Repairing the human brain after stroke: I. Mechanisms of spontaneous recovery

Local neuronal sleep after stroke: The role of cortical bistability in brain reorganization

BACKGROUND

Acute cerebral ischemia triggers a number of cellular mechanisms not only leading to excitotoxic cell death but also to enhanced neuroplasticity, facilitating neuronal reorganization and functional recovery.

OBJECTIVE

Transferring these cellular mechanisms to neurophysiological correlates adaptable to patients is crucial to promote recovery post-stroke. The combination of TMS and EEG constitutes a promising readout of neuronal network activity in stroke patients.

METHODS

We used the combination of TMS and EEG to investigate the development of local signal processing and global network alterations in 40 stroke patients with motor deficits alongside neural reorganization from the acute to the chronic phase.

RESULTS

We show that the TMS-EEG response reflects information about reorganization and signal alterations associated with persistent motor deficits throughout the entire post-stroke period. In the early post-stroke phase and in a subgroup of patients with severe motor deficits, TMS applied to the lesioned motor cortex evoked a sleep-like slow wave response associated with a cortical off-period, a manifestation of cortical bistability, as well as a rapid disruption of the TMS-induced formation of causal network effects. Mechanistically, these phenomena were linked to lesions affecting ascending activating brainstem fibers. Of note, slow waves invariably vanished in the chronic phase, but were highly indicative of a poor functional outcome.

CONCLUSION

In summary, we found evidence that transient effects of sleep-like slow waves and cortical bistability within ipsilesional M1 resulting in excessive inhibition may interfere with functional reorganization, leading to a less favorable functional outcome post-stroke, pointing to a new therapeutic target to improve recovery of function.

Correlations in abnormal synergies between the upper and lower extremities across various phases of stroke

The flexion synergy and extension synergy are a representative consequence of a stroke and appear in the upper extremity and the lower extremity. Since the ipsilesional corticospinal tract (CST) is the most influential neural pathway for both extremities in motor execution, damage by a stroke to this tract could lead to similar motor pathological features (e.g., abnormal synergies) in both extremities. However, less attention has been paid to the interlimb correlations in the flexion synergy and extension synergy across different recovery phases of a stroke. We used results of the Fugl-Meyer assessment (FMA) to characterize those correlations in a total of 512 participants with hemiparesis after stroke from the acute phase to 1 year. The FMA provides indirect indicators of the degrees of the flexion synergy and extension synergy after stroke. We found that, generally, strong interlimb correlations (r > 0.65 with all P values < 0.0001) between the flexion synergy and extension synergy appeared in the acute-to-subacute phase (<90 days). However, the correlations of the lower-extremity extension synergy with the upper-extremity flexion synergy and extension synergy decreased (down to r = 0.38) 360 days after stroke (P < 0.05). These results suggest that the preferential use of alternative neural pathways after damage by a stroke to the CST enhances the interlimb correlations between the flexion synergy and extension synergy. At the same time, the results imply that the recovery of CST integrity or/and the fragmentation (remodeling) of the alternative neural substrates in the chronic phase may contribute to diversity in neural pathways in motor execution, eventually leading to reduced interlimb correlations.NEW & NOTEWORTHY For the first time, this article addresses the asynchronous relationships in the strengths of flexion and extension synergy expressions between the paretic upper extremity and lower extremity across various phases of stroke.

Cross-Frequency Coupling as a Biomarker for Early Stroke Recovery

BACKGROUND

The application of neuroimaging-based biomarkers in stroke has enriched our understanding of post-stroke recovery mechanisms, including alterations in functional connectivity based on synchronous oscillatory activity across various cortical regions. Phase-amplitude coupling, a type of cross-frequency coupling, may provide additional mechanistic insight.

OBJECTIVE

To determine how the phase of prefrontal cortex delta (1-3 Hz) oscillatory activity mediates the amplitude of motor cortex beta (13-20 Hz) oscillations in individual's early post-stroke.

METHODS

Participants admitted to an inpatient rehabilitation facility completed resting and task-based EEG recordings and motor assessments around the time of admission and discharge along with structural neuroimaging. Unimpaired controls completed EEG procedures during a single visit. Mixed-effects linear models were performed to assess within- and between-group differences in delta-beta prefrontomotor coupling. Associations between coupling and motor status and injury were also determined.

RESULTS

Thirty individuals with stroke and 17 unimpaired controls participated. Coupling was greater during task versus rest conditions for all participants. Though coupling during affected extremity task performance decreased during hospitalization, coupling remained elevated at discharge compared to controls. Greater baseline coupling was associated with better motor status at admission and discharge and positively related to motor recovery. Coupling demonstrated both positive and negative associations with injury involving measures of lesion volume and overlap injury to anterior thalamic radiation, respectively.

CONCLUSIONS

This work highlights the utility of prefrontomotor cross-frequency coupling as a potential motor status and recovery biomarker in stroke. The frequency- and region-specific neurocircuitry featured in this work may also facilitate novel treatment strategies in stroke.

Stroke as a career option for neurologists

Stroke is one of the most common acute neurological disorders and a leading cause of disability worldwide. Evidence-based treatments over the last two decades have driven a revolution in the clinical management and design of stroke services. We need a highly skilled, multidisciplinary workforce that includes neurologists as core members to deliver modern stroke care. In the UK, the dedicated subspecialty training programme for stroke medicine has recently been integrated into the neurology curriculum. All neurologists will be trained to contribute to each aspect of the stroke care pathway. We discuss how training in stroke medicine is evolving for neurologists and the opportunities and challenges around practising stroke medicine in the UK and beyond.

Prospero Homeobox 1 and Doublecortin Correlate with Neural Damage after Ischemic Stroke

OBJECTIVE

Markers of neuroinflammation during ischemic stroke are well characterized, but additional markers of neural damage are lacking. The study identified associations of behavioral disorders after stroke with histologic neural damage and molecular biological change.

METHODS

Eight-week-old, 25 g male mice of the C57BL/6J strain were subjected to middle cerebral artery occlusion (MCAO) to induce ischemic stroke. The control group was a healthy wild type (WT), and the experimental group were designed as a low severity MCAO1 and a high severity MCAO2 based on post-stroke neurological scoring. All groups underwent behavioral tests, realtime polymerase chain reaction, triphenyltetrazolium chloride (TTC) staining and Hematoxylin and Eosin staining. One-way analysis of variance was used to analyze statistical significance between groups.

RESULTS

In TTC staining, MCAO1 showed 29.02% and MCAO2 showed 38.94% infarct volume (p<0.0001). The pro-inflammatory cytokine interleukin (IL)-1β was most highly expressed in MCAO2 (WT 0.44 vs. MCAO1 2.69 vs. MCAO2 5.02, p<0.0001). From the distance to target in the Barnes maze test, WT had a distance of 178 cm, MCAO1 had a distance of 276 cm, and MCAO2 had a distance of 1051 (p=0.0015). The latency to target was 13.3 seconds for WT, 27.9 seconds for MCAO1, and 87.9 seconds for MCAO2 (p=0.0007). Prospero homeobox 1 (Prox1) was most highly expressed in MCAO2 (p=0.0004). Doublecortin (Dcx) was most highly expressed in MCAO2 (p<0.0001).

CONCLUSION

The study demonstrated that histological damage to neural cells and changes in brain mRNA expression were associated with behavioral impairment after ischemic stroke. Prox1 and Dcx may be biomarkers of neural damage associated with long-term cognitive decline, and increased expression at the mRNA level was consistent with neural damage and long-term cognitive dysfunction.

Top-Down and Bottom-Up Mechanisms of Motor Recovery Poststroke

Stroke remains a leading cause of disability. Motor recovery requires the interaction of top-down and bottom-up mechanisms, which reinforce each other. Injury to the brain initiates a biphasic neuroimmune process, which opens a window for spontaneous recovery during which the brain is particularly sensitive to activity. Physical activity during this sensitive period can lead to rapid recovery by potentiating anti-inflammatory and neuroplastic processes. On the other hand, lack of physical activity can lead to early closure of the sensitive period and downstream changes in muscles, such as sarcopenia, muscle stiffness, and reduced cardiovascular capacity, and blood flow that impede recovery.

Transcranial direct current stimulation (tDCS) for neurological disability among subacute stroke survivors to improve multiple domains in health-related quality of life: Randomized controlled trial protocol

OBJECTIVES

The primary goal of the current proposal is to fill the gaps in the literature by studying the effectiveness of transcranial direct current stimulation (tDCS) on lifestyle parameters, and physical, behavioral, and cognitive functions among stroke survivors, and understanding the factors that mediate the effects of various domains related to Health-related Quality of life (HRQoL) improvements.

METHODS

Anticipated 64 volunteer subacute stroke survivors (>7 days to 3 months post stroke) aged 40-75 years with National Institutes of Health stroke scale (NIHSS) score of >10 and Mini-Mental State Examination (MMSE) score between 18 and 23 will be randomly assigned at a ratio of 1:1 to receive either: (1) 20 sessions of anodal tDCS or (2) sham tDCS in addition to conventional rehabilitation. Battery driven tDCS will be applied at 2 mA intensity to the dorsolateral prefrontal cortex and primary motor cortex for 20 minutes. The primary endpoints of study will be 36-Item Short Form Survey (SF-36) post intervention at 4 weeks. The secondary outcomes will include Stroke Specific Quality of Life Scale (SS_QOL), Montreal cognitive assessment (MCA), Beck Anxiety Inventory (BAI), Fugl-Meyer Assessment (FMA), 10 m walk test and Modified Barthel Activities of daily living (ADL) Index. At 0.05 level of significance, data normality, within group and between group actual differences will be analyzed with a moderate scope software.

DISCUSSION

Our knowledge of this technique and its use is expanding daily as tDCS motor recovery studies-mostly single-center studies-in either single session or many sessions have been completed and shown positive results. The field is prepared for a multi-center, carefully planned, sham-controlled, double-blinded tDCS study to comprehensively examine its feasibility and effectiveness in enhancing outcomes in stroke population.

CONCLUSION

The function of Transcranial Direct Current Stimulation in aiding stroke recuperation will be ascertained.

Smartphone-Based Speech Therapy for Poststroke Dysarthria: Pilot Randomized Controlled Trial Evaluating Efficacy and Feasibility

BACKGROUND

Dysarthria is a common poststroke speech disorder affecting communication and psychological well-being. Traditional speech therapy is effective but often poses challenges in terms of accessibility and patient adherence. Emerging smartphone-based therapies may offer promising alternatives for the treatment of poststroke dysarthria.

OBJECTIVE

This study aimed to assess the efficacy and feasibility of smartphone-based speech therapy for improving speech intelligibility in patients with acute and early subacute poststroke dysarthria. This study also explored the impact of the intervention on psychological well-being, user experience, and overall feasibility in a clinical setting.

METHODS

Participants were divided into 2 groups for this randomized, evaluator-blinded trial. The intervention group used a smartphone-based speech therapy app for 1 hour per day, 5 days per week, for 4 weeks, with guideline-based standard stroke care. The control group received standard guideline-based stroke care and rehabilitation. Speech intelligibility, psychological well-being, quality of life, and user acceptance were assessed using repeated measures ANOVA.

RESULTS

In this study, 40 patients with poststroke dysarthria were enrolled, 32 of whom completed the trial (16 in each group). The intervention group showed significant improvements in speech intelligibility compared with the control group. This was evidenced by improvements from baseline (F1,30=34.35; P<.001), between-group differences (F1,30=6.18; P=.02), and notable time-by-group interactions (F1,30=6.91; P=.01). Regarding secondary outcomes, the intervention led to improvements in the percentage of correct consonants over time (F1,30=5.57; P=.03). In addition, significant reductions were noted in the severity of dysarthria in the intervention group over time (F1,30=21.18; P<.001), with a pronounced group effect (F1,30=5.52; P=.03) and time-by-group interaction (F1,30=5.29; P=.03). Regarding quality of life, significant improvements were observed as measured by the EQ-5D-3L questionnaire (F1,30=13.25; P<.001) and EQ-VAS (F1,30=7.74; P=.009) over time. The adherence rate to the smartphone-based app was 64%, with over half of the participants completing all the sessions. The usability of the app was rated high (system usability score 80.78). In addition, the intervention group reported increased self-efficacy in using the app compared with the control group (F1,30=10.81; P=.003).

CONCLUSIONS

The smartphone-based speech therapy app significantly improved speech intelligibility, articulation, and quality of life in patients with poststroke dysarthria. These findings indicate that smartphone-based speech therapy can be a useful assistant device in the management of poststroke dysarthria, particularly in the acute and early subacute stroke stages.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05146765; https://clinicaltrials.gov/ct2/show/NCT05146765.

The test-retest reliability of non-navigated transcranial magnetic stimulation (TMS) measures of corticospinal pathway excitability early after stroke

PURPOSE

Motor evoked potential (MEP) characteristics are potential biomarkers of whether rehabilitation interventions drive motor recovery after stroke. The test-retest reliability of Transcranial Magnetic Stimulation (TMS) measurements in sub-acute stroke remains unclear. This study aims to determine the test-retest reliability of upper limb MEP measures elicited by non-neuronavigated transcranial magnetic stimulation in sub-acute-stroke.

METHODS

In two identical data collection sessions, 1-3 days apart, TMS measures assessed: motor threshold (MT), amplitude, latency (MEP-L), silent period (SP), recruitment curve slope in the biceps brachii (BB), extensor carpi radialis (ECR), and abductor pollicis brevis (APB) muscles of paretic and non-paretic upper limbs. Test-retest reliability was calculated using the intra-class correlation coefficient (ICC) and 95% confidence intervals (CI). Acceptable reliability was set at a lower 95% CI of 0.70 or above. The limits of agreement (LOA) and smallest detectable change (SDC) were calculated.

RESULTS

30 participants with sub-acute stroke were included (av 36 days post stroke) reliability was variable between poor to good for the different MEP characteristics. The SDC values differed across muscles and MEP characteristics in both paretic and less paretic limbs.

CONCLUSIONS

The present findings indicate there is limited evidence for acceptable test-retest reliability of non-navigated TMS outcomes when using the appropriate 95% CI for ICC, SDC and LOA values.

CLINICAL TRIAL REGISTRATION

Current Controlled Trials: ISCRT 19090862, http://www.controlled-trials.com.

The Temporal Relationship between Blood-Brain Barrier Integrity and Microglial Response following Neonatal Hypoxia Ischemia

Blood-brain barrier (BBB) dysfunction and neuroinflammation are key mechanisms of brain injury. We performed a time-course study following neonatal hypoxia-ischemia (HI) to characterize these events. HI brain injury was induced in postnatal day 10 rats by single carotid artery ligation followed by hypoxia (8% oxygen, 90 min). At 6, 12, 24, and 72 h (h) post-HI, brains were collected to assess neuropathology and BBB dysfunction. A significant breakdown of the BBB was observed in the HI injury group compared to the sham group from 6 h in the cortex and hippocampus (p < 0.001), including a significant increase in albumin extravasation (p < 0.0033) and decrease in basal lamina integrity and tight-junction proteins. There was a decrease in resting microglia (p < 0.0001) transitioning to an intermediate state from as early as 6 h post-HI, with the intermediate microglia peaking at 12 h (p < 0.0001), which significantly correlated to the peak of microbleeds. Neonatal HI insult leads to significant brain injury over the first 72 h that is mediated by BBB disruption within 6 h and a transitioning state of the resident microglia. Key BBB events coincide with the appearance of the intermediate microglial state and this relationship warrants further research and may be a key target for therapeutic intervention.

Sleep duration and all-cause mortality among stroke survivors

BACKGROUND

Post stroke sleep duration could increase the risk of death. This study tested the hypothesis that inadequate sleep duration is associated with increased mortality among stroke survivors.

METHODS

The REasons for Geographic And Racial Differences in Stroke (REGARDS), a national population-based longitudinal study, was the data source. Sleep duration was ascertained between 2013 and 2016 among stroke survivors who were subsequently followed up until death or censored on December 31, 2022. Sleep duration was estimated as the difference between wake-up time and bedtime to which was subtracted the time spent in bed without sleep. Cox proportional hazards regression models were employed to investigate the association between sleep duration and all-cause mortality adjusting for demographic factors, socioeconomic factors, behavioral factors, and co-morbidities.

RESULTS

A total of 468 non-Hispanic Black and White stroke survivors were included in this analysis. The mean age was 76.3 years, 52.6% were females and 56.0% were non-Hispanic White individuals. The distribution of short (≤6 h), adequate (7.0-8.9 h), and long sleep (≥9 h) was 30.3%, 44.7%, and 25%, respectively. Over a mean follow-up of 5.0 years, 190 (40.6%) deaths occurred. Compared to stroke survivors with adequate sleep (7.0-8.9 h), stroke survivors with long sleep (≥9 h) were at increased risk of all-cause mortality (HR=1.46, 95% CI=1.01, 2.12). However, short sleep (≤6 h) was not significantly associated with an increased risk of all-cause mortality (HR=1.31, 95% CI=0.90, 1.91). Subgroup analyses indicated higher risk in the age <75 years, females, non-Hispanic Black individuals, and those living in the Stroke Belt region, but those differences were not statistically significant.

CONCLUSION

In this study of stroke survivors, 9 hours or more of sleep per day was associated with an increased risk of all-cause mortality. This finding suggests that excessive sleep duration may be a warning sign of poor life expectancy in stroke survivors.

Environmental Enrichment in Stroke Research: an Update

Environmental enrichment (EE) refers to different forms of stimulation, where the environment is designed to improve the levels of sensory, cognitive, and motor stimuli, inducing stroke recovery in animal models. Stroke is a leading cause of mortality and neurological disability among older adults, hence the importance of developing strategies to improve recovery for such patients. This review provides an update on recent findings, compiling information regarding the parameters affected by EE exposure in both preclinical and clinical studies. During stroke recovery, EE exposure has been shown to improve both the cognitive and locomotor aspects, inducing important neuroplastic alterations, increased angiogenesis and neurogenesis, and modified gene expression, among other effects. There is a need for further research in this field, particularly in those aspects where the evidence is inconclusive. Moreover, it is necessary refine and adapt the EE paradigms for application in human patients.

Coherent activity within and between hemispheres: cortico-cortical connectivity revealed by rTMS of the right posterior parietal cortex

Introduction

Low frequency (1 Hz) repetitive transcranial stimulation (rTMS) applied over right posterior parietal cortex (rPPC) has been shown to reduce cortical excitability both of the stimulated area and of the interconnected contralateral homologous areas. In the present study, we investigated the whole pattern of intra- and inter-hemispheric cortico-cortical connectivity changes induced by rTMS over rPPC.

Methods

To do so, 14 healthy participants underwent resting state EEG recording before and after 30 min of rTMS at 1 Hz or sham stimulation over the rPPC (electrode position P6). Real stimulation was applied at 90% of motor threshold. Coherence values were computed on the electrodes nearby the stimulated site (i.e., P4, P8, and CP6) considering all possible inter- and intra-hemispheric combinations for the following frequency bands: delta (0.5-4 Hz), theta (4-8 Hz), alpha (8-12Hz), low beta (12-20 Hz), high beta (20-30 Hz), and gamma (30-50 Hz).

Results and discussion

Results revealed a significant increase in coherence in delta, theta, alpha and beta frequency bands between rPPC and the contralateral homologous sites. Moreover, an increase in coherence in theta, alpha, beta and gamma frequency bands was found between rPPC and right frontal sites, reflecting the activation of the fronto-parietal network within the right hemisphere. Summarizing, subthreshold rTMS over rPPC revealed cortico-cortical inter- and intra-hemispheric connectivity as measured by the increase in coherence among these areas. Moreover, the present results further confirm previous evidence indicating that the increase of coherence values is related to intra- and inter-hemispheric inhibitory effects of rTMS. These results can have implications for devising evidence-based rehabilitation protocols after stroke.

Immersive virtual reality-based rehabilitation for subacute stroke: a randomized controlled trial

OBJECTIVE

Few effective treatments improve upper extremity (UE) function after stroke. Immersive virtual reality (imVR) is a novel and promising strategy for stroke UE recovery. We assessed the extent to which imVR-based UE rehabilitation can augment conventional treatment and explored changes in brain functional connectivity (FC) that were related to the rehabilitation.

METHODS

An assessor-blinded, parallel-group randomized controlled trial was performed with 40 subjects randomly assigned to either imVR or Control group (1:1 allocation), each receiving rehabilitation 5 times per week for 3 weeks. Subjects in the imVR received both imVR and conventional rehabilitation, while those in the Control received conventional rehabilitation only. Our primary and secondary outcomes were the Fugl-Meyer assessment's upper extremity subscale (FMA-UE) and the Barthel Index (BI), respectively. Both intention-to-treat (ITT) and per-protocol (PP) analyses were performed to assess the effectiveness of the trial. For both the FMA-UE/BI, a one-way analysis of covariance (ANCOVA) model was used, with the FMA-UE/BI at post-intervention or at follow-up, respectively, as the dependent variable, the two groups as the independent variable, baseline FMA-UE/BI, age, sex, site, time since onset, hypertension and diabetes as covariates.

RESULTS

Both ITT and PP analyses demonstrated the effectiveness of imVR-based rehabilitation. The FMA-UE score was greater in the imVR compared with the Control at the post-intervention (mean difference: 9.1 (95% CI 1.6, 16.6); P = 0.019) and follow-up (mean difference:11.5 (95% CI 1.9, 21.0); P = 0.020). The results were consistent for BI scores. Moreover, brain FC analysis found that the motor function improvements were associated with a change in degree in ipsilesional premotor cortex and ipsilesional dorsolateral prefrontal cortex immediately following the intervention and in ipsilesional visual region and ipsilesional middle frontal gyrus after the 12-week follow-up.

CONCLUSIONS

ImVR-based rehabilitation is an effective tool that can improve the recovery of UE functional capabilities of subacute stroke patients when added to standard care. These improvements were associated with distinctive brain changes at two post-stroke timepoints. The study results will benefit future patients with stroke and provide evidence for a promising new method of stroke rehabilitation.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03086889.

Impact of Early Mobilization on Patients With Acute Ischemic Stroke Treated With Thrombolysis or Thrombectomy: A Randomized Controlled Trial

BACKGROUND

Early mobilization (EM) within 24 to 72 hours post-stroke may improve patients' performance and ability. However, after intravenous thrombolysis (IVT) or mechanical thrombectomy (MT), the increased risk of hemorrhagic complications impacts the implementation of early out-of-bed mobilization. Few studies have investigated EM after IVT or MT for acute ischemic stroke (AIS), and its impact in these patients is unknown.

OBJECTIVE

To investigate the effect of EM on AIS treated with IVT or MT.|.

METHODS

We recruited 122 patients with first AIS; 60 patients were treated with IVT, and 62 patients were treated with MT. For each IVT and MT cohort, the control groups received standard early rehabilitation, and the intervention groups received an EM protocol. The training lasted 30 minutes/day, 5 days/week until discharge.

MAIN OUTCOMES MEASURES

The effectiveness of the interventions was evaluated using the motor domain of the Functional Independence Measure (FIM-motor) and the Postural Assessment Scale for Stroke Patients (PASS) at baseline, 2-week, 4-week, and 3-month post-stroke, the Functional Ambulation Category 2-week post-stroke, and the total length of stay at the stroke center.

RESULTS

Both IVT and MT treatment groups showed improved FIM-motor and PASS scores over time; however, only the IVT EM group had significantly improved FIM-motor performance within 1 month after stroke than the control group. Conclusion. An EM protocol with the same intervention time and session frequency per day as in the standard care protocol was effective in improving the functional ability of stroke patients after IVT.

Dexterity in the Acute Phase of Stroke: Impairments and Neural Substrates

BACKGROUND

Stroke can impair manual dexterity, leading to loss of independence following incomplete recovery. Enhancing our understanding of dexterity impairment may improve neurorehabilitation.

OBJECTIVES

The study aimed to measure dexterity components in acute stroke patients with and without hand motor deficits, compare them to those of healthy controls (HC), and to explore the neural substrates involved in specific components of dexterity.

METHODS

We used the Dextrain Manipulandum to quantify fine finger force control, finger selection accuracy, coactivation, and reaction time (RT). Dexterity was evaluated twice (2 days apart) in 74 patients and 14 HC. Voxel-Lesion-Symptom-Mapping (VLSM) was used to analyze the relationship between tissue damage and dexterity. Results. Due to severe paresis or fatigue, 24 patients could not perform these tasks. In 50 patients (included 4.6 ± 3.3 days post-stroke), finger force control improved (P < .001), as it did in HC (P = .03) who performed better than patients on both evaluations. Accuracy of finger selection did not improve significantly in any group, but the HC performed better on both evaluations. Unexpectedly, coactivation was better in patients than in HC at D3 (P = .03). There were no between-group differences in RT. VLSM showed that damage to the superior temporal gyrus (STG) impaired finger force control while damage to the posterior limb of the internal capsule (PLIC) impaired finger selectivity.

CONCLUSIONS

Acute stroke affecting the STG or PLIC impaired selective components of dexterity. Patients with mild to moderate impairment showed better finger force control and accuracy selection within 48 hours, suggesting the feasibility of detecting early dexterity improvements.

The Relevance of Reperfusion Stroke Therapy for miR-9-3p and miR-9-5p Expression in Acute Stroke-A Preliminary Study

Reperfusion stroke therapy is a modern treatment that involves thrombolysis and the mechanical removal of thrombus from the extracranial and/or cerebral arteries, thereby increasing penumbra reperfusion. After reperfusion therapy, 46% of patients are able to live independently 3 months after stroke onset. MicroRNAs (miRNAs) are essential regulators in the development of cerebral ischemia/reperfusion injury and the efficacy of the applied treatment. The first aim of this study was to examine the change in serum miRNA levels via next-generation sequencing (NGS) 10 days after the onset of acute stroke and reperfusion treatment. Next, the predictive values of the bioinformatics analysis of miRNA gene targets for the assessment of brain ischemic response to reperfusion treatment were explored. Human serum samples were collected from patients on days 1 and 10 after stroke onset and reperfusion treatment. The samples were subjected to NGS and then validated using qRT-PCR. Differentially expressed miRNAs (DEmiRNAs) were used for enrichment analysis. Hsa-miR-9-3p and hsa-miR-9-5p expression were downregulated on day 10 compared to reperfusion treatment on day 1 after stroke. The functional analysis of miRNA target genes revealed a strong association between the identified miRNA and stroke-related biological processes related to neuroregeneration signaling pathways. Hsa-miR-9-3p and hsa-miR-9-5p are potential candidates for the further exploration of reperfusion treatment efficacy in stroke patients.

Endovascular thrombectomy plus medical care versus medical care alone for large ischaemic stroke: 1-year outcomes of the SELECT2 trial

BACKGROUND

Multiple randomised trials have shown efficacy and safety of endovascular thrombectomy in patients with large ischaemic stroke. The aim of this study was to evaluate long-term (ie, at 1 year) evidence of benefit of thrombectomy for these patients.

METHODS

SELECT2 was a phase 3, open-label, international, randomised controlled trial with blinded endpoint assessment, conducted at 31 hospitals in the USA, Canada, Spain, Switzerland, Australia, and New Zealand. Patients aged 18-85 years with ischaemic stroke due to proximal occlusion of the internal carotid artery or of the first segment of the middle cerebral artery, showing large ischaemic core on non-contrast CT (Alberta Stroke Program Early Computed Tomographic Score of 3-5 [range 0-10, with lower values indicating larger infarctions]) or measuring 50 mL or more on CT perfusion and MRI, were randomly assigned, within 24 h of ischaemic stroke onset, to thrombectomy plus medical care or to medical care alone. The primary outcome for this analysis was the ordinal modified Rankin Scale (range 0-6, with higher scores indicating greater disability) at 1-year follow-up in an intention-to-treat population. The trial is registered at ClinicalTrials.gov (NCT03876457) and is completed.

FINDINGS

The trial was terminated early for efficacy at the 90-day follow-up after 352 patients had been randomly assigned (178 to thrombectomy and 174 to medical care only) between Oct 11, 2019, and Sept 9, 2022. Thrombectomy significantly improved the 1-year modified Rankin Scale score distribution versus medical care alone (Wilcoxon-Mann-Whitney probability of superiority 0·59 [95% CI 0·53-0·64]; p=0·0019; generalised odds ratio 1·43 [95% CI 1·14-1·78]). At the 1-year follow-up, 77 (45%) of 170 patients receiving thrombectomy had died, compared with 83 (52%) of 159 patients receiving medical care only (1-year mortality relative risk 0·89 [95% CI 0·71-1·11]).

INTERPRETATION

In patients with ischaemic stroke due to a proximal occlusion and large core, thrombectomy plus medical care provided a significant functional outcome benefit compared with medical care alone at 1-year follow-up.

FUNDING

Stryker Neurovascular.

Spontaneous Behavioural Recovery Following Stroke Relates to the Integrity of Parietal and Temporal Regions

Stroke is a devastating disease that results in neurological deficits and represents a leading cause of death and disability worldwide. Following a stroke, there is a degree of spontaneous recovery of function, the neural basis of which is of great interest among clinicians in their efforts to reduce disability following stroke and enhance rehabilitation. Conventionally, work on spontaneous recovery has tended to focus on the neural reorganization of motor cortical regions, with comparably little attention being paid to changes in non-motor regions and how these relate to recovery. Here we show, using structural neuroimaging in a macaque stroke model (N = 31) and by exploiting individual differences in spontaneous behavioural recovery, that the preservation of regions in the parietal and temporal cortices predict animal recovery. To characterize recovery, we performed a clustering analysis using Non-Human Primate Stroke Scale (NHPSS) scores and identified a good versus poor recovery group. By comparing the preservation of brain volumes in the two groups, we found that brain areas in integrity of brain areas in parietal, temporal and somatosensory cortex were associated with better recovery. In addition, a decoding approach performed across all subjects revealed that the preservation of specific brain regions in the parietal, somatosensory and medial frontal cortex predicted recovery. Together, these findings highlight the importance of parietal and temporal regions in spontaneous behavioural recovery.

Efficacy and feasibility of a digital speech therapy for post-stroke dysarthria: protocol for a randomized controlled trial

Background

Dysarthria is a motor speech disorder caused by various neurological diseases, particularly stroke. Individuals with post-stroke dysarthria experience impaired speech intelligibility, communication difficulties, and a reduced quality of life. However, studies on the treatment of post-stroke dysarthria are lacking. Digital speech therapy applications have the advantages of being personalized and easily accessible. However, evidence for their efficacy is not rigorous. Moreover, no studies have investigated both the acute to subacute, and chronic phases of stroke. This study aims to investigate the efficacy and feasibility of digital speech therapy applications in addressing these gaps in dysarthria treatment.

Methods and design

This study is a multicenter, prospective, randomized, evaluator-blinded non-inferiority trial. We aim to recruit 76 participants with post-stroke dysarthria. Eligible participants will be stratified based on the onset period of stroke into acute to subacute, and chronic phases. Participants will be randomized in a 1:1 to receive either a personalized digital speech therapy application or conventional therapy with a workbook for 60 min daily, 5 days a week, for 4 weeks. The primary outcome is the improvement in speech intelligibility. This will be measured by how accurately independent listeners can transcribe passages read by the participants. Secondary outcomes, which include speech function, will be evaluated remotely by speech-language pathologists. This includes the maximum phonation time, oral diadochokinetic rate, and percentage of consonants correct. Participants' psychological well-being will also be assessed using self-report questionnaires, such as depressive symptoms (Patient Health Questionnaire-9) and quality of life (Quality of Life in the Dysarthric Speaker scale). The trial will also assess the feasibility, participant adherence, and usability of the application. Rigorous data collection and monitoring will be implemented to ensure patient safety.

Conclusion

This trial aims to investigate the efficacy and feasibility of digital speech therapy applications for treating post-stroke dysarthria. The results could establish foundational evidence for future clinical trials with larger sample sizes.

Clinical trial registration

Clinicaltrials.gov, identifier: NCT05865106.

A Comprehensive Review on the Role of Resting-State Functional Magnetic Resonance Imaging in Predicting Post-Stroke Motor and Sensory Outcomes

Stroke is a major leading cause of chronic disability, often affecting patients' motor and sensory functions. Functional magnetic resonance imaging (fMRI) is the most commonly used method of functional neuroimaging, and it allows for the non-invasive study of brain activity. The time-dependent coactivation of different brain regions at rest is described as resting-state activation. As a non-invasive task-independent functional neuroimaging approach, resting-state fMRI (rs-fMRI) may provide therapeutically useful information on both the focal vascular lesion and the connectivity-based reorganization and subsequent functional recovery in stroke patients. Considering the role of a prompt and accurate prognosis in stroke survivors along with the potential of rs-fMRI in identifying patterns of neuroplasticity in different post-stroke phases, this review provides a comprehensive overview of the latest literature regarding the role of rs-fMRI in stroke prognosis in terms of motor and sensory outcomes. Our comprehensive review suggests that with the advancement of MRI acquisition and data analysis methods, rs-fMRI emerges as a promising tool to study the motor and sensory outcomes in stroke patients and evaluate the effects of different interventions.

Mobile health applications for improving physical function, physical activity, and quality of life in stroke survivors: a systematic review

PURPOSE

To evaluate the effectiveness of mobile health applications (mHealth apps) containing a physical training component on physical function and physical activity in stroke rehabilitation.

MATERIALS AND METHODS

A systematic literature search was conducted in three databases for studies published from inception to 12 July 2022. Clinical trials including mHealth apps with a physical training component were included using outcomes of physical function and physical activity. Quality of life was extracted as a secondary outcome.

RESULTS

Five RCTs, two non-RCTs, and four uncontrolled clinical trials were included with a total of 264 stroke survivors. Eleven apps were identified with a physical training component using features of gamification (six apps), exercise prescription (three apps), and physical activity (two apps). Six out of seven studies reported statistically significant improvements in physical function in favor of the experimental group, with the most robust findings for upper extremity function. For physical activity, statistically significant improvements were seen in the experimental groups. Only one study showed significant improvement in quality of life. Overall study quality was fair.

CONCLUSIONS

mHealth apps containing a physical training component are promising for physical function and physical activity in stroke rehabilitation. Further research is warranted to confirm these conclusions.Implications for rehabilitationDesign content of mobile apps with a physical training component were focused on gamification, exercise prescription, and physical activityUsing mobile app-delivered therapy seem promising for improving upper extremity function in stroke rehabilitationUsing mobile apps also supported an increase of physical activity in people with strokeStudies using mobile apps should report more specifically the dosage of physical training and adherenceUsing mobile apps seems promising as an additional tool for clinical work, however, more studies are required to understand their effectiveness in stroke rehabilitation.

Motor rehabilitation after stroke: European Stroke Organisation (ESO) consensus-based definition and guiding framework

PURPOSE

To propose a consensus-based definition and framework for motor rehabilitation after stroke.

METHODS

An expert European working group reviewed the literature, attaining internal consensus after external feedback.

FINDINGS

Motor rehabilitation is defined as a process that engages people with stroke to benefit their motor function, activity capacity and performance in daily life. It is necessary for people with residual motor disability whose goal is to enhance their functioning, independence and participation. Motor rehabilitation operates through learning- and use-dependent mechanisms. The trajectory of motor recovery varies across patients and stages of recovery. Early behavioral restitution of motor function depends on spontaneous biological mechanisms. Further improvements in activities of daily living are achieved by compensations. Motor rehabilitation is guided by regular assessment of motor function and activity using consensus-based measures, including patient-reported outcomes. Results are discussed with the patient and their carers to set personal goals. During motor rehabilitation patients learn to optimize and adapt their motor, sensory and cognitive functioning through appropriately dosed repetitive, goal-oriented, progressive, task- and context-specific training. Motor rehabilitation supports people with stroke to maximize health, well-being and quality of life. The framework describes the International Classification of Functioning, Disability and Health in the context of stroke, describes neurobiological mechanisms of behavioral restitution and compensation, and summarizes recommendations for clinical assessment, prediction tools, and motor interventions with strong recommendations from clinical practice guidelines (2016-2022).

CONCLUSIONS

This definition and framework may guide clinical educators, inform clinicians on current recommendations and guidelines, and identify gaps in the evidence base.

Ginkgolide B promotes spontaneous recovery and enhances endogenous netrin-1 after neonatal hypoxic-ischemic brain damage

OBJECTIVES

Perinatal hypoxic-ischemic encephalopathy (HIE) is a condition that can lead to long-term cognitive, motor, and behavioral impairments in newborns. Although brain hypothermia therapy is currently the standard treatment for HIE, it does not provide complete neuroprotection. As a result, there is a need to explore additional therapies to enhance treatment outcomes. This study aims to investigate the potential role of Ginkgolide B (GB) in promoting neuroplasticity and facilitating spontaneous recovery after HIE.

METHODS

In this study, we employed a neonatal rat model of HIE to investigate the effects of GB on spontaneous recovery. GB treatment was initiated 24 h after hypoxia and administered continuously for a duration of 14 days. We evaluated several outcome measures after the treatment period, including spontaneous behavioral recovery and brain repair. Additionally, we quantified the levels of netrin-1 in both plasma and the peri-ischemic zone after the occurrence of HIE.

RESULTS

We found that GB treatment significantly facilitated spontaneous behavioral recovery in the HIE pups. Furthermore, cognitive function was restored, and brain tissue repair had a noticeable acceleration. We observed increased cell proliferation in the subventricular, stratum, and subgranular zones. Of particular interest, we observed elevated levels of netrin-1 in both plasma and the ischemic penumbra following GB treatment.

CONCLUSION

Our findings suggest that GB promotes neuroplasticity and enhances spontaneous recovery in newborns affected by HIE. The observed upregulation of netrin-1 may be crucial in mediating these effects. These results highlight the promising potential of GB as a post-HIE therapy, particularly in enhancing spontaneous recovery and improving long-term outcomes.

Longitudinal optogenetic mapping reveals enhanced motor control by the contralesional cortex after traumatic brain injury in mice

Traumatic brain injury (TBI) is a significant cause of human disability, and understanding its spontaneous recovery pattern after injury is critical for potential treatments. However, studies on the function of the contralesional cortex after TBI have mostly focused on acute-phase changes, and long-term dynamic changes in the control of the affected limb by the contralesional cortex are less understood. To unravel long-term adaptations in the contralesional cortex, we developed a mouse model of TBI and used longitudinal optogenetic motor mapping to observe the function of contralesional corticospinal neurons (CSNs) projecting to the unilateral seventh cervical (C7) segment of the spinal cord. We injected a retrograde adeno-associated virus (AAV) expressing channelrhodopsin-2 to optogenetically stimulate and map the functional connections of the motor-sensory cortex. We validated the effectiveness of transcranial optogenetic stimulation for functional mapping and observed a general increase in the control of the affected limb by the contralesional cortex over time. Using retrograde labeling techniques, we showed that TBI does not affect the distribution of C7-CSNs but alters their function, and the labeled CSNs are concentrated in the caudal and rostral forelimb areas. Our findings provide new insights into harnessing contralesional cortical plasticity to improve treatment for affected limbs. This study sheds light on the long-term adaptations in the contralesional cortex after TBI, paving the way for potential clinical applications of optogenetic stimulation to improve motor control and rehabilitation outcomes.

High-definition transcranial direct current stimulation for upper extremity rehabilitation in moderate-to-severe ischemic stroke: a pilot study

Introduction

Previous studies found that post-stroke motor impairments are associated with damage to the lesioned corticospinal tract (CST) and hyperexcitability of the contralesional cortico-reticulospinal tract (CRST). This proof-of-concept study aims to develop a non-invasive brain stimulation protocol that facilitates the lesioned CST and inhibits the contralesional CRST to improve upper extremity rehabilitation in individuals with moderate-to-severe motor impairments post-stroke.

Methods

Fourteen individuals (minimum 3 months post ischemic stroke) consented. Physician decision of the participants baseline assessment qualified eight to continue in a randomized, double-blind cross-over pilot trial (ClinicalTrials.gov Identifier: NCT05174949) with: (1) anodal high-definition transcranial direct stimulation (HD-tDCS) over the ipsilesional primary motor cortex (M1), (2) cathodal HD-tDCS over contralesional dorsal premotor cortex (PMd), (3) sham stimulation, with a two-week washout period in-between. Subject-specific MR images and computer simulation were used to guide HD-tDCS and verified by Transcranial Magnetic Stimulation (TMS) induced Motor Evoked Potential (MEP). The motor behavior outcome was evaluated by an Fugl-Meyer Upper Extremity score (primary outcome measure) and the excitability of the ipslesoinal CST and contralesional CRST was determined by the change of MEP latencies and amplitude (secondary outcome measures).

Results

The baseline ipsilesional M1 MEP latency and amplitude were correlated with FM-UE. FM-UE scores were improved post HD-tDCS, in comparison to sham stimulation. Both anodal and cathodal HD-tDCS reduced the latency of the ipsilesional M1 MEP. The contralesional PMd MEP disappeared/delayed after HD-tDCS.

Discussion

These results suggest that HD-tDCS could improve the function of the lesioned corticospinal tract and reduce the excitability of the contralesional cortico-reticulospinal tract, thus, improving motor function of the upper extremity in more severely impaired individuals.

Advanced rehabilitation in ischaemic stroke research

At present, due to the rapid progress of treatment technology in the acute phase of ischaemic stroke, the mortality of patients has been greatly reduced but the number of disabled survivors is increasing, and most of them are elderly patients. Physicians and rehabilitation therapists pay attention to develop all kinds of therapist techniques including physical therapy techniques, robot-assisted technology and artificial intelligence technology, and study the molecular, cellular or synergistic mechanisms of rehabilitation therapies to promote the effect of rehabilitation therapy. Here, we discussed different animal and in vitro models of ischaemic stroke for rehabilitation studies; the compound concept and technology of neurological rehabilitation; all kinds of biological mechanisms of physical therapy; the significance, assessment and efficacy of neurological rehabilitation; the application of brain-computer interface, rehabilitation robotic and non-invasive brain stimulation technology in stroke rehabilitation.

Resting-State Connectivity in Acute and Subacute Poststroke Aphasia: A Functional Near-Infrared Spectroscopy Pilot Study

Background: Understanding how brain function and language skills change during early (acute and subacute) stroke phases is critical for maximizing patient recovery, yet functional neuroimaging studies of early aphasia are scarce. In this pilot study, we used functional near-infrared spectroscopy (fNIRS) to investigate how resting-state functional connectivity (rs-FC) in early aphasia differs from neurologically healthy adults and is related to language deficits. Materials and Methods: Twenty individuals with aphasia (12 acute and 8 subacute phase) and 15 healthy controls underwent rs-fNIRS imaging with a 46-channel montage centered over bilateral perisylvian language areas. FC was computed using a prewhitening, autoregressive Pearson correlation routine applied to preprocessed oxyhemoglobin (HbO) data. Connections were classified as left intra-, right intra-, or interhemispheric. We then compared rs-FC between groups by connection type and examined Spearman correlations between rs-FC averages and language measures within patients. Results: Participants in the acute phase had significantly reduced global rs-FC across all HbO-based connections compared to healthy controls. No significant differences were found in rs-FC between controls and patients in the subacute phase. Controlling for days since stroke, stronger right intra- and interhemispheric rs-FC was related to milder aphasia across all patients. Exploratory correlations revealed that relationships between language measures and rs-FC differed between acute and subacute patient groups. Conclusion: This study provides preliminary evidence that fNIRS-based rs-FC measures may be a viable metric to index the early impacts of stroke in people with aphasia.

Effectiveness of task-specific training using assistive devices and task-specific usual care on upper limb performance after stroke: a systematic review and meta-analysis

PURPOSE

Task-specific rehabilitation is a key indicator for successful rehabilitation to improve the upper limb performance after stroke. Assistive robotic and non-robotic devices are emerging to provide rehabilitation therapy; however, the effectiveness of task-specific training programs using assistive training devices compared with task-specific usual care training has not been summarized yet. Therefore, the effectiveness of task-specific training using assistive arm devices (TST-AAD) compared with task-specific usual care (TSUC) on the upper limb performance of patients with a stroke was investigated. To assess task specificity, a set of criteria was proposed: participation, program, relevant, repeated, randomized, reconstruction and reinforced.

MATERIALS AND METHODS

Out of 855 articles, 17 fulfilled the selection criteria. A meta-analysis was performed on the Fugl-Meyer Assessment scores in the subacute and chronic stages after stroke and during follow-up.

RESULTS AND CONCLUSION

Both TST-AAD and TSUC improved the upper limb performance after stroke. In the sub-acute phase after stroke, TST-AAD was more effective than TSUC in reducing the upper limb impairment, although findings were based on only three studies. In the chronic phase, TST-AAD and TSUC showed similar effectiveness. No differences between the two types of training were found at the follow-up measurements. Future studies should describe training, device usage and criteria of task specificity in a standardized way to ease comparison.Implications for rehabilitationArm or hand function is often undertreated in stroke patients, assistive training devices may be able to improve the upper limb performance.Task-specific training using assistive devices is effective in improving the upper limb performance after stroke.Task-specific training using assistive devices seems to be more effective in reducing impairment compared with task specific usual care in the subacute phase after stroke, but they are equally effective in the chronic phase of stroke.

Test-Retest Reliability and Responsiveness of the Computerized Adaptive Testing System of the Functional Assessment of Stroke

OBJECTIVE

To examine the test-retest reliability, responsiveness, and clinical utility of the Computerized Adaptive Testing System of the Functional Assessment of Stroke (CAT-FAS) in persons with stroke.

DESIGN

Repeated measurements design.

SETTING

A department of rehabilitation in a medical center.

PARTICIPANTS

30 persons with chronic stroke (for test-retest reliability) and 65 persons with subacute stroke (for responsiveness) were recruited. To examine the test-retest reliability, the participants received measurements twice at 1-month intervals. To examine the responsiveness, the data were collected at admission and discharge from hospital.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASUREMENT TOOL

CAT-FAS.

RESULTS

The intra-class correlation coefficients of the CAT-FAS were ≥0.82, indicating good to excellent test-retest reliability. The Kazis' effect size and standardized response mean of the CAT-FAS were ≥0.96, indicating good group-level responsiveness. For individual-level responsiveness, approximately two-thirds of the participants exceeded the conditional minimal detectable change. On average, the CAT-FAS was completed within 9 items and 3 minutes per administration.

CONCLUSIONS

Our results suggest the CAT-FAS is an efficient measurement tool with good to excellent test-retest reliability and responsiveness. In addition, the CAT-FAS can be used routinely in clinical settings to monitor progress of the crucial 4 domains for persons with stroke.

Therapies and Challenges in the Post-Stroke Aphasia Rehabilitation Arena: Current and Future Prospects

Aphasia is a serious consequence of stroke that results in a breakdown in communication. The course of aphasia recovery differs between afflicted individuals, and responsiveness to treatment cannot be predicted. Aphasiologists continue to investigate numerous behavioral treatment protocols that have shifted their focus to complimentary rehabilitation strategies. The aim of this study is threefold. First, to summarize the different categories of aphasia interventions post-stroke, considering their respective protocols, and present available evidence on the effectiveness of those protocols. Second, to document the challenges regarding the prediction of aphasia treatment response post-stroke in individual patients. Third, to report the challenges faced by researchers in recruiting people with aphasia (PWA) for treatment studies, and provide recommendations on how to increase participant recruitment and retention. This study provides up-to-date information on (i) effective therapies and aphasia recovery processes, and (ii) research recruitment hurdles together with potential strategies for overcoming them.

The role of microRNA in neuronal inflammation and survival in the post ischemic brain: a review

Each year, more than 790 000 people in the United States suffer from a stroke. Although progress has been made in diagnosis and treatment of ischemic stroke (IS), new therapeutic interventions to protect the brain during an ischemic insult is highly needed. MicroRNAs (miRNAs) are small, non-coding RNAs that regulate gene expression post-transcriptionally. Growing evidence suggests that miRNAs have a profound impact on ischemic stroke progression and are potential targets of novel treatments. Notably, inflammatory pathways play an important role in the pathogenesis of ischemic stroke and its pathophysiologic progression. Experimental and clinical studies have illustrated that inflammatory molecular events collaboratively contribute to neuronal and glial cell survival, edema formation and regression, and vascular integrity. In the present review, we examine recent discoveries regarding miRNAs and their roles in post-ischemic stroke neuropathogenesis.

Adaptive Neuroplasticity in Brain Injury Recovery: Strategies and Insights

This review addresses the relationship between neuroplasticity and recovery from brain damage. Neuroplasticity's ability to adapt becomes crucial since brain injuries frequently result in severe impairments. We begin by describing the fundamentals of neuroplasticity and how it relates to rehabilitation. Examining different forms of brain injuries and their neurological effects highlights the complex difficulties in rehabilitation. By revealing cellular processes, we shed light on synaptic adaptability following damage. Our study of synaptic plasticity digs into axonal sprouting, dendritic remodeling, and the balance of long-term potentiation. These processes depict neural resilience amid change. Then, after damage, we investigate immediate and slow neuroplastic alterations, separating reorganizations that are adaptive from those that are maladaptive. As we go on to rehabilitation, we evaluate techniques that use neuroplasticity's potential. These methods take advantage of the brain's plasticity for healing, from virtual reality and brain-computer interfaces to constraint-induced movement therapy. Ethics and individualized neurorehabilitation are explored. We scrutinize the promise of combination therapy and the difficulties in putting new knowledge into clinical practice. In conclusion, this analysis highlights neuroplasticity's critical role in brain injury recovery, providing sophisticated approaches to improve life after damage.

Evaluation of BCAS1-positive immature oligodendrocytes after cerebral ischemic stroke and SVD

Ischemic cerebrovascular disease is an important cause of physical disability and dementia. Oligodendrocytes (OLGs), which differentiate from oligodendrocyte precursor cells (OPCs), are crucial for remyelination of the damaged brain and functional recovery. Breast carcinoma amplified sequence 1 (BCAS1) has recently been shown to be highly expressed in newly formed pre-myelinating oligodendrocytes (pre-mOLGs), while its expression level is reduced in mature OLGs. In this study, we analyzed BCAS1 expression by immunohistochemical analysis of human post-mortem brain tissue from six stroke patients (death within 2 months after stroke onset) and eight small vessel disease (SVD) patients. Control post-mortem brain tissue was from eight age-matched patients without any obvious central nervous system (CNS) pathology. The Olig2 expression in the area corresponding to the same section of the BCAS1-stained slice was analyzed to determine the total oligodendrocyte lineage. The percentage of differentiating OPCs in the oligodendrocyte lineage was calculated as the ratio of BCAS1+ to Olig2+ cells (BCAS1+/Olig2+). The stroke and SVD cases showed demyelination with decreased expression of myelin basic protein (MBP, a mature OLG marker). The stroke cases showed significantly increased numbers of early-stage BCAS1+ cells with an immature morphology and Olig2+ cells (pan-oligodendrocyte lineages) in the peri-infarct areas in both the cortex and white matter, but showed no increase in the number of late-stage BCAS1+ cells with a mature morphology. In contrast, the SVD cases showed no significant increase in Olig2+ and BCAS1+ cells. These results indicated that remyelination dysfunction could be attributed to insufficient maturation of OPCs in stroke and impaired recruitment of OPCs in SVD.

The Extent of Evidence Supporting the Effectiveness of Extended Reality Telerehabilitation on Different Qualitative and Quantitative Outcomes in Stroke Survivors: A Systematic Review

Objective: To present the extent of evidence concerning the effectiveness of extended reality telerehabilitation and patients' experiences of using different types of virtual reality exercises at home. Methods: We included studies on virtual reality and augmented reality telerehabilitation published in English. Systematic searches were undertaken in PubMed, Web of Sciences, Medline, Embase, CINAHL, and PEDro, with no date limitations. We included only RCTs and qualitative studies exploring patients' experiences. Methodological quality was assessed using the Cochrane Risk of Bias assessment tool for quantitative papers and the CASP scale for qualitative studies. All results are presented narratively. Results: Thirteen studies, nine quantitative and four qualitative, were included, with one qualitative and seven quantitative having a high risk of bias. All studies reported that extended reality-based telerehabilitation may be effective compared to conventional exercises or other extended reality exercises. Seven quantitative studies focused on upper limb function. Qualitative papers suggested that VR exercises were perceived as feasible by patients. Conclusions: The literature suggests VR home exercises are feasible and potentially effective for patients after a stroke in the upper limb. Further high-quality studies are needed to examine the effectiveness of XR exercises early adoption on different qualitative and quantitative outcomes. Registration number: (CRD42022384356).

Investigating the Predictive Value of Thyroid Hormone Levels for Stroke Prognosis

Given the expansion of life expectancy, the aging of the population, and the anticipated rise in the number of stroke survivors in Europe with severe neurological consequences in the coming decades, stroke is becoming the most prevalent cause of functional disability. Therefore, the prognosis for a stroke must be timely and precise. Two databases (MEDLINE and Scopus) were searched to identify all relevant studies published between 1 January 2005 and 31 December 2022 that investigated the relationship between thyroid hormone levels and acute stroke severity, mortality, and post-hospital prognosis. Only full-text English-language articles were included. This review includes Thirty articles that were traced and incorporated into the present review. Emerging data regarding the potential predictive value of thyroid hormone levels suggests there may be a correlation between low T3 syndrome, subclinical hypothyroidism, and poor stroke outcome, especially in certain age groups. These findings may prove useful for rehabilitation and therapy planning in clinical practice. Serum thyroid hormone concentration measurement is a non-invasive, relatively harmless, and secure screening test that may be useful for this purpose.

Multiscale effects of excitatory-inhibitory homeostasis in lesioned cortical networks: A computational study

Stroke-related disruptions in functional connectivity (FC) often spread beyond lesioned areas and, given the localized nature of lesions, it is unclear how the recovery of FC is orchestrated on a global scale. Since recovery is accompanied by long-term changes in excitability, we propose excitatory-inhibitory (E-I) homeostasis as a driving mechanism. We present a large-scale model of the neocortex, with synaptic scaling of local inhibition, showing how E-I homeostasis can drive the post-lesion restoration of FC and linking it to changes in excitability. We show that functional networks could reorganize to recover disrupted modularity and small-worldness, but not network dynamics, suggesting the need to consider forms of plasticity beyond synaptic scaling of inhibition. On average, we observed widespread increases in excitability, with the emergence of complex lesion-dependent patterns related to biomarkers of relevant side effects of stroke, such as epilepsy, depression and chronic pain. In summary, our results show that the effects of E-I homeostasis extend beyond local E-I balance, driving the restoration of global properties of FC, and relating to post-stroke symptomatology. Therefore, we suggest the framework of E-I homeostasis as a relevant theoretical foundation for the study of stroke recovery and for understanding the emergence of meaningful features of FC from local dynamics.

Scalp acupuncture regulates functional connectivity of cerebral hemispheres in patients with hemiplegia after stroke

Background

Stroke is a common cause of acquired disability on a global scale. Patients with motor dysfunction after a stroke have a reduced quality of life and suffer from an economic burden. Scalp acupuncture has been proven to be an effective treatment for motor recovery after a stroke. However, the neural mechanism of scalp acupuncture for motor function recovery remains to be researched. This study aimed to investigate functional connectivity (FC) changes in region of interest (ROI) and other brain regions to interpret the neural mechanism of scalp acupuncture.

Methods

Twenty-one patients were included and randomly divided into patient control (PCs) and scalp acupuncture (SAs) groups with left hemiplegia due to ischemic stroke, and we also selected 20 matched healthy controls (HCs). The PCs were treated with conventional Western medicine, while the SAs were treated with scalp acupuncture (acupuncture at the right anterior oblique line of vertex temporal). All subjects received whole-brain resting-state functional magnetic resonance imaging (rs-fMRI) scan before treatment, and the patients received a second scan after 14 days of treatment. We use the National Institutes of Health Stroke Scale (NIHSS) scores and the analyses of resting-state functional connectivity (RSFC) as the observational indicators.

Results

The contralateral and ipsilateral cortex of hemiplegic patients with cerebral infarction were associated with an abnormal increase and decrease in basal internode function. An abnormal increase in functional connectivity mainly exists in the ipsilateral hemisphere between the cortex and basal ganglia and reduces the abnormal functional connectivity in the cortex and contralateral basal ganglia. Increased RSFC was observed in the bilateral BA6 area and bilateral basal ganglia and the connectivity between bilateral basal ganglia nuclei improved. However, the RSFC of the conventional treatment group only improved in the unilateral basal ganglia and contralateral BA6 area. The RSFC in the left middle frontal gyrus, superior temporal gyrus, precuneus, and other healthy brain regions were enhanced in SAs after treatment.

Conclusion

The changes in functional connectivity between the cerebral cortex and basal ganglia in patients with cerebral infarction showed a weakening of the bilateral hemispheres and the enhancement of the connections between the hemispheres. Scalp acupuncture has the function of bidirectional regulation, which makes the unbalanced abnormal brain function state restore balance.

Rehabilitation in Animal Models of Stroke

OBJECTIVE

The purpose of this review was to evaluate the efficacy of rehabilitation strategies in animal models of stroke and their correlation with human stroke studies.

METHODS

General description of a stroke, functional recovery, and rehabilitation modalities were included from published studies in the field of animal models of cerebral ischemia and ischemia-reperfusion.

RESULTS

In stroke survivors, rehabilitation plays a significant role to improve motor function, cognition, and other subtle behaviors. Targeted pharmacological agents, including neuroprotective drugs, are helpful in animal models of stroke. However, no drug has yet been found that meets the criteria that would make it the Food and Drug Administration-approved treatment for human stroke. Instead, the rehabilitation of stroke in humans is limited to physical and occupational therapy, speech therapy, environmental enrichment, and social activities, as well as spiritual and family support.

CONCLUSION

Studies on stroke injury and the significance of stroke animals' rehabilitation, including physical and pharmacological, approaches are highlighted.

Patient-tailored transcranial direct current stimulation to improve stroke rehabilitation: study protocol of a randomized sham-controlled trial

BACKGROUND

Many patients do not fully regain motor function after ischemic stroke. Transcranial direct current stimulation (TDCS) targeting the motor cortex may improve motor outcome as an add-on intervention to physical rehabilitation. However, beneficial effects on motor function vary largely among patients within and across TDCS trials. In addition to a large heterogeneity of study designs, this variability may be caused by the fact that TDCS was given as a one-size-fits-all protocol without accounting for anatomical differences between subjects. The efficacy and consistency of TDCS might be improved by a patient-tailored design that ensures precise targeting of a physiologically relevant area with an appropriate current strength.

METHODS

In a randomized, double-blinded, sham-controlled trial, patients with subacute ischemic stroke and residual upper-extremity paresis will receive two times 20 min of focal TDCS of ipsilesional primary motor hand area (M1-HAND) during supervised rehabilitation training three times weekly for 4 weeks. Anticipated 60 patients will be randomly assigned to active or sham TDCS of ipsilesional M1-HAND, using a central anode and four equidistant cathodes. The placement of the electrode grid on the scalp and current strength at each cathode will be personalized based on individual electrical field models to induce an electrical current of 0.2 V/m in the cortical target region resulting in current strengths between 1 and 4 mA. Primary endpoint will be the difference in change of Fugl-Meyer Assessment of Upper Extremity (FMA-UE) score between active TDCS and sham at the end of the intervention. Exploratory endpoints will include UE-FMA at 12 weeks. Effects of TDCS on motor network connectivity and interhemispheric inhibition will be assessed with functional MRI and transcranial magnetic stimulation.

DISCUSSION

The study will show the feasibility and test the efficacy of personalized, multi-electrode anodal TDCS of M1-HAND in patients with subacute stroke patients with upper-extremity paresis. Concurrent multimodal brain mapping will shed light into the mechanisms of action of therapeutic personalized TDCS of M1-HAND. Together, the results from this trial may inform future personalized TDCS studies in patients with focal neurological deficits after stroke.

Predicted resting metabolic rate and prognosis in patients with ischemic stroke

PURPOSE

Resting metabolic rate (RMR) could represent metabolic health status. This study aims to examine the association of the predicted RMR with 1-year poor functional outcome and all-cause mortality in patients with ischemic stroke as a proxy of metabolic profile.

METHODS

A total of 15,166 patients with ischemic stroke or transient ischemic attack (TIA) from the Third China National Stroke Registry (CNSR-III) were enrolled in this study. The Harris-Benedict equation based on sex, age, weight, and height was used to predict RMR. The primary endpoints were poor functional outcome defined as ≥3 modified Rankin Scale (mRS) score and all-cause mortality within 1 year. The association between predicted RMR and prognosis was assessed by multivariable regression analysis. Besides that, subgroup analysis of age, sex, and body mass index (BMI) with predicted RMR was also performed.

RESULTS

12.85% (1657) individuals had poor functional outcome and 2.87% (380) died of whatever causes within 1 year. An inverse association was found between predicted RMR with poor functional outcome and all-cause mortality. Compared to the lowest quartile, the highest quartile was significantly associated with lower risk of poor functional outcome (adjusted odds ratio [OR], 0.43 [95% confidence interval (CI) 0.33-0.56]) and all-cause mortality (adjusted hazard ratio [HR], 0.44 [95% CI 0.28-0.71]). No significant interaction was between predicted RMR and specified subgroup.

CONCLUSIONS

Predicted RMR by the Harris-Benedict equation seems to be an independent protective predictor of poor functional outcome and all-cause mortality after ischemic stroke as a metabolic proxy.

Stroke self-efficacy questionnaire - Denmark (SSEQ-DK): test-retest of the Danish version

BACKGROUND

In stroke rehabilitation, measurement tools measuring self-efficacy with sound psychometric properties are needed. The Stroke Self-Efficacy Questionnaire (SSEQ) has recently been translated and validated into a Danish version (SSEQ-DK).

OBJECTIVES

To evaluate the test-retest reliability of the SSEQ-DK.

METHODS

Fifty people with stroke ≥ 18 years in the sub-acute and chronic phase were included from February 2019 to August 2020. The SSEQ-DK was completed twice; on day 1 and day 7-14. Test-retest reliability of the single items was assessed using weighted Cohen's kappa and percentage agreement. The activity and self-management scales were assessed by the intraclass correlation coefficient (ICC). Measurement error was assessed by calculating the Smallest Detectable Change (SDC) based on the standard error of measurement.

RESULTS

Overall, kappa values showed fair to substantial test-retest reliability of the single items. However, several kappa values were missing as the statistical prerequisites were not present. The percentage agreement ranged from 78% to 94%. Based on the reported confidence interval of the estimated intraclass correlation coefficient, the test-retest reliability of the activity and self-management scales was poor to excellent in all analysis. Ceiling effects appeared in the single items. Conversely, no floor effect was seen.

CONCLUSION

The SSEQ-DK showed good test-retest reliability of the single items based on agreement among a population with stroke in the subacute and chronic phase. Broad ICC confidence intervals bar any firm conclusions concerning the test-retest reliability of the activity and self-management scales.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03183960. Reg. 15 June 2017.

Effects of virtual reality-based telerehabilitation for stroke patients: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Telerehabilitation provides an essential opportunity to deliver continuous rehabilitation services for stroke patients at home, especially amid a global pandemic. Virtual reality is a simulation technology that has shown promising outcomes in stroke rehabilitation. Combining telerehabilitation and virtual reality is an emerging and innovative approach that enriches the rehabilitation experience and potentially enhances functional recovery outcomes. This review synthesized current evidence of using virtual reality-based telerehabilitation for patients after stroke and compared it with conventional in-person rehabilitation.

METHODS

Randomized controlled trials were searched across six databases published after 2000. Two independent reviewers conducted study selection, data extraction and quality assessment. The Physiotherapy Evidence Databases scale was used to evaluate the methodological quality. Qualitative synthesis and meta-analysis were conducted to compare functional outcomes after Virtual reality-based telerehabilitation with conventional in-person rehabilitation.

RESULTS

Nine studies including 260 participants were selected from 933 relevant records. Seven studies met the criteria for good quality based on the Physiotherapy Evidence Databases scale, two studies were fair quality. Compared with conventional in-person rehabilitation, the meta-analysis indicated that virtual reality-based telerehabilitation had comparable outcomes of upper extremity function and balance function. Both groups demonstrated similar effects on outcomes in mobility, cognition, activities of daily life, and quality of life.

CONCLUSIONS

Virtual reality-based telerehabilitation is an effective alternative approach for patients with stroke, given the barriers and restrictions of traditional in-person rehabilitation.

Segmental motor recovery after cervical spinal cord injury relates to density and integrity of corticospinal tract projections

Cervical spinal cord injury (SCI) causes extensive impairments for individuals which may include dextrous hand function. Although prior work has focused on the recovery at the person-level, the factors determining the recovery of individual muscles are poorly understood. Here, we investigate the muscle-specific recovery after cervical spinal cord injury in a retrospective analysis of 748 individuals from the European Multicenter Study about Spinal Cord Injury (NCT01571531). We show associations between corticospinal tract (CST) sparing and upper extremity recovery in SCI, which improves the prediction of hand muscle strength recovery. Our findings suggest that assessment strategies for muscle-specific motor recovery in acute spinal cord injury are improved by accounting for CST sparing, and complement person-level predictions.

Motivation, Physical Activity, and Affect in Community-Dwelling Stroke Survivors: An Ambulatory Assessment Approach

BACKGROUND

Motivation is a frequently reported but far less studied driver for post-stroke physical activity participation. Motivation and physical activity may be important contributors to the prevention management and alleviation of affective symptoms among stroke survivors.

PURPOSE

To investigate the real-time associations between motivation, physical activity, and affect in the daily lives of community-dwelling stroke survivors using ecological momentary assessment (EMA) and accelerometry.

METHODS

Forty community-dwelling stroke survivors wore an accelerometer on the thigh and completed EMA surveys assessing motivation (autonomous motivation, controlled motivation) and affect (negative affect, positive affect) eight times daily for 7 days. Multivariate regression analysis and multilevel modeling investigated the associations between motivation, physical activity, and affect.

RESULTS

Greater autonomous motivation for physical activity was associated with less sedentary behavior (β = -0.40, p = .049) and more moderate-to-vigorous physical activity (β = 0.45, p = .020) participation in daily life. Greater autonomous motivation was momentarily associated with less depressed affect (β = -0.05, p < .001) and greater positive affect (β = 0.13, p < .001). Moreover, greater controlled motivation was momentarily associated with greater depressed affect (β = 0.06, p < .001). More intense physical activity was momentarily associated with greater positive affect (β = 0.13, p = .016). No moderating effect of motivation on the association between physical activity and affect was found.

CONCLUSIONS

Motivation and physical activity are momentarily associated with affect among stroke survivors. Assessing and fostering autonomous motivation may be beneficial for promoting physical activity and managing positive and depressed affect as stroke survivors return to the community.

Extended Poststroke Rehabilitation Combined with Cerebrolysin Promotes Upper Limb Motor Recovery in Early Subacute Phase of Rehabilitation: A Randomized Clinical Study

Background and Objectives: The recovery of stroke patients with severe impairment is usually poor and limited and, unfortunately, under-investigated in clinical studies. In order to support neuroplasticity and modulate motor recovery, Cerebrolysin combined with rehabilitation treatment has proven effective in the acute stroke phase in moderate to severe motor impairment. The aim of this study was to determine the efficacy of extended poststroke rehabilitation combined with Cerebrolysin on upper limb motor recovery in subacute stroke patients with severe upper limb motor impairment. Materials and Methods: A randomized, double-blind, placebo-controlled study was conducted. Sixty patients at the early stage of severe sub-acute stroke who fulfilled all eligibility criteria were randomly assigned to the Cerebrolysin group or placebo group (𝑛 = 30 each). Both groups, after conducting three weeks of conventional rehabilitation treatment five days per week, continued to perform conventional rehabilitation treatment three times per week until 90 days of rehabilitation treatment. The primary outcome measure was the Action Research Arm Test (ARAT), and the secondary outcomes were the Fugl-Meyer Assessment-Upper Extremity (FMA-UE) motor score, Barthel index (BI), and the National Institutes of Health Stroke Scale (NIHSS). The outcome data were evaluated before, after three weeks of treatment, and on the 90th day of rehabilitation treatment, and compared within groups and between the two groups. There were no adverse events. Results: Both groups showed a significant improvement (p < 0.001) over time in BI, FMA-UE, ARAT, and NIHSS scores. Patients receiving Cerebrolysin showed more significant improvement in post-stroke upper limb motor impairment and functioning compared to the placebo group after only three weeks, and the trend was maintained after 90 days of follow up. Conclusion: Cerebrolysin delivered in the early subacute post-stroke phase added to extended conventional rehabilitation treatment is beneficial and improves motor functional recovery in patients with severe motor impairment, especially on the paretic upper extremity.

Feasibility of an Enhanced Therapy Model of Care for Hospitalized Stroke Patients

INTRODUCTION

The aim of this study was to determine the safety and feasibility of an enhanced therapy model for hospitalized stroke patients.

METHODS

This was a quasi-experimental cohort study of acute stroke patients from a single hospital. In the intervention group, all hospitalized patients on the acute stroke service were seen by at least two therapy disciplines daily in addition to routine stroke care. The comparison group consisted of all patients admitted to the same stroke service 1 year before who received the standard of care. The primary endpoint was the number of completed therapy sessions. Exploratory endpoints compared the length of hospital stay, hospital readmission rates, and degree of disability measured by the 90-day modified Rankin Scale score.

RESULTS

A total of 1110 records were analyzed with 553 subjects in the intervention group and 557 in the control group. The intervention group received a significantly higher number of therapy sessions. There was no significant difference in length of hospital stay. However, 30-day readmission rates were lower, and the percentage of patients who achieved a good functional outcome on the modified Rankin Scale was higher during the intervention period.

CONCLUSION

Increasing exposure to intensive multidisciplinary therapy comparable with that of acute inpatient rehabilitation in the hospital setting is feasible and may reduce both readmission rates and disability.

Bringing High-Dose Neurorestorative Behavioral Training Into the Acute Stroke Unit

ABSTRACT

Stroke remains common and is a leading cause of adult disability. While there have been enormous system changes for the diagnosis and delivery of hyperacute stroke treatments at comprehensive stroke centers, few advances have been made in those same centers for treatments focused on behavioral recovery and brain repair. Specifically, during the early hospital period, there is a paucity of approaches available for reduction of impairment beyond what is expected from spontaneous biological recovery. Thus, patients in the early stroke recovery period are not receiving the kind of training needed, at the requisite intensity and dose, to exploit a potential critical period of heightened brain plasticity that could maximize true recovery instead of just compensation. Here, we describe an ongoing pilot program to reconfigure the acute stroke unit experience to allow for a new emphasis on brain repair. More specifically, we have introduced a novel room-based video-gaming intervention; restorative neuroanimation, into the acute stroke hospital setting. This new intervention provides the opportunity for an extra hour(s) of high-intensity neurorestorative behavioral treatment that is complementary to conventional rehabilitation. To accomplish this, system redesign was required to insert this new treatment into the patient day, to properly stratify patients behaviorally and physiologically for the treatment, to optimize the digital therapeutic approach itself, and to maintain the impairment reduction after discharge.

Clinical Predictors for Upper Limb Recovery after Stroke Rehabilitation: Retrospective Cohort Study

After stroke, recovery of upper limb (UL) motor function is enhanced by a high dose of rehabilitation and is supposed to be supported by attentive functions. However, their mutual influence during rehabilitation is not well known yet. The aim of this retrospective observational cohort study was to investigate the association between rehabilitation dose and motor and cognitive functions, during UL motor recovery. Inpatients with first unilateral stroke, without time restrictions from onset, and undergoing at least 15 h of rehabilitation were enrolled. Data on dose and modalities of rehabilitation received, together with motor and cognitive outcomes before and after therapy, were collected. Fugl-Meyer values for the Upper Extremity were the primary outcome measure. Logistic regression models were used to detect any associations between UL motor improvement and motor and cognitive-linguistic features at acceptance, regarding dose of rehabilitation received. Thirty-five patients were enrolled and received 80.57 ± 30.1 h of rehabilitation on average. Manual dexterity, level of independence and UL motor function improved after rehabilitation, with no influence of attentive functions on motor recovery. The total amount of rehabilitation delivered was the strongest factor (p = 0.031) influencing the recovery of UL motor function after stroke, whereas cognitive-linguistic characteristics were not found to influence UL motor gains.

Additional therapy promotes a continued pattern of improvement in upper-limb function and independence post-stroke

BACKGROUND

Upper-limb motor impairment after stroke is common and disabling. Growing evidence suggests that rehabilitation is effective in the chronic period. However, there is limited knowledge on the effects of ongoing targeted rehabilitation programs on patient outcomes.

OBJECTIVES

This study investigated the effects of delivering two programs of dose-matched evidence-based upper-limb rehabilitation to community-dwelling post-acute stroke patients with low, moderate and high motor-function.

MATERIALS AND METHODS

12 patients (2 female) aged 50.5±18.2 years and 13.8±10.8 months post-stroke completed 2-weeks of modified-Constraint-Induced Movement Therapy followed by 2-weeks of Wii-based Movement Therapy after a mean interval of 9.6±1.1 months (range 6-19months). Function was assessed at 6 time points (i.e. before and after each therapy program and 6-month follow-up after each program). Primary outcome measures were the Wolf Motor Function Test timed-tasks (WMFT-tt), upper-limb Fugl-Meyer Assessment (F-M) and the Motor Activity Log Quality of Movement Scale (MALQOM). Improvement and maintenance was analyzed using Paired T-Tests and Wilcoxon Signed Rank Tests.

RESULTS

Upper-limb function significantly improved on all primary outcome measures with the first therapy program (WMFT-tt p=0.008, F-M p=0.007 and MALQOM p<0.0001). All scores continued to improve with the second therapy program with significant improvements in the F-M (p=0.048) and the MALQOM (p=0.001).

CONCLUSIONS

All patients showed a pattern of continued improvement in upper-limb motor-function and independence in activities of daily living. These improvements demonstrate the benefit of ongoing post-stroke rehabilitation for community-dwelling stroke survivors for individuals of varying baseline functional status.