Stroke population-specific neuroanatomical CT-MRI brain atlas.

PURPOSE: Development of a freely available stroke population-specific anatomical CT/MRI atlas with a reliable normalisation pipeline for clinical CT. METHODS: By reviewing CT scans in suspected stroke patients and filtering the AIBL MRI database, respectively, we collected 50 normal-for-age CT and MRI scans to build a standard-resolution CT template and a high-resolution MRI template. The latter was manually segmented into anatomical brain regions. We then developed and validated a MRI to CT registration pipeline to align the MRI atlas onto the CT template. Finally, we developed a CT-to-CT-normalisation pipeline and tested its reliability by calculating Dice coefficient (Dice) and Average Hausdorff Distance (AHD) for predefined areas in 100 CT scans from ischaemic stroke patients. RESULTS: The resulting CT/MRI templates were age and sex matched to a general stroke population (median age 71.9 years (62.1-80.2), 60% male). Specifically, this accounts for relevant structural changes related to aging, which may affect registration. Applying the validated MRI to CT alignment (Dice > 0.78, Average Hausdorff Distance < 0.59 mm) resulted in our final CT-MRI atlas. The atlas has 52 manually segmented regions and covers the whole brain. The alignment of four cortical and subcortical brain regions with our CT-normalisation pipeline was reliable for small/medium/large infarct lesions (Dice coefficient > 0.5). CONCLUSION: The newly created CT-MRI brain atlas has the potential to standardise stroke lesion segmentation. Together with the automated normalisation pipeline, it allows analysis of existing and new datasets to improve prediction tools for stroke patients (free download at https://forms.office.com/r/v4t3sWfbKs ).

Timing and Dose of Upper Limb Motor Intervention After Stroke: A Systematic Review.

This systematic review aimed to investigate timing, dose, and efficacy of upper limb intervention during the first 6 months poststroke. Three online databases were searched up to July 2020. Titles/abstracts/full-text were reviewed independently by 2 authors. Randomized and nonrandomized studies that enrolled people within the first 6 months poststroke, aimed to improve upper limb recovery, and completed preintervention and postintervention assessments were included. Risk of bias was assessed using Cochrane reporting tools. Studies were examined by timing (recovery epoch), dose, and intervention type. Two hundred and sixty-one studies were included, representing 228 (n=9704 participants) unique data sets. The number of studies completed increased from one (n=37 participants) between 1980 and 1984 to 91 (n=4417 participants) between 2015 and 2019. Timing of intervention start has not changed (median 38 days, interquartile range [IQR], 22-66) and study sample size remains small (median n=30, IQR 20-48). Most studies were rated high risk of bias (62%). Study participants were enrolled at different recovery epochs: 1 hyperacute (<24 hours), 13 acute (1-7 days), 176 early subacute (8-90 days), 34 late subacute (91-180 days), and 4 were unable to be classified to an epoch. For both the intervention and control groups, the median dose was 45 (IQR, 600-1430) min/session, 1 (IQR, 1-1) session/d, 5 (IQR, 5-5) d/wk for 4 (IQR, 3-5) weeks. The most common interventions tested were electromechanical (n=55 studies), electrical stimulation (n=38 studies), and constraint-induced movement (n=28 studies) therapies. Despite a large and growing body of research, intervention dose and sample size of included studies were often too small to detect clinically important effects. Furthermore, interventions remain focused on subacute stroke recovery with little change in recent decades. A united research agenda that establishes a clear biological understanding of timing, dose, and intervention type is needed to progress stroke recovery research. Prospective Register of Systematic Reviews ID: CRD42018019367/CRD42018111629.

Surveillance of SARS-CoV-2 transmission in educational institutions, August to December 2020, Germany.

This study aims at providing estimates on the transmission risk of SARS-CoV-2 in schools and day-care centres. We calculated secondary attack rates (SARs) using individual-level data from state-wide mandatory notification of index cases in educational institutions, followed by contact tracing and PCR-testing of high-risk contacts. From August to December 2020, every sixth of overall 784 independent index cases was associated with secondary cases in educational institutions. Monitoring of 14 594 institutional high-risk contacts (89% PCR-tested) of 441 index cases during quarantine revealed 196 secondary cases (SAR 1.34%, 0.99-1.78). SARS-CoV-2 infection among high-risk contacts was more likely around teacher-indexes compared to student-/child-indexes (incidence rate ratio (IRR) 3.17, 1.79-5.59), and in day-care centres compared to secondary schools (IRR 3.23, 1.76-5.91), mainly due to clusters around teacher-indexes in day-care containing a higher mean number of secondary cases per index case (142/113 = 1.26) than clusters around student-indexes in schools (82/474 = 0.17). In 2020, SARS-CoV-2 transmission risk in educational settings was low overall, but varied strongly between setting and role of the index case, indicating the chance for targeted intervention. Surveillance of SARS-CoV-2 transmission in educational institutions can powerfully inform public health policy and improve educational justice during the pandemic.

Occlusive Disease and Upright Activity in Acute Ischemic Stroke.

The impact of out-of-bed upright activity on outcomes in ischemic stroke patients with severe extra- and intracranial stenosis or occlusion is unknown. Using ultrasound findings from a cohort recruited to A Very Early Rehabilitation Trial (AVERT) which compared higher dose very early mobilisation (VEM) to usual care (UC), we aimed to explore the association between occlusive disease and 3-month outcomes and occlusive disease-by-mobilisation treatment interactions. Participants with ischemic stroke, with carotid and transcranial Doppler ultrasounds performed ≤1 week after admission, were included in this single centre substudy in Melbourne, Australia. Reports were retrospectively reviewed to determine the degree of stenosis or presence of occlusion in the relevant arterial territory. Stenosis ≥70% extracranial or ≥50% intracranial were classified as severe or occlusion. Overall, 19% (n = 36/191) had occlusive disease in the affected circulation. About 40% (n = 14/36) with occlusive disease and 51% (n = 79/155) without had a 3-month favourable outcome (mRS 0-2) (adjusted OR0.53, CI0.17-1.67). Fourteen percent (n = 5) with occlusive disease and 4% (n = 6) without died by 3 months (adjusted OR2.52, CI0.6-10.7). Fifty percent (n = 11/22) of UC (adjusted OR0.86, CI0.23-3.2) and 21% (n = 3/14) of VEM participants (adjusted OR0.16, CI0.01-2.7) with occlusive disease had a favourable outcome. Almost 30% (n = 4) VEM participants with occlusive disease died (adjusted OR3.99, CI0.69-22.9) compared to 5% (n = 1) UC participants with occlusive disease (adjusted OR0.45, CI0.02-8.6), however numbers were small. No stenosis-by-treatment interactions were found. High quality prospective studies are needed to help guide decision making about when patients with occlusive disease should commence upright activity in acute stroke.

Brain activation associated with pride and shame.

BACKGROUND: Self-referential emotions such as shame/guilt and pride provide evaluative information about persons themselves. In addition to emotional aspects, social and self-referential processes play a role in self-referential emotions. Prior studies have rather focused on comparing self-referential and other-referential processes of one valence, triggered mostly by external stimuli. In the current study, we aimed at investigating the valence-specific neural correlates of shame/guilt and pride, evoked by the remembrance of a corresponding autobiographical event during functional magnetic resonance imaging. METHOD: A total of 25 healthy volunteers were studied. The task comprised a negative (shame/guilt), a positive (pride) and a neutral condition (expecting the distractor). Each condition was initiated by a simple cue, followed by the remembrance and finished by a distracting picture. RESULTS: Pride and shame/guilt conditions both activated typical emotion-processing circuits including the amygdala, insula and ventral striatum, as well as self-referential brain regions such as the bilateral dorsomedial prefrontal cortex. Comparing the two emotional conditions, emotion-processing circuits were more activated by pride than by shame, possibly due to either hedonic experiences or stronger involvement of the participants in positive self-referential emotions due to a self-positivity bias. However, the ventral striatum was similarly activated by pride and shame/guilt. In the whole-brain analysis, both self-referential emotion conditions activated medial prefrontal and posterior cingulate regions, corresponding to the self-referential aspect and the autobiographical evocation of the respective emotions. CONCLUSION: Autobiographically evoked self-referential emotions activated basic emotional as well as self-referential circuits. Except for the ventral striatum, emotional circuits were more active with pride than with shame.

Neural activity associated with self-reflection.

BACKGROUND: Self-referential cognitions are important for self-monitoring and self-regulation. Previous studies have addressed the neural correlates of self-referential processes in response to or related to external stimuli. We here investigated brain activity associated with a short, exclusively mental process of self-reflection in the absence of external stimuli or behavioural requirements. Healthy subjects reflected either on themselves, a personally known or an unknown person during functional magnetic resonance imaging (fMRI). The reflection period was initialized by a cue and followed by photographs of the respective persons (perception of pictures of oneself or the other person). RESULTS: Self-reflection, compared with reflecting on the other persons and to a major part also compared with perceiving photographs of one-self, was associated with more prominent dorsomedial and lateral prefrontal, insular, anterior and posterior cingulate activations. Whereas some of these areas showed activity in the "other"-conditions as well, self-selective characteristics were revealed in right dorsolateral prefrontal and posterior cingulate cortex for self-reflection; in anterior cingulate cortex for self-perception and in the left inferior parietal lobe for self-reflection and -perception. CONCLUSIONS: Altogether, cingulate, medial and lateral prefrontal, insular and inferior parietal regions show relevance for self-related cognitions, with in part self-specificity in terms of comparison with the known-, unknown- and perception-conditions. Notably, the results are obtained here without behavioural response supporting the reliability of this methodological approach of applying a solely mental intervention. We suggest considering the reported structures when investigating psychopathologically affected self-related processing.

Ambulatory activity in stroke survivors associated with functional outcome and quality of life: An observational cohort study.

BACKGROUND: Physical activity is beneficial in stroke prevention and recovery. Understanding activity dynamics and its effect on outcome after stroke is important to improve recommendations and develop interventions. OBJECTIVES: We examined serial changes in daily ambulatory activity (AA) averaged over 1 week in people with subacute to chronic stroke and its association with functional outcome (modified Rankin scale [mRS]) and quality of life (EQ-5D-3L). METHODS: This observational study examined AA in stroke survivors with no to moderate disability (US National Institute of Stroke Scale [NIHSS] score) who were mostly community dwelling and had cryptogenic stroke based on data from the Continuous Cardiac Monitoring to Assess Atrial Fibrillation After Cryptogenic Stroke study. The participants underwent long-term AA monitoring by accelerometric activity data obtained from an insertable cardiac monitor without receiving any specific encouragement regarding physical activity. We analysed AA changes and assessed the association between baseline AA and mRS/EQ-5D-3L scores. A small group of participants had follow-up data for 2 years, which allowed for analysing long-term serial changes. RESULTS: We included 186 participants (mean [SD] age 61.3 [11.2] years, 67% male, mean 39 [28] days after stroke). AA increased during the subacute phase in individuals with mild (NIHSS score 1-4, P<0.001) and moderate (NIHSS score 5-10, P=0.013) disability but not in the non-impaired group. Baseline AA was inversely associated with NIHSS score (P<0.001) and was associated with mRS score (P=0.001) and weakly correlated with EQ-5D-3L score at 6 months (P=0.032, r=0.22). For the 45 participants with follow-up data (mean age 64.5 [9.7] years, 80% male, mean 34 [21] days after stroke), AA remained stable. CONCLUSION: AA increased in stroke survivors with impairments but remained stable in those whose symptoms had resolved. AA during the early subacute period was associated with mRS and EQ-5D-3L scores at 6 months. Insertable cardiac monitoring offers a feasible method for monitoring activity over prolonged periods in people after stroke. Its increased use may offer an opportunity to overcome the limited reliability and validity of many existing measures. TRIAL REGISTRATION: ClinicalTrials.gov (NCT00924638).

Self-related awareness and emotion regulation.

The regulation of emotions is an ongoing internal process and often a challenge. Current related neural models concern the intended control of reactions towards external events, mediated by prefrontal cortex regions upon basal emotion processing as in the amygdala. Cognitive strategies to regulate emotions in the context of affective disorders or stress reduction, increasingly applied in clinical practice, are also related to mindfulness techniques. We questioned their effects on neural emotion processing and investigated brain activity during purely internal mental self-referential processes of making current emotions and self-related cognitions aware. Thirty healthy subjects performed a task comprising periods of cognitive self-reflection, of introspection for actual own emotions and feelings, and of a neutral condition, while they were scanned with functional magnetic resonance imaging. Brain activations of twenty-seven subjects during emotion-introspection and self-reflection, and also a conjunction of both, were compared with the neutral condition. The conditions of self-reflection and emotion-introspection showed distinguishable activations in medial and ventrolateral prefrontal areas, in parietal regions and in the amygdala. Notably, amygdala activity decreased during emotion-introspection and increased compared to 'neutral' during self-reflection. The results indicate that already the self-referential mental state of making the actual emotional state aware is capable of attenuating emotional arousal. This extends current theories of emotion regulation and has implications for the application of mindfulness techniques as a component of psychotherapeutic strategies in affective disorders and also for possible everyday emotion regulation.

Safety of Performing a Graded Exercise Test Early after Stroke and Transient Ischemic Attack.

BACKGROUND: Low cardiorespiratory fitness (CRF) is a predictor of stroke risk and poor outcome poststroke. Fitness levels are rarely assessed in the acute phase and it is unclear if it is safe for stroke survivors and people with transient ischemic attack (TIA) to perform a graded exercise test to assess fitness. OBJECTIVE: To determine if people within 14 days post stroke can safely perform a graded exercise test. DESIGN: Observational study. SETTING: Research institute. PARTICIPANTS: People with stroke or TIA admitted to an acute stroke unit. INTERVENTION: Not applicable. MAIN OUTCOME MEASURES: Safety of performing a graded exercise test early post stroke. Safety outcomes were (1) occurrence of an adverse event or (2) <85% blood oxygen saturation (SpO2 ). Participants performed a graded exercise test on a recumbent stepper at a research institute <2 weeks postevent. CRF was determined by measuring peak volume of oxygen uptake (VO2peak ) using a metabolic cart. RESULTS: Twenty-nine participants were enrolled in the study (median age 69 years; interquartile range 58-75). Sixteen were diagnosed with TIA and 13 with a mild stroke. Twenty-eight participants completed the test; one participant was unable to perform the test due to back pain. The test was terminated due to standardized stopping criteria in 26 cases (5 = volitional fatigue, 6 = unable to keep required cadence, 15 = reaching 85% HRmax ), one due to safety (ie, SpO2 < 85%), and one was inadvertently terminated before stopping criteria were reached. Average CRF determined by the exercise test was low; mean VO2peak of 16.2 ± 4.5 mL/kg/min for men (n = 20) and 12.4 ± 3.6 mL/kg/min for women (n = 8). CONCLUSIONS: Determining exercise capacity early post stroke and TIA using a graded exercise test appears to be safe in patients with mild deficits. This information should be useful to plan tailored exercise programs. Further research should focus on determining safety of exercise testing in more severely affected stroke survivors.

A systematic review protocol of timing, efficacy and cost effectiveness of upper limb therapy for motor recovery post-stroke.

BACKGROUND: Improving upper limb (UL) motor recovery after stroke represents a major clinical and scientific goal. We aim to complete three systematic reviews to estimate the (1) association between time to start of UL therapy and motor recovery, (2) relative efficacy of different UL therapy approaches post-stroke and (3) cost-effectiveness of UL therapy interventions. METHODS: We have designed a systematic review protocol to address three systematic review questions that were each registered with PROSPERO. The search will be conducted in MEDLINE, EMBASE, and Cochrane Controlled Register of Trials. We will include randomised controlled trials, non-randomised clinical trials, before-after studies and observational studies of adult stroke survivors with an average stroke onset < 6 months, undergoing hospital-based therapy to improve UL function. Eligible interventions will aim to promote UL functional recovery. Two reviewers will independently screen, select and extract data. Study risk of bias will be appraised using appropriate tools. Clinical measures of motor recovery will be investigated (primary measure Fugl Meyer UL assessment), as well as measures of health-related quality of life (primary measure EQ-5D) and all cost-effectiveness analyses completed. Secondary outcomes include therapy dose (minutes, weeks, repetitions as available) and safety (i.e. adverse events, serious adverse events). A narrative synthesis will describe quality and content of the evidence. If feasible, we will conduct random effects meta-analyses where appropriate. DISCUSSION: We anticipate the findings of this review will increase our understanding of UL therapy and inform the generation of novel, data-driven hypotheses for future UL therapy research post-stroke. SYSTEMATIC REVIEW REGISTRATION: PROSPERO, http://www.crd.york.ac.uk/PROSPERO/display_record.php?ID=CRD42018019367, http://www.crd.york.ac.uk/PROSPERO/display_record.php?ID=CRD42018111629, http://www.crd.york.ac.uk/PROSPERO/display_record.php?ID=CRD42018111628.

Chronometric features of processing unpleasant stimuli: a functional MRI-based transcranial magnetic stimulation study.

The quick identification of potentially threatening events is a crucial cognitive capacity to survive in a changing environment. Previous functional MRI data revealed the right dorsolateral prefrontal cortex and the region of the left intraparietal sulcus (IPS) to be involved in the perception of emotionally negative stimuli. For assessing chronometric aspects of emotion processing, we applied transcranial magnetic stimulation above these areas at different times after negative and neutral picture presentation. An interference with emotion processing was found with transcranial magnetic stimulation above the dorsolateral prefrontal cortex 200-300 ms and above the left intraparietal sulcus 240/260 ms after negative stimuli. The data suggest a parallel and conjoint involvement of prefrontal and parietal areas for the identification of emotionally negative stimuli.

Neural correlates of altered general emotion processing in social anxiety disorder.

Specific anxiety disorders are characterized by altered emotion processing of phobia-specific stimuli at the neurobiological level. Recent work has concentrated on specific anxiety-provoking stimuli; focusing on arousal- or fear-related brain areas such as the amygdala. We analyzed brain activation during the cued anticipation of unpleasant or uncertain emotional stimuli as a means of modeling an unspecific anxiety-laden situation. Sixteen patients with social anxiety disorder (SAD) and eighteen healthy control subjects completed a task during functional magnetic resonance imaging involving the anticipation of cued visual stimuli with prior known emotional valence (positive, negative, and neutral) or prior unknown/ambiguous emotional content. The anticipated stimuli had no social phobia specific content. During the anticipation of emotional stimuli of prior known negative and prior ambiguous emotional valence, brain activity in patients with SAD was increased in the upper midbrain/dorsal thalamus, the amygdala, and in temporo-occipital and parietal regions as compared to control subjects. Activity was decreased in SAD in left orbitofrontal cortex. Activations in the amygdala and in occipital regions correlated with trait anxiety and social anxiety measures. In conclusion, SAD was associated with enhanced activation in brain regions involved in emotional arousal as well as in attention and perception processing during the anticipation of non-specific, general emotional stimuli. Hence, our results suggest that patients with SAD not only have an altered processing of specific feared stimuli, but also a more generally disturbed emotion processing in basic neural pathways. These findings have implications for diagnostic models and the treatment of SAD.

Neural correlates of personality dimensions and affective measures during the anticipation of emotional stimuli.

Neuroticism and extraversion are proposed personality dimensions for individual emotion processing. Neuroticism is correlated with depression and anxiety disorders, implicating a common neurobiological basis. Extraversion is rather inversely correlated with anxiety and depression. We examined neural correlates of personality in relation to depressiveness and anxiety in healthy adult subjects with functional magnetic resonance imaging during the cued anticipation of emotional stimuli. Distributed particularly prefrontal but also other cortical regions and the thalamus were associated with extraversion. Parieto-occipital and temporal regions and subcortically the caudate were correlated with neuroticism and affective measures. Neuroticism-related regions were partially cross-correlated with anxiety and depression and vice versa. Extraversion-related activity was not correlated with the other measures. The neural correlates of extraversion compared with those of neuroticism and affective measures fit with concepts of different neurobiological bases of the personality dimensions and point at predispositions for affective disorders.

Serotonergic and noradrenergic modulation of emotion processing by single dose antidepressants.

Serotonergic and noradrenergic pathways are the main targets of antidepressants. Their differential effects on emotion processing-related brain activation are, however, to be further characterized. We aimed at elucidating the neural sites of action of an acute differential serotonergic and noradrenergic influence on an emotion-processing task, which was earlier shown to be associated with depressiveness. In a single-blind pseudo-randomized crossover study, 21 healthy subjects (16 subjects finally included in the analysis) participated to ingest a single dose at three time points of either 40 mg citalopram, a selective serotonin-reuptake inhibitor, 8 mg reboxetine, a selective noradrenaline-reuptake inhibitor, or placebo 2-3 h before functional magnetic resonance imaging (fMRI). During fMRI, subjects performed a task comprising the anticipation and perception of pictures of either 'known' (positive, negative, neutral) or 'unknown' valence (randomly 50% positive or negative). In direct comparison with citalopram and with placebo, reboxetine increased brain activity in the medial thalamus. Citalopram modulated certain prefrontal and insular areas more prominently. Other frontal and parieto-occipital areas were modulated by both drugs. In conclusion, the functional network involved in emotional information processing could be modulated by the acute application of selective noradrenergic and serotonergic drugs revealing a noradrenergic effect in thalamic and frontal areas, and a prefrontal and insular focus of serotonergic modulation. These findings could have implications for future selection criteria concerning personalized antidepressant medication in depression.

Negative bias of processing ambiguously cued emotional stimuli.

Daily we cope with upcoming potentially disadvantageous events. Therefore, it makes sense to be prepared for the worst case. Such a 'pessimistic' bias is reflected in brain activation during emotion processing. Healthy individuals underwent functional neuroimaging while viewing emotional stimuli that were earlier cued ambiguously or unambiguously concerning their emotional valence. Presentation of ambiguously announced pleasant pictures compared with unambiguously announced pleasant pictures resulted in increased activity in the ventrolateral prefrontal, premotor and temporal cortex, and in the caudate nucleus. This was not the case for the respective negative conditions. This indicates that pleasant stimuli after ambiguous cueing provided 'unexpected' emotional input, resulting in the adaptation of brain activity. It strengthens the hypothesis of a 'pessimistic' bias of brain activation toward ambiguous emotional events.

Neural correlates of a 'pessimistic' attitude when anticipating events of unknown emotional valence.

Since we do not know what future holds for us, we prepare for expected emotional events in order to deal with a pleasant or threatening environment. From an evolutionary perspective, it makes sense to be particularly prepared for the worst-case scenario. We were interested to evaluate whether this assumption is reflected in the central nervous information processing associated with expecting visual stimuli of unknown emotional valence. While being scanned with functional magnetic resonance imaging, healthy subjects were cued to expect and then perceive visual stimuli with a known emotional valence as pleasant, unpleasant, and neutral, as well as stimuli of unknown valence that could have been either pleasant or unpleasant. While anticipating pictures of unknown valence, the activity of emotion processing brain areas was similar to activity associated with expecting unpleasant pictures, but there were no areas in which the activity was similar to the activity when expecting pleasant pictures. The activity of the revealed regions, including bilateral insula, right inferior frontal gyrus, medial thalamus, and red nucleus, further correlated with the individual ratings of mood: the worse the mood, the higher the activity. These areas are supposedly involved in a network for internal adaptation and preparation processes in order to act according to potential or certain unpleasant events. Their activity appears to reflect a 'pessimistic' bias by anticipating the events of unknown valence to be unpleasant.

Modulation of anticipatory emotion and perception processing by cognitive control.

Strategies of cognitive control are helpful in reducing anxiety experienced during anticipation of unpleasant or potentially unpleasant events. We investigated the associated cerebral information processing underlying the use of a specific cognitive control strategy during the anticipation of affect-laden events. Using functional magnetic resonance imaging, we examined differential brain activity during anticipation of events of unknown and negative emotional valence in a group of eighteen healthy subjects that used a cognitive control strategy, similar to "reality checking" as used in psychotherapy, compared with a group of sixteen subjects that did not exert cognitive control. While expecting unpleasant stimuli, the "cognitive control" group showed higher activity in left medial and dorsolateral prefrontal cortex areas but reduced activity in the left extended amygdala, pulvinar/lateral geniculate nucleus and fusiform gyrus. Cognitive control during the "unknown" expectation was associated with reduced amygdalar activity as well and further with reduced insular and thalamic activity. The amygdala activations associated with cognitive control correlated negatively with the reappraisal scores of an emotion regulation questionnaire. The results indicate that cognitive control of particularly unpleasant emotions is associated with elevated prefrontal cortex activity that may serve to attenuate emotion processing in for instance amygdala, and, notably, in perception related brain areas.