of white matter projections. Ten patients with CBS were compared with 10 age‐matched healthy controls. Fiber tracts were computed using a Monte‐Carlo simulation approach. Tract‐specific mean values of the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were determined. CBS patients showed a reduction of corticospinal tract (CST) fibers on the first affected side with significantly increased ADC and reduced FA values. In the corpus callosum (CC), particularly in the posterior trunk, patients also had significantly reduced fiber projections, with a higher ADC and lower FA than controls. This pattern indicates changes of the white matter integrity in both CST and CC. Thus, magnetic resonance DTI can be used to assess motor pathway involvement in CBS patients. © 2008 Movement Disorder Society