Citations

Large sample sizes are required in randomized clinical trials designed to meet typical one‐sided 2.5% α‐level and 80% power. This may not be achievable when the disease is rare. We simulated a series of two‐arm superiority trials over a 15‐year period. The design parameters examined were the α‐level and the number of trials conducted over the 15‐year period (thus, trial sample size). Different disease severities and accrual rates were considered. The future treatment effect was characterized by its associated hazard rate; different hypotheses of how treatments improve over time were considered. We defined the total survival benefit as the relative difference of the hazard rates at year 15 versus year 0. The optimal design was defined by maximizing the expected total survival benefit, provided that the risk of selecting at year 15 a treatment inferior to the initial control treatment remains below 1%. Compared with two larger trials with typical one‐sided 2.5% α‐level, performing a series of small trials with relaxed α‐levels leads on average to larger survival benefits over a 15‐year research horizon, but also to higher risk of selecting a worse treatment at the end of the research period. Under reasonably optimistic assumptions regarding the future treatment effects, optimal designs outperform traditional ones when the disease is severe (baseline median survival ≤ 1 year) and the accrual is ≥100 patients per year, whereas no major improvement is observed in diseases with better prognosis. Trial designs aiming to maximize survival gain over a long research horizon across a series of trials are worth discussing in the context of rare diseases. Copyright © 2016 John Wiley & Sons, Ltd.

ObjectivesTo describe medium‐ to long‐term follow‐up of patients undergoing device closure of patent foramen ovale (PFO) for stroke or transient ischemic attack (TIA).BackgroundTranscatheter device closure of PFO continues to be used for secondary prevention of cryptogenic stroke or TIA, but data are lacking regarding long‐term outcomes.MethodsWe reviewed the Mayo Clinic Rochester PFO database for patients who underwent device closure of PFO for secondary prevention of stroke/TIA from December 2001 to June 2012. Demographic, clinical, procedural, and follow‐up data were reviewed. Recurrence rate of stroke/TIA were calculated. Data were analyzed to identify risk factors of recurrent neurologic events.ResultsSeven hundred and thirty patients (mean age 53 years; 40% female) were included in our study. Most patients (72%) had cryptogenic stroke as their qualifying event for PFO closure. There were no procedure‐related deaths or strokes. The most commonly used device was the Amplatzer Septal Occluder (82%). Median follow‐up was 6 years. A 3.9% of patients had documented residual right‐to‐left shunting at last echocardiogram. Recurrent stroke and/or TIA were reported in 45 patients, (6.3% of patients with follow‐up data). Patients who experienced recurrent stroke/TIA were older and had a higher rate of diabetes and hypertension than those who did not. The presence of residual shunt did not correlate with risk of recurrent events.ConclusionsDevice closure of PFO can be performed safely with very good long‐term resolution of atrial shunting. Recurrent neurologic events after PFO closure may reflect additional comorbid risk factors unrelated to the potential for paradoxical embolism. © 2016 Wiley Periodicals, Inc.

ABSTRACTNonmotor manifestations of Parkinson's disease (PD) can begin well before motor PD begins. It is now clear, from clinical and autopsy studies, that there is significant Lewy‐type α‐synucleinopathy present outside the nigro‐striatal pathway and that this may underlie these nonmotor manifestations. This review discusses neuropathological findings that may underlie nonmotor symptoms that either predate motor findings or occur as the disease progresses. © 2016 International Parkinson and Movement Disorder Society

AbstractBackground and AimNonalcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease worldwide. Several studies have suggested that short sleep duration could be a risk factor for NAFLD. However, results of those reports are inconsistent. This meta‐analysis was conducted with an attempt to summarize all available data.MethodsA comprehensive literature review was performed using MEDLINE and EMBASE database. Studies that reported relative risks, odd ratios or hazard ratios comparing the risk of NAFLD among participants who had short sleep duration versus those with longer sleep duration were included. Pooled risk ratios and 95% confidence interval were calculated using a random‐effect, generic inverse variance method.ResultsSix studies met the eligibility criteria and were included in the meta‐analysis. The risk of NAFLD in participants who had short sleep duration was significantly higher than participants with longer sleep duration with pooled risk ratios of 1.19 (95% confidence interval, 1.04–1.36, I2 = 0%).ConclusionsOur study demonstrated a small but significantly increased risk of NAFLD among participants who had short sleep duration.

The function and connectivity of human brain is disrupted in epilepsy. We previously reported that the region of epileptic brain generating focal seizures, i.e., the seizure onset zone (SOZ), is functionally isolated from surrounding brain regions in focal neocortical epilepsy. The modulatory effect of behavioral state on the spatial and spectral scales over which the reduced functional connectivity occurs, however, is unclear. Here we use simultaneous sleep staging from scalp EEG with intracranial EEG recordings from medial temporal lobe to investigate how behavioral state modulates the spatial and spectral scales of local field potential synchrony in focal epileptic hippocampus. The local field spectral power and linear correlation between adjacent electrodes provide measures of neuronal population synchrony at different spatial scales, ∼1 and 10 mm, respectively. Our results show increased connectivity inside the SOZ and low connectivity between electrodes in SOZ and outside the SOZ. During slow-wave sleep, we observed decreased connectivity for ripple and fast ripple frequency bands within the SOZ at the 10 mm spatial scale, while the local synchrony remained high at the 1 mm spatial scale. Further study of these phenomena may prove useful for SOZ localization and help understand seizure generation, and the functional deficits seen in epileptic eloquent cortex.