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Professor MacLaren awarded 2013 ARVO Vision Foundation Pfizer Ophthalmics Carl Camras Translational Research Award
Sleep regularity index as a novel indicator of sleep disturbance in stroke survivors: a secondary data analysis
Abstract Sleep disturbance is common but often overlooked after stroke. Regular sleep is increasingly recognised as important for overall health, yet little is known about how sleep regularity changes after stroke. This study examined differences in the Sleep Regularity Index (SRI) between stroke survivors and healthy controls using actigraphy data from an existing dataset (~ 1 week per participant). Data were analysed for 162 stroke survivors (mean age 61 ± 14 years, 5 ± 5 years post-stroke, 89 males) and 60 controls (mean age 57 ± 17 years, 32 males). Stroke survivors had significantly lower SRI scores than controls (p = 0.001), indicating less regular sleep. In the stroke group, higher SRI correlated with longer total sleep time (p = 0.003) and better self-reported sleep quality (p = 0.001) but not with other sleep metrics. Lower SRI was associated with worse depressive symptoms (p = 0.006) and lower quality of life (p = 0.001) but not with disability (p = 0.886) or time since stroke (p = 0.646). These findings suggest that sleep regularity is disrupted post-stroke and may influence well-being. Future research should explore interventions to improve sleep regularity and related health outcomes in stroke survivors.
Nurse-delivered sleep restriction therapy in primary care for adults with insomnia disorder: a mixed-methods process evaluation
BackgroundSleep restriction therapy (SRT) is a behavioural therapy for insomnia.AimTo conduct a process evaluation of a randomised controlled trial comparing SRT delivered by primary care nurses plus a sleep hygiene booklet with the sleep hygiene booklet only for adults with insomnia disorder.Design and settingA mixed-methods process evaluation in a general practice setting.MethodSemi-structured interviews were conducted in a purposive sample of patients receiving SRT, the practice nurses who delivered the therapy, and also GPs or practice managers at the participating practices. Qualitative data were explored using framework analysis, and integrated with nurse comments and quantitative data, including baseline Insomnia Severity Index score and serial sleep efficiency outcomes to investigate the relationships between these.ResultsIn total, 16 patients, 13 nurses, six practice managers, and one GP were interviewed. Patients had no previous experience of behavioural therapy, needed flexible appointment times, and preferred face-to-face consultations; nurses felt prepared to deliver SRT, accommodating patient concerns, tailoring therapy, and negotiating sleep timings despite treatment complexity and delays between training and intervention delivery. How the intervention produced change was explored, including patient and nurse interactions and patient responses to SRT. Difficulties maintaining SRT, negative attitudes towards treatment, and low self-efficacy were highlighted. Contextual factors, including freeing GP time, time constraints, and conflicting priorities for nurses, with suggestions for alternative delivery options, were raised. Participants who found SRT a positive process showed improvements in sleep efficiency, whereas those who struggled did not.ConclusionSRT was successfully delivered by practice nurses and was generally well received by patients, despite some difficulties delivering and applying the intervention in practice.
Sleep and motor learning in stroke (SMiLES): a longitudinal study investigating sleep-dependent consolidation of motor sequence learning in the context of recovery after stroke
IntroductionThere is growing evidence that sleep is disrupted after stroke, with worse sleep relating to poorer motor outcomes. It is also widely acknowledged that consolidation of motor learning, a critical component of poststroke recovery, is sleep-dependent. However, whether the relationship between disrupted sleep and poor outcomes after stroke is related to direct interference of sleep-dependent motor consolidation processes, is currently unknown. Therefore, the aim of the present study is to understand whether measures of motor consolidation mediate the relationship between sleep and clinical motor outcomes post stroke.Methods and analysisWe will conduct a longitudinal observational study of up to 150 participants diagnosed with stroke affecting the upper limb. Participants will be recruited and assessed within 7 days of their stroke and followed up at approximately 1 and 6 months. The primary objective of the study is to determine whether sleep in the subacute phase of recovery explains the variability in upper limb motor outcomes after stroke (over and above predicted recovery potential from the Predict Recovery Potential algorithm) and whether this relationship is dependent on consolidation of motor learning. We will also test whether motor consolidation mediates the relationship between sleep and whole-body clinical motor outcomes, whether motor consolidation is associated with specific electrophysiological sleep signals and sleep alterations during subacute recovery.Ethics and disseminationThis trial has received both Health Research Authority, Health and Care Research Wales and National Research Ethics Service approval (IRAS: 304135; REC: 22/LO/0353). The results of this trial will help to enhance our understanding of the role of sleep in recovery of motor function after stroke and will be disseminated via presentations at scientific conferences, peer-reviewed publication, public engagement events, stakeholder organisations and other forms of media where appropriate.Trial registration numberClinicalTrials.gov:NCT05746260, registered on 27 February 2023.
Nurse-delivered sleep restriction therapy to improve insomnia disorder in primary care: the HABIT RCT
Background Insomnia is a prevalent and distressing sleep disorder. Multicomponent cognitive–behavioural therapy is the recommended first-line treatment, but access remains extremely limited, particularly in primary care where insomnia is managed. One principal component of cognitive–behavioural therapy is a behavioural treatment called sleep restriction therapy, which could potentially be delivered as a brief single-component intervention by generalists in primary care. Objectives The primary objective of the Health-professional Administered Brief Insomnia Therapy trial was to establish whether nurse-delivered sleep restriction therapy in primary care improves insomnia relative to sleep hygiene. Secondary objectives were to establish whether nurse-delivered sleep restriction therapy was cost-effective, and to undertake a process evaluation to understand intervention delivery, fidelity and acceptability. Design Pragmatic, multicentre, individually randomised, parallel-group, superiority trial with embedded process evaluation. Setting National Health Service general practice in three regions of England. Participants Adults aged ≥ 18 years with insomnia disorder were randomised using a validated web-based randomisation programme. Interventions Participants in the intervention group were offered a brief four-session nurse-delivered behavioural treatment involving two in-person sessions and two by phone. Participants were supported to follow a prescribed sleep schedule with the aim of restricting and standardising time in bed. Participants were also provided with a sleep hygiene leaflet. The control group received the same sleep hygiene leaflet by e-mail or post. There was no restriction on usual care. Main outcome measures Outcomes were assessed at 3, 6 and 12 months. Participants were included in the primary analysis if they contributed at least one post-randomisation outcome. The primary end point was self-reported insomnia severity with the Insomnia Severity Index at 6 months. Secondary outcomes were health-related and sleep-related quality of life, depressive symptoms, work productivity and activity impairment, self-reported and actigraphy-defined sleep, and hypnotic medication use. Cost-effectiveness was evaluated using the incremental cost per quality-adjusted life-year. For the process evaluation, semistructured interviews were carried out with participants, nurses and practice managers or general practitioners. Due to the nature of the intervention, both participants and nurses were aware of group allocation. Results We recruited 642 participants (n = 321 for sleep restriction therapy; n = 321 for sleep hygiene) between 29 August 2018 and 23 March 2020. Five hundred and eighty participants (90.3%) provided data at a minimum of one follow-up time point; 257 (80.1%) participants in the sleep restriction therapy arm and 291 (90.7%) participants in the sleep hygiene arm provided primary outcome data at 6 months. The estimated adjusted mean difference on the Insomnia Severity Index was −3.05 (95% confidence interval −3.83 to −2.28; p < 0.001, Cohen’s d = −0.74), indicating that participants in the sleep restriction therapy arm [mean (standard deviation) Insomnia Severity Index = 10.9 (5.5)] reported lower insomnia severity compared to sleep hygiene [mean (standard deviation) Insomnia Severity Index = 13.9 (5.2)]. Large treatment effects were also found at 3 (d = –0.95) and 12 months (d = −0.72). Superiority of sleep restriction therapy over sleep hygiene was evident at 3, 6 and 12 months for self-reported sleep, mental health-related quality of life, depressive symptoms, work productivity impairment and sleep-related quality of life. Eight participants in each group experienced serious adverse events but none were judged to be related to the intervention. The incremental cost per quality-adjusted life-year gained was £2075.71, giving a 95.3% probability that the intervention is cost-effective at a cost-effectiveness threshold of £20,000. The process evaluation found that sleep restriction therapy was acceptable to both nurses and patients, and delivered with high fidelity. Limitations While we recruited a clinical sample, 97% were of white ethnic background and 50% had a university degree, which may limit generalisability to the insomnia population in England. Conclusions Brief nurse-delivered sleep restriction therapy in primary care is clinically effective for insomnia disorder, safe, and likely to be cost-effective. Future work Future work should examine the place of sleep restriction therapy in the insomnia treatment pathway, assess generalisability across diverse primary care patients with insomnia, and consider additional methods to enhance patient engagement with treatment. Trial registration This trial is registered as ISRCTN42499563. Funding The award was funded by the National Institute of Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 16/84/01) and is published in full in Health Technology Assessment; Vol. 28, No. 36. See the NIHR Funding and Awards website for further award information.
Neurofeedback modulation of insula activity via MEG-based brain-machine interface: a double-blind randomized controlled crossover trial.
Insula activity has often been linked to pain perception, making it a potential target for therapeutic neuromodulation strategies such as neurofeedback. However, it is not known whether insula activity is under cognitive control and, if so, whether this activity is consequently causally related to pain. Here, we conducted a double-blind randomized controlled crossover trial to test the modulation of insula activity and pain thresholds using neurofeedback training. Nineteen healthy subjects underwent neurofeedback training for upmodulation and downmodulation of right insula activity using our magnetoencephalography (MEG)-based brain-machine interface. We observed significant differences in insula activity between the upmodulation and downmodulation training sessions. Furthermore, resting-state insula activity significantly decreased following downmodulation training compared to following upmodulation training. Compared with upmodulation training, downmodulation training was also associated with increased pain thresholds, albeit with no significant interaction effect. These findings show that humans can cognitively modulate insula activity as a potential route to develop therapeutic MEG neurofeedback systems for clinical testing. However, the present findings do not provide direct evidence of a causal link between modulation of insula activity and changes in pain thresholds.
Alzheimer's disease patient-derived high-molecular-weight tau impairs bursting in hippocampal neurons.
Tau accumulation is closely related to cognitive symptoms in Alzheimer's disease (AD). However, the cellular drivers of tau-dependent decline of memory-based cognition remain elusive. Here, we employed in vivo Neuropixels and patch-clamp recordings in mouse models and demonstrate that tau, independent of β-amyloid, selectively debilitates complex-spike burst firing of CA1 hippocampal neurons, a fundamental cellular mechanism underpinning learning and memory. Impaired bursting was associated with altered hippocampal network activities that are coupled to burst firing patterns (i.e., theta rhythms and high-frequency ripples) and was concurrent with reduced neuronal expression of CaV2.3 calcium channels, which are essential for burst firing in vivo. We subsequently identify soluble high molecular weight (HMW) tau, isolated from human AD brain, as the tau species responsible for suppression of burst firing. These data provide a cellular mechanism for tau-dependent cognitive decline in AD and implicate a rare species of intracellular HMW tau as a therapeutic target.
Progression and life expectancy in primary lateral sclerosis
Objectives To characterise the clinical characteristics and longitudinal outcomes in primary lateral sclerosis (PLS), including median survival from symptom onset and age at death. Methods The authors retrospectively reviewed electronic health records of patients diagnosed with PLS referred to a specialised motor neuron disorders clinic from 2002 to 2024, analysed longitudinal Revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R) assessments using joint models and used Kaplan-Meier methods and life tables to calculate median survival and age at death compared with population-based values. Results Of 52 patients, 34 (65%) were male, 41 (79%) first noted symptoms in the lower limbs and 10 (19%) in corticobulbar function. Median age of symptom onset was 53 years. The mean annual rate of functional decline was -1.92 ALSFRS-R points (95% CI -3.03 to -0.78), with equal highest rates of decline in fine and gross motor subscores. Five patients (10%) received gastrostomy and three (6%) non-invasive ventilation. Median survival from symptom onset was 23.1 years (22.7 to not reached), and median age at death was 79.5 years (77.8 to not reached) compared with a population-based reference mean of 81.9 years (81.1 to 82.8). Discussion PLS may be commensurate with near-normal life expectancy. Significant disability arises from limb motor dysfunction, with a minority of patients requiring nutritional or respiratory support. This has important implications for counselling and trial design.
Ultra‐high temporal resolution 4D angiography using arterial spin labeling with subspace reconstruction
AbstractPurposeTo achieve ultra‐high temporal resolution non‐contrast 4D angiography with improved spatiotemporal fidelity.MethodsContinuous data acquisition using 3D golden‐angle sampling following an arterial spin labeling preparation allows for flexibly reconstructing 4D dynamic angiograms at arbitrary temporal resolutions. However, k‐space data is often temporally “binned” before image reconstruction, negatively affecting spatiotemporal fidelity and limiting temporal resolution. In this work, a subspace was extracted by linearly compressing a dictionary constructed from simulated curves of an angiographic kinetic model. The subspace was used to represent and reconstruct the voxelwise signal timecourse at the same temporal resolution as the data acquisition without temporal binning. Physiological parameters were estimated from the resulting images using a Bayesian fitting approach. A group of eight healthy subjects were scanned and the in vivo results reconstructed by different methods were compared. Because of the difficulty of obtaining ground truth 4D angiograms with ultra‐high temporal resolution, the in vivo results were cross‐validated with numerical simulations.ResultsThe proposed method enables 4D time‐resolved angiography with much higher temporal resolution (14.7 ms) than previously reported (˜50 ms) while maintaining high spatial resolution (1.1 mm isotropic). Blood flow dynamics were depicted in greater detail, thin vessel visibility was improved, and the estimated physiological parameters also exhibited more realistic spatial patterns with the proposed method.ConclusionIncorporating a subspace compressed kinetic model into the reconstruction of 4D ASL angiograms notably improved the temporal resolution and spatiotemporal fidelity, which was subsequently beneficial for accurate physiological modeling.
Early neurological deterioration in patients with minor stroke: A single-center study conducted in Vietnam
A minor ischemic stroke is associated with a higher likelihood of poor clinical outcomes at 90 days when there is early neurological deterioration (END). The objective of this case-control study conducted in a comprehensive stroke facility in Vietnam is to examine the frequency, forecast, and outcomes of patients with END in minor strokes. The study employs a descriptive observational design, longitudinally tracking patients with minor strokes admitted to Bach Mai Hospital’s Stroke Center between December 1, 2023, and August 31, 2024. Hospitalized within 24 hours of symptom onset, minor stroke patients with National Institutes of Health Stroke Scale (NIHSS) scores ≤ 5 and items 1a, 1b, and 1c on the NIHSS scale, each equal to 0, were included in the study. The primary measure of interest is the END rate, defined as a rise of 2 or more points in the NIHSS score during the first 72 hours after admission. We conduct a logistic regression analysis to identify forecasting factors for END. Out of 839 patients, 88 (10.5%) had END. In the END group, we found that most patients had complications within the first 24 hours of stroke, accounting for 43.2%; the 24 – 48-hour window accounted for 35.2%, and the 48 – 72-hour window accounted for 21.6%. END was associated with a higher likelihood of poor outcomes (mRS 2 – 6) at discharge (OR = 22.76; 95% CI 11.22 – 46.20; p < 0.01), 30 days post-stroke(OR = 24.38; 95% CI 14.40 – 41.29; p < 0.01), and 90 days post-stroke (OR = 21.74; 95% CI 12.63 – 37.43; p < 0.01). Some of the prognostic factors for END were admission NIHSS score (OR = 1.24; 95% CI 1.03 – 1.49; p = 0.02), admission systolic blood pressure greater than 150mmHg (OR = 1.70; 95% CI 1.03 – 2.81; p = 0.04), admission blood glucose (OR = 1.07; 95% CI 1.01 – 1.14; p = 0.02), reperfusion therapy (OR = 3.35; 95% CI 1.50 – 7.49; p < 0.01), use of antiplatelet monotherapy (OR = 3.69; 95% CI 2.24 – 6.08; p < 0.01), internal capsule infarction (OR = 2.54; 95% CI 1.37 – 4.71; p < 0.01), hemorrhagic transformation (OR = 5.72; 95% CI 1.07 – 30.45; p = 0.04), corresponding extracranial carotid artery occlusion (OR = 4.84; 95% CI 1.26 – 18.65; p = 0.02), and middle cerebral artery occlusion OR = 3.06; 95% CI 1.29 – 7.30; p = 0.01). END in minor stroke patients accounts for 10.5% and is a risk factor for poor neurological outcomes. Admission NIHSS score, higher systolic blood pressure, admission blood glucose, reperfusion therapy, use of antiplatelet monotherapy, internal capsule infarction, hemorrhagic transformation, corresponding extracranial carotid artery occlusion, and middle cerebral artery occlusion were some of the prognostic factors for END in our observational study.
Mapping of validated apathy scales onto the apathy diagnostic criteria for neurocognitive disorders.
BACKGROUND: Diagnostic criteria for apathy in neurocognitive disorders (DCA-NCD) have recently been updated. OBJECTIVES: We investigated whether validated scales measuring apathy severity capture the three dimensions of the DCA-NCD (diminished initiative, diminished interest, diminished emotional expression). MEASUREMENTS: Degree of mapping ("not at all", "weakly", or "strongly") between items on two commonly used apathy scales, the Neuropsychiatric Inventory-Clinician (NPI-C) apathy and Apathy Evaluation Scale (AES), with the DCA-NCD overall and its 3 dimensions was evaluated by survey. DESIGN: Survey participants, either experts (n = 12, DCA-NCD authors) or scientific community members (n = 19), rated mapping for each item and mean scores were calculated. Interrater reliability between expert and scientific community members was assessed using Cohen's kappa. RESULTS: According to experts, 9 of 11 (81.8%) NPI-C apathy items and 6 of 18 (33.3%) AES items mapped strongly onto the DCA-NCD overall. For the scientific community group, 10 of 11 (90.9%) NPI-C apathy items and 7 of 18 (38.8%) AES items mapped strongly onto the DCA-NCD overall. The overall mean mapping scores were higher for the NPI-C apathy compared to the AES for both expert (t (11) = 3.13, p = .01) and scientific community (t (17) = 3.77, p = .002) groups. There was moderate agreement between the two groups on overall mapping for the NPI-C apathy (kappa= 0.74 (0.57, 1.00)) and AES (kappa= 0.63 (0.35, 1.00)). CONCLUSIONS: More NPI-C apathy than AES items mapped strongly and uniquely onto the DCA-NCD and its dimensions. The NPI-C apathy may better capture the DCA-NCD and its dimensions compared with the AES.