Impairment In Stroke Patients Research Articles

The distribution of transcallosal inhibition to upper extremity muscles is altered in chronic stroke

ObjectiveTo determine if the distribution of transcallosal inhibition (TI) acting on proximal and distal upper extremity muscles is altered in chronic stroke. MethodsWe examined thirteen healthy controls and sixteen mildly to moderately impaired chronic stroke patients. We used transcranial magnetic stimulation (TMS) to probe TI from the contralesional onto ipsilesional hemisphere (assigned in controls). We recorded the ipsilateral silent period in the paretic biceps (BIC) and first dorsal interosseous (FDI). We measured TI strength, distribution gradient (TI difference between muscles), and motor impairment (Fugl-Meyer Assessment). ResultsBoth groups had stronger TI acting on their FDIs than BICs (p < 0.001). However, stroke patients also had stronger TI acting on their BICs than controls (p = 0.034), resulting in a flatter distribution of inhibition (p = 0.028). In patients, stronger FDI inhibition correlated with less hand impairment (p = 0.031); BIC inhibition was not correlated to impairment. ConclusionTI is more evenly distributed to the paretic FDI and BIC in chronic stroke. The relative increase in proximal inhibition does not relate to better function, as it does distally. SignificanceThe results expand our knowledge about segment-specific neurophysiology and its relevance to impairment after stroke.

A systematic investigation of detectors for low signal-to-noise ratio EMG signals

Background: Active participation of stroke survivors during robot-assisted movement therapy is essential for sensorimotor recovery. Robot-assisted therapy contingent on movement intention is an effective way to encourage patients' active engagement. For severely impaired stroke patients with no residual movements, a surface electromyogram (EMG) has been shown to be a viable option for detecting movement intention. Although numerous algorithms for EMG detection exist, the detector with the highest accuracy and lowest latency for low signal-to-noise ratio (SNR) remains unknown. Methods: This study, therefore, investigates the performance of 13 existing EMG detection algorithms on simulated low SNR (0dB and -3dB) EMG signals generated using three different EMG signal models: gaussian, Laplacian, and biophysical model. The detector performance was quantified using the false positive rate (FPR), false negative rate (FNR), and detection latency. Any detector that consistently showed FPR and FNR of no more than 20%, and latency of no more than 50ms, was considered an appropriate detector for use in robot-assisted therapy. Results: The results indicate that the Modified Hodges detector – a simplified version of the threshold-based Hodges detector introduced in the current study – was the most consistent detector across the different signal models and SNRs. It consistently performed for ~90% and ~40% of the tested trials for 0dB and -3dB SNR, respectively. The two statistical detectors (Gaussian and Laplacian Approximate Generalized Likelihood Ratio) and the Fuzzy Entropy detectors have a slightly lower performance than Modified Hodges. Conclusions: Overall, the Modified Hodges, Gaussian and Laplacian Approximate Generalized Likelihood ratio, and the Fuzzy Entropy detectors were identified as the potential candidates that warrant further investigation with real surface EMG data since they had consistent detection performance on low SNR EMG data.

Thrombolysis Outcomes in Acute Ischaemic Stroke Patients with Pre-Existing Cognitive Impairment.

Thrombolysis treatment for ischaemic stroke in patients with pre-existing disabilities, including cognitive impairment, remains controversial. Previous studies have suggested functional outcomes post-thrombolysis are worse in patients with cognitive impairment. This study aimed to compare and explore factors contributing to thrombolysis outcomes, including haemorrhagic complications, in cognitively and non-cognitively impaired patients with ischaemic stroke. A retrospective analysis of 428 ischaemic stroke patients who were thrombolysed between January 2016 and February 2021 was performed. Cognitive impairment was defined as a diagnosis of dementia, mild cognitive impairment, or clinical evidence of the condition. The outcome measures included morbidity (using NIHSS and mRS), haemorrhagic complications, and mortality, and were analysed using multivariable logistic regression models. The analysis of the cohort revealed that 62 patients were cognitively impaired. When compared to those without cognitive impairment, this group showed worse functional status at discharge (mRS 4 vs. 3, p < 0.001) and a higher probability of dying within 90 days (OR 3.34, 95% CI 1.85-6.01, p < 0.001). A higher risk of a fatal ICH post-thrombolysis was observed in the cognitively impaired patients, and, after controlling for covariates, cognitive impairment remained a significant predictor of a fatal haemorrhage (OR 4.79, 95% CI 1.24-18.45, p = 0.023). Cognitively impaired ischaemic stroke patients experience increased morbidity, mortality, and haemorrhagic complications following thrombolytic therapy. However cognitive status is not independently predictive of most outcome measures. Further work is required to elucidate contributing factors to the poor outcomes observed in these patients and help guide thrombolysis decision-making in clinical practice.

Effectiveness of Truncal Motor Imagery Practice on Trunk Performance, Gait Performance and Functional Outcome Among Patients with Acute Hemiparetic Stroke

BACKGROUND: “Motor imagery” is considered to be as one of the latest rehabilitation strategies to treat the post-stroke disabilities. It is beneficial to treat upper and lower limb motor impairment in stroke patients, but the effect of imagery in the trunk recovery have not been reported yet. OBJECTIVE: To find the effectiveness of truncal motor imagery practice on trunk performance, gait performance and functional outcome among the patients with acute hemiparetic stroke. METHODOLOGY: A quasi-experimental study with a purposive sampling technique was conducted at KMCH institute of health sciences, Coimbatore. Patients who were clinically diagnosed with stroke and fit the study's eligibility criteria were chosen and were randomly allocated into two groups. Group A (30 patients) received Truncal motor imagery technique along with conventional therapy and Group B (30 patients) received conventional therapy alone as 1 session(90min) /day, 4 days a week for 6 weeks. OUTCOME MEASURES: The outcome measures such as trunk performance, gait performance, functional outcome were assessed with trunk impairment scale (TIS), Dynamic gait index(DGI) and functional independence measure respectively. RESULTS: Among 60 patients included in the study, The outcomes were measured in three different time periods and were analysed with One way ANOVA. Post hoc analysis was done with Tukey’s HSD test analysis effect size showed statistically significant improvement (p&lt; .05) CONCLUSION: Truncal motor imagery in addition to the physical practice showed benefits in improving trunk performance, gait performance and functional outcome among patients with acute hemiparetic stroke. Keywords: [Motor imagery, trunk performance, gait performance, functional outcome, acute hemiparetic stroke.]

Application of physical therapy methods for patients after stroke with spasticity in the early period

acute cerebrovascular accident is the leading cause of disability. Stroke ranks 4th among diseases that lead to death or disability. The consequences of stroke include neurological disorders, motor disorders (plegia, hemiparesis, paresis, muscle spasticity), loss of sensation, pelvic dysfunction, loss of coordination and balance, high risk of falls, and impaired ability to move independently and perform daily activities. To achieve optimal independence, stroke patients need qualified rehabilitation care as part of a multidisciplinary team. Evidence-based medicine, treatment, and rehabilitation interventions have improved significantly in the acute and early periods for stroke patients. However, in the late period, today, more than half of patients remain limited in their daily activities and have movement disorders that significantly affect their quality of life and independence. Description of the objective. To substantiate the use of evidence-based medicine methods in physical therapy to restore motor function in patients after stroke in the early period. Materials and methods. From October to December 2021, 20 patients with spasticity, aged 47-85 years, who had suffered an ischemic and hemorrhagic stroke, took part in the examination and rehabilitation activities at Kyiv City Clinical Hospital № 6, Palliative Care Department, for a period of 3 weeks to 1 month. Voluntary consent for examination, treatment, and rehabilitation was obtained from all patients and their caregivers. The diagnostic methods used were computed tomography, magnetic resonance imaging, and, if necessary, laboratory tests. Tests and scales for physical therapy were used to determine functional impairment in stroke patients with muscle spasticity: Rankin Scale, Riverbed Mobility Index, Pain Score, Modified Ashworth Scale, Degree of Arm and Hand Recovery; Degree of Leg and Foot Recovery. Results. After analyzing the methods of evidence-based medicine on the topic of the problem, we have confirmation that in the early period, recovery rates are high. However, in the late period after a stroke, the onset of muscle spasticity significantly limits the motor capabilities of patients and complicates the recovery process. In the late period, the effectiveness of methods to overcome spasticity has not been fully developed, and attention is not focused on the complications that arise and accompany them throughout the recovery period. The appearance of muscle spasticity significantly limits the motor capabilities of patients, affects the psycho-emotional state of a person, and causes pain, which prevents the full use of the affected limb. Muscle spasticity inhibits and complicates the restoration of motor function in the long term. Conclusions. The study confirms the high effectiveness of the proposed methods of evidence-based medicine in reducing pain and increasing the range of motion in the shoulder, elbow, and wrist joints in the early period in patients after stroke. As for the late period, this issue remains incomplete and requires further study. In the palliative care unit of Kyiv City Clinical Hospital № 6, an individual multidisciplinary approach to patients after stroke was used, which contributed to the achievement of the goals. It can be stated that evidence-based medicine methods for the acute and early period have a positive effect on patient independence, and improve cognitive function and motor activity of the affected limbs.

A Serious Game System for Upper Limb Motor Function Assessment of Hemiparetic Stroke Patients.

Stroke often results in hemiparesis, impairing the patient's motor abilities and leading to upper extremity motor deficits that require long-term training and assessment. However, existing methods for assessing patients' motor function rely on clinical scales that require experienced physicians to guide patients through target tasks during the assessment process. This process is not only time-consuming and labor-intensive, but the complex assessment process is also uncomfortable for patients and has significant limitations. For this reason, we propose a serious game that automatically assesses the degree of upper limb motor impairment in stroke patients. Specifically, we divide this serious game into a preparation stage and a competition stage. In each stage, we construct motor features based on clinical a priori knowledge to reflect the ability indicators of the patient's upper limbs. These features all correlated significantly with the Fugl-Meyer Assessment for Upper Extremity (FMA-UE), which assesses motor impairment in stroke patients. In addition, we design membership functions and fuzzy rules for motor features in combination with the opinions of rehabilitation therapists to construct a hierarchical fuzzy inference system to assess the motor function of upper limbs in stroke patients. In this study, we recruited a total of 24 patients with varying degrees of stroke and 8 healthy controls to participate in the Serious Game System test. The results show that our Serious Game System was able to effectively differentiate between controls, severe, moderate, and mild hemiparesis with an average accuracy of 93.5%.

Linkage of blood cell division cycle 42 with T helper cells, and their correlation with anxiety, depression, and cognitive impairment in stroke patients.

Cell division cycle 42 (CDC42) regulates T helper (Th) cell differentiation and is related to psychological disorders. This study aimed to assess the correlation between blood CDC42 and Th cells, and their association with mental issues in stroke patients. Peripheral blood samples were obtained from 264 stroke patients and 50 controls. Then, serum CDC42 was measured by enzyme-linked immunosorbent assay, and Th1, Th2, and Th17 cells were detected by flow cytometry. Hospital Anxiety and Depression Scale (HADS) and Mini Mental State Examination (MMSE) were applied to patients. CDC42 was decreased (P<0.001), Th1 (P=0.013) and Th17 (P<0.001) cells were elevated, while Th2 cells (P=0.108) showed no difference in stroke patients compared to controls. In addition, CDC42 was negatively associated to Th1 (P=0.013) and Th17 (P<0.001) cells in stroke patients but were not associated with Th2 cells (P=0.223). Interestingly, CDC42 was negatively associated with HADS-anxiety (P<0.001) and HADS-depression scores (P=0.034) and positively associated with MMSE score (P<0.001) in stroke patients. Lower CDC42 was associated to lower occurrence of anxiety (P=0.002), depression (P=0.001), and cognitive impairment (P=0.036) in stroke patients. Furthermore, increased Th17 cells were positively correlated with HADS-anxiety and HADS-depression scores and inversely correlated with MMSE score, which were also associated with higher occurrence of anxiety, depression, and cognitive impairment in stroke patients (all P<0.05). Blood CDC42 and Th17 cells were correlated, and both of them were linked to the risk of anxiety, depression, and cognitive impairment. However, the findings need further large-scale validation, and the implicated mechanism needs more investigation.

Study on the Cutoff Value of Backward Walking Speed to Distinguish the Mobility Deficits of Stroke Patients.

ABSTRACT BACKGROUND: Backward walking speed is an objective index to evaluate motor ability, but it is not clear whether it can screen stroke patients with mobility disorders. This study aims to test the diagnostic efficacy of backward maximum walking speed (BMWS) and backward comfortable walking speed (BCWS) on mobility defects in stroke patients and obtain the cutoff values of them. METHODS: We conducted a cross-sectional study of poststroke patients who were hospitalized from July 2021 to January 2022. 98 poststroke patients were selected for 6 functional tests and divided into the high–mobility function group and low–mobility function group by K-means cluster analysis. According to the test results of BMWS and BCWS, the receiver operating characteristic curve was drawn to determine the cutoff values and compare the diagnostic efficiency of the 2 indexes. RESULTS: The BMWS of stroke patients was 0.54 (0.29) m/s, and the BCWS was 0.37 (0.19) m/s. Receiver operating characteristic results showed that the cutoff value of BMWS for the diagnosis of mobility impairment in stroke patients was 0.3 m/s, the area under the curve was 0.95 (95% confidence interval, 0.89-0.98), the specificity was 0.86, and the sensitivity was 0.93. The cutoff value of BCWS was 0.27 m/s, the area under the curve was 0.91 (95% confidence interval, 0.84-0.96), the specificity was 0.91, and the sensitivity was 0.8. There was no significant difference between the 2 indexes in the diagnosis of mobility defects in stroke patients (P &gt; .05). CONCLUSIONS: Backward walking speed is a useful indicator for discriminating stroke patients with mobility deficits. Considering the risks associated with backward walking, BCWS can be used in clinical assessments to guide nurses in the development and implementation of rehabilitation programs.

Oscillatory neurofeedback networks and poststroke rehabilitative potential in severely impaired stroke patients

Motor restoration after severe stroke is often limited. However, some of the severely impaired stroke patients may still have a rehabilitative potential. Biomarkers that identify these patients are sparse.Eighteen severely impaired chronic stroke patients with a lack of volitional finger extension participated in an EEG study. During sixty-six trials of kinesthetic motor imagery, a brain-machine interface turned event-related beta-band desynchronization of the ipsilesional sensorimotor cortex into opening of the paralyzed hand by a robotic orthosis. A subgroup of eight patients participated in a subsequent four-week rehabilitation training. Changes of the movement extent were captured with sensors which objectively quantified even discrete improvements of wrist movement. Albeit with the same motor impairment level, patients could be differentiated into two groups, i.e., with and without task-related increase of bilateral cortico-cortical phase synchronization between frontal/premotor and parietal areas. This fronto-parietal integration (FPI) was associated with a significantly higher volitional beta modulation range in the ipsilesional sensorimotor cortex. Following the four-week training, patients with FPI showed significantly higher improvement in wrist movement than those without FPI. Moreover, only the former group improved significantly in the upper extremity Fugl-Meyer-Assessment score.Neurofeedback-related long-range oscillatory coherence may differentiate severely impaired stroke patients with regard to their rehabilitative potential, a finding that needs to be confirmed in larger patient cohorts.

Validation of the UK English Oxford cognitive screen-plus in sub-acute and chronic stroke survivors.

Stroke survivors are routinely screened for cognitive impairment with tools that often fail to detect subtle impairments. The Oxford Cognitive Screen-Plus (OCS-Plus) is a brief tablet-based screen designed to detect subtle post-stroke cognitive impairments. We examined its psychometric properties in two UK English-speaking stroke cohorts (subacute: <3 months post-stroke, chronic: >6 months post-stroke) cross-sectionally. This study included 347 stroke survivors (mean age = 73 years; mean education = 13 years; 43.06% female; 74.42% ischaemic stroke). The OCS-Plus was completed by 181 sub-acute stroke survivors and 166 chronic stroke survivors. All participants also completed the Oxford Cognitive Screen (OCS) and a subset completed the Montreal Cognitive Assessment (MoCA) and further neuropsychological tests. First, convergent construct validity of OCS-Plus tasks to task-matched standardized neuropsychological tests was confirmed (r > 0.30). Second, we evaluated divergent construct validity of all OCS-Plus subtasks (r < 0.19). Third, we report the sensitivity and specificity of each OCS-Plus subtask compared to neuropsychological test performance. Fourth, we found that OCS-Plus detected cognitive impairments in a large proportion of those classed as unimpaired on MoCA (100%) and OCS (98.50%). The OCS-Plus provides a valid screening tool for sensitive detection of subtle cognitive impairment in stroke patients. Indeed, the OCS-Plus detected subtle cognitive impairment at a similar level to validated neuropsychological assessments and exceeded detection of cognitive impairment compared to standard clinical screening tools.

Motor Impairment in Stroke Patients Is Associated With Network Properties During Consecutive Motor Imagery.

Our study aimed to predict the Fugl-Meyer assessment (FMA) upper limb using network properties during motor imagery using electroencephalography (EEG) signals. The subjects performed a finger tapping imagery task according to consecutive cues. We measured the weighted phase lag index (wPLI) as functional connectivity and directed transfer function (DTF) as causal connectivity in healthy controls and stroke patients. The network properties based on the wPLI and DTF were calculated. We predicted the FMA upper limb using partial least squares regression. A higher DTF in the mu band was observed in stroke patients than in healthy controls. Notably, the difference in local properties at node F3 was negatively correlated with motor impairment in stroke patients. Finally, using significant network properties based on the wPLI and DTF, we predicted motor impairments using the FMA upper limb with a root-mean-square error of 1.68 ( R2 = 0.97). This outperformed the state-of-the-art predictors. These findings demonstrate that network properties based on functional and causal connectivity were highly associated with motor function in stroke patients. Our network properties can help calculate the predictor of motor impairments in stroke rehabilitation and provide insight into the neural correlates related to motor function based on EEG after reorganization induced by stroke.

Blood Th17 cells and IL-17A as candidate biomarkers estimating the progression of cognitive impairment in stroke patients.

BackgroundT helper (Th) cells regulate immunity and inflammation to engage in cognitive impairment in several neurological diseases, while their clinical relevance in stroke patients is not clear. The current study intended to assess the relationship of Th1 cells, Th17 cells, interferon‐gamma (IFN‐γ), and interleukin (IL)‐17A with cognitive function in stroke patients.MethodsOne hundred twenty stroke patients and 40 controls were enrolled in this muticenter study. Th1 and Th17 cells in peripheral blood were assessed by flow cytometry; meanwhile, IFN‐γ and IL‐17A in serum were detected by enzyme‐linked immunosorbent assay. Cognitive function of stroke patients was evaluated by Mini‐Mental State Examination (MMSE) score at enrollment (baseline), year 1, year 2, and year 3.ResultsTh1 cells (p = 0.037) and IFN‐γ (p = 0.048) were slightly increased, while Th17 cells (p < 0.001) and IL‐17A (p < 0.001) were greatly elevated in stroke patients compared with controls. Th17 cells (r s = −0.374, p < 0.001) and IL‐17A (r s = −0.267, p = 0.003) were negatively correlated with MMSE score at baseline, but Th1 cells and IFN‐γ were not. Meanwhile, Th17 cells (p = 0.001) and IL‐17A (p = 0.024) were increased in patients with cognitive impairment compared to those without cognitive impairment. Notably, Th17 cells were positively associated with 1‐year (r s = 0.331, p < 0.001), 2‐year (r s = 0.261, p = 0.006), and 3‐year (r s = 0.256, p = 0.011) MMSE decline; IL‐17A was positively correlated with 1‐year (r s = 0.262, p = 0.005), 2‐year (r s = 0.193, p = 0.045), but not 3‐year MMSE decline. However, both Th1 cells and IFN‐γ were not linked with MMSE decline.ConclusionTh17 cells and IL‐17A estimate the progression of cognitive impairment in stroke patients.

A Novel Patient-Tailored, Cumulative Neurotechnology-Based Therapy for Upper-Limb Rehabilitation in Severely Impaired Chronic Stroke Patients: The AVANCER Study Protocol.

Effective, patient-tailored rehabilitation to restore upper-limb motor function in severely impaired stroke patients is still missing. If suitably combined and administered in a personalized fashion, neurotechnologies offer a large potential to assist rehabilitative therapies to enhance individual treatment effects. AVANCER (clinicaltrials.gov NCT04448483) is a two-center proof-of-concept trial with an individual based cumulative longitudinal intervention design aiming at reducing upper-limb motor impairment in severely affected stroke patients with the help of multiple neurotechnologies. AVANCER will determine feasibility, safety, and effectivity of this innovative intervention. Thirty chronic stroke patients with a Fugl-Meyer assessment of the upper limb (FM-UE) <20 will be recruited at two centers. All patients will undergo the cumulative personalized intervention within two phases: the first uses an EEG-based brain-computer interface to trigger a variety of patient-tailored movements supported by multi-channel functional electrical stimulation in combination with a hand exoskeleton. This phase will be continued until patients do not improve anymore according to a quantitative threshold based on the FM-UE. The second interventional phase will add non-invasive brain stimulation by means of anodal transcranial direct current stimulation to the motor cortex to the initial approach. Each phase will last for a minimum of 11 sessions. Clinical and multimodal assessments are longitudinally acquired, before the first interventional phase, at the switch to the second interventional phase and at the end of the second interventional phase. The primary outcome measure is the 66-point FM-UE, a significant improvement of at least four points is hypothesized and considered clinically relevant. Several clinical and system neuroscience secondary outcome measures are additionally evaluated. AVANCER aims to provide evidence for a safe, effective, personalized, adjuvant treatment for patients with severe upper-extremity impairment for whom to date there is no efficient treatment available.

Impact on quitting smoking of cognitive impairment in stroke patients

IntroductionSmoking is a well-established risk factor for strokes, leading to a high incidence of cognitive deficits. Since the impact of cognitive impairment on the effectiveness of interventions for smoking cessation is not yet known, we considered important to assess it. MethodsWe compared, from April 2012 to November 2015, the success rate of quitting smoking in two groups of acutely hospitalised adult smokers. The first group consisted of stroke patients (SP, n = 54) with lesions confirmed by cerebral imaging. The second used as a control group (NSP, n = 38), included patients hospitalised for any reason other than stroke and characterised by normal global cognition. All participants were assessed twice, in acute phase (T0) and 3 months later (T1), using exhaled carbon monoxide (CO) and several questionnaires. ResultsAt T1, we observed in SP group an inverse correlation between the Montreal Cognitive Assessment (MoCA) and CO (r = −0.33, p = 0.015). Amongst patients who continued smoking, a higher increase in CO between T0 and T1 was observed in SP group (average 20 ± 15, p < 0.001) than NSP (average 9 ± 13, p = 0.002). ConclusionsThe inverse correlation between CO and cognitive parameters at T1 in SP group suggests an increased susceptibility to tobacco dependency in case of residual cognitive impairment. The global cognitive assessment should thus be taken into consideration when providing assistance with quitting smoking, especially in case of stroke patients.

Quantitative Assessment of Hand Function in Healthy Subjects and Post-Stroke Patients with the Action Research Arm Test

The Action Research Arm Test (ARAT) can provide subjective results due to the difficulty assessing abnormal patterns in stroke patients. The aim of this study was to identify joint impairments and compensatory grasping strategies in stroke patients with left (LH) and right (RH) hemiparesis. An experimental study was carried out with 12 patients six months after a stroke (three women and nine men, mean age: 65.2 ± 9.3 years), and 25 healthy subjects (14 women and 11 men, mean age: 40.2 ± 18.1 years. The subjects were evaluated during the performance of the ARAT using a data glove. Stroke patients with LH and RH showed significantly lower flexion angles in the MCP joints of the Index and Middle fingers than the Control group. However, RH patients showed larger flexion angles in the proximal interphalangeal (PIP) joints of the Index, Middle, Ring, and Little fingers. In contrast, LH patients showed larger flexion angles in the PIP joints of the Middle and Little fingers. Therefore, the results showed that RH and LH patients used compensatory strategies involving increased flexion at the PIP joints for decreased flexion in the MCP joints. The integration of a data glove during the performance of the ARAT allows the detection of finger joint impairments in stroke patients that are not visible from ARAT scores. Therefore, the results presented are of clinical relevance.

Improvement of poststroke cognitive impairment by intermittent theta bursts: A double-blind randomized controlled trial.

BackgroundIntermittent theta burst stimulation (iTBS) is known to improve cognitive impairment caused by Alzheimer's disease and Parkinson's disease, but studies are lacking with respect to the efficacy of iTBS on poststroke cognitive impairment (PSCI).ObjectiveThis study was conducted to investigate the effect of left dorsolateral prefrontal cortex (DLPFC) iTBS on improving cognitive function in stroke patients.MethodsFifty‐eight patients with PSCI are randomly divided into iTBS (n = 28) and sham stimulation groups (n = 30). Both groups receive routine cognitive‐related rehabilitation. The iTBS group is treated with iTBS intervention of the left DLPFC, and the sham stimulation group is treated with the same parameters at the same site for 2 weeks. Outcome measures are assessed at baseline (T0) and immediately after the last intervention (T1) by mini‐mental state examination (MMSE), Oxford cognitive screen, and event‐related potential P300.ResultsThere are no differences in baseline clinical characteristics between the two groups. After intervention, the MMSE scores and P300 amplitude increase significantly for both groups, and the P300 incubation period reduces significantly. The change value of the iTBS group is significantly higher than that of sham stimulation group (p < .05). Compared with the sham stimulation group, the iTBS group has more significant changes in semantic comprehension and executive function (p < .05).ConclusioniTBS can effectively and safely improve overall cognitive impairment in stroke patients, including semantic understanding and executive function, and it also has a positive impact on memory function. Future randomized controlled studies with large samples and long‐term follow‐up should be conducted to further validate the results of the present study

314 Exoskeletons increase paretic limb use in stroke survivors during a bimanual virtual reality reaching task

OBJECTIVES/GOALS: Almost 8 million Americans live with disability caused by stroke. However, recent advances in stroke rehabilitation are costly and lack resemblance to activities of daily living. The goal of this study was to develop a rehabilitation platform to increase stroke patients paretic limb use using inexpensive virtual reality and exoskeleton devices. METHODS/STUDY POPULATION: We conducted a feasibility study with 2 hemiplegic stroke participants. They reached for targets in a virtual reality environment using both hands. They completed 162 reaches divided into 3 blocks. Following baseline, we used an exoskeleton to provide 50% arm weight compensation to the paretic limb and used wrist weights to provide 50% arm weight resistance to the non-paretic limb. We removed the exoskeleton and wrist weights during the retention block. We used electromyography to approximate muscle activity in the biceps brachii. Relative contribution (RC) was calculated as the displacement of the paretic arm divided by the sum of displacements for both arms. Muscle contribution (MC) was calculated as the root mean square of paretic arm muscle activity divided by the sum of activity for both arms. RESULTS/ANTICIPATED RESULTS: During baseline, RC of the impaired limb was 44% and 48%, and MC of the impaired bicep was 43% and 35% in two mild to moderately impaired patients (Fugl-Meyer Upper Extremity scores of 43 and 37, respectively). During loading, RC increased by 5.6% and 1.1% and MC decreased by 8.3% and 11.8%. These data suggest hemiplegic stroke participants alter limb coordination when our device normalizes muscular output asymmetries between limbs. Importantly, these results closely match data from our previous work in 12 healthy controls, where we found a 2% increase in RC is significantly predicted by a 11% decrease in MC. By collecting more data on stroke patients, we will quantify this tradeoff between coordination and muscle activity modulation, allowing us to optimize the exoskeleton mechanics to maximize paretic limb use. DISCUSSION/SIGNIFICANCE: We demonstrate our platform is well tolerated by mild to moderately impaired stroke patients; this feasibility study forms the basis for low cost at-home technologies for stroke rehabilitation. With further development, clinicians can use our platform to fine-tune the level of limb constraint based on the individual needs of the patient.

Occupational therapy for cognitive impairment in stroke patients.

Occupational therapy for cognitive impairment in stroke patients.

Cortical thickness of contralesional cortices positively relates to future outcome after severe stroke.

Imaging studies have evidenced that contralesional cortices are involved in recovery after motor stroke. Cortical thickness (CT) analysis has proven its potential to capture the changes of cortical anatomy, which have been related to recovery and treatment gains under therapy. An open question is whether CT obtained in the acute phase after stroke might inform correlational models to explain outcome variability. Data of 38 severely impaired (median NIH Stroke Scale 9, interquartile range: 6-13) acute stroke patients of 2 independent cohorts were reanalyzed. Structural imaging data were processed via the FreeSurfer pipeline to quantify regional CT of the contralesional hemisphere. Ordinal logistic regression models were fit to relate CT to modified Rankin Scale as an established measure of global disability after 3-6 months, adjusted for the initial deficit, lesion volume, and age. The data show that CT of contralesional cortices, such as the precentral gyrus, the superior frontal sulcus, and temporal and cingulate cortices, positively relates to the outcome after stroke. This work shows that the baseline cortical anatomy of selected contralesional cortices can explain the outcome variability after severe stroke, which further contributes to the concept of structural brain reserve with respect to contralesional cortices to promote recovery.

Anti-Stroke Chinese Herbal Medicines Inhibit Abnormal Amyloid-β Protein Precursor Processing in Alzheimer's Disease.

Chinese Herbal Medicines (CHMs), as an important and integral part of a larger system of medicine practiced in China, called Traditional Chinese Medicine (TCM), have been used in stroke therapy for centuries. A large body of studies suggest that some Chinese herbs can help reverse cognitive impairment in stroke patients, while whether these herbs also exert therapeutic benefits for Alzheimer's disease remains to be seen. To address this issue, we selected four types of CHMs that are commonly prescribed for stroke treatment in clinical practice, namely DengZhanXiXin (D1), TongLuoJiuNao (T2), QingKaiLing (Q3), and HuangQinGan (H4), and tested their effects on amyloid-β protein precursor (AβPP) processing in vitro. AβPP, β-secretase (BACE1), and 99-amino acid C-terminal fragment of AβPP (C99) stably transfected cells were used for the tests of AβPP processing. The production of Aβ, activity of BACE1, neprilysin (NEP), and γ-secretase were assessed by ELISA, RT-PCR, and western blot. By upregulating BACE1 activity, D1 increased Aβ production whereas decreased the ratio of Aβ42/Aβ40; by downregulating BACE1 activity and modulating the expression of γ-secretase, T2 decreased Aβ production and the ratio of Aβ42/Aβ40; by downregulating BACE1 activity, Q3 decreased Aβ production; H4 did not change Aβ production due to the simultaneously downregulation of BACE1 and NEP activity. Our study indicates that these four anti-stroke CHMs regulate AβPP processing through different mechanisms. Particularly, T2 with relatively simple components and prominent effect on AβPP processing may be a promising candidate for the treatment of AD.