The PRIPS study: screening battery for subjects at risk for Parkinson's disease.

BACKGROUND AND PURPOSE: Screening batteries to narrow down a target-at-risk population are essential for trials testing neuroprotective compounds aiming to delay or prevent onset of Parkinson's disease (PD). METHODS: The PRIPS study focuses on early detection of incident PD in 1847 at baseline PD-free subjects, and assessed age, male gender, positive family history, hyposmia, subtle motor impairment and enlarged substantia nigra hyperechogenicity (SN+). RESULTS: After 3 years follow-up 11 subjects had developed PD. In this analysis of the secondary outcome parameters, sensitivity and specificity of baseline markers for incident PD were calculated in 1352 subjects with complete datasets (10 PD patients). The best approach for prediction of incident PD comprised three steps: (i) prescreening for age, (ii) primary screening for positive family history and/or hyposmia, and (iii) secondary screening for SN+. CONCLUSION: With this approach, one out of 16 positively screened participants developed PD compared to one out of 135 in the original cohort. This corresponds to a sensitivity of 80.0%, a specificity of 90.6% and a positive predictive value of 6.1%. These values are higher than for any single screening instrument but still too low for a feasible and cost-effective screening strategy which might require longer follow-up intervals and application of additional instruments.

Prevalence of primary headaches and cranial neuralgias in men and women aged 55-94 years (Bruneck Study).

The aim of the current study was to estimate the prevalence of all primary headaches and cranial neuralgias in the general community. As part of the population-based Bruneck Study, 574 men and women aged 55-94 years underwent extensive neurological and laboratory examinations involving a standardized headache interview. In the Bruneck Study population the lifetime prevalence of all primary headaches combined and of cranial neuralgias was 51.7 and 1.6%, respectively. Tension-type headache (40.9%) and migraine (19.3%) emerged as the most common types of headache. In men and women aged 55-94 years the 1-year prevalence of primary headaches was high at 40.5%. In this age range headaches caused significant impairment of health-related quality of life. The Bruneck Study has confirmed the high lifetime prevalence of primary headaches and cranial neuralgias in the general population and provided first valid prevalence data for all primary headaches based on International Classification of Headache Disorders, 2nd edition criteria.

Decision making under risk and under ambiguity in Parkinson's disease.

In the present study we investigate decision making under ambiguity and decision making under risk in Parkinson's disease (PD) patients without cognitive impairment and in patients affected by Parkinson's disease dementia (PDD). In decisions under ambiguity, participants are not aware of the rules for gains and losses and have to learn about the utility of their selections through feedback. The two patient groups showed significant deficits and did not differ in the frequency of advantageous choices, though they had a markedly different cognitive profile. In decisions under risk, explicit information on the options' probabilities as well as on the associated gains and losses is given. PD patients and healthy controls performed at the same level, whereas PDD patients made significantly more risky and disadvantageous decisions. Results of the study suggest that both patient groups are impaired in decision making when learning by feedback and emotional processing is required, while only the PDD group shows difficulties when decision making is based on cognitive reasoning strategies.

Burden of atherosclerosis and risk of venous thromboembolism in patients with migraine.

BACKGROUND: Previous studies have yielded evidence of an enhanced risk of cardiovascular disease, especially stroke, among patients with migraine. Our understanding of the underlying mechanisms is far from complete. The aims of the present study were to investigate the potential association between migraine and atherosclerosis and to assess the risk of venous thromboembolism as a clinical surrogate for a procoagulant state in patients with migraine. METHODS: The examination was part of the population-based Bruneck Study. During the 2005 evaluation, 574 participants aged 55-94 years underwent neurologic and laboratory examinations involving a standardized headache interview and scanning of the carotid and femoral arteries to evaluate presence, severity, and progression (2000-2005) of atherosclerosis. RESULTS: A large number of well-founded and putative cardiovascular risk factors have emerged as being unrelated to migraine status. Prevalence, severity, and 5-year progression of carotid and femoral atherosclerosis did not differ significantly between migraineurs with and without aura and nonmigraineurs. In fact, there was even a tendency for atherosclerosis to be less pronounced among patients with migraine, and for the intima-media thickness to be lower (p = 0.029). As a novel finding migraineurs faced a significantly enhanced risk of venous thromboembolism (18.9% vs 7.6% in nonmigraineurs, age/sex-adjusted p = 0.031). CONCLUSION: This study is the first to compare the burden of atherosclerosis as quantified by high-resolution duplex ultrasound between migraineurs and nonmigraineurs in the general community, and provides solid evidence against the view that migraine predisposes to atherosclerosis. The higher risk for venous thromboembolism among migraineurs (prothrombotic state) awaits confirmation and elaboration in future research.

Tracing surfactant transformation from cellular release to insertion into an air-liquid interface.

Pulmonary surfactant is secreted by alveolar type II cells as lipid-rich, densely packed lamellar body-like particles (LBPs). The particulate nature of released LBPs might be the result of structural and/or thermodynamic forces. Thus mechanisms must exist that promote their transformation into functional units. To further define these mechanisms, we developed methods to follow LBPs from their release by cultured cells to insertion in an air-liquid interface. When released, LBPs underwent structural transformation, but did not disperse, and typically preserved a spherical appearance for days. Nevertheless, they were able to modify surface tension and exhibited high surface activity when measured with a capillary surfactometer. When LBPs inserted in an air-liquid interface were analyzed by fluorescence imaging microscopy, they showed remarkable structural transformations. These events were instantaneous but came to a halt when the interface was already occupied by previously transformed material or when surface tension was already low. These results suggest that the driving force for LBP transformation is determined by cohesive and tensile forces acting on these particles. They further suggest that transformation of LBPs is a self-regulated interfacial process that most likely does not require structural intermediates or enzymatic activation.