Enhancing Brain Plasticity to Promote Stroke Recovery

Visuomotor paired associative stimulation enhances corticospinal excitability in post-stroke patients with upper-limb hemiparesis

We assess the effectiveness of a visuomotor paired associative stimulation (vm-PAS) protocol targeting the Action Observation Network (AON) in chronic post-stroke patients with upper-limb mild hemiparesis. Vm-PAS consisted of hand-grasping action observation stimuli repeatedly paired with transcranial magnetic stimulation (TMS) pulses over the ipsilesional primary motor cortex (M1). Fifteen post-stroke patients underwent a session of the vm-PAS and, as a control, of the standard excitatory PAS (M1-PAS), during which slow-rate electrical stimulation of the paretic limb was paired with M1-TMS. Before and after each PAS, we assessed corticospinal excitability (CSE), short-interval intracortical inhibition (SICI), and paretic wrist's voluntary movements. The two protocols induce distinct muscle-specific CSE enhancements: vm-PAS increases motor-evoked potentials (MEPs) recorded from the paretic first dorsal interosseous muscle. Conversely, M1-PAS increases MEPs recorded from the electrically stimulated extensor carpi radialis muscle. Vm-PAS efficacy correlates with hemiparesis chronicity: the higher the time elapsed since the stroke, the greater vm-PAS effects on CSE. Neither protocol affected SICI or wrist movements. Our results suggest that vm-PAS leads to muscle-specific enhancements of CSE in post-stroke patients, highlighting its potential for modulating M1 excitability after stroke. These findings show the efficacy of a cross-modal PAS protocol targeting the AON in an injured motor system.

Melatonin enhances neurogenesis and neuroplasticity in long-term recovery following cerebral ischemia in mice

The important therapeutic role of melatonin in neuropathological conditions is underscored by a broad array of studies, many of which elucidated its neuroprotective properties. Yet, our scientific knowledge still needs several approaches to uncover molecular mechanisms. In this study, we contextually modelled cerebral ischemia through transient intraluminal middle cerebral artery occlusion. Melatonin was administered via an intraperitoneally placed mini osmotic pump, and released periodically from 3 days post-ischemia (dpi) to 56 dpi. We conferred several lines of evidence to address the fundamental questions about melatonin's cytoprotective functions after cerebral ischemia. We demonstrated that melatonin assisted post-ischemic neuro-restoration and micro-vascularization. In addition, it restricted glial scar formation, which interferes with neuronal interactions and stands as a barrier against plasticity. Even more interestingly, axonal plasticity, which was studied on the pyramidal tract using an anterograde tract tracer, proved the role of melatonin in remodeling across the injury site. In addition, plasticity-associated membrane-localized proteins, ephrin b1, ephrin b2, brevican, and versican were also modulated by melatonin. These findings suggested that melatonin orchestrated neurological recovery which was accompanied by molecular alterations resulting in cellular and extracellular structural changes. Based on the molecular signatures, ipsilesional and contralesional brain tissues were finely tuned by melatonin to compensate the loss after ischemia. Accordingly, neurological improvements correlated with the brain's molecular changes over time. It was suggested that melatonin enabled neuronal recovery by regulating neurogenesis and neuroplasticity in long term.

Effectiveness of Occupational Therapy Interventions on Activities of Daily Living, Cognitive Function, and Physical Function in Middle-Aged and Older People with Chronic Stroke: A Systematic Review with Meta-Analysis

Background: Occupational therapy (OT) interventions on activities of daily living (ADL), cognitive functions, and physical function in middle-aged and older people with chronic stroke. Methods: A systematic review search until November 2024 using five generic databases: PubMed/Medline, Web of Science, Scopus, ScienceDirect, and OT seeker. The PRISMA checklist, RoB 2 (Cochrane, London, UK), and GRADEpro (Evidence Prime Inc., Hamilton, CA) tools assessed the evidence's methodological quality and certainty. The protocol was registered in PROSPERO (code: CRD42024568225). Results: Of 1733 records were identified across the databases, nine studies were analyzed using the PICOS format. The meta-analysis revealed significant improvements in independent performance of activities of daily living (ADL), as measured by the Canadian Occupational Performance Measure (COPM), in favor of the experimental groups (p = 0.03). No significant differences were found for the other variables analyzed. Conclusions: Performance on ADLs improved significantly according to the COPM, whereas no significant improvements in cognitive or physical function were observed among middle-aged and older chronic stroke survivors. Individual studies highlight the potential benefits of OT interventions that combine cognitive, motor, and technological approaches, such as virtual reality and brain stimulation.

Neuroplasticity changes in cortical activity, grey matter, and white matter of stroke patients after upper extremity motor rehabilitation via a brain-computer interface therapy program

Objective. Upper extremity (UE) motor function loss is one of the most impactful consequences of stroke. Recently, brain-computer interface (BCI) systems have been utilized in therapy programs to enhance UE motor recovery after stroke, widely attributed to neuroplasticity mechanisms. However, the effect that the BCI's closed-loop feedback can have in these programs is unclear. The aim of this study was to quantitatively assess and compare the neuroplasticity effects elicited in stroke patients by a UE motor rehabilitation BCI therapy and by its sham-BCI counterpart.Approach. Twenty patients were randomly assigned to either the experimental group (EG), who controlled the BCI system via UE motor intention, or the control group (CG), who received random feedback. The elicited neuroplasticity effects were quantified using asymmetry metrics derived from electroencephalography (EEG), functional magnetic resonance imaging (fMRI), and diffusion tensor imaging (DTI) data acquired before, at the middle, and at the end of the intervention, alongside UE sensorimotor function evaluations. These asymmetry indexes compare the affected and unaffected hemispheres and are robust to lesion location variability.Main results. Most patients from the EG presented brain activity lateralisation to one brain hemisphere, as described by EEG (8 patients) and fMRI (6 patients) metrics. Conversely, the CG showed less pronounced lateralisations, presenting primarily bilateral activity patterns. DTI metrics showed increased white matter integrity in half of the EG patients' unaffected hemisphere, and in all but 2 CG patients' affected hemisphere. Individual patient analysis suggested that lesion location was relevant since functional and structural lateralisations occurred towards different hemispheres depending on stroke site.Significance. This study shows that a BCI intervention can elicit more pronounced neuroplasticity-related lateralisations than a sham-BCI therapy. These findings could serve as future biomarkers, helping to better select patients and increasing the impact that a BCI intervention can achieve. Clinical trial: NCT04724824.

Immune genes involved in synaptic plasticity during early postnatal brain development contribute to post-stroke damage in the aging male rat brain

Stroke remains a leading cause of mortality and long-term disability worldwide, underscoring the urgent need to identify novel therapeutic targets to enhance brain circuitry repair and functional recovery. This study explores the concept of longevity assurance genes, which primarily function within genetic pathways responsible for repair and maintenance. These pathways encompass molecular and metabolic processes as well as organ- and system-level functions. To investigate this, we employed comparative transcriptomics to analyze gene expression patterns across three age groups with progressively decreasing brain plasticity: native postnatal day seven brains, and young and old naïve and lesioned rat male brains. Analysis revealed a highly symmetrical distribution of upregulated and downregulated genes in postnatal day 7 brains. In contrast, the gene expression profiles of post-stroke brains exhibited significant asymmetry, with a disproportionate increase in upregulated genes compared to downregulated ones in both young and old post-ischemic brains. Gene variance in juvenile brains predominantly reflected processes associated with brain plasticity (e.g., Dcx, Tubb2b, Dok4, Dpysl5) and cell proliferation (e.g., Bex4). Conversely, gene expression variance in young and aged post-stroke brains was largely linked to inflammatory pathways, driven by cytokine and chemokine signaling. Notably, several genes specifically upregulated in aged brains were identified, including Ehd4, Fut7, Lilrb4, Plek, Slfn13, Slc14a1, and Smpdl3a. Immune genes that facilitate synaptic plasticity during early postnatal brain development-through processes such as pruning and sprouting to establish new connections in response to external stimuli-also contribute to post-stroke damage, confirming the concept of antagonistic pleiotropy. Our results suggest that targeting age-related immune responses could be an effective therapeutic strategy for stroke recovery.

A Combined Extract Derived from Black Sticky Rice and Dill Improves Clinical Symptoms and Ischemic Stroke Biomarkers in Transient Ischemic Attack and Ischemic Stroke Patients

Currently, the adjuvant therapy to optimize the restorative process after stroke is required due to the unsatisfied therapeutic efficacy. A combined extract of black sticky rice and dill showed potential in the preclinical state, so we hypothesized that it could provide clinical benefits. A three-arm, randomized, placebo-controlled study was set up to elucidate this issue. Both males and females (18-80 years old) who had experienced transient ischemic attacks or ischemic strokes within the last 5-10 days with an NIHSS score ≤ 7 and received standard treatment were randomly assigned to receive either a placebo or capsule containing a combined extract of black sticky rice and dill at a dose of 600 or 1200 mg per day. The safety parameters, movement control, and degree of disability were assessed 1, 2, and 6 weeks after the intervention, and serum stroke biomarkers were assessed at the mentioned time points, except at 2 weeks. After week 1, the high-dose (1200 mg/day) treatment group had improved NIHSSS, VCAM1, and MMP-9. Both S100β and VCAM1 also improved at week 6, while the low-dose treatment group (600 mg/day) only exhibited improved VCAM1. Therefore, a high dose of the developed adjuvant supplement improves stroke recovery by improving motor impairment by reducing endothelial dysfunction and inflammation.

Evaluating the impact of transcranial electrical stimulation on post-stroke dysphagia: a systematic review and meta-analysis

OBJECTIVE

To conduct a systematic review and meta-analysis to assess the impact of transcranial electrical stimulation (TES), proposed as a potential therapy for post-stroke dysphagia, on swallowing function in stroke survivors.

METHODS

The PubMed, Embase, Web of Science, and Cochrane Library databases were searched for relevant studies on TES for post-stroke dysphagia. Search results were reviewed following PRISMA guidelines, and the following data were extracted from included studies: study characteristics, demographics, and outcomes. Bias was assessed using the Cochrane tool. Heterogeneity and effect sizes were analysed using I2 statistics and appropriate effects models. The study protocol was registered with PROSPERO (registration No. CRD42024578243).

RESULTS

Six randomized controlled trials met the inclusion criteria (I2 = 0.0%). The meta-analysis indicated a significant improvement in dysphagia with TES (standardized mean difference [SMD] 0.43, 95% confidence interval [CI] 0.13, 0.73). Subgroup analysis suggested that low-intensity TES was effective (SMD 0.46, 95% CI 0.09, 0.82), whereas high-intensity TES showed no significant improvement (SMD 0.37, 95% CI -0.17, 0.91). No publication bias was detected.

CONCLUSION

TES may improve swallowing in stroke patients, with potential benefits from low-intensity protocols.

Restoring of Interhemispheric Symmetry in Patients With Stroke Following Bilateral or Unilateral Robot-Assisted Upper-Limb Rehabilitation: A Pilot Randomized Controlled Trial

Bilateral robotic rehabilitation has proven helpful in the recovery of upper limb motor function in patients with stroke, but its effects on the cortical reorganization mechanisms underlying recovery are still unclear. This pilot Randomized Controlled Trial (RCT) aimed to evaluate the effects on the interhemispheric balance of unilateral or bilateral robotic treatments in patients with subacute stroke, using Quantitative Electroencephalography (qEEG). 19 patients with ischemic stroke underwent a 30-session upper limb neurorehabilitation intervention using a bilateral upper limb exoskeleton. Each patient was randomly assigned to the bilateral (BG, n=10) or unilateral treatment group (UG, n=9). EEG evaluations were performed before (T0) and right after (T [Formula: see text] the first treatment session, after 30 treatment sessions (T1), and at 1-week follow-up (T2), in both eyes open and eyes closed conditions. From the acquired EEG data, the pairwise-derived Brain Symmetry Index (pdBSI) was computed. In addition, clinical evaluation was performed at T0 and T1 with validated clinical scales. After the treatment, a significant improvement in clinical and EEG evaluations was observed for both groups, but only the BG showed reduced pdBSI in delta and theta bands. In the cluster of sensorimotor channels, there was no significant difference between groups. The observed changes were not maintained at follow-up. No significant changes were observed in the pdBSI after a single rehabilitation session. Results suggest that balancing of interhemispheric symmetry comes along with a clinical improvement in the upper extremity and that the pdBSI can be used to investigate the mechanisms of neuronal plasticity involved in robotic rehabilitation after stroke.

Effects of motor imagery-based brain-computer interface-controlled electrical stimulation on lower limb function in hemiplegic patients in the acute phase of stroke: a randomized controlled study

Background

Lower limb motor dysfunction is one of the most serious consequences of stroke; however, there is insufficient evidence for optimal rehabilitation strategies. Improving lower limb motor function through effective rehabilitation strategies is a top priority for stroke patients. Neuroplasticity is a key factor in the recovery of motor function. The extent to which neuroplasticity-based rehabilitation therapy using brain-computer interface (BCI) is effective in treating lower limb motor dysfunction in acute ischemic stroke patients has not been extensively investigated.

Objective

This study aimed to assess the impact of BCI rehabilitation on lower limb motor dysfunction in individuals with acute ischemic stroke by evaluating motor function, walking ability, and daily living activities.

Methods

This study was conducted in a randomized controlled trial, involving 64 patients with acute ischemic stroke who experienced lower limb motor dysfunction. All patients were divided into two groups, with 32 patients assigned to the control group was given conventional rehabilitation once a day for 70 min, 5 times a week for 2 weeks, and the experimental group (n = 32) was given BCI rehabilitation on top of the conventional rehabilitation for 1 h a day, 30 min of therapy in the morning and an additional 30 min in the afternoon, for a total of 20 sessions over a two-week period. The primary outcome was lower extremity motor function, which was assessed using the lower extremity portion of the Fugl-Meyer Rating Scale (FMA-LE), and the secondary endpoints were the Functional Ambulation Scale (FAC), and the Modified Barthel index (MBI).

Results

After 20 sessions of treatment, both groups improved in motor function, walking function, and activities of daily living, and the improvements in FMA-LE scores (p < 0.001), FAC (p = 0.031), and MBI (p < 0.001) were more pronounced in the experimental group compared with the control group.

Conclusion

Conventional rehabilitation therapy combined with BCI rehabilitation therapy can improve the lower limb motor function of hemiplegic patients with stroke, enhance the patient's ability to perform activities of daily living, and promote the improvement of walking function, this is an effective rehabilitation policy to promote recovery from lower extremity motor function disorders.

Hebbian plasticity induced by temporally coincident BCI enhances post-stroke motor recovery

Functional electrical stimulation (FES) can support functional restoration of a paretic limb post-stroke. Hebbian plasticity depends on temporally coinciding pre- and post-synaptic activity. A tight temporal relationship between motor cortical (MC) activity associated with attempted movement and FES-generated visuo-proprioceptive feedback is hypothesized to enhance motor recovery. Using a brain-computer interface (BCI) to classify MC spectral power in electroencephalographic (EEG) signals to trigger FES-delivery with detection of movement attempts improved motor outcomes in chronic stroke patients. We hypothesized that heightened neural plasticity earlier post-stroke would further enhance corticomuscular functional connectivity and motor recovery. We compared subcortical non-dominant hemisphere stroke patients in BCI-FES and Random-FES (FES temporally independent of MC movement attempt detection) groups. The primary outcome measure was the Fugl-Meyer Assessment, Upper Extremity (FMA-UE). We recorded high-density EEG and transcranial magnetic stimulation-induced motor evoked potentials before and after treatment. The BCI group showed greater: FMA-UE improvement; motor evoked potential amplitude; beta oscillatory power and long-range temporal correlation reduction over contralateral MC; and corticomuscular coherence with contralateral MC. These changes are consistent with enhanced post-stroke motor improvement when movement is synchronized with MC activity reflecting attempted movement.

Change of function and brain activity in patients of right spastic arm paralysis combined with aphasia after contralateral cervical seventh nerve transfer surgery

Left hemisphere injury can cause right spastic arm paralysis and aphasia, and recovery of both motor and language functions shares similar compensatory mechanisms and processes. Contralateral cervical seventh cross transfer (CC7) surgery can provide motor recovery for spastic arm paralysis by triggering interhemispheric plasticity, and self-reports from patients indicate spontaneous improvement in language function but still need to be verified. To explore the improvements in motor and language function after CC7 surgery, we performed this prospective observational cohort study. The Upper Extremity part of Fugl-Meyer scale (UEFM) and Modified Ashworth Scale were used to evaluate motor function, and Aphasia Quotient calculated by Mandarin version of the Western Aphasia Battery (WAB-AQ, larger score indicates better language function) was assessed for language function. In 20 patients included, the average scores of UEFM increased by .40 and 3.70 points from baseline to 1-week and 6-month post-surgery, respectively. The spasticity of the elbow and fingers decreased significantly at 1-week post-surgery, although partially recurred at 6-month follow-up. The average scores of WAB-AQ were increased by 9.14 and 10.69 points at 1-week and 6-month post-surgery (P < .001 for both), respectively. Post-surgical fMRI scans revealed increased activity in the bilateral hemispheres related to language centrals, including the right precentral cortex and right gyrus rectus. These findings suggest that CC7 surgery not only enhances motor function but may also improve the aphasia quotient in patients with right arm paralysis and aphasia due to left hemisphere injuries.

Synaptic reorganization of synchronized neuronal networks with synaptic weight and structural plasticity

Abnormally strong neural synchronization may impair brain function, as observed in several brain disorders. We computationally study how neuronal dynamics, synaptic weights, and network structure co-emerge, in particular, during (de)synchronization processes and how they are affected by external perturbation. To investigate the impact of different types of plasticity mechanisms, we combine a network of excitatory integrate-and-fire neurons with different synaptic weight and/or structural plasticity mechanisms: (i) only spike-timing-dependent plasticity (STDP), (ii) only homeostatic structural plasticity (hSP), i.e., without weight-dependent pruning and without STDP, (iii) a combination of STDP and hSP, i.e., without weight-dependent pruning, and (iv) a combination of STDP and structural plasticity (SP) that includes hSP and weight-dependent pruning. To accommodate the diverse time scales of neuronal firing, STDP, and SP, we introduce a simple stochastic SP model, enabling detailed numerical analyses. With tools from network theory, we reveal that structural reorganization may remarkably enhance the network's level of synchrony. When weaker contacts are preferentially eliminated by weight-dependent pruning, synchrony is achieved with significantly sparser connections than in randomly structured networks in the STDP-only model. In particular, the strengthening of contacts from neurons with higher natural firing rates to those with lower rates and the weakening of contacts in the opposite direction, followed by selective removal of weak contacts, allows for strong synchrony with fewer connections. This activity-led network reorganization results in the emergence of degree-frequency, degree-degree correlations, and a mixture of degree assortativity. We compare the stimulation-induced desynchronization of synchronized states in the STDP-only model (i) with the desynchronization of models (iii) and (iv). The latter require stimuli of significantly higher intensity to achieve long-term desynchronization. These findings may inform future pre-clinical and clinical studies with invasive or non-invasive stimulus modalities aiming at inducing long-lasting relief of symptoms, e.g., in Parkinson's disease.

The Effectiveness of Paired Associative Stimulation on Motor Recovery after Stroke: A Scoping Review

Paired associative stimulation (PAS) is a non-invasive brain stimulation technique combining transcranial magnetic stimulation and peripheral nerve stimulation. PAS allows connections between cortical areas and peripheral nerves (C/P PAS) or between cortical regions (C/C PAS) to be strengthened or weakened by spike-timing-dependent neural plasticity mechanisms. Since PAS modulates both neurophysiological features and motor performance, there is growing interest in its application in neurorehabilitation. We aimed to synthesize evidence on the motor rehabilitation role of PAS in stroke patients. We performed a literature search following the PRISMA Extension for Scoping Reviews Framework. Eight studies were included: one investigated C/C PAS between the cerebellum and the affected primary motor area (M1), seven applied C/P PAS over the lesional, contralesional, or both M1. Seven studies evaluated the outcome on upper limb and one on lower limb motor recovery. Although several studies omit crucial methodological details, PAS highlighted effects mainly on corticospinal excitability, and, more rarely, an improvement in motor performance. However, most studies failed to prove a correlation between neurophysiological changes and motor improvement. Although current studies seem to suggest a role of PAS in post-stroke rehabilitation, their heterogeneity and limited number do not yet allow definitive conclusions to be drawn.

The stratified effects of repetitive transcranial magnetic stimulation in upper limb motor impairment recovery after stroke: a meta-analysis

Background

The recovery of upper extremity motor impairment after stroke remains a challenging task. The clinical effectiveness of repetitive transcranial magnetic stimulation (rTMS), which is believed to aid in the recovery process, is still uncertain.

Methods

A systematic search was conducted in Medline (Ovid), Cochrane and Embase electronic databases from March 28, 2014, to March 28, 2023. The inclusion criteria consisted of randomized controlled trials that assessed the effects of rTMS on the recovery of upper limb motor impairment among stroke patients. Various measurements, including the Fugl Meyer Assessment Upper Extremity Scale (FMA-UE), Brunnstrom recovery stage, Action Research Arm Test (ARAT), and Barthel index, were evaluated both before and after the intervention.

Results

Nineteen articles with 865 patients were included. When considering only the rTMS parameters, both inhibitory and excitatory rTMS improved FMA-UE (MD = 1.87, 95% CI = [0.88]-[2.86], p < 0.001) and Barthel index (MD = 9.73, 95% CI = [4.57]-[14.89], p < 0.001). When considering only the severity of upper limb hemiplegia, both less severe (MD = 1.56, 95% CI = [0.64]-[2.49], p < 0.001) and severe (MD = 2.05, 95% CI = [1.09]-[3.00], p < 0.001) hemiplegia benefited from rTMS based on FMA-UE. However, when considering the rTMS parameters, severity of hemiplegia and stroke stages simultaneously, inhibitory rTMS was found to be significantly effective for less severe hemiplegia in the acute and subacute phases (MD = 4.55, 95% CI = [2.49]-[6.60], p < 0.001), but not in the chronic phase based on FMA-UE. For severe hemiplegia, inhibitory rTMS was not significantly effective in the acute and subacute phases, but significantly effective in the chronic phase (MD = 2.10, 95% CI = [0.75]-[3.45], p = 0.002) based on FMA-UE. Excitatory rTMS was found to be significantly effective for less severe hemiplegia in the acute and subacute phases (MD = 1.93, 95% CI = [0.58]-[3.28], p = 0.005) based on FMA-UE. The improvements in Brunnstrom recovery stage and ARAT need further research.

Conclusion

The effectiveness of rTMS depends on its parameters, severity of hemiplegia, and stroke stages. It is important to consider all these factors together, as any single grouping method is incomplete.

Effect of prothymosin α on neuroplasticity following cerebral ischemia‑reperfusion injury

Prothymosin α (ProT), a highly acidic nuclear protein with multiple cellular functions, has shown potential neuroprotective properties attributed to its anti‑necrotic and anti‑apoptotic activities. The present study aimed to investigate the beneficial effect of ProT on neuroplasticity after ischemia‑reperfusion injury and elucidate its underlying mechanism of action. Primary cortical neurons were either treated with ProT or overexpressing ProT by gene transfection and exposed to oxygen‑glucose deprivation for 2 h in vitro. Immunofluorescence staining for ProT and MAP‑2 was performed to quantify ProT protein expression and assess neuronal arborization. Mice treated with vehicle or ProT (100 µg/kg) and ProT overexpression in transgenic mice received middle cerebral artery occlusion for 50 min to evaluate the effect of ProT on neuroplasticity‑associated protein following ischemia‑reperfusion injury. The results demonstrated that in cultured neurons ProT significantly increased neurite lengths and the number of branches, accompanied by an upregulation mRNA level of brain‑derived neurotrophic factor. Furthermore, ProT administration improved the protein expressions of synaptosomal‑associated protein, 25 kDa and postsynaptic density protein 95 after ischemic‑reperfusion injury in vivo. These findings suggested that ProT can potentially induce neuroplasticity effects following ischemia‑reperfusion injury.

Spinal Cord Stimulation for Poststroke Hemiparesis: A Scoping Review

IMPORTANCE

Spinal cord stimulation (SCS) is a neuromodulation technique that can improve paresis in individuals with spinal cord injury. SCS is emerging as a technique that can address upper and lower limb hemiparesis. Little is understood about its effectiveness with the poststroke population.

OBJECTIVE

To summarize the evidence for SCS after stroke and any changes in upper extremity and lower extremity motor function.

DATA SOURCES

PubMed, Web of Science, Embase, and CINAHL. The reviewers used hand searches and reference searches of retrieved articles. There were no limitations regarding publication year.

STUDY SELECTION AND DATA COLLECTION

This review followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) checklist. The inclusion and exclusion criteria included a broad range of study characteristics. Studies were excluded if the intervention did not meet the definition of SCS intervention, used only animals or healthy participants, did not address upper or lower limb motor function, or examined neurological conditions other than stroke.

FINDINGS

Fourteen articles met the criteria for this review. Seven studies found a significant improvement in motor function in groups receiving SCS.

CONCLUSIONS AND RELEVANCE

Results indicate that SCS may provide an alternative means to improve motor function in the poststroke population. Plain-Language Summary: The results of this study show that spinal cord stimulation may provide an alternative way to improve motor function after stroke. Previous neuromodulation methods have targeted the impaired supraspinal circuitry after stroke. Although downregulated, spinal cord circuitry is largely intact and offers new possibilities for motor recovery.

Simultaneous high-definition transcranial direct current stimulation and robot-assisted gait training in stroke patients

This study investigates whether simultaneous high-definition transcranial direct current stimulation (HD-tDCS) enhances the effects of robot-assisted gait training in stroke patients. Twenty-four participants were randomly allocated to either the robot-assisted gait training with real HD-tDCS group (real HD-tDCS group) or robot-assisted gait training with sham HD-tDCS group (sham HD-tDCS group). Over four weeks, both groups completed 10 sessions. The 10 Meter Walk Test, Timed Up and Go, Functional Ambulation Category, Functional Reach Test, Berg Balance Scale, Dynamic Gait Index, Fugl-Meyer Assessment, and Korean version of the Modified Barthel Index were conducted before, immediately after, and one month after the intervention. The real HD-tDCS group showed significant improvements in the 10 Meter Walk Test, Timed Up and Go, Functional Reach Test, and Berg Balance Scale immediately and one month after the intervention, compared with before the intervention. Significant improvements in the Dynamic Gait Index and Fugl-Meyer Assessment were also observed immediately after the intervention. The sham HD-tDCS group showed no significant improvements in any of the tests. Application of HD-tDCS during robot-assisted gait training has a positive effect on gait and physical function in chronic stroke patients, ensuring long-term training effects. Our results suggest the effectiveness of HD-tDCS as a complementary tool to enhance robotic gait rehabilitation therapy in chronic stroke patients.

Vagus nerve stimulation to improve post‐stroke motor function and activity

This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

To assess the effectiveness and safety of vagus nerve stimulation as an add‐on treatment to rehabilitate people with post‐stroke motor function impairments and activity limitations.

Effectiveness of an Intensive, Functional, and Gamified Rehabilitation Program on Upper Limb Function in People With Stroke (EnteRtain): A Multicenter Randomized Clinical Trial

BACKGROUND1

Despite a growing interest in gaming rehabilitation for upper limb (UL) recovery post-stroke, studies investigating the effects of game-based rehabilitation incorporating functional games are lacking.

OBJECTIVE

To investigate the efficacy of an intensive, functional, gamified rehabilitation program compared to task-based training on UL motor function in acute/sub-acute stroke survivors.

METHODS

This randomized, multicenter, single-blind, clinical trial comprises 120 participants with unilateral stroke who were randomized to receive either gamified training (n = 64) using the ArmAble™ [experimental group (EG)] or task-based training (n = 56) in conjunction with conventional therapy for 2 hours per day, 6 days per week for 2 weeks, followed by UL rehabilitation for another 4 weeks at home. Primary outcomes evaluated by a blinded assessor included the Fugl-Meyer Assessment-Upper Extremity (FM-UE), and Action Research Arm Test (ARAT). Data were analyzed using a linear mixed-effect regression model.

RESULTS

The mean (standard deviation) age of the participants was 54.4 ± 11.7 years (78.1% men) in the EG and 57.7 ± 10.9 years (73.2% men) in the comparator group (CG). The median (interquartile range) time since stroke was 30.0 (54.0) days in the EG and 22.5 (45.0) days in the CG. Following the 2-week intervention, a statistically significant improvement was observed in the EG for the FM-UE [between-group mean differences (95% confidence interval): -3.9 (-6.5, -1.3); P = .003]; but not for the ARAT [-2.9 (-5.8, 0.0); P = .051]. Gains at 6 weeks were significantly greater in the EG for both FM-UE [-3.9 (-6.5, -1.3); P = .003]; and ARAT [-3.0 (-5.9, -0.0); P = .046].

CONCLUSION

Gamified rehabilitation using the ArmAble™ device has shown immediate and short-term improvement in UL function after acute/sub-acute stroke.

CLINICAL TRIALS REGISTRY NUMBER

CTRI/2020/09/027651.

The Multifaceted Role of Cofilin in Neurodegeneration and Stroke: Insights into Pathogenesis and Targeting as a Therapy

This comprehensive review explores the complex role of cofilin, an actin-binding protein, across various neurodegenerative diseases (Alzheimer's, Parkinson's, schizophrenia, amyotrophic lateral sclerosis (ALS), Huntington's) and stroke. Cofilin is an essential protein in cytoskeletal dynamics, and any dysregulation could lead to potentially serious complications. Cofilin's involvement is underscored by its impact on pathological hallmarks like Aβ plaques and α-synuclein aggregates, triggering synaptic dysfunction, dendritic spine loss, and impaired neuronal plasticity, leading to cognitive decline. In Parkinson's disease, cofilin collaborates with α-synuclein, exacerbating neurotoxicity and impairing mitochondrial and axonal function. ALS and frontotemporal dementia showcase cofilin's association with genetic factors like C9ORF72, affecting actin dynamics and contributing to neurotoxicity. Huntington's disease brings cofilin into focus by impairing microglial migration and influencing synaptic plasticity through AMPA receptor regulation. Alzheimer's, Parkinson's, and schizophrenia exhibit 14-3-3 proteins in cofilin dysregulation as a shared pathological mechanism. In the case of stroke, cofilin takes center stage, mediating neurotoxicity and neuronal cell death. Notably, there is a potential overlap in the pathologies and involvement of cofilin in various diseases. In this context, referencing cofilin dysfunction could provide valuable insights into the common pathologies associated with the aforementioned conditions. Moreover, this review explores promising therapeutic interventions, including cofilin inhibitors and gene therapy, demonstrating efficacy in preclinical models. Challenges in inhibitor development, brain delivery, tissue/cell specificity, and long-term safety are acknowledged, emphasizing the need for precision drug therapy. The call to action involves collaborative research, biomarker identification, and advancing translational efforts. Cofilin emerges as a pivotal player, offering potential as a therapeutic target. However, unraveling its complexities requires concerted multidisciplinary efforts for nuanced and effective interventions across the intricate landscape of neurodegenerative diseases and stroke, presenting a hopeful avenue for improved patient care.

Exploring the transformative influence of neuroplasticity on stroke rehabilitation: a narrative review of current evidence

This review aims to assess the role of neuroplasticity in facilitating stroke recovery and identify the challenges and limitations associated with its implementation. A comprehensive literature search was conducted to identify relevant studies, which were meticulously evaluated to determine the potential solutions for effectively harnessing neuroplasticity. The results indicate that neuroplasticity holds significant promise in stroke rehabilitation; however, individual variability in response to interventions, timing and duration of interventions and sociocultural and clinical factors pose challenges. Tailoring interventions to individual patient characteristics is crucial for optimising the impact of neuroplasticity. Despite challenges and limitations, the transformative potential of neuroplasticity in stroke rehabilitation is undeniable. The abstract concludes by emphasising the importance of a comprehensive understanding of individual variability, optimising intervention timing and duration and considering sociocultural and clinical factors. Future research and clinical practice should prioritise personalised interventions and interdisciplinary collaborations to fully exploit the vast potential of neuroplasticity in stroke recovery.

The potential role of the novel orodispersible film from rice polymer loaded with silkworm pupae hydrolysate and the combined extract of holy basil and ginger for the management of stroke with stress

The prevalence of stroke under stress conditions is rising and the severity of stroke is increasing. Owing to the limitation of the current therapeutic strategy, a novel effective strategy for treating this condition is needed. In this study, we explored the neuroprotective effect of an orodispersible film derived from a rice polymer loaded with silkworm pupae and the combined extract of holy basil and ginger (JP1). Male Wistar rats weighing 200-250 g were administered JP1 at the doses of 1, 10, and 100 mg/kg BW 45 min prior to an exposure to a 6-h immobilization stress for 14 days. Permanent, occlusion of the right middle cerebral artery (MCAO) was performed, and JP1 was administered continually for 21 days after MCAO. Assessments of the brain infarction volume, oxidative stress, inflammation, and apoptosis in the cerebral cortex were carried out 24 h after MCAO. Neurological severity scores were also determined for the rats every 7 days after MCAO until the end of the study period. The results clearly showed that all doses of JP1 decreased the brain infarct volume, oxidative stress, inflammation, and apoptosis and improved neurological deficits. Therefore, JP1 is a potential novel neuroprotective supplement for combating ischemic stroke under stress conditions. However, a clinical trial is essential to confirm this beneficial effect.

Neurofunctional correlates of a neurorehabilitation system based on eye movements in chronic stroke impairment levels: A pilot study

INTRODUCTION

Rehabilitation after a stroke is widely considered fundamental to improve secondary functional impairments. Accessible methods based on motor learning, motor transfer and virtual environments are necessary to help to improve stroke patients' quality of life.

OBJECTIVES

Continuing the line of our previous studies, this work investigated the effect of our new and innovative game-based virtual reality training using the control of virtual objects with gaze in three chronic stroke survivors.

METHODS

All participants performed an eye-controlled virtual training task for 4 weeks. Pre- and post-training evaluation were carried out with the Fugl-Meyer Assessment for upper extremity scale as well as performing a tracking task inside an MRI scanner with a MRI-compatible eye-tracker or a joystick.

RESULTS

Neural results for each participant show the increase of activity in the motor cortex, basal ganglia and cerebellum for both effectors (hand or eye).

CONCLUSION

These promising results have a potential application as a new game-based neurorehabilitation approach to enhance the motor activity of stroke patients.

Left or right ear? A neuroimaging study using combined taVNS/fMRI to understand the interaction between ear stimulation target and lesion location in chronic stroke

BACKGROUND

Implanted vagus nerve stimulation (VNS) and transcutaneous auricular VNS (taVNS) have been primarily administered clinically to the unilateral-left vagus nerve. This left-only convention has proved clinically beneficial in brain disorders. However, in stroke survivors, the presence of a lesion in the brain may complicate VNS-mediated signaling, and it is important to understand the laterality effects of VNS in stroke survivors to optimize the intervention.

OBJECTIVE

To understand whether taVNS delivered to different ear targets relative to the lesion (ipsilesional vs contralesional vs bilateral vs sham) impacts blood oxygenation level dependent (BOLD) signal propagation in stroke survivors.

METHODS

We enrolled 20 adults with a prior history of stroke. Each participant underwent a single visit, during which taVNS was delivered concurrently during functional magnetic resonance imaging (fMRI) acquisition. Each participant received three discrete active stimulation conditions (ipsilesional, contralesional, bilateral) and one sham condition in a randomized order. Stimulation-related BOLD signal changes in the active conditions were compared to sham conditions to understand the interaction taVNS and laterality effects.

RESULTS

All active taVNS conditions deactivated the contralesional default mode network related regions compared to sham, however only ipsilesional taVNS enhanced the activations in the ipsilesional visuomotor and secondary visual cortex. Furthermore, we reveal an interaction in task activations between taVNS and cortical visuomotor areas, where ipsilesional taVNS significantly increased ipsilesional visuomotor activity and decreased contralesional visuomotor activity compared to sham.

CONCLUSION

Laterality of taVNS relative to the lesion is a critical factor in optimizing taVNS in a stroke population, with ipsilesional stimulation providing largest direct brain activation and should be explored further when designing taVNS studies in neurorehabilitation.

Global sphingosine-1-phosphate receptor 2 deficiency attenuates neuroinflammation and ischemic-reperfusion injury after neonatal stroke

Arterial ischemic stroke is common in neonates-1 per 2,300-5,000 births-and therapeutic targets remain insufficiently defined. Sphingosine-1-phosphate receptor 2 (S1PR2), a major regulator of the CNS and immune systems, is injurious in adult stroke. Here, we assessed whether S1PR2 contributes to stroke induced by 3 h transient middle cerebral artery occlusion (tMCAO) in S1PR2 heterozygous (HET), knockout (KO), and wild type (WT) postnatal day 9 pups. HET and WT of both sexes displayed functional deficits in Open Field test whereas injured KO at 24 h reperfusion performed similarly to naives. S1PR2 deficiency protected neurons, attenuated infiltration of inflammatory monocytes, and altered vessel-microglia interactions without reducing increased cytokine levels in injured regions at 72 h. Pharmacologic inhibition of S1PR2 after tMCAO by JTE-013 attenuated injury 72 h after tMCAO. Importantly, the lack of S1PR2 alleviated anxiety and brain atrophy during chronic injury. Altogether, we identify S1PR2 as a potential new target for mitigating neonatal stroke.

Acetylated α-tubulin alleviates injury to the dendritic spines after ischemic stroke in mice

BACKGROUND AND AIM

Functional recovery is associated with the preservation of dendritic spines in the penumbra area after stroke. Previous studies found that polymerized microtubules (MTs) serve a crucial role in regulating dendritic spine formation and plasticity. However, the mechanisms that are involved are poorly understood. This study is designed to understand whether the upregulation of acetylated α-tubulin (α-Ac-Tub, a marker for stable, and polymerized MTs) could alleviate injury to the dendritic spines in the penumbra area and motor dysfunction after ischemic stroke.

METHODS

Ischemic stroke was mimicked both in an in vivo and in vitro setup using middle cerebral artery occlusion and oxygen-glucose deprivation models. Thy1-YFP mice were utilized to observe the morphology of the dendritic spines in the penumbra area. MEC17 is the specific acetyltransferase of α-tubulin. Thy1 Cre^ERT2-eYFP and MEC17^fl/fl mice were mated to produce mice with decreased expression of α-Ac-Tub in dendritic spines of pyramidal neurons in the cerebral cortex. Moreover, AAV-PHP.B-DIO-MEC17 virus and tubastatin A (TBA) were injected into Thy1 Cre^ERT2-eYFP and Thy1-YFP mice to increase α-Ac-Tub expression. Single-pellet retrieval, irregular ladder walking, rotarod, and cylinder tests were performed to test the motor function after the ischemic stroke.

RESULTS

α-Ac-Tub was colocalized with postsynaptic density 95. Although knockout of MEC17 in the pyramidal neurons did not affect the density of the dendritic spines, it significantly aggravated the injury to them in the penumbra area and motor dysfunction after stroke. However, MEC17 upregulation in the pyramidal neurons and TBA treatment could maintain mature dendritic spine density and alleviate motor dysfunction after stroke.

CONCLUSION

Our study demonstrated that α-Ac-Tub plays a crucial role in the maintenance of the structure and functions of mature dendritic spines. Moreover, α-Ac-Tub protected the dendritic spines in the penumbra area and alleviated motor dysfunction after stroke.

Effectiveness and Electrophysiological Mechanisms of Focal Vibration on Upper Limb Motor Dysfunction in Patients with Subacute Stroke: A Randomized Controlled Trial

Upper limb motor dysfunction is a common complication after stroke, which has a negative impact on the daily life of patients. Focal vibration (FV) has been used to improve upper limb motor function in acute and chronic stroke patients, but its application in subacute stroke patients has not been extensively explored. Therefore, the purpose of this study was to explore the therapeutic effect of FV on upper limb motor function in subacute stroke patients and its underlying electrophysiological mechanism. Twenty-nine patients were enrolled and randomized into two groups: control group and vibration group. The control group were treated with conventional therapy including passive and active physical activity training, standing and sitting balance exercises, muscle strength training, hand extension and grasping exercises. The vibration group were given conventional rehabilitation and vibration therapy. A deep muscle stimulator (DMS) with a frequency of 60 Hz and an amplitude of 6 mm was used to provide vibration stimulation, which was sequentially applied along the biceps muscle to the flexor radialis of the affected limb for 10 minutes, once a day, and 6 times a week. Both groups received treatments for 4 consecutive weeks. In the vibration group, the motor evoked potential (MEP) latency and the somatosensory evoked potential (SEP) latency were significantly shortened (P<0.05) immediately after vibration and 30 minutes after vibration; the SEP amplitude and MEP amplitude were significantly increased (P<0.05) immediately after vibration and 30 minutes after vibration. The MEP latency (P=0.001) and SEP N20 latency (P=0.001) were shortened, and the MEP amplitude (P=0.011) and SEP N20 amplitude (P=0.017) were significantly increased after 4 weeks in the vibration group. After 4 consecutive weeks, the vibration group showed significant improvements in Modified Ashworth Scale (MAS) (P=0.037), Brunnstrom stage for upper extremity (BS-UE) (P=0.020), Fugl-Meyer assessment for upper extremity (FMA-UE) (P=0.029), Modified Barthel Index (MBI) (P=0.024), and SEP N20 (P=0.046) compared to the control group. The Brunnstrom stage for hand (BS-H) (P=0.451) did not show significant differences between the two groups. This study showed that FV was effective in improving upper limb motor function in subacute stroke patients. The underlying mechanism of FV may be that it enhances the efficacy of sensory pathways and induces plastic changes in the sensorimotor cortex.

The Efficacy of the Speed of Processing Training Program in Improving Functional Outcome: From Restoration to Generalization

OBJECTIVE

To examine the efficacy of Speed of Processing Training (SOPT) in improving everyday functional outcomes in persons with multiple sclerosis (MS).

DESIGN

Randomized controlled trial.

SETTING

A nonprofit rehabilitation research institution and the community.

PARTICIPANTS

In total, 60 participants with MS with impaired processing speed were randomly assigned to SOPT (n=33) or an active control group (n=27).

INTERVENTION

SOPT, a restorative computerized cognitive intervention involving 10 treatment sessions consisting of visual tasks designed to improve speed and accuracy of information processing MAIN OUTCOME MEASURES: Outcomes included performance on the Timed Instrumental Activities of Daily Living (TIADL) and self-report of functional behavior, quality of life, and affect.

RESULTS

The treatment group showed improvement in the total TIADL score and 2 subtests compared with the active control group. Participants in the treatment group who demonstrated improved cognitive performance after the intervention also showed improved performance on one TIADL subtest. Quality of life, affective symptomatology, and self-reported functional status were not changed after the intervention.

CONCLUSIONS

Improvement in underlying cognitive or perceptual deficits is thought to promote recovery and everyday performance as per the restorative approach to cognitive rehabilitation. However, this study showed only selected improvements in everyday functional outcomes for persons with MS.

The efficacy of gait rehabilitations for the treatment of incomplete spinal cord injury: a systematic review and network meta-analysis

BACKGROUND

Recent pieces of evidence about the efficacy of gait rehabilitation for incomplete spinal cord injury remain unclear. We aimed to estimate the treatment effect and find the best gait rehabilitation to regain velocity, distance, and Walking Index Spinal Cord Injury (WISCI) among incomplete spinal cord injury patients.

METHOD

PubMed and Scopus databases were searched from inception to October 2022. Randomized controlled trials (RCTs) were included in comparison with any of the following: conventional physical therapy, treadmill, functional electrical stimulation and robotic-assisted gait training, and reported at least one outcome. Two reviewers independently selected the studies and extracted the data. Meta-analysis was performed using random-effects or fixed-effect model according to the heterogeneity. Network meta-analysis (NMA) was indirectly compared with all interventions and reported as pooled unstandardized mean difference (USMD) and 95% confidence interval (CI). Surface under the cumulative ranking curve (SUCRA) was calculated to identify the best intervention.

RESULTS

We included 17 RCTs (709 participants) with the mean age of 43.9 years. Acute-phase robotic-assisted gait training significantly improved the velocity (USMD 0.1 m/s, 95% CI 0.05, 0.14), distance (USMD 64.75 m, 95% CI 27.24, 102.27), and WISCI (USMD 3.28, 95% CI 0.12, 6.45) compared to conventional physical therapy. In NMA, functional electrical stimulation had the highest probability of being the best intervention for velocity (66.6%, SUCRA 82.1) and distance (39.7%, SUCRA 67.4), followed by treadmill, functional electrical stimulation plus treadmill, robotic-assisted gait training, and conventional physical therapy, respectively.

CONCLUSION

Functional electrical stimulation seems to be the best treatment to improve walking velocity and distance for incomplete spinal cord injury patients. However, a large-scale RCT is required to study the adverse events of these interventions.

TRIAL REGISTRATION

PROSPERO number CRD42019145797.

Responsiveness of the Mini-Balance Evaluation System Test in Type 2 Diabetic Patients with Peripheral Neuropathy

Background

Mini-BESTest is an instrument for assessing the balance impairment; however, the use of the Mini-BESTest in type 2 diabetic patients with peripheral neuropathy is not well documented in the literature. The aim of this study was to examine the responsiveness and the minimal important change (MIC) of the Mini-BESTest after four weeks of the balance exercises.

Methods

A prospective single group pretest-posttest design was applied, and forty-eight type 2 diabetic patients with peripheral neuropathy were participated (mean age of 59.04 ± 7.533 years; 3 males and 45 females). All participants were given an intervention program including foot care and balance exercises (50-minute sessions, three times a week for four weeks). The responsiveness of the Mini-BESTest was determined using two approaches: 1) the distribution-based method evaluating the change scores (pre- and post-intervention), the effect size (ES), the standard response mean (SRM), the standard error of measurement (SEM) and the minimum detectable change (MDC₉₅) and 2) the anchor-based method evaluating the MIC using the Global Rating of Change scale (GRC) as an external criterion.

Results

After the balance exercises treatment, the Mini-BESTest scores significantly improved (p < 0.001) with an ES of 3.9 and SRM of 4.32. SEM was 0.73 and MDC₉₅ was 2.03 points. The area under the receiver operating characteristic (ROC) curve corresponded to 81%. The cutoff point of the Mini-BESTest was ≥5 points corresponding to the GRC ≤3 versus >3 for the discrimination of the Mini-BESTest between improvement and no improvement after exercises.

Conclusion

The Mini-BESTest can be demonstrated as high responsiveness according to the determination of the distribution-based and the anchor-based methods. The MIC of the Mini-BESTest was taken as ≥5 points and could be used as an outcome measure for the discriminated evaluation of type 2 diabetic patients with peripheral neuropathy.

COMIRESTROKE—A clinical study protocol for monitoring clinical effect and molecular biological readouts of COMprehensive Intensive REhabilitation program after STROKE: A four-arm parallel-group randomized double blinded controlled trial with a longitudinal design

Introduction

While the role of physiotherapy as part of a comprehensive inpatient rehabilitation is indisputable, clear evidence concerning the effectiveness of different rehabilitation managements [interdisciplinary implementing the International Classification of Functioning, disability and health (ICF) vs. multidisciplinary model] and physiotherapy categories (neuroproprioceptive “facilitation, inhibition” vs. motor/skill acquisitions using technologies) are still lacking. In this study, four kinds of comprehensive inpatient rehabilitation with different management and content of physical therapy will be compared. Moreover, focus will be placed on the identification of novel biological molecules reflective of effective rehabilitation. Long non-coding RNAs (lncRNAs) are transcripts (&gt;200 bps) of limited coding potential, which have recently been recognized as key factors in neuronal signaling pathways in ischemic stroke and as such, may provide a valuable readout of patient recovery and neuroprotection during therapeutic progression.

Methods and analysis

Adults after the first ischemic stroke in an early sub-acute phase with motor disability will be randomly assigned to one of four groups and undergo a 3 weeks comprehensive inpatient rehabilitation of different types: interdisciplinary team work using ICF model as a guide; multidisciplinary teamwork implementing neuroproprioceptive “facilitation and inhibition” physiotherapy; multidisciplinary teamwork implementing technology-based physiotherapy; and standard multidisciplinary teamwork. Primary (the Goal Attainment Scale, the Patient-Reported Outcomes Measurement Information System, and the World Health Organization Disability Assessment Schedule) and secondary (motor, cognitive, psychological, speech and swallowing functions, functional independence) outcomes will be measured. A blood sample will be obtained upon consent (20 mls; representing pre-rehabilitation molecular) before and after the inpatient program. Primary outcomes will be followed up again 3 and 12 months after the end of the program. The overarching aim of this study is to determine the effectiveness of various rehabilitation managements and physiotherapeutic categories implemented by patients post ischemic stroke via analysis of primary, secondary and long non-coding RNA readouts. This clinical trial will offer an innovative approach not previously tested and will provide new complex analysis along with public assessable molecular biological evidence of various rehabilitation methodology for the alleviation of the effects of ischemic stroke.

Clinical trial registration

NCT05323916, https://clinicaltrials.gov/ct2/show/NCT05323916.

Neurotrophic factor-based pharmacological approaches in neurological disorders

Aging is a physiological event dependent on multiple pathways that are linked to lifespan and processes leading to cognitive decline. This process represents the major risk factor for aging-related diseases such as Alzheimer's disease, Parkinson's disease, and ischemic stroke. The incidence of all these pathologies increases exponentially with age. Research on aging biology has currently focused on elucidating molecular mechanisms leading to the development of those pathologies. Cognitive deficit and neurodegeneration, common features of aging-related pathologies, are related to the alteration of the activity and levels of neurotrophic factors, such as brain-derived neurotrophic factor, nerve growth factor, and glial cell-derived neurotrophic factor. For this reason, treatments that modulate neurotrophin levels have acquired a great deal of interest in preventing neurodegeneration and promoting neural regeneration in several neurological diseases. Those treatments include both the direct administration of neurotrophic factors and the induced expression with viral vectors, neurotrophins' binding with biomaterials or other molecules to increase their bioavailability but also cell-based therapies. Considering neurotrophins' crucial role in aging pathologies, here we discuss the involvement of several neurotrophic factors in the most common brain aging-related diseases and the most recent therapeutic approaches that provide direct and sustained neurotrophic support.

Effects and mechanisms of mindfulness training and physical exercise on cognition, emotional wellbeing, and brain outcomes in chronic stroke patients: Study protocol of the MindFit project randomized controlled trial

Background

Post-stroke cognitive and emotional complications are frequent in the chronic stages of stroke and have important implications for the functionality and quality of life of those affected and their caregivers. Strategies such as mindfulness meditation, physical exercise (PE), or computerized cognitive training (CCT) may benefit stroke patients by impacting neuroplasticity and brain health.

Materials and methods

One hundred and forty-one chronic stroke patients are randomly allocated to receive mindfulness-based stress reduction + CCT (n = 47), multicomponent PE program + CCT (n = 47), or CCT alone (n = 47). Interventions consist of 12-week home-based programs five days per week. Before and after the interventions, we collect data from cognitive, psychological, and physical tests, blood and stool samples, and structural and functional brain scans.

Results

The effects of the interventions on cognitive and emotional outcomes will be described in intention-to-treat and per-protocol analyses. We will also explore potential mediators and moderators, such as genetic, molecular, brain, demographic, and clinical factors in our per-protocol sample.

Discussion

The MindFit Project is a randomized clinical trial that aims to assess the impact of mindfulness and PE combined with CCT on chronic stroke patients' cognitive and emotional wellbeing. Furthermore, our design takes a multimodal biopsychosocial approach that will generate new knowledge at multiple levels of evidence, from molecular bases to behavioral changes.

Clinical trial registration

www.ClinicalTrials.gov, identifier NCT04759950.

A Preliminary Study to Design and Evaluate Pneumatically Controlled Soft Robotic Actuators for a Repetitive Hand Rehabilitation Task

A stroke is an infarction in the cortical region of the brain that often leads to isolated hand paresis. This common side effect renders individuals compromised in their ability to actively flex or extend the fingers of the affected hand. While there are currently published soft robotic glove designs, this article proposed a unique design that allows users to self-actuate their therapy due to the ability to re-extend the hand using a layer of resistive flexible steel. The results showed a consistently achieved average peak of 75° or greater for each finger while the subjects’ hands were at rest during multiple trials of pneumatic assisted flexion. During passive assisted testing, human subject testing on 10 participants showed that these participants were able to accomplish 80.75% of their normal active finger flexion range with the steel-layer-lined pneumatic glove and 87.07% with the unlined pneumatic glove on average when neglecting outliers. An addition of the steel layer lowered the blocked tip force by an average of 18.13% for all five fingers. These data show strong evidence that this glove would be appropriate to advance to human subject testing on those who do have post stroke hand impairments.

MRI-Based Optimization Design of the Pre-Spinal Route of Contralateral C7 Nerve Transfer for Spastic Arm Paralysis

Purpose

The prespinal route of contralateral cervical 7 nerve transfer developed by Prof. Wendong Xu helps realize the direct anastomosis of the bilateral cervical 7 nerves. However, 20% of operations still require a nerve graft, which leads to an unfavorable prognosis. This study aims to explore the optimized prespinal route with MRI to further improve the prognosis.

Methods

The current study enrolled 30 patients who suffered from central spastic paralysis of an upper limb and who underwent contralateral cervical 7 nerve transfer via Prof. Xu’s prespinal route through the anterior edge of the contralateral longus colli. MRI images were used to analyze the route length, vertebral artery exposure, and contralateral cervical 7 nerve included angle. Three prespinal routes were virtually designed and analyzed. The selected optimal route was applied to another 50 patients with central spastic paralysis of an upper limb for contralateral cervical 7 nerve transfer.

Results

By the interventions on the 30 patients, the middle and posterior routes were shorter than the anterior route in length, but with no statistical difference between the two routes. Of 30 contralateral vertebral arteries, 26 were located at the posterior medial edge of the longus colli. The average included angles of the anterior, middle, and posterior routes were 108.02 ± 7.89°, 95.51 ± 6.52°, and 72.48 ± 4.65°, respectively. According to these data, the middle route was optimally applied to 50 patients, in whom the rate of nerve transplantation was only 4%, and no serious complications such as vertebral artery or brachial plexus injury occurred.

Conclusion

The low rate of nerve transplantation in 50 patients and the absence of any serious complications in these cases suggests that the middle route is the optimal one.

Effects of control strategies on gait in robot-assisted post-stroke lower limb rehabilitation: a systematic review

BACKGROUND

Stroke related motor function deficits affect patients' likelihood of returning to professional activities, limit their participation in society and functionality in daily living. Hence, robot-aided gait rehabilitation needs to be fruitful and effective from a motor learning perspective. For this reason, optimal human-robot interaction strategies are necessary to foster neuroplastic shaping during therapy. Therefore, we performed a systematic search on the effects of different control algorithms on quantitative objective gait parameters of post-acute stroke patients.

METHODS

We conducted a systematic search on four electronic databases using the Population Intervention Comparison and Outcome format. The heterogeneity of performance assessment, study designs and patients' numerosity prevented the possibility to conduct a rigorous meta-analysis, thus, the results were presented through narrative synthesis.

RESULTS

A total of 31 studies (out of 1036) met the inclusion criteria, without applying any temporal constraints. No controller preference with respect to gait parameters improvements was found. However, preferred solutions were encountered in the implementation of force control strategies mostly on rigid devices in therapeutic scenarios. Conversely, soft devices, which were all position-controlled, were found to be more commonly used in assistive scenarios. The effect of different controllers on gait could not be evaluated since conspicuous heterogeneity was found for both performance metrics and study designs.

CONCLUSIONS

Overall, due to the impossibility of performing a meta-analysis, this systematic review calls for an outcome standardisation in the evaluation of robot-aided gait rehabilitation. This could allow for the comparison of adaptive and human-dependent controllers with conventional ones, identifying the most suitable control strategies for specific pathologic gait patterns. This latter aspect could bolster individualized and personalized choices of control strategies during the therapeutic or assistive path.

The nature of blindsight: implications for current theories of consciousness

Blindsight regroups the different manifestations of preserved discriminatory visual capacities following the damage to the primary visual cortex. Blindsight types differentially impact objective and subjective perception, patients can report having no visual awareness whilst their behaviour suggests visual processing still occurs at some cortical level. This phenomenon hence presents a unique opportunity to study consciousness and perceptual consciousness, and for this reason, it has had an historical importance for the development of this field of research. From these studies, two main opposing models of the underlying mechanisms have been established: (a) blindsight is perception without consciousness or (b) blindsight is in fact degraded vision, two views that mirror more general theoretical options about whether unconscious cognition truly exists or whether it is only a degraded form of conscious processing. In this article, we want to re-examine this debate in the light of recent advances in the characterization of blindsight and associated phenomena. We first provide an in-depth definition of blindsight and its subtypes, mainly blindsight type I, blindsight type II and the more recently described blindsense. We emphasize the necessity of sensitive and robust methodology to uncover the dissociations between perception and awareness that can be observed in brain-damaged patients with visual field defects at different cognitive levels. We discuss these different profiles of dissociation in the light of both contending models. We propose that the different types of dissociations reveal a pattern of relationship between perception, awareness and metacognition that is actually richer than what is proposed by either of the existing models. Finally, we consider this in the framework of current theories of consciousness and touch on the implications the findings of blindsight have on these.

Brain Network Organization Following Post-Stroke Neurorehabilitation

Brain network analysis can offer useful information to guide the rehabilitation of post-stroke patients. We applied functional network connection models based on multiplex-multilayer network analysis (MMN) to explore functional network connectivity changes induced by robot-aided gait training (RAGT) using the Ekso, a wearable exoskeleton, and compared it to conventional overground gait training (COGT) in chronic stroke patients. We extracted the coreness of individual nodes at multiple locations in the brain from EEG recordings obtained before and after gait training in a resting state. We found that patients provided with RAGT achieved a greater motor function recovery than those receiving COGT. This difference in clinical outcome was paralleled by greater changes in connectivity patterns among different brain areas central to motor programming and execution, as well as a recruitment of other areas beyond the sensorimotor cortices and at multiple frequency ranges, contemporarily. The magnitude of these changes correlated with motor function recovery chances. Our data suggest that the use of RAGT as an add-on treatment to COGT may provide post-stroke patients with a greater modification of the functional brain network impairment following a stroke. This might have potential clinical implications if confirmed in large clinical trials.

Cellular and Molecular Targets for Non-Invasive, Non-Pharmacological Therapeutic/Rehabilitative Interventions in Acute Ischemic Stroke

BACKGROUND

Cerebral circulation delivers the blood flow to the brain through a dedicated network of sanguine vessels. A healthy human brain can regulate cerebral blood flow (CBF) according to any physiological or pathological challenges. The brain is protected by its self-regulatory mechanisms, which are dependent on neuronal and support cellular populations, including endothelial ones, as well as metabolic, and even myogenic factors.

OBJECTIVES

Accumulating data suggest that "non-pharmacological" approaches might provide new opportunities for stroke therapy, such as electro-/acupuncture, hyperbaric oxygen therapy, hypothermia/cooling, photobiomodulation, therapeutic gases, transcranial direct current stimulations, or transcranial magnetic stimulations. We reviewed the recent data on the mechanisms and clinical implications of these non-pharmaceutical treatments.

METHODS

To present the state-of-the-art for currently available non-invasive, non-pharmacological-related interventions in acute ischemic stroke, we accomplished this synthetic and systematic literature review based on the Preferred Reporting Items for Systematic Principles Reviews and Meta-Analyses (PRISMA).

RESULTS

The initial number of obtained articles was 313. After fulfilling the five steps in the filtering/selection methodology, 54 fully eligible papers were selected for synthetic review. We enhanced our documentation with other bibliographic resources connected to our subject, identified in the literature within a non-standardized search, to fill the knowledge gaps. Fifteen clinical trials were also identified.

DISCUSSION

Non-invasive, non-pharmacological therapeutic/rehabilitative interventions for acute ischemic stroke are mainly holistic therapies. Therefore, most of them are not yet routinely used in clinical practice, despite some possible beneficial effects, which have yet to be supplementarily proven in more related studies. Moreover, few of the identified clinical trials are already completed and most do not have final results.

CONCLUSIONS

This review synthesizes the current findings on acute ischemic stroke therapeutic/rehabilitative interventions, described as non-invasive and non-pharmacological.

Capturing Neuroplastic Changes after iTBS in Patients with Post-Stroke Aphasia: A Pilot fMRI Study

Intermittent theta-burst stimulation (iTBS) is a high-efficiency transcranial magnetic stimulation (TMS) paradigm that has been applied to post-stroke aphasia (PSA). However, its efficacy mechanisms have not been clarified. This study aimed to explore the immediate effects of iTBS of the primary motor cortex (M1) of the affected hemisphere, on the functional activities and connectivity of the brains of PSA patients. A total of 16 patients with aphasia after stroke received iTBS with 800 pulses for 300 s. All patients underwent motor, language, and cognitive assessments and resting-state functional MRI scans immediately before and after the iTBS intervention. Regional, seed-based connectivity, and graph-based measures were used to test the immediate functional effects of the iTBS intervention, including the fractional amplitude of low-frequency fluctuation (fALFF), degree centrality (DC), and functional connectivity (FC) of the left M1 area throughout the whole brain. The results showed that after one session of iTBS intervention, the fALFF, DC, and FC values changed significantly in the patients' brains. Specifically, the DC values were significantly higher in the right middle frontal gyrus and parts of the left parietal lobe (p < 0.05), while fALFF values were significantly lower in the right medial frontal lobe and parts of the left intracalcarine cortex (p < 0.05), and the strength of the functional connectivity between the left M1 area and the left superior frontal gyrus was reduced (p < 0.05). Our findings provided preliminary evidences that the iTBS on the ipsilesional M1 could induce neural activity and functional connectivity changes in the motor, language, and other brain regions in patients with PSA, which may promote neuroplasticity and functional recovery.

Effectiveness of Virtual Reality in the Rehabilitation of Motor Function of Patients With Subacute Stroke: A Meta-Analysis

Stroke is a major cause of death and disability in adults. Conventional therapy (CT) has limited effectiveness, and therefore, various virtual reality (VR) rehabilitation programs have been designed. However, their efficacy in regaining motor function in patients with subacute stroke is questionable. Therefore, we conducted this meta-analysis to determine the efficacy of VR, compared to CT, in restoring motor function in this patient population. Up to October 10, 2020, nine electronic databases were searched for relevant articles reporting the effectiveness of VR in regaining motor function in patients with subacute stroke. This search was updated on March 7, 2021, with no additional added articles. The control group included CT, physical therapy, occupational therapy, or a combination of them. Effectiveness is defined as the positive change from baseline values to the last follow-up point. The Cochrane's revised risk-of-bias tool was used to determine the quality of included trials. A metaregression analysis was conducted to determine the effect of "time since last stroke" on reported outcomes. Publication bias and sensitivity analyses were also carried out. A total of 19 studies (17 randomized controlled trials, 1 cohort study, and 1 crossover trial) were included in the qualitative analysis, whereas 16 trials were meta-analyzed. A great improvement in motor function was noted in the VR group, when compared to preintervention values [standardized mean difference (SMD) = 1.14; 95% confidence interval (CI) = 0.77-1.52; I ² = 82%; P < 0.001]. When compared to CT, VR resulted in mild improvement in motor function (SMD = 0.47; 95% CI = 0.22-0.72; I ² = 75%; P < 0.001). However, upon trim-and-fill adjustment, this finding was deemed insignificant (SMD = 0.08; 95% CI = -0.16 to 0.33; I ² = 82.6%; P < 0.001). Ten studies had low risk, five had some concerns, three had high risk, and one had a moderate risk of bias. VR programs can be used jointly with CT for the rehabilitation of the motor function of patients with subacute stroke. However, more studies are still warranted to determine the effectiveness of these interventions in retaining the cognitive function and physical performance of such patients.

A multi-modal modified feedback self-paced BCI to control the gait of an avatar

Brain-computer interfaces (BCI) have been used to control the gait of a virtual self-avatar with a proposed application in the field of gait rehabilitation.

OBJECTIVE

to develop a high performance multi-modal BCI to control single steps and forward walking of an immersive virtual reality avatar. This system will overcome the limitation of existing systems.

APPROACH

This system used MI of these actions, in cue-paced and self-paced modes. Twenty healthy participants participated in this 4 sessions study across 4 different days. They were cued to imagine a single step forward with their right or left foot, or to imagine walking forward. They were instructed to reach a target by using the MI of multiple steps (self-paced switch-control mode) or by maintaining MI of forward walking (continuous-control mode). The movement of the avatar was controlled by two calibrated RLDA classifiers that used the µ power spectral density (PSD) over the foot area of the motor cortex as a feature. The classifiers were retrained after every session. For a subset of the trials, positive modified feedback was presented to half of the participants.

MAIN RESULTS

All participants were able to operate the BCI. Their average offline performance, after retraining the classifiers was 86.0 ± 6.1%, showing that the recalibration of the classifiers enhanced the offline performance of the BCI (p < 0.01). The average online performance was 85.9 ± 8.4% showing that modified feedback enhanced BCI performance (p =0.001). The average performance was 83% at self-paced switch control and 92% at continuous control mode.

SIGNIFICANCE

This study reports on the first novel integration of different design approaches, different control modes and different performance enhancement techniques, all in parallel in one single high performance and multi-modal BCI system, to control single steps and forward walking of an immersive virtual reality avatar.