Rehabilitation Therapy Doses Are Low After Stroke and Predicted by Clinical Factors

Genetic Variation and Stroke Recovery: The STRONG Study

BACKGROUND

Genetic association studies can reveal biology and treatment targets but have received limited attention for stroke recovery. STRONG (Stroke, Stress, Rehabilitation, and Genetics) was a prospective, longitudinal (1-year), genetic study in adults with stroke at 28 US stroke centers. The primary aim was to examine the association that candidate genetic variants have with (1) motor/functional outcomes and (2) stress-related outcomes.

METHODS

For motor/functional end points, 3 candidate gene variants (ApoE ε4, BDNF [brain-derived neurotrophic factor], and a dopamine polygenic score) were analyzed for associations with change in grip strength (3 months-baseline), function (3-month Stroke Impact Scale-Activities of Daily Living), mood (3-month Patient Health Questionnaire-8), and cognition (12-month telephone-Montreal Cognitive Assessment). For stress-related outcomes, 7 variants (serotonin transporter gene-linked promoter region, ACE [angiotensin-converting enzyme], oxytocin receptor, FKBP5 [FKBP prolyl isomerase 5], FAAH [fatty acid amide hydrolase], BDNF, and COMT [catechol-O-methyltransferase]) were assessed for associations with posttraumatic stress disorder ([PTSD]; PTSD Primary Care Scale) and depression (Patient Health Questionnaire-8) at 6 and 12 months; stress-related genes were examined as a function of poststroke stress level. Statistical models (linear, negative binomial, or Poisson regression) were based on response variable distribution; all included stroke severity, age, sex, and ancestry as covariates. Stroke subtype was explored secondarily. Data were Holm-Bonferroni corrected. A secondary replication analysis tested whether the rs1842681 polymorphism (identified in the GISCOME study [Genetics of Ischaemic Stroke Functional Outcome]) was related to 3-month modified Rankin Scale score in STRONG.

RESULTS

The 763 enrollees were 63.1±14.9 (mean±SD) years of age, with a median initial National Institutes of Health Stroke Scale score of 4 (interquartile range, 2-9); outcome data were available in n=515 at 3 months, n=500 at 6 months, and n=489 at 12 months. At 1 year poststroke, the rs6265 (BDNF) variant was associated with poorer cognition (0.9-point lower telephone-Montreal Cognitive Assessment score, P=1×10-5). For stress-related outcomes, rs4291 (ACE) and rs324420 (FAAH) were risk factors linking increased poststroke stress with higher 1-year depression and PTSD symptoms (P<0.05), while rs4680 (COMT) linked poststroke stress with lower 1-year depression and PTSD. Findings were unchanged when considering stroke subtype. STRONG replicated GISCOME: rs1842681 was associated with lower 3-month modified Rankin Scale score (P=3.2×10-5).

CONCLUSIONS

This study identified genetic associations with cognitive function, depression, and PTSD 1 year poststroke. Genetic susceptibility to PTSD and depressive symptoms varied according to the amount of poststroke stress, underscoring the critical role of lived experiences in recovery. Together, the results suggest that genetic association studies provide insights into the biology of stroke recovery in humans.

Vagus Nerve Stimulation Paired With Rehabilitation for Chronic Stroke: Characterizing Responders

BACKGROUND AND PURPOSE

Implantable vagus nerve stimulation (VNS) paired with volitional upper extremity rehabilitation can improve impairment and function among moderately to severely impaired, chronic stroke survivors. This study is a retrospective analysis of the in-clinic rehabilitation phase of the blinded, placebo-controlled, randomized pivotal VNS-REHAB trial to determine whether dosing parameters during in-clinic paired VNS therapy were associated with responder status and whether covariates might impact that determination.

METHODS

Data were limited to 53 participants in the active VNS group who had received VNS implants prior to undergoing 6 weeks of in-clinic rehabilitation paired with VNS. Tasks were standardized across all participants. Dosing parameters included number of stimulations and task time. The primary outcome was the Fugl-Meyer Upper Extremity Assessment (FMA-UE), evaluated at the end of 6 weeks (Post-1). Participants were classified a priori as responders based on an improvement of ≥6 points on the FMA-UE from baseline to Post-1.

RESULTS

Dosing parameters were not associated with FMA-UE responder status at the end of 6 weeks. Covariates including age, gender, paretic hand, baseline severity, and chronicity of stroke were also not significant associations of response.

DISCUSSION AND CONCLUSIONS

While responders to VNS could be defined, therapy dosing and participant attributes did not provide greater specification for association of responder status. Limitations of this study include small sample size and non-linearity of the FMA-UE. Future studies will include reassessing responder categorization using more linear scales and examining stroke lesion characteristics to determine whether these measures are more sensitive to dosing parameters.

VIDEO ABSTRACT AVAILABLE

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Transcranial Direct Current Stimulation to Ameliorate Post-Stroke Cognitive Impairment

Post-stroke cognitive impairment is a common and disabling condition with few effective therapeutic options. After stroke, neural reorganization and other neuroplastic processes occur in response to ischemic injury, which can result in clinical improvement through spontaneous recovery. Neuromodulation through transcranial direct current stimulation (tDCS) is a promising intervention to augment underlying neuroplasticity in order to improve cognitive function. This form of neuromodulation leverages mechanisms of neuroplasticity post-stroke to optimize neural reorganization and improve function. In this review, we summarize the current state of cognitive neurorehabilitation post-stroke, the practical features of tDCS, its uses in stroke-related cognitive impairment across cognitive domains, and special considerations for the use of tDCS in the post-stroke patient population.

Motor Learning Following Stroke: Mechanisms of Learning and Techniques to Augment Neuroplasticity

Sensorimotor impairments are common after stroke requiring stroke survivors to relearn lost motor skills or acquire new ones in order to engage in daily activities. Thus, motor skill learning is a cornerstone of stroke rehabilitation. This article provides an overview of motor control and learning theories that inform stroke rehabilitation interventions, discusses principles of neuroplasticity, and provides a summary of practice conditions and techniques that can be used to augment motor learning and neuroplasticity in stroke rehabilitation.

Telerehabilitation Following Stroke

Stroke remains a major cause of disability. Intensive rehabilitation therapy can improve outcomes, but most patients receive limited doses. Telehealth methods can overcome obstacles to delivering intensive therapy and thereby address this unmet need. A specific example is reviewed in detail, focused on a telerehabilitation system that targets upper extremity motor deficits after stroke. Strengths of this system include provision of daily therapy associated with very high patient compliance, safety and feasibility in the inpatient or home setting, comparable efficacy to dose-matched therapy provided in-clinic, and a holistic approach that includes assessment, education, prevention, and activity-based therapy.

Transforming modeling in neurorehabilitation: clinical insights for personalized rehabilitation

Practicing clinicians in neurorehabilitation continue to lack a systematic evidence base to personalize rehabilitation therapies to individual patients and thereby maximize outcomes. Computational modeling- collecting, analyzing, and modeling neurorehabilitation data- holds great promise. A key question is how can computational modeling contribute to the evidence base for personalized rehabilitation? As representatives of the clinicians and clinician-scientists who attended the 2023 NSF DARE conference at USC, here we offer our perspectives and discussion on this topic. Our overarching thesis is that clinical insight should inform all steps of modeling, from construction to output, in neurorehabilitation and that this process requires close collaboration between researchers and the clinical community. We start with two clinical case examples focused on motor rehabilitation after stroke which provide context to the heterogeneity of neurologic injury, the complexity of post-acute neurologic care, the neuroscience of recovery, and the current state of outcome assessment in rehabilitation clinical care. Do we provide different therapies to these two different patients to maximize outcomes? Asking this question leads to a corollary: how do we build the evidence base to support the use of different therapies for individual patients? We discuss seven points critical to clinical translation of computational modeling research in neurorehabilitation- (i) clinical endpoints, (ii) hypothesis- versus data-driven models, (iii) biological processes, (iv) contextualizing outcome measures, (v) clinical collaboration for device translation, (vi) modeling in the real world and (vii) clinical touchpoints across all stages of research. We conclude with our views on key avenues for future investment (clinical-research collaboration, new educational pathways, interdisciplinary engagement) to enable maximal translational value of computational modeling research in neurorehabilitation.

The effect of post-acute rehabilitation setting on 90-day mobility after stroke: A difference-in-difference analysis

Background

After discharged from the hospital for acute stroke, individuals typically receive rehabilitation in one of three settings: inpatient rehabilitation facilities (IRFs), skilled nursing facilities (SNFs), or home with community services (i.e., home health or outpatient clinics). The initial setting of post-acute care (i.e., discharge location) is related to mortality and hospital readmission; however, the impact of this setting on the change in functional mobility at 90-days after discharge is still poorly understood. The purpose of this work was to examine the impact of discharge location on the change in functional mobility between hospital discharge and 90-days post-discharge.

Methods

In this retrospective cohort study, we used the electronic health record to identify individuals admitted to Johns Hopkins Medicine with an acute stroke and who had measurements of mobility [Activity Measure for Post Acute Care Basic Mobility (AM-PAC BM)] at discharge from the acute hospital and 90-days post-discharge. Individuals were grouped by discharge location (IRF=190 [40%], SNF=103 [22%], Home with community services=182 [(38%]). We compared the change in mobility from time of discharge to 90-days post-discharge in each group using a difference-in-differences analysis and controlling for demographics, clinical characteristics, and social determinants of health.

Results

We included 475 individuals (age 64.4 [14.8] years; female: 248 [52.2%]). After adjusting for covariates, individuals who were discharged to an IRF had a significantly greater improvement in AM-PAC BM from time of discharge to 90-days post-discharge compared to individuals discharged to a SNF or home with community services (β=-3.5 (1.4), p=0.01 and β=-8.2 (1.3), p=<0.001, respectively).

Conclusions

These findings suggest that the initial post-acute rehabilitation setting impacts the magnitude of functional recovery at 90-days after discharge from the acute hospital. These findings support the need for high-intensity rehabilitation and for policies that facilitate the delivery of high-intensity rehabilitation after stroke.

Physiotherapy practices in acute and sub-acute stroke in a low resource country: A prospective observational study in Benin

BACKGROUND AND OBJECTIVE

Physiotherapy is highly recommended for early recovery from stroke. This study aimed to document physiotherapy practices for people with acute and early sub-acute stroke in Benin.

METHODS

In this prospective observational study, physiotherapists working with acute stroke people documented the content of their treatment from six hospitals in Benin during the first session, at 2-week, and 1-month post-stroke with a standardized physiotherapy documentation form. We used the motricity index (MI) and trunk control test (TCT) to assess impairments, and the 10-meter walk test (10mWT), functional independence measure (FIM), walking, stair climbing, and dressing upper body subscales were used for activity limitations.

RESULTS

Fifteen physiotherapists (60 % male, mean±SD age=31.3±5.8 years) recorded treatment sessions for 77 stroke participants (53.2 % male, mean±SD age=57.7±12.5 years). Physiotherapists focused on conventional physiotherapy approaches, including musculoskeletal (67 % of pre-functional activity time) and neuromuscular (53 % of sitting activity time) interventions. A significant difference was found between the therapy time delivered for people with mild, moderate, and severe stroke (p < 0.001). The MI (p= 0.033) and TCT (p= 0.002) measures showed significant improvement at 2-week and 1-month (p< 0.001) post-stroke, while 10mWT, FIM walking, stair climbing, and dressing upper body items significantly increased at 1-month (p< 0.001) but not at 2-week post-stroke.

CONCLUSION

Physiotherapists working with acute stroke patients in Benin mainly use conventional neuromuscular and musculoskeletal interventions. In contrast, aerobic exercises were rarely employed regardless of stroke severity. Furthermore, our findings showed that the volume of physiotherapy sessions varied by stroke severity.

Combining high dose therapy, bilateral motor priming, and vagus nerve stimulation to treat the hemiparetic upper limb in chronic stroke survivors: a perspective on enhancing recovery

Stroke is a leading cause of disability worldwide and upper limb hemiparesis is the most common post-stroke disability. Recent studies suggest that clinically significant motor recovery is possible in chronic stroke survivors with severe impairment of the upper limb. Three promising strategies that have been investigated are (1) high dose rehabilitation therapy (2) bilateral motor priming and (3) vagus nerve stimulation. We propose that the future of effective and efficient upper limb rehabilitation will likely require a combination of these approaches.