Found 16014 matches for
6 April 2018
Continuous high-frequency DBS is an established treatment for essential tremor and Parkinson's disease. Current developments focus on trying to widen the therapeutic window of DBS. Adaptive DBS (aDBS), where stimulation is dynamically controlled by feedback from biomarkers of pathological brain circuit activity, is one such development. Relevant biomarkers may be central, such as local field potential activity, or peripheral, such as inertial tremor data. Moreover, stimulation may be directed by the amplitude or the phase (timing) of the biomarker signal. In this review, we evaluate existing aDBS studies as proof-of-principle, discuss their limitations, most of which stem from their acute nature, and propose what is needed to take aDBS into a chronic setting. © 2017 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.
Subthalamic beta dynamics mirror Parkinsonian bradykinesia months after neurostimulator implantation.
3 April 2018
BACKGROUND: Exaggerated oscillatory activity in the beta frequency band in the subthalamic nucleus has been suggested to be related to bradykinesia in Parkinson's disease (PD). However, studies seeking correlations between such activity in the local field potential and motor performance have been limited to the immediate postoperative period, which may be confounded by a stun effect that leads to the temporary alleviation of PD deficits. METHODS: Local field potentials were recorded simultaneously with motor performance in PD patients several months after neurostimulator implantation. This was enabled by the chronic implantation of a pulse generator with the capacity to record and transmit local field potentials from deep brain stimulation electrodes. Specifically, we investigated oscillatory beta power dynamics and objective measures of bradykinesia during an upper limb alternating pronation and supination task in 9 patients. RESULTS: Although beta power was suppressed during continuously repeated movements, this suppression progressively diminished over time in tandem with a progressive decrement in the frequency and amplitude of movements. The relationship between changes within local field potentials and movement parameters was significant across patients, and not present for theta/alpha frequencies (5-12 Hz). Change in movement frequency furthermore related to beta power dynamics within patients. CONCLUSIONS: Changes in beta power are linked to changes in movement performance and the sequence effect of bradykinesia months after neurostimulator implantation. These findings provide further evidence that beta power may serve as a biomarker for bradykinesia and provide a suitable substrate for feedback control in chronic adaptive deep brain stimulation. © 2017 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.
28 March 2018
PURPOSE OF REVIEW: Over the past decade, digital solutions have been developed to support the dissemination of Cognitive Behavioral Therapy (CBT). In this paper, we review the evidence for and implications of digital CBT (dCBT) for insomnia. RECENT FINDINGS: We propose three categories of dCBT, which differ in the amount of clinician time needed, level of automatization, costs, and scalability: dCBT as support, guided dCBT, and fully automated dCBT. Consistent evidence has been published on the effectiveness of dCBT to address insomnia disorder, in a variety of populations, with effects extending into well-being. Important gaps in the literature are identified around moderators and mediators of dCBT, cost-effectiveness, and the implementation of dCBT. SUMMARY: The evidence base for dCBT is rapidly developing and already suggests that dCBT for insomnia is effective. However, further science and digital innovation is required to realize the full potential of dCBT and address important clinical questions.
Validation of a French version of the Sleep Condition Indicator: a clinical screening tool for insomnia disorder according to DSM-5 criteria.
7 March 2018
Insomnia disorder is frequent in the population, yet there is no French screening instrument available that is based on the updated DSM-5 criteria. We evaluated the validity and reliability of the French version of an insomnia screening instrument based on DSM-5 criteria, the Sleep Condition Indicator, in a population-based sample of adults. A total of 366 community-dwelling participants completed a face-to-face clinical interview to determine insomnia disorder against DSM-5 criteria and several questionnaires including the French Sleep Condition Indicator version. Three-hundred and twenty-nine participants completed the Sleep Condition Indicator again after 1 month. Statistical analyses were performed to determine the reliability, construct validity, divergent validity and temporal stability of the French translation of the Sleep Condition Indicator. In addition, an explanatory factor analysis was performed to assess the underlying structure. The internal consistency (α = 0.87) and temporal stability (r = 0.86, P < 0.001) of the French Sleep Condition Indicator were high. When using the previously defined cut-off value of ≤ 16, the area under the receiver operating characteristic curve was 0.93 with a sensitivity of 95% and a specificity of 75%. Additionally, good construct and divergent validity were demonstrated. The factor analyses showed a two-factor structure with a focus on sleep and daytime effects. The French version of the Sleep Condition Indicator demonstrates satisfactory psychometric properties while being a useful instrument in detecting cases of insomnia disorder, consistent with features of DSM-5, in the general population.
31 January 2018
BACKGROUND: Insomnia symptoms are associated with type 2 diabetes incidence but are also associated with a range of potential time-varying covariates which may confound and/or mediate associations. We aimed to assess whether cumulative exposure to insomnia symptoms has a causal effect on type 2 diabetes incidence. METHODS: A prospective cohort study in the West of Scotland, following respondents for 20 years from age 36. 996 respondents were free of diabetes at baseline and had valid data from up to four follow-up visits. Type 2 diabetes was assessed at the final visit by self-report, taking diabetic medication, or blood-test (HbA1c ≥ 6.5% or 48 mmol/mol). Effects of cumulative insomnia exposure on type 2 diabetes incidence were estimated with traditional regression and marginal structural models, adjusting for time-dependent confounding (smoking, diet, physical inactivity, obesity, heavy drinking, psychiatric distress) as well as for gender and baseline occupational class. RESULTS: Traditional regression yielded an odds ratio (OR) of 1.34 (95% CI: 1.06-1.70) for type 2 diabetes incidence for each additional survey wave in which insomnia was reported. Marginal structural models adjusted for prior covariates (assuming concurrently measured covariates were potential mediators), reduced this OR to 1.20 (95% CI: 0.98-1.46), and when concurrent covariates were also included (viewing them as potential confounders) this dropped further to 1.08 (95% CI: 0.85-1.37). CONCLUSIONS: The association between cumulative experience of insomnia and type 2 diabetes incidence appeared confounded. Evidence for a residual causal effect depended on assumptions as to whether concurrently measured covariates were confounders or mediators.
14 March 2018
BACKGROUND: Impaired sleep quality is common and associated with an increased risk of cardiovascular disease (CVD), thought to be mediated through adverse effects on established vascular risk factors, particularly hypertension. We determined if a web-delivered sleep intervention (sleep-hygiene education, stimulus control, and cognitive behavioral therapy) reduces blood pressure compared to vascular risk factor education (standard care) alone. METHODS: Phase II randomized, blinded, controlled trial of 134 participants without CVD with mild sleep impairment and blood pressure 130-160/<110 mm Hg. The primary outcome was the difference in the mean change in 24-hour ambulatory systolic blood pressure (SBP) over 8 weeks between intervention and control groups. Secondary outcomes included measures of sleep quality and psychosocial health, namely Insomnia Severity Index (ISI), Pittsburgh Sleep Quality Index (PSQI), Beck Depression Inventory (BDI), and Beck Anxiety Inventory (BAI). RESULTS: Participants in the sleep intervention group showed significantly greater improvements in sleep quality, including ISI [difference in mean improvement 2.8; 95% confidence interval (CI), 1.3-4.4], PSQI (1.1; 95% CI, 0.1-2.2), sleep condition indicator (0.8; 95% CI, 0.2-1.4), and psychosocial health, including BDI (2.0; 95% CI, 0.3-3.7) and BAI (1.4; 95% CI, 0.02-2.8). The mean improvement in 24-hour ambulatory SBP did not differ between the sleep intervention (0.9 mm Hg) and control (0.8 mm Hg) arms, (difference in mean improvement 0.1; 95% CI, -3.4 to 3.2). CONCLUSION: A simple, low-cost, web-delivered sleep intervention is feasible and significantly improves sleep quality and measures of psychosocial health in individuals with mild sleep impairment but does not result in short-term improvements in blood pressure.
27 October 2017
Behavioural treatments of sleep patterns and disorders have been widely studied in ‘normal’ populations, with reported benefits to quantitative and qualitative aspects of sleep and to subsequent daytime performance. This study represents the first attempt to apply such procedures to an individual with profound mental handicaps. A case study is presented which demonstrates that the development of an optimal sleep‐schedule led to markedly improved daytime functioning and a reduction in challenging behaviour. It is argued that people with mental handicaps may benefit considerably from optimal scheduling since arbitrary sleep—wake patterns often meet administrative rather than personal needs. 1992 Blackwell Publishing Ltd
20 March 2018
Early detection of the behavioural deficits of neurodegenerative diseases may help to describe the pathogenesis of such diseases and establish important biomarkers of disease progression. The aim of this study was to identify how sensorimotor adaptation of the upper limb, a cerebellar-dependent process restoring movement accuracy after introduction of a perturbation, is affected at the pre-clinical and clinical stages of spinocerebellar ataxia type 6 (SCA6), an inherited neurodegenerative disease. We demonstrate that initial adaptation to the perturbation was significantly impaired in the eighteen individuals with clinical motor symptoms but mostly preserved in the five pre-clinical individuals. Moreover, the amount of error reduction correlated with the clinical symptoms, with the most symptomatic patients adapting the least. Finally both pre-clinical and clinical individuals showed significantly reduced de-adaptation performance after the perturbation was removed in comparison to the control participants. Thus, in this large study of motor features in SCA6, we provide novel evidence for the existence of subclinical motor dysfunction at a pre-clinical stage of SCA6. Our findings show that testing sensorimotor de-adaptation could provide a potential predictor of future motor deficits in SCA6.
20 December 2017
© 2017 by Quintessence Publishing Co Inc. Aims: To prospectively assess the incidence and etiology (ie, primary vs symptomatic) of headache in women during the first month postdelivery, with particular emphasis on the type of presentation as a clue for identifying potentially harmful etiologies. A secondary aim was to evaluate the relative frequency of migraine- vs tension-type headache in cases of primary headache. Methods: A total of 900 consecutive women were enrolled in the study and examined within 3 days of delivery, both clinically and with transcranial color-coded sonography (TCCS). During the course of follow-up, all subjects presenting with headache suspected of being secondary to intracranial pathology underwent a complete clinical and instrumental assessment with TCCS and magnetic resonance imaging (MRI) and angiography. A telephone interview was administered to all subjects 1 month after delivery. Two-tailed t test, Mann-Whitney test, Pearson chi-square test, and multiple logistic regression were used to analyze the data. Results: At the end of the follow-up period, 241 women (26.8% of the sample) reported at least one headache attack. In 88 of these 241 cases (9.8%), the headache attack occurred soon after delivery and was already recorded at the first visit. Thunderclap headache occurred in 34 (3.8%) of the subjects. In all but one of these subjects, the course was spontaneously benign. None of the recorded variables allowed discrimination of the subjects with thunderclap headache from those without headache. Three subjects had thunderclap headache following dural anesthesia, and one subject was found to have reversible cerebral vasoconstriction syndrome. Headache with gradual onset was recorded in 207 subjects (23%). Three of these subjects fulfilled the criteria for pre-eclampsia, and 13 had postural headache after dural anesthesia. Migraine history and urinary protein were independent predictors of gradual onset headache, and migraine history and parity were significant independent predictors of pulsating pain with gradual onset headache. Conclusion: Headache appeared early in the first days postdelivery, and its incidence increased in the first month thereafter. Predictors were different according to whether the headache had a gradual onset or a thunderclap presentation. Primary headache accounted for the overwhelming majority of the recorded cases.