BackgroundThe upper-extremity portion of the Fugl-Meyer Scale (UE-FM) is one of the most established and commonly used outcome measures in stroke rehabilitative trials. Empirical work is needed to determine the amount of change in UE-FM scores that can be regarded as important and clinically meaningful for health professionals, patients, and other stakeholders.ObjectiveThis study used anchor-based methods to estimate the clinically important difference (CID) for the UE-FM in people with minimal to moderate impairment due to chronic stroke.MethodOne hundred forty-six individuals with stable, mild to moderate upper-extremity (UE) hemiparesis were administered the UE-FM before and after an intervention targeting their affected UEs. The treating therapists rated each participant's perceived amount of UE motor recovery on a global rating of change (GROC) scale evaluating several facets of UE movement (grasp, release, move the affected UE, perform 5 important functional tasks with the affected UE, overall UE function). Estimated CID of the UE-FM scores was calculated using receiver operating characteristic (ROC) curve with the GROC scores as the anchor.ResultsThe ROC curve analysis revealed that change in UE-FM scores during the intervention period distinguished participants who experienced clinically important improvement from those that did not based on the therapists' GROC scores. The area under the curve ranged from 0.61 to 0.70 for the different facets of UE movement.ConclusionsThe estimated CID of the UE-FM scores ranged from 4.25 to 7.25 points, depending on the different facets of UE movement.

Although further protocol optimization is needed to improve overground translation of treadmill gains, a definitive RCT comparing HIT and MCT appears to be feasible and warranted.

Background and Purpose-Walking ability poststroke is commonly assessed using gait speed categories developed by Perry et al. The purpose of this study was to reexamine factors that predict home and community ambulators determined from real-world walking activity data using activity monitors. Methods-Secondary analyses of real-world walking activity from 2 stroke trials. Home (100-2499 steps/d), most limited community (2500-4499 steps/d), least limited community (5000-74 999), and full community (≥7500 steps/d) walking categories were developed based on normative data. Independent variables to predict walking categories were comfortable and fast gait speed, 6-minute walk test, Berg Balance Scale, Fugl Meyer, and Stroke Impact Scale. Data were analyzed using multivariate analyses to identify significant variables associated with walking categories, bootstrap method to select the most stable model and receiver-operating characteristic to identify cutoff values. Results-Data from 441 individuals poststroke were analyzed. The 6-minute walk test, Fugl Meyer, and Berg Balance Scale combined were the strongest predictors of home versus community and limited versus unlimited community ambulators. The 6-minute walk test was the strongest individual variable in predicting home versus community (receiver-operating characteristic area under curve=0.82) and limited versus full community ambulators (receiver-operating characteristic area under curve=0.76). A comfortable gait speed of 0.49 m/s discriminated between home and community and a comfortable gait speed of 0.93 m/s discriminated between limited community and full community ambulators. Conclusions-The 6-minute walk test was better able to discriminate among home, limited community, and full community ambulators than comfortable gait speed. Gait speed values commonly used to distinguish between home and community walkers may overestimate walking activity.

Aerobic exercise may acutely prime the brain to be more responsive to rehabilitation, thus facilitating neurologic recovery from conditions like stroke. This aerobic priming effect could occur through multiple mechanisms, including upregulation of circulating brain-derived neurotrophic factor (BDNF), increased corticospinal excitability, and decreased intracortical inhibition. However, optimal exercise parameters for targeting these mechanisms are poorly understood. This study tested the effects of exercise intensity on acute BDNF and neurophysiological responses. Sixteen ambulatory persons >6 mo poststroke performed three different 20-min exercise protocols in random order, approximately 1 wk apart, including the following: 1) treadmill high-intensity interval training (HIT-treadmill); 2) seated-stepper HIT (HIT-stepper); and 3) treadmill moderate-intensity continuous exercise (MCT-treadmill). Serum BDNF and transcranial magnetic stimulation measures of paretic lower limb excitability and inhibition were assessed at multiple time points during each session. Compared with MCT-treadmill, HIT-treadmill elicited significantly greater acute increases in circulating BDNF and corticospinal excitability. HIT-stepper initially showed BDNF responses similar to HIT-treadmill but was no longer significantly different from MCT-treadmill after decreasing the intensity in reaction to two hypotensive events. Additional regression analyses showed that an intensity sufficient to accumulate blood lactate appeared to be important for eliciting BDNF responses, that the interval training approach may have facilitated the corticospinal excitability increases, and that the circulating BDNF response was (negatively) related to intracortical inhibition. These findings further elucidate neurologic mechanisms of aerobic exercise and inform selection of optimal exercise-dosing parameters for enhancing acute neurologic effects. NEW & NOTEWORTHY Acute exercise-related increases in circulating BDNF and corticospinal excitability are thought to prime the brain for learning. Our data suggest that these responses can be obtained among persons with stroke using short-interval treadmill high-intensity interval training, that a vigorous aerobic intensity sufficient to generate lactate accumulation is needed to increase BDNF, that interval training facilitates increases in paretic quadriceps corticospinal excitability, and that greater BDNF response is associated with lesser intracortical inhibition response.

Sedentary lifestyle after stroke is common which results in poor cardiovascular health. Aerobic exercise has the potential to reduce cardiovascular risk factors and improve functional capacity and quality of life in people after stroke. However, aerobic exercise is a therapeutic intervention that is underutilized by healthcare professionals after stroke. The purpose of this review paper is to provide information on exercise prescription using the FITT principle (frequency, intensity, time, type) for people after stroke and to guide healthcare professionals to incorporate aerobic exercise into the plan of care. This article discusses the current literature outlining the evidence base for incorporating aerobic exercise into stroke rehabilitation. Recently, high-intensity interval training has been used with people following stroke. Information is provided regarding the early but promising results for reaching higher target heart rates.

During the subacute stage of recovery, individuals poststroke who experience improvements in gait speed of 0.175 m/s or greater are likely to exhibit a meaningful improvement in walking ability. The estimated clinically important change value of 0.175 m/s can be used by clinicians to set goals and interpret change in individual patients and by researchers to compare important change between groups.

Background. Exercise intensity can influence functional recovery after stroke, but the mechanisms remain poorly understood. Objective. In chronic stroke, an intensity-dependent increase in circulating brain-derived neurotrophic factor (BDNF) was previously found during vigorous exercise. Using the same serum samples, this study tested acute effects of exercise intensity on other circulating molecules related to neuroplasticity, including vascular-endothelial growth factor (VEGF), insulin-like growth factor-1 (IGF1), and cortisol, with some updated analyses involving BDNF. Methods. Using a repeated-measures design, 16 participants with chronic stroke performed 3 exercise protocols in random order: treadmill high-intensity interval training (HIT-treadmill), seated-stepper HIT (HIT-stepper), and treadmill moderate-intensity continuous exercise (MCT-treadmill). Serum molecular changes were compared between protocols. Mediation and effect modification analyses were also performed. Results. VEGF significantly increased during HIT-treadmill, IGF1 increased during both HIT protocols and cortisol nonsignificantly decreased during each protocol. VEGF response was significantly greater for HIT-treadmill versus MCT-treadmill when controlling for baseline. Blood lactate positively mediated the effect of HIT on BDNF and cortisol. Peak treadmill speed positively mediated effects on BDNF and VEGF. Participants with comfortable gait speed ≥0.4 m/s had significantly lower VEGF and higher IGF1 responses, with a lower cortisol response during MCT-treadmill. Conclusions. BDNF and VEGF are promising serum molecules to include in future studies testing intensity-dependent mechanisms of exercise on neurologic recovery. Fast training speed and anaerobic intensity appear to be critical ingredients for eliciting these molecular responses. Serum molecular response differences between gait speed subgroups provide a possible biologic basis for previously observed differences in training responsiveness.

After stroke, people with weakness enter a vicious cycle of limited activity and deconditioning that limits functional recovery and exacerbates cardiovascular risk factors. Conventional aerobic exercise improves aerobic capacity, function, and overall cardiometabolic health after stroke. Recently, a new exercise strategy has shown greater effectiveness than conventional aerobic exercise for improving aerobic capacity and other outcomes among healthy adults and people with heart disease. This strategy, called high-intensity interval training (HIT), uses bursts of concentrated effort alternated with recovery periods to maximize exercise intensity. Three poststroke HIT studies have shown preliminary effectiveness for improving functional recovery. However, these studies were varied in approach and the safety of poststroke HIT has received little attention. The objectives of this narrative review are to (1) propose a framework for categorizing HIT protocols; (2) summarize the safety and effectiveness evidence of HIT among healthy adults and people with heart disease and stroke; (3) discuss theoretical mechanisms, protocol selection, and safety considerations for poststroke HIT; and (4) provide directions for future research.