Damage to fronto-parietal networks impairs motor imagery ability after stroke : a voxel-based lesion symptom mapping study

Background: mental practice with motor imagery has been shown to promote motor skill acquisition in healthy subjects and patients. Although lesions of the common motor imagery and motor execution neural network are expected to impair motor imagery ability, functional equivalence appears to be at least partially preserved in stroke patients.Aim: to identify brain regions that are mandatory for preserved motor imagery ability after stroke.Method: thirty-seven patients with hemiplegia after a first time stroke participated. Motor imagery ability was measured using a Motor Imagery questionnaire and temporal congruence test. A voxelwise lesion symptom mapping approach was used to identify neural correlates of motor imagery in this cohort within the first year post-stroke.Results: poor motor imagery vividness was associated with lesions in the left putamen, left ventral premotor cortex and long association fibres linking parieto-occipital regions with the dorsolateral premotor and prefrontal areas. Poor temporal congruence was otherwise linked to lesions in the more rostrally located white matter of the superior corona radiata. Conclusion: This voxel-based lesion symptom mapping study confirms the association between white matter tract lesions and impaired motor imagery ability, thus emphasizing the importance of an intact fronto-parietal network for motor imagery. Our results further highlight the crucial role of the basal ganglia and premotor cortex when performing motor imagery tasks

New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

Somatosensory Impairments in the Upper Limb Poststroke: Distribution and Association With Motor Function and Visuospatial Neglect.

Background. A thorough understanding of the presence of different upper-limb somatosensory deficits poststroke and the relation with motor performance remains unclear. Additionally, knowledge about the relation between somatosensory deficits and visuospatial neglect is limited. Objective. To investigate the distribution of upper-limb somatosensory impairments and the association with unimanual and bimanual motor outcomes and visuospatial neglect. Methods. A cross-sectional observational study was conducted, including 122 patients within 6 months after stroke (median = 82 days; interquartile range = 57-133 days). Somatosensory measurement included the Erasmus MC modification of the (revised) Nottingham Sensory Assessment (Em-NSA), Perceptual Threshold of Touch (PTT), thumb finding test, 2-point discrimination, and stereognosis subscale of the NSA. Upper-limb motor assessment comprised the Fugl-Meyer assessment, motricity index, Action Research Arm Test, and Adult-Assisting Hand Assessment Stroke. Screening for visuospatial neglect was performed using the Star Cancellation Test. Results. Upper-limb somatosensory impairments were common, with prevalence rates ranging from 21% to 54%. Low to moderate Spearman ρ correlations were found between somatosensory and motor deficits (r = 0.22-0.61), with the strongest associations for PTT (r = 0.56-0.61) and stereognosis (r = 0.51-0.60). Visuospatial neglect was present in 27 patients (22%). Between-group analysis revealed somatosensory deficits that occurred significantly more often and more severely in patients with visuospatial neglect (P <.05). Results showed consistently stronger correlations between motor and somatosensory deficits in patients with visuospatial neglect (r = 0.44-0.78) compared with patients without neglect (r = 0.08-0.59). Conclusions. Somatosensory impairments are common in subacute patients poststroke and are related to motor outcome. Visuospatial neglect was associated with more severe upper-limb somatosensory impairment

Early and Intensive Motor Training for people with spinal cord injuries (the SCI-MT Trial):protocol of the process evaluation

INTRODUCTION: People with spinal cord injury receive physical rehabilitation to promote neurological recovery. Physical rehabilitation commences as soon as possible when a person is medically stable. One key component of physical rehabilitation is motor training. There is initial evidence to suggest that motor training can enhance neurological recovery if it is provided soon after injury and in a high dosage. The Early and Intensive Motor Training Trial is a pragmatic randomised controlled trial to determine whether 10 weeks of intensive motor training enhances neurological recovery for people with spinal cord injury. This pragmatic randomised controlled trial will recruit 220 participants from 15 spinal injury units in Australia, Scotland, Italy, Norway, England, Belgium and the Netherlands. This protocol paper describes the process evaluation that will run alongside the Early and Intensive Motor Training Trial. This process evaluation will help to explain the trial results and explore the potential facilitators and barriers to the possible future rollout of the trial intervention. METHODS AND ANALYSIS: The UK Medical Research Council process evaluation framework and the Implementation Research Logic Model will be used to explain the trial outcomes and inform future implementation. Key components of the context, implementation and mechanism of impact, as well as the essential elements of the intervention and outcomes, will be identified and analysed. Qualitative and quantitative data will be collected and triangulated with the results of the Early and Intensive Motor Training Trial to strengthen the findings of this process evaluation. ETHICS AND DISSEMINATION: Ethical approval for the Early and Intensive Motor Training Trial and process evaluation has been obtained from the Human Research Ethics Committee at the Northern Sydney Local Health District (New South Wales) in Australia (project identifier: 2020/ETH02540). All participants are required to provide written consent after being informed about the trial and the process evaluation. The results of this process evaluation will be published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: Australian New Zealand Clinical Trial Registry (ACTRN12621000091808); Universal Trial Number (U1111-1264-1689)

Early and intensive motor training to enhance neurological recovery in people with spinal cord injury:trial protocol

Study designProtocol for a multi-centre randomised controlled trial (the SCI-MT trial).ObjectivesTo determine whether 10 weeks of intensive motor training enhances neurological recovery in people with recent spinal cord injury (SCI).SettingFifteen spinal injury units in Australia, Scotland, England, Italy, Netherlands, Norway, and Belgium.MethodsA pragmatic randomised controlled trial will be undertaken. Two hundred and twenty people with recent SCI (onset in the preceding 10 weeks, American Spinal Injuries Association Impairment Scale (AIS) A lesion with motor function more than three levels below the motor level on one or both sides, or an AIS C or D lesion) will be randomised to receive either usual care plus intensive motor training (12 h of motor training per week for 10 weeks) or usual care alone. The primary outcome is neurological recovery at 10 weeks, measured with the Total Motor Score from the International Standards for Neurological Classification of SCI. Secondary outcomes include global measures of motor function, ability to walk, quality of life, participants' perceptions about ability to perform self-selected goals, length of hospital stay and participants' impressions of therapeutic benefit at 10 weeks and 6 months. A cost-effectiveness study and process evaluation will be run alongside the trial. The first participant was randomised in June 2021 and the trial is due for completion in 2025.ConclusionsThe findings of the SCI-MT Trial will guide recommendations about the type and dose of inpatient therapy that optimises neurological recovery in people with SCI

A Genome-Wide Association Study of Depressive Symptoms

<p>Background: Depression is a heritable trait that exists on a continuum of varying severity and duration. Yet, the search for genetic variants associated with depression has had few successes. We exploit the entire continuum of depression to find common variants for depressive symptoms.</p><p>Methods: In this genome-wide association study, we combined the results of 17 population-based studies assessing depressive symptoms with the Center for Epidemiological Studies Depression Scale. Replication of the independent top hits (p <1 x 10(-5)) was performed in five studies assessing depressive symptoms with other instruments. In addition, we performed a combined meta-analysis of all 22 discovery and replication studies.</p><p>Results: The discovery sample comprised 34,549 individuals (mean age of 66.5) and no loci reached genome-wide significance (lowest p = 1.05 x 10(-7)). Seven independent single nucleotide polymorphisms were considered for replication. In the replication set (n = 16,709), we found suggestive association of one single nucleotide polymorphism with depressive symptoms (rs161645, 5q21, p = 9.19 x 10(-3)). This 5q21 region reached genome-wide significance (p = 4.78 x 10(-8)) in the overall meta-analysis combining discovery and replication studies (n = 51,258).</p><p>Conclusions: The results suggest that only a large sample comprising more than 50,000 subjects may be sufficiently powered to detect genes for depressive symptoms.</p>