Spontaneous Recovery of Upper Extremity Motor Impairment After Ischemic Stroke: Implications for Stem Cell-Based Therapeutic Approaches

Robotic-based ACTive somatoSENSory (Act.Sens) retraining on upper limb functions with chronic stroke survivors: study protocol for a pilot randomised controlled trial

Background

Prior studies have established that senses of the limb position in space (proprioception and kinaesthesia) are important for motor control and learning. Although nearly one-half of stroke patients have impairment in the ability to sense their movements, somatosensory retraining focusing on proprioception and kinaesthesia is often overlooked. Interventions that simultaneously target motor and somatosensory components are thought to be useful for relearning somatosensory functions while increasing mobility of the affected limb. For over a decade, robotic technology has been incorporated in stroke rehabilitation for more controlled therapy intensity, duration, and frequency. This pilot randomised controlled trial introduces a compact robotic-based upper-limb reaching task that retrains proprioception and kinaesthesia concurrently.

Methods

Thirty first-ever chronic stroke survivors (> 6-month post-stroke) will be randomly assigned to either a treatment or a control group. Over a 5-week period, the treatment group will receive 15 training sessions for about an hour per session. Robot-generated haptic guidance will be provided along the movement path as somatosensory cues while moving. Audio-visual feedback will appear following every successful movement as a reward. For the same duration, the control group will complete similar robotic training but without the vision occluded and robot-generated cues. Baseline, post-day 1, and post-day 30 assessments will be performed, where the last two sessions will be conducted after the last training session. Robotic-based performance indices and clinical assessments of upper limb functions after stroke will be used to acquire primary and secondary outcome measures respectively. This work will provide insights into the feasibility of such robot-assisted training clinically.

Discussion

The current work presents a study protocol to retrain upper-limb somatosensory and motor functions using robot-based rehabilitation for community-dwelling stroke survivors. The training promotes active use of the affected arm while at the same time enhances somatosensory input through augmented feedback. The outcomes of this study will provide preliminary data and help inform the clinicians on the feasibility and practicality of the proposed exercise.

Trial registration

ClinicalTrials.gov NCT04490655. Registered 29 July 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40814-021-00948-3.

Analysis of Prognostic Risk Factors Determining Poor Functional Recovery After Comprehensive Rehabilitation Including Motor-Imagery Brain-Computer Interface Training in Stroke Patients: A Prospective Study

Objective: Upper limb (UL) motor function recovery, especially distal function, is one of the main goals of stroke rehabilitation as this function is important to perform activities of daily living (ADL). The efficacy of the motor-imagery brain-computer interface (MI-BCI) has been demonstrated in patients with stroke. Most patients with stroke receive comprehensive rehabilitation, including MI-BCI and routine training. However, most aspects of MI-BCI training for patients with subacute stroke are based on routine training. Risk factors for inadequate distal UL functional recovery in these patients remain unclear; therefore, it is more realistic to explore the prognostic factors of this comprehensive treatment based on clinical practice. The present study aims to investigate the independent risk factors that might lead to inadequate distal UL functional recovery in patients with stroke after comprehensive rehabilitation including MI-BCI (CRIMI-BCI). Methods: This prospective study recruited 82 patients with stroke who underwent CRIMI-BCI. Motor-imagery brain-computer interface training was performed for 60 min per day, 5 days per week for 4 weeks. The primary outcome was improvement of the wrist and hand dimensionality of Fugl-Meyer Assessment (δFMA-WH). According to the improvement score, the patients were classified into the efficient group (EG, δFMA-WH > 2) and the inefficient group (IG, δFMA-WH ≤ 2). Binary logistic regression was used to analyze clinical and demographic data, including aphasia, spasticity of the affected hand [assessed by Modified Ashworth Scale (MAS-H)], initial UL function, age, gender, time since stroke (TSS), lesion hemisphere, and lesion location. Results: Seventy-three patients completed the study. After training, all patients showed significant improvement in FMA-UL (Z = 7.381, p = 0.000^**), FMA-SE (Z = 7.336, p = 0.000^**), and FMA-WH (Z = 6.568, p = 0.000^**). There were 35 patients (47.9%) in the IG group and 38 patients (52.1%) in the EG group. Multivariate analysis revealed that presence of aphasia [odds ratio (OR) 4.617, 95% confidence interval (CI) 1.435-14.860; p < 0.05], initial FMA-UL score ≤ 30 (OR 5.158, 95% CI 1.150-23.132; p < 0.05), and MAS-H ≥ level I+ (OR 3.810, 95% CI 1.231-11.790; p < 0.05) were the risk factors for inadequate distal UL functional recovery in patients with stroke after CRIMI-BCI. Conclusion: We concluded that CRIMI-BCI improved UL function in stroke patients with varying effectiveness. Inferior initial UL function, significant hand spasticity, and presence of aphasia were identified as independent risk factors for inadequate distal UL functional recovery in stroke patients after CRIMI-BCI.

Brain-Computer Interface Coupled to a Robotic Hand Orthosis for Stroke Patients' Neurorehabilitation: A Crossover Feasibility Study

Brain-Computer Interfaces (BCI) coupled to robotic assistive devices have shown promise for the rehabilitation of stroke patients. However, little has been reported that compares the clinical and physiological effects of a BCI intervention for upper limb stroke rehabilitation with those of conventional therapy. This study assesses the feasibility of an intervention with a BCI based on electroencephalography (EEG) coupled to a robotic hand orthosis for upper limb stroke rehabilitation and compares its outcomes to conventional therapy. Seven subacute and three chronic stroke patients (M = 59.9 ± 12.8) with severe upper limb impairment were recruited in a crossover feasibility study to receive 1 month of BCI therapy and 1 month of conventional therapy in random order. The outcome measures were comprised of: Fugl-Meyer Assessment of the Upper Extremity (FMA-UE), Action Research Arm Test (ARAT), motor evoked potentials elicited by transcranial magnetic stimulation (TMS), hand dynamometry, and EEG. Additionally, BCI performance and user experience were measured. All measurements were acquired before and after each intervention. FMA-UE and ARAT after BCI (23.1 ± 16; 8.4 ± 10) and after conventional therapy (21.9 ± 15; 8.7 ± 11) were significantly higher (p < 0.017) compared to baseline (17.5 ± 15; 4.3 ± 6) but were similar between therapies (p > 0.017). Via TMS, corticospinal tract integrity could be assessed in the affected hemisphere of three patients at baseline, in five after BCI, and four after conventional therapy. While no significant difference (p > 0.05) was found in patients’ affected hand strength, it was higher after the BCI therapy. EEG cortical activations were significantly higher over motor and non-motor regions after both therapies (p < 0.017). System performance increased across BCI sessions, from 54 (50, 70%) to 72% (56, 83%). Patients reported moderate mental workloads and excellent usability with the BCI. Outcome measurements implied that a BCI intervention using a robotic hand orthosis as feedback has the potential to elicit neuroplasticity-related mechanisms, similar to those observed during conventional therapy, even in a group of severely impaired stroke patients. Therefore, the proposed BCI system could be a suitable therapy option and will be further assessed in clinical trials.

Physiopathology of ischemic stroke and its modulation using memantine: evidence from preclinical stroke

Ischemic stroke is the most common type of cerebrovascular disease and is caused by an interruption of blood flow in the brain. In this disease, two different damage areas are identifying: the lesion core, in which cells quickly die; and the penumbra (surrounding the lesion core), in which cells are functionally weakened but may recover and restore their functions. The currently approved treatments for ischemic stroke are the recombinant tissue plasminogen activator and endovascular thrombectomy, but they have a short therapeutic window (4.5 and 6 hours after stroke onset, respectively) and a low percentage of stroke patients actually receive these treatments. Memantine is an approved drug for the treatment of Alzheimer’s disease. Memantine is a noncompetitive, low affinity and use-dependent antagonist of N-methyl-D-aspartate glutamate receptor. Memantine has several advantages over developing a new drug to treat focal ischemic stroke, but the most important is that it has sufficient safe probes in preclinical models and humans, and if the preclinical studies provide more evidence about pharmacological actions in tissue protection and repair, this could help to increase the number of clinical trials. The present review summarizes the physiopathology of isquemic stroke and the pharmacological actions in neuroprotection and neuroplasticity of memantine in the post stroke stage of preclinical stroke models, to illustrate their potential to improve functional recovery in human patients.

Adipose tissue derived stromal vascular fraction as an adjuvant therapy in stroke rehabilitation: Case reports

INTRODUCTION

Stroke often causes residual hemiparesis, and upper extremity motor impairment is usually more disabling than lower extremity in those who are suffering from post-stroke hemiparesis. Cell therapy is one of the promising therapies to reduce post-stroke disability.

PATIENT CONCERNS

Three male participants were included in the study to investigate the feasibility and tolerability of autologous adipose tissue derived stromal vascular fraction.

DIAGNOSIS

All participants had hemiparesis after 1st-ever stroke longer than 6 months previously.

INTERVENTIONS

Under general anesthesia, liposuction of abdominal subcutaneous fat was performed. Stromal vascular fraction freshly isolated from the adipose tissue extract was injected into the muscles of paretic upper extremity. All participants received inpatient stroke rehabilitation consisted of physical and occupational therapy more than 3 hours a day for 2 months or more.

OUTCOMES

The whole procedure did not produce any significant adverse event in all participants. Adipose tissue extracts yielded sufficient stromal cells. One participant showed clinically important change in upper extremity Fugl-Meyer assessment after the injection and it lasted up to 6 months. Functional magnetic resonance imaging showed concomitant increase in ipsilesional cortical activity. The other 2 participants did not show remarkable changes.

LESSONS

Intramuscular injection of autologous adipose tissue derived stromal vascular fraction seems to be a safe and tolerable procedure in subjects with chronic stroke, and its utility in rehabilitation needs further investigation.

Psychological Nursing of Patients With Stroke in China: A Systematic Review and Meta-Analysis

The present study aimed to evaluate the efficacy of psychological nursing of patients with stroke in China. The Embase, PubMed, Cochrane Library, CNKI, and Wanfang databases were searched from inception to February 1, 2020. Randomized controlled trials (RCTs) reporting the efficacy of psychological nursing of patients with stroke were included. Revman 5.3 and Stata 15.0 were used for data analysis. Twelve RCTs and 1,013 patients with stroke were included in this systematic review and meta-analysis. The results revealed a significant difference in the Hamilton depression score between the psychological nursing and usual care groups. The meta-analysis of three studies (n = 235) that used a depressive symptom control of ≥25% as the outcome measure showed a significant difference between the two groups. In addition, significant differences were detected in the National Institute of Health stroke scale score and activities of daily living score between the two groups. The present meta-analysis suggests that in China, compared to the usual care, psychological nursing is more effective for alleviating depressive symptoms, improving neurological rehabilitation, and recovering the ability of daily life.

MicroRNA-101a Regulates Autophagy Phenomenon via the MAPK Pathway to Modulate Alzheimer's-Associated Pathogenesis

Alzheimer’s disease (AD) is a type of neurodegenerative disorder and the most common form of dementia. MicroRNA (miRNA) has been shown to play a role in various diseases, including AD. It also has been reported to regulate autophagy. We extracted miRNA from blood samples and constructed an miRNA-101a lentivirus vector. In this study we found the level of miRNA-101a was significantly reduced in the plasma of patients with AD and APPswe/PS1ΔE9 transgenic mice. The relative expression of miRNA-101a exhibited a relatively high diagnostic performance (area under receiver operating characteristic curve: 0.8725) in the prediction of AD with a sensitivity of 0.913 and a specificity of 0.733 at the threshold of 0.6463. Under electron microscopy, autophagic vacuoles in AD-related cells numbered more than the cells up-regulating miRNA-101a in the in vitro experiments. Dual-luciferase reporter assay and Western blot results proved that the MAPK1 pathway plays a role in the formation of autophagic vacuoles in AD. This study found that the autophagy phenomenon regulated by miRNA-101a via the MAPK pathway might be a new mechanism in AD. This could provide new insights into AD formation and treatment.

The insights into molecular pathways of hypoxia-inducible factor in the brain

The objectives of this present work were to review recent developments on the role of hypoxia-inducible factor (HIF) in the survival of cells under normoxic versus hypoxic and inflammatory brain conditions. The dual nature of HIF effects appears well established, based on the accumulated evidence of HIF playing both the role of adaptive factor and mediator of cell demise. Cellular HIF responses depend on pathophysiological conditions, developmental phase, comorbidities, and administered medications. In addition, HIF-1α and HIF-2α actions may vary in the same tissues. The multiple roles of HIF in stem cells are emerging. HIF not only regulates expression of target genes and thereby influences resultant protein levels but also contributes to epigenetic changes that may reciprocally provide feedback regulations loops. These HIF-dependent alterations in neurological diseases and its responses to treatments in vivo need to be examined alongside with a functional status of subjects involved in such studies. The knowledge of HIF pathways might be helpful in devising HIF-mimetics and modulating drugs, acting on the molecular level to improve clinical outcomes, as exemplified here by clinical and experimental data of selected brain diseases, occasionally corroborated by the data from disorders of other organs. Because of complex role of HIF in brain injuries, prospective therapeutic interventions need to differentially target HIF responses depending on their roles in the molecular mechanisms of neurologic diseases.

Pharmacological approaches promoting stem cell-based therapy following ischemic stroke insults

Stroke can lead to long-term neurological deficits. Adult neurogenesis, the continuous generation of newborn neurons in distinct regions of the brain throughout life, has been considered as one of the appoaches to restore the neurological function following ischemic stroke. However, ischemia-induced spontaneous neurogenesis is not suffcient, thus cell-based therapy, including infusing exogenous stem cells or stimulating endogenous stem cells to help repair of injured brain, has been studied in numerous animal experiments and some pilot clinical trials. While the effects of cell-based therapy on neurological function during recovery remains unproven in randomized controlled trials, pharmacological agents have been administrated to assist the cell-based therapy. In this review, we summarized the limitations of ischemia-induced neurogenesis and stem-cell transplantation, as well as the potential proneuroregenerative effects of drugs that may enhance efficacy of cell-based therapies. Specifically, we discussed drugs that enhance proliferation, migration, differentiation, survival and function connectivity of newborn neurons, which may restore neurobehavioral function and improve outcomes in stroke patients.

Cell Therapy in Stroke-Cautious Steps Towards a Clinical Treatment

In the future, stroke patients may receive stem cell therapy as this has the potential to restore lost functions. However, the development of clinically deliverable therapy has been slower and more challenging than expected. Despite recommendations by STAIR and STEPS consortiums, there remain flaws in experimental studies such as lack of animals with comorbidities, inconsistent approaches to experimental design, and concurrent rehabilitation that might lead to a bias towards positive results. Clinical studies have typically been small, lacking control groups as well as often without clear biological hypotheses to guide patient selection. Furthermore, they have used a wide range of cell types, doses, and delivery methods, and outcome measures. Although some ongoing and recent trial programs offer hints that these obstacles are now being tackled, the Horizon2020 funded RESSTORE trial will be given as an example of inconsistent regulatory requirements and challenges in harmonized cell production, logistic, and clinical criteria in an international multicenter study. The PISCES trials highlight the complex issues around intracerebral cell transplantation. Therefore, a better understanding of translational challenges is expected to pave the way to more successful help for stroke patients.

Getting Closer to an Effective Intervention of Ischemic Stroke: The Big Promise of Stem Cell

Stem cell therapy for ischemic stroke has widely been explored. Results from both preclinical and clinical studies have immensely supported the judicious use of stem cells as therapy. These provide an attractive means for preserving and replacing the damaged brain tissues following an ischemic attack. Since the past few years, researchers have used various types of stem cells to replenish insulted neuronal and glial cells in neurological disorders. In the present review, we discuss different types of stem cells employed for the treatment of ischemic stroke and mechanisms and challenges these cells face once introduced into the living system. Further, we also present different ways to maneuver and overcome challenges to translate the advances made at the preclinical level to clinics.

Attitudes to Stem Cell Therapy Among Ischemic Stroke Survivors in the Lund Stroke Recovery Study

Preclinical studies suggest that stem cell therapy (SCT) may improve poststroke recovery, and clinical trials investigating safety are ongoing. However, knowledge about patients' attitudes to SCT in stroke is limited. We evaluated the knowledge and attitudes to this therapeutic approach as well as possible factors influencing this among stroke patients potentially suitable for SCT. Consecutive first-ever acute ischemic stroke patients aged 20-75 years with NIH stroke scale scores 1-18 were included. Exclusion criteria were severe comorbidities or infratentorial stroke. Clinical follow-up after 3-5 years assessed severity of residual stroke symptoms, cognitive function, functional status, patient-reported outcome, and comorbidity, and after receiving standardized information, the participants also completed an eight-item questionnaire on knowledge and attitudes about SCT. The relationships between clinical variables and positive attitude to SCT were assessed with logistic regression analyses. Of 108 patients included at baseline, 84 participated at follow-up and completed the questionnaire. In total, 12% had prior knowledge of SCT. When informed, 63% were positive toward it and 36% reported willingness to participate in SCT trials. Only 5%-8% expressed ethical considerations regarding different stem cell sources. Positive attitudes to SCT were associated with male gender (OR: 3.74; 95% CI: 1.45-9.61; P < 0.01) and better patient-reported outcome (OR: 1.02; 95% CI: 1.00-1.04; P < 0.05). In conclusion, stroke patients had limited prior knowledge of SCT, yet attitudes were positive among the majority after receiving standardized and neutral information. Gender and degree of stroke recovery may influence attitudes to SCT, indicating a need for targeted information to improve knowledge about SCT.