Motor Recovery Of Upper Limb Research Articles

A meta-analysis of the efficacy of anodal transcranial direct current stimulation for upper limb motor recovery in stroke survivors

Study DesignSystematic review and meta-analysis. IntroductionPrior reviews on the effects of anodal transcranial direct current stimulation (a-tDCS) have shown the effectiveness of a-tDCS on corticomotor excitability and motor function in healthy individuals but nonsignificant effect in subjects with stroke. PurposeTo summarize and evaluate the evidence for the efficacy of a-tDCS in the treatment of upper limb motor impairment after stroke. MethodsA meta-analysis of randomized controlled trials that compared a-tDCS with placebo and change from baseline. ResultsA pooled analysis showed a significant increase in scores in favor of a-tDCS (standard mean difference [SMD]=0.40, 95% confidence interval [CI]=0.10–0.70, p=0.010, compared with baseline). A similar effect was observed between a-tDCS and sham (SMD=0.49, 95% CI=0.18–0.81, p=0.005). ConclusionThis meta-analysis of eight randomized placebo-controlled trials provides further evidence that a-tDCS may benefit motor function of the paretic upper limb in patients suffering from chronic stroke. Level of EvidenceLevel 1a.

The Mirror Therapy Program Enhances Upper-Limb Motor Recovery and Motor Function in Acute Stroke Patients

The purpose of this study was to evaluate the effects of the mirror therapy program on upper-limb motor recovery and motor function in patients with acute stroke. Twenty-six patients who had an acute stroke within 6 mos of study commencement were assigned to the experimental group (n = 13) or the control group (n = 13). Both experimental and control group members participated in a standard rehabilitation program, but only the experimental group members additionally participated in mirror therapy program, for 25 mins twice a day, five times a week, for 4 wks. The Fugl-Meyer Assessment, Brunnstrom motor recovery stage, and Manual Function Test were used to assess changes in upper-limb motor recovery and motor function after intervention. In upper-limb motor recovery, the scores of Fugl-Meyer Assessment (by shoulder/elbow/forearm items, 9.54 vs. 4.61; wrist items, 2.76 vs. 1.07; hand items, 4.43 vs. 1.46, respectively) and Brunnstrom stages for upper limb and hand (by 1.77 vs. 0.69 and 1.92 vs. 0.50, respectively) were improved more in the experimental group than in the control group (P < 0.05). In upper-limb motor function, the Manual Function Test score (by shoulder item, 5.00 vs. 2.23; hand item, 5.07 vs. 0.46, respectively) was significantly increased in the experimental group compared with the control group (P < 0.01). No significant differences were found between the groups for the coordination items in Fugl-Meyer Assessment. This study confirms that mirror therapy program is an effective intervention for upper-limb motor recovery and motor function improvement in acute stroke patients. Additional research on mirror therapy program components, intensity, application time, and duration could result in it being used as a standardized form of hand rehabilitation in clinics and homes.

Abstract P289: Therapist-Based and Robot-Assisted Physical Training Have Differential Effects on Motor Control of Upper Limb and Quality of Life after Chronic Stroke

Introduction: Compensatory strategies for stroke-related motor impairment may cause a pattern of disuse that might limit the improvement of upper limb (UL) motor function, and incomplete UL motor recovery might detrimentally impact quality of life. Previous studies showed that bilateral arm physical training (BAT) can improve UL function after stroke and improves trunk stabilization. However, it remains uncertain that whether BAT can reduce trunk compensation during reaching. Furthermore, there is no study investigating therapist-guided bilateral arm training (TBAT) versus robot-assisted bilateral arm training (RBAT). Hypothesis: We tested the hypothesis that TBAT and RBAT, compared with control treatment (CT), would result in the better outcomes on movement control in the affected UL and less trunk compensation in reaching tasks and would improve quality of life. In addition, TBAT and RBAT may have differential effects on motor control and quality of life. Methods: Forty-two community dwelling chronic stroke survivors (54 years old; 18 months after stroke) were randomized to TBAT (N=14), RBAT (N=14), or CT (N=14) groups. Each group received a 90- to 105-minute training session, 5 days/week, for 4 weeks. The TBAT participants practiced a variety of bilateral functional tasks with each arm simultaneously under one-on-one supervision of therapists. In the RBAT, the robot-assisted arm trainer, Bi-Manu-Track, was introduced. The CT group involved some conventional therapeutic activities on the paretic arms, unilateral and bilateral fine motor tasks, and compensatory practice on functional tasks. Outcome measures consisted of kinematic analyses for motor control in unilateral and bilateral reaching tasks, and the Stroke Impact Scale for quality of life. Results: The kinematic results indicated that the TBAT group experienced better temporal efficiency and smoothness in unilateral reaching than the CT group. The TBAT group demonstrated less compensatory trunk movement than the CT or RBAT groups in both unilateral and bilateral tasks. In contrast, the RBAT engendered a larger improvement in shoulder flexion than the other groups. The RBAT demonstrated improved quality of life than the CT group characterized by better strength, physical function, and total scores of Stroke Impact Scale. Conclusions: TBAT and RBAT engendered differential effects on outcome measures than CT. TBAT may have better results on temporal efficiency, smoothness, and trunk control. In contrast, RBAT may experience the improved shoulder flexion and quality of life.

Abstract 15: Surface Electrical Stimulation Does Not Improve Hand Function in Subacute Stroke

Background and Objective: Prior studies have suggested that EMG-triggered and cyclic surface electrical stimulation (ES) mediated hand opening exercises facilitate motor recovery of the hemiparetic upper limb. EMG-triggered ES is believed to more effective than cyclic ES due to the addition of cognitive input to trigger the ES. However, these 2 types of ES have not been compared in a placebo controlled randomized clinical trial. This trial tested the hypothesis that EMG-triggered ES is more effective than cyclic ES in facilitating the motor recovery of the hemiparetic upper limb, and that both are more effective than placebo. Methods: Stroke survivors who were within 6-mo of their stroke were randomized to treatment with EMG-triggered ES (EMG), cyclic ES (cyclic) or placebo. The EMG group received the ES by initiating volition finger extension. The resulting EMG from the extensor digitorum communis (EDC) then triggered the ES. The cyclic group received the ES to the EDC in a repetitive timed sequence without volitional activation. For the placebo group, a stimulating electrode was placed on the dorsal forearm away from the motor point of the EDC, and the stimulation intensity was set at sensory threshold with no motor activation. Duty cycle was gradually increased from 5 sec on/20 sec off to 5 sec on/5 sec off as tolerated for all participants. All participants were treated 80 min/day, 5 days a week for 8 weeks. Motor impairment (Fugl-Meyer Motor Assessment-FMA) and activities limitation (Arm Motor Abilities Test-AMAT) outcomes were assessed in a blinded manner at baseline, mid-treatment, end of treatment and at 1, 3 and 6-mo after end of treatment. Data were analyzed using repeated measures ANOVA in an intent-to-treat manner. Results: A total of 122 participants enrolled in the study (EMG: 41; Cyclic: 39; and placebo: 42). Baseline characteristics were comparable between groups. All three groups experienced significant improvement in FMA (F=54.5, p&lt;0.001) and AMAT (F=21.7, p&lt;0.001) scores. However, there were no differences between treatment groups (FMA: F=0.25, p=0.78; AMAT: F=0.43, p=0.55). Conclusions: EMG-triggered and cyclic ES were no more effective than placebo in facilitating the motor recovery of the hemiparetic upper limb. The improvements in FMA and AMAT scores likely represent natural recovery. However, since sensory stimulation without motor activation may not be placebo, the possibility of therapeutic effect of sensory stimulation cannot be ruled out in the present design.

Functional Recovery of Upper Limb Post-Stroke: Mental Practice with Motor and Non-Motor Imagery

Problem statement: Mental Practice (MP) with motor imagery consists of a method of training in which motor imagery is used to improve performance. The aim of this study was to investigate the efficacy of MP with motor imagery on motor recovery of the paretic upper limb of post-stroke patients in comparison with MP with non-motor imagery. Approach: Four post-stroke patients were divided into two groups: experimental (the physical practice of motor tasks and MP of the same tasks: n = 2) and control (the physical practice of motor tasks and MP of non-motor tasks: n = 2). We evaluated: Heart Rate (HR) and systolic (SBP) and Diastolic Blood Pressure (DBP), immediately before and after execution and imagination of the tasks; time of execution and imagination of each task; and motor function of the paretic upper limb through the questionnaires “Fugl-Meyer for Upper Extremity” and “quality of movement section of arm motor ability test” before and after the 10 weeks of treatment. Results: The qualitative analysis showed that regardless of training, patients spent less time on imagery motor tasks than to execute them; and have increased in HR, SBP and DBP after execution as well as after imagery of motor tasks. The training caused a reduction in the time of execution of motor tasks in both groups and increment on the motor function of the paretic upper limb only in the experimental group. Conclusion: These results suggest that an MP with motor imagery may be an effective method for the functional recovery of the paretic upper limb of post-stroke patients.

P20.14 Combining transcranial direct current stimulation with robot therapy for the impaired upper limb after sub-acute stroke

Introduction: Optimal gain of upper limb (UL) function is pivotal for people with stroke in order to carry out functional activities. However, half of the people surviving stroke remain with some form of UL impairment. Robot Therapy (RT) is one technique that can increase the intensity of rehabilitation and evidence shows that robot-assisted arm training results in improved short- and long-term arm strength and function of people with stroke. RT has also been combined with a non-invasive method of brain stimulation, transcranial Direct Current Stimulation (tDCS). The pilot study by Hesse et al. (2007) suggests that using both RT and tDCS results in short-term UL motor recovery of people with sub-acute stroke however, long-term and neurophysiological measurements were not involved in this study. Main Objective: To develop a protocol exploring the effectiveness and short- and long-term neural changes of tDCS and robot therapy on UL impairment and function of people with sub-acute stroke. Methods: An systematic literature review was carried out investigating different methodologies used for applying tDCS and RT, leading to the finalised protocol. Results: A pilot, double-blinded randomised controlled trial will be carried out involving two groups: 1) Armeo RT and active tDCS, and 2) Armeo RT and sham tDCS with 20 participants with sub-acute stroke in each group. Active or sham tDCS will be delivered before RT. In total, participants will receive 18 hours of RT and tDCS, spread out over 8 weeks. Clinical and neurophysiological measures using Transcranial Magnetic Stimulation will be utilised pre- and post- intervention and at 3 month follow-up. Conclusions: Research into non-invasive brain stimulation and RT seems promising but to translate research findings into clinical stroke practice, further research is needed. In the upcoming months, the aforementioned trial will be initiated which will add to the body of knowledge of neurorehabilitation research.

Training effects on upper limb motor recovery in stroke patients with the prototype robot MEMOS-2

Training effects on upper limb motor recovery in stroke patients with the prototype robot MEMOS-2

Influence of Continuous Positive Airway Pressure on Outcomes of Rehabilitation in Stroke Patients With Obstructive Sleep Apnea

In stroke patients, obstructive sleep apnea (OSA) is associated with poorer functional outcomes than in those without OSA. We hypothesized that treatment of OSA by continuous positive airway pressure (CPAP) in stroke patients would enhance motor, functional, and neurocognitive recovery. This was a randomized, open label, parallel group trial with blind assessment of outcomes performed in stroke patients with OSA in a stroke rehabilitation unit. Patients were assigned to standard rehabilitation alone (control group) or to CPAP (CPAP group). The primary outcomes were the Canadian Neurological scale, the 6-minute walk test distance, sustained attention response test, and the digit or spatial span-backward. Secondary outcomes included Epworth Sleepiness scale, Stanford Sleepiness scale, Functional Independence measure, Chedoke McMaster Stroke assessment, neurocognitive function, and Beck depression inventory. Tests were performed at baseline and 1 month later. Patients assigned to CPAP (n=22) experienced no adverse events. Regarding primary outcomes, compared to the control group (n=22), the CPAP group experienced improvement in stroke-related impairment (Canadian Neurological scale score, P<0.001) but not in 6-minute walk test distance, sustained attention response test, or digit or spatial span-backward. Regarding secondary outcomes, the CPAP group experienced improvements in the Epworth Sleepiness scale (P<0.001), motor component of the Functional Independence measure (P=0.05), Chedoke-McMaster Stroke assessment of upper and lower limb motor recovery test of the leg (P=0.001), and the affective component of depression (P=0.006), but not neurocognitive function. Treatment of OSA by CPAP in stroke patients undergoing rehabilitation improved functional and motor, but not neurocognitive outcomes. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00221065.

*Poster 87: Effect of Different Training Environments on Upper-Limb Motor Recovery Following Stroke

*Poster 87: Effect of Different Training Environments on Upper-Limb Motor Recovery Following Stroke

Recovery of Upper Limb Function After Cerebellar Stroke

Loss of movement coordination is the main postacute symptom after cerebellar infarction. Although the course of motor recovery has been described previously, detailed kinematic descriptions of acute stage ataxia are rare and no attempt has been made to link improvements in motor function to measures of neural recovery and lesion location. This study provides a comprehensive assessment of how lesion site and arm dysfunction are associated in the acute stage and outlines the course of upper limb motor recovery for the first 4 months after the infarction. Sixteen adult patients with cerebellar stroke and 11 age-matched healthy controls participated. Kinematics of goal-directed and unconstrained finger-pointing movements were measured at the acute stage and in 2-week and 3-month follow-ups. MRI data were obtained for the acute and 3-month follow-up sessions. A voxel-based lesion map subtraction analysis was performed to examine the effect of ischemic lesion sites on kinematic performance. In the acute stage, nearly 70% of patients exhibited motor slowing with hand velocity and acceleration maxima below the range of the control group. MRI analysis revealed that in patients with impaired motor performance, lesions were more common in paravermal lobules IV/V and affected the deep cerebellar nuclei. Stroke affecting the superior cerebellar artery led to lower motor performance than infractions of the posterior cerebellar artery. By the 2-week-follow-up, hand kinematics had improved dramatically (gains in acceleration up to 86%). Improvements between the 2-week and the 3-month-follow-ups were less pronounced. In the acute stage, arm movements were mainly characterized by abnormal slowness (bradykinesia) and not dyscoordination (ataxia). The motor signs were associated with lesions in paravermal regions of lobules IV/V and the deep cerebellar nuclei. Motor recovery was fast, with the majority of gains in upper limb function occurring in the first 2 weeks after the acute phase.

Acupuncture of Motor-Implicated Acupoints on Subacute Stroke Patients: An fMRI Evaluation Study

Abstract Background: Motor impairment is common after stroke. Along with classic integrated physical and occupational therapy, acupuncture is also suggested as an adjunctive therapy. Objective: To evaluate the effectiveness of acupuncture on upper limb motor recovery of patients with subacute stroke. Design, Setting, and Patients: Eighteen subacute stroke patients, transferred from a regional acute hospital to a convalescent hospital for rehabilitation in Hong Kong, from March 2005 to November 2007. Two clinical and behavioral evaluations for motor function were given to each participant along with 2 functional magnetic resonance imaging (fMRI) scans. Intervention: Patients were treated with acupuncture 3 times a week over 8 weeks. The intervention set of 3 acupoints is known to influence the motor system, while a second control set does not. Physical and occupational therapy were also used as treatment (parallel to the interventions with acupuncture). Main Outcome Measures: The primary outcome measure wa...

Effects of Conventional Physical Therapy and Functional Strength Training on Upper Limb Motor Recovery After Stroke: A Randomized Phase II Study

Background. Functional training and muscle strength training may improve upper limb motor recovery after stroke. Combining these as functional strength training (FST) might enhance the benefit, but it is unclear whether this is better than conventional physical therapy (CPT). Comparing FST with CPT is not straightforward. Objective. This study aimed at assessing the feasibility of conducting a phase III trial comparing CPT with FST for upper limb recovery. Methods. Randomized, observer-blind, phase II trial. Subjects had upper limb weakness within 3 months of anterior circulation infarction. Subjects were randomized to CPT (no extra therapy), CPT + CPT, and CPT + FST. Intervention lasted 6 weeks. Primary outcome measure was the Action Research Arm Test (ARAT). Measurements were taken before treatment began, after 6 weeks of intervention, and 12 weeks thereafter. Attrition rate was calculated and differences between groups were interpreted using descriptive statistics. ARAT data were used to inform a power calculation. Results. Thirty subjects were recruited (8% of people screened). Attrition rate was 6.7% at outcome and 40% at follow-up. At outcome the CPT + FST group showed the largest increase in ARAT score and this was above the clinically important level of 5.7 points. Median (interquartile range) increases were 11.5 (21.0) for CPT; 8.0 (13.3) for CPT + CPT; and 19.5 (22.0) for CPT + FST. The estimated sample size for an adequately powered subsequent phase III trial was 279 subjects at outcome. Conclusion. Further work toward a phase III clinical trial appears justifiable.

P183 Usefulness of robotics for improving and monitoring upper limb motor recovery in stroke patients

P183 Usefulness of robotics for improving and monitoring upper limb motor recovery in stroke patients

Cortical Brain Stimulation: A Potential Therapeutic Agent for Upper Limb Motor Recovery Following Stroke

There is emerging interest in the use of cortical electrical stimulation as a novel physical agent for the treatment of upper limb motor impairment after stroke. Evidence from animal models suggests that both motor learning and cortical stimulation alter intracortical inhibitory circuits and can facilitate long-term potentiation and cortical remodeling. This article reviews current research on the physiology and use of cortical stimulation animal models and in humans with stroke-related hemiplegia. Both transcranial cortical stimulation techniques and targeted epidural cortical stimulation are discussed in detail.

Effects of Robot-Aided Bilateral Force-Induced Isokinetic Arm Training Combined With Conventional Rehabilitation on Arm Motor Function in Patients With Chronic Stroke

Chang J-J, Tung W-L, Wu W-L, Huang M-H, Su F-C. Effects of robot-aided bilateral force-induced arm training combined with conventional rehabilitation on arm motor function in patients with chronic stroke. Objective To analyze the effects of conventional rehabilitation combined with bilateral force-induced isokinetic arm movement training on paretic upper-limb motor recovery in patients with chronic stroke. Design Single-cohort, pre- and postretention design. Setting Rehabilitation department at a medical university. Participants Twenty subjects who had unilateral strokes at least 6 months before enrolling in the study. Intervention A training program (40min/session, 3 sessions/wk for 8wk) consisting of 10 minutes of conventional rehabilitation and 30 minutes of robot-aided, bilateral force-induced, isokinetic arm movement training to improve paretic upper-limb motor function. Main Outcome Measures The interval of pretest, post-test, and retention test was set at 8 weeks. Clinical arm motor function (Fugl-Meyer Assessment [FMA], upper-limb motor function, Frenchay Arm Test, Modified Ashworth Scale), paretic upper-limb strength (grip strength, arm push and pull strength), and reaching kinematics analysis (peak velocity, percentage of time to peak velocity, movement time, normalized jerk score) were used as outcome measures. Results After comparing the sets of scores, we found that the post-test and retention test in arm motor function significantly improved in terms of grip ( P=.009), push ( P=.001), and pull ( P=.001) strengths, and FMA upper-limb scale ( P<.001). Reaching kinematics significantly improved in terms of movement time ( P=.015), peak velocity ( P=.035), percentage of time to peak velocity ( P=.004), and normalized jerk score ( P=.008). Improvement in reaching ability was not sustained in the retention test. Conclusions Preliminary results showed that conventional rehabilitation combined with robot-aided, bilateral force-induced, isokinetic arm training might enhance the recovery of strength and motor control ability in the paretic upper limb of patients with chronic stroke.

Virtual Reality in Stroke Rehabilitation: A Systematic Review of its Effectiveness for Upper Limb Motor Recovery

Purpose: It is estimated that 50% to 75% of individuals who experience a stroke have persistent impairment of the affected upper limb (UL). There is a need to identify the best training strategies for retraining motor function of the UL. One intervention showing promise is virtual reality (VR), using either immersive or nonimmersive technology. Before recommending VR for use in clinical practice, it is important to understand the evidence regarding its effectiveness. Method: Two questions about the effectiveness of VR for UL rehabilitation in stroke were posed: (1) Is the use of immersive VR more effective than conventional therapy or no therapy in the rehabilitation of the UL in patients with hemiplegia? (2) Is the use of nonimmersive VR more effective than conventional therapy or no therapy in the rehabilitation of the UL in patients with hemiplegia? Results: There is level 1b evidence suggesting an advantage to training in immersive VR environments versus no therapy in UL rehabilitation, and level 5 evidence for training in immersive VR versus conventional therapy. There is level 4 evidence showing conflicting results for training in nonimmersive VR versus no therapy, and level 2b evidence for training in nonimmersive VR versus conventional therapy. Conclusion: The current evidence on the effectiveness of using VR in the rehabilitation of the UL in patients with stroke is limited but sufficiently encouraging to justify additional clinical trials in this population.

Induction of cortical plastic changes in wrist muscles by paired associative stimulation in healthy subjects and post-stroke patients

It has been shown on hand muscles in normal subjects that paired associative stimulation (PAS) combining peripheral nerve stimulation and transcranial magnetic stimulation (TMS) induces lasting changes in cortical motor excitability (Stefan et al., Brain 123 (Pt3):572-584, 2000). Because the motor recovery of distal upper limb and particularly wrist extension in post-stroke patients is one of the major rehabilitation challenge, we investigate here the effect of one session of paired associative stimulation on the excitability of the corticospinal projection to extensor carpi radialis (ECR) muscle (motor evoked potential size) before and after PAS in 17 healthy subjects and in two patients 5 months after stroke. The time course, the topographical specificity, changes in rest motor threshold (RMT), short intracortical inhibition and intracortical facilitation (SICI and ICF), the respective role of cutaneous and muscular afferents and the effect of a prolonged peripheral stimulation alone were also studied in normal subjects. Using a protocol derived from that of Ridding et al. J Physiol 537:623-631 (2001), PAS was able to induce lasting changes in the excitability of corticospinal projection to wrist muscles in healthy subjects and in the two post-stroke patients studied. Electrophysiological features of these plastic changes were similar to those previously observed in hand muscles: rapid evolution, 30-60 min duration, reversibility, relative topographical specificity and associative dependence suggesting an LTP-like mechanism. A contribution of cutaneous afferents in inducing PAS effects was also demonstrated. The decrease in ECR RMT after PAS observed in patients and in healthy subjects was an unexpected result because it has not been previously reported in the hand muscles of healthy subjects. However, it has been observed in dystonic patients (Quartarone et al., Brain 126:2586-2596, 2003). This suggests that other mechanisms like changes in membrane excitability could be involved in ECR facilitation after PAS. Further studies performed on patients using daily repeated PAS protocols and showing a functional improvement in hand motor function will be necessary to confirm that this technique could be relevant in motor rehabilitation, at least for some selected patients.

Diffusion Tensor Imaging in Patients with Thalamic Hemorrhage: Correlations between Diffusion Anisotropy and Motor Recovery

Diffusion tensor imaging (DTI) provides quantitative information in the magnetic resonance imaging on the diffusion anisotropy about the integrity of white matter tracts. The aim of this study was to measure diffusion anisotropy and to correlate with upper-limb motor recovery in four chronic hemiparetic patients with thalamic hemorrhage. Fractional anisotropy (FA) was measured in the posterior limb of internal capsules (IC) in the affected side and in the corresponding contralateral normal side before and after 6 week motor training. The correlation between motor recovery of the affected hand and the ratio of FAs of the affected side and the contralateral normal side were investigated. Both FA ratio and motor function significantly increased after the training. A significant correlation was found between motor recovery and FA in the posterior limb of IC. The degree of impairment in diffusion anisotropy of hemiparetic patients might be helpful in prognosis of the motor function.

Impact of Time on Improvement of Outcome After Stroke

Longitudinal conducted studies show that neurologic and functional recovery show faster recovery in the first weeks poststroke. The aim of the present study was to study the effects of progress of time on observed improvements in motor strength, synergisms, and activities during the first 16 weeks poststroke. Based on data from a previous study, 101 patients with first-ever ischemic middle cerebral artery strokes were prospectively investigated during the first 16 weeks after stroke. Progress of time was categorized into 8 biweekly time intervals and was used as the independent covariate in a first-order longitudinal regression model. The biweekly time change (progress of time) was related to improvement in upper and lower limb motor recovery assessed with Fugl-Meyer score and Motricity Index, reduction in visuospatial inattention based on the letter cancellation task, and improvement in walking ability, dexterity, and activities of daily living measured with the Functional Ambulation Categories, Action Research Arm test, and Barthel Index. Time explained a significant change of 8.4 (42%) measurement units on the Barthel Index for the first 10 weeks poststroke, 1.1 (22%) measurement units on Functional Ambulation Categories, and 19% on the Action Research Arm test for the first 6 and 8 weeks poststroke. Approximately 25% (for Fugl-Meyer-arm) to 26% (for Motricity Index-arm) of the significant change in measurements units was explained by time alone for the upper limb compared with 33% for Fugl-Meyer-leg and 39% for Motricity Index-leg of the lower limb. Time accounted for a reduction of 16% in the letter cancellation task. Observed associations did not change after controlling for covariates such as age, gender, hemisphere of stroke, type of stroke, or intervention. Progress of time is an independent covariate that reflects spontaneous recovery of body functions and activities explaining &16% to 42% of the observed improvements in the first 6 to 10 weeks after stroke onset.

Motor Impairment and Recovery in the Upper Limb After Stroke

Motor recovery after stroke is associated with cerebral reorganization. However, few studies have investigated the relationship directly, and findings are equivocal. We therefore aimed to characterize the relationship between motor impairment, motor recovery, and task-related changes in regional cerebral blood flow (DeltarCBF) longitudinally. We obtained a profile of motor impairment and recovery in the upper limb and conducted positron emission tomography motor activation studies using a simple finger-tapping task in 9 stroke patients 2 to 7 weeks after stroke and 6 months later. For correlation analysis, mean images of task-related DeltarCBF for each individual were linearly regressed with motor impairment scores. Motor recovery was correlated with longitudinal DeltarCBF images. Patients (7 males; 72.0+/-9.8 years) demonstrated a wide range of impairment severity and variable recovery. Upper-limb motor function was linearly correlated with task-related DeltarCBF. Importantly, sites of correlated DeltarCBF differed over time. Subacutely correlated DeltarCBF was observed in supplementary motor area (SMA), bilateral cingulate, and contralesional insula with a small area in ipsilesional primary sensorimotor cortex (SM1). Conversely, at the 6-month study, correlated DeltarCBF was primarily in ipsilesional SM1, extending to the cingulate gyrus. Better motor recovery was correlated with reduction in contralesional activity and increase in ipsilesional SM1. Upper-limb motor function and recovery are correlated with DeltarCBF in SMA, cingulate, insula, and SM1, highlighting the role of these areas in the recovery process. The dynamic nature of the relationship suggests ongoing adaptation within motor networks.