Neurorehabilitation and Neural Repair

Purpose. Walking speed is a cardinal indicator of poststroke gait performance; however, no consensus exists regarding the optimal treatment method(s) for its enhancement. The most widely accepted criterion for establishing the contribution of treatment to walking speed is the gain in speed. The actual speed, however, at the end of the intervention (final speed) may be more important for functional community ambulation. This review examines the contribution of the prevailing methods for gait rehabilitation to final walking speed. Method. Walking speed information was derived from studies included in meta-analyses, systematic reviews, and clinical practice guidelines. Recent references, not included in the mentioned sources, were incorporated in cases when gait speed was an outcome variable. Final speed was assessed by the reported speed values and by inferring the capacity for functional community walking at the end of the intervention period. Results. Similar outcomes for final walking speed were found for the different prevailing treatment methods. Treatment gains were likewise comparable and generally insufficient for upgrading patients' functional community walking capacity. Conclusions. Different treatment methods exist for poststroke gait rehabilitation. Their availability, mode of application, and costs vary, yet outcomes are largely similar. Therefore, choosing an appropriate method may be guided by a pragmatic approach. Simple “low technology” and conventional exercise to date is at least as efficacious as more complex strategies such as treadmill and robotic-based interventions.

Background. The majority of patients with multiple sclerosis (MS) develop progressive gait impairment, which can start early in the disease and worsen over a lifetime. A promising outpatient intervention to help improve gait function with potential for addressing this treatment gap is task-repetitive gait training. Methods. Body weight supported treadmill training (BWSTT) with or without robotic assistance (Lokomat) was tested using a randomized crossover design in 13 patients with relapsing-remitting, secondary progressive or primary progressive MS. Patients received 6 training sessions over 3 weeks of each intervention. Outcomes included changes in the timed 25-foot walk (T25FW), the 6-minute walk treadmill test (6MW) distance, the Kurtzke Expanded Disability Status Scale (EDSS), as well as double-limb support time and step length ratio. Results. There were no major differences in outcomes between treatment groups. The study population significantly improved on gait outcomes and the EDSS following BWSTT, including a 31% improvement in the T25FW, a 38.5% improvement in the 6MW, and a 1-point gain for the EDSS. Differences in pre/post changes were noted depending on gender, disease subtype, affected limb, and baseline EDSS. Conclusions. Although no differences in gait outcomes or the EDSS were found between treatment groups, this small pilot study of task-repetitive gait training resulted in significant within-subject improvements. BWSTT appears to be an activity-dependent intervention with potential to reduce gait impairment in MS.

Background. For clinical trials in stroke rehabilitation, self-selected walking speed has been used to stratify persons to predict functional walking status and to define clinical meaningfulness of changes. However, this stratification was validated primarily using self-report questionnaires. Objective. This study aims to validate the speed-based classification system with quantitative measures of walking performance. Methods. A total of 59 individuals who had hemiparesis for more than 6 months after stroke participated in this study. Spatiotemporal and kinetic measures included the percentage of total propulsion generated by the paretic leg (Pp), the percentage of the stride length accounted for by the paretic leg step length (PSR), and the percentage of the gait cycle spent in paretic preswing (PPS). Additional measures included the synergy portion of the Fugl-Meyer Assessment and the average number of steps/day in the home and community measured with a step activity monitor. Participants were stratified by self-selected gait speed into 3 groups: household (<0.4 m/s), limited community (0.4-0.8 m/s), and community (>0.8 m/s) ambulators. Group differences were analyzed using a Kruskal—Wallis H test with rank sums test post hoc analyses. Results. Analyses demonstrated a main effect in all measures, but only steps/day and PPS demonstrated a significant difference between all 3 groups. Conclusions. Classifying individuals poststroke by self-selected walking speed is associated with home and community-based walking behavior as quantified by daily step counts. In addition, PPS distinguishes all 3 groups. Pp differentiates the moderate from the fast groups and may represent a contribution to mechanisms of increasing walking speed. Speed classification presents a useful yet simple mechanism to stratify subjects poststroke and may be mechanically linked to changes in PPS.

Background. Little is known about whether changes in coordination patterns of muscle activation after stroke are related to functional recovery of walking. Objective . The present study investigated the longitudinal relationship between changes in neuromuscular activation patterns of paretic muscles in hemiplegic gait and improvement in walking ability after stroke. Methods. Thirteen patients diagnosed with a first unilateral ischemic stroke had their recovery of walking measured by the Rivermead Mobility Index, Functional Ambulation Categories, Barthel Index, Trunk Control Test, Motricity Index, and comfortable walking speed. Surface electromyography (SEMG) of the erector spinae, gluteus maximus, gluteus medius, rectus femoris, vastus lateralis, semitendinosus, gastrocnemius, and tibialis anterior muscles of both legs was used to quantify coordination patterns in comfortable walking mode. All clinical and electromyography-related measurements were taken at 3, 6, 9, 12, and 24 weeks poststroke. Timing parameters of the SEMG patterns were calculated, using an objective burst detection algorithm, and analyzed with the measures of functional recovery. Results . All functional measures, except Trunk Control Test, showed statistically significant improvement over time, whereas SEMG patterns did not change significantly over time. Conclusion. The lack of significant change in SEMG patterns over time suggests that functional gait improvements may be more related to compensatory strategies in muscle activation of the unaffected leg and biomechanical changes than by restitution of muscle coordination patterns in the affected leg.

Background. Objective assessment of impairments after stroke is vital for evidence-based therapy and progress monitoring. Objective. This study determines the utility of outcome measures obtained from an instrumented wrist rig for future rehabilitation trials. The tests undertaken were evaluated in terms of sensitivity to detect differences between normal and impaired participants, test-retest repeatability (repeatability coefficient and intraclass correlation coefficient [ICC]), and interrater agreement (Bland and Altman limits of agreement). Methods . Twelve participants with chronic poststroke hemiparesis (mean 5.6 years); and 12 unimpaired volunteers performed a series of tasks in the rig. The hemiparetic arm (impaired group) and dominant arm (unimpaired group) were tested in 3 sessions on the same day by 2 assessors. Signals were analyzed to derive a tracking index (motor control), stretch index (spasticity), flexor modulation index (FMI) (muscle activation), force angle index (FAI) (stiffness), range of movement, and isometric force. Results and Conclusions. The means of all tests differed between impaired and unimpaired participants except for range of movement into flexion, the FAI, and the FMI. Repeatability coefficients for each test are presented as benchmark values for use in future trials in which the wrist rig tests may be used to detect change. Test-retest reliability was excellent in the impaired group (ICC = 0.88-0.98) and poor to excellent in the unimpaired group (ICC = 0.06-0.89). The Bland-Altman ranges showed no bias between assessors, and that the interassessor variability was similar to that between repeats by the same assessor for most tests.

Background and Purpose . Task-related training (TRT) but not resistive exercise (RE) was found to improve the path of the hand of a hemiparetic upper extremity when reaching to targets. Forward movement of the trunk, however, compensated for the poststroke motor impairment. Prior studies also demonstrated that short-term practice of reaching to grasp objects with truncal motion restrained (compared to unrestrained practice) increased elbow extension, lessened compensatory trunk movement, and improved interjoint coordination during performance with the trunk unrestrained. Objective. To determine the effects of TRT and RE on unrestrained reaching following extended practice in which compensatory truncal motion was limited. Methods. Using a restraining device to reduce movement of the trunk, hemiparetic patients with moderately severe motor impairment were given 12 sessions over 4 weeks of TRT (n = 5) or RE (n = 6). Reaching when the trunk was not restrained to targets located ipsilateral, midline, and contralateral to the impaired arm was tested before and 2 days after training by 3D kinematic analyses. Results. After both training protocols, kinematic analysis showed that trunk flexion decreased (P < .01, η² = .53) scapular motion shifted toward protraction (P < .01, η² = .57) and elbow extension increased (P < .04, η² = .39). Only after TRT did the path of the hand straighten (P < .02, η² = .46), deceleration time decrease (P < .03, η² = .44), and, at the difficult ipsilateral target, shoulder flexion increase (P < .03, η ² = .31). Conclusions. Training that restricted compensatory truncal motion during TRT improved the precision of reaching more than during RE. Truncal restraint during rehabilitation of reaching may be an effective therapeutic strategy in patients with moderately severe hemiparetic stroke, especially when combined with TRT.

Objective. The aim of this study was to establish the efficacy of a therapeutic intervention based on functional electrical stimulation (FES) therapy to improve reaching and grasping function after severe hemiplegia due to stroke. Methods. A total of 21 subjects with acute stroke were randomized into 2 groups, FES plus conventional occupational and physiotherapy (FES group) or only conventional therapy (control group) 5 days a week for 12 to 16 weeks. A third group of 7 subjects with chronic hemiplegia (at least 5 months poststroke) received only FES therapy (chronic group) and pre—post training changes were compared. FES was applied to proximal and then distal muscle groups during specific motor tasks. At baseline and at the end of treatment, grasping function was assessed using the Rehabilitation Engineering Laboratory Hand Function Test, along with more standard measures of rehabilitation outcome. Results. The FES group improved significantly more than the control group in terms of object manipulation, palmar grip torque, pinch grip pulling force, Barthel Index, Upper Extremity Fugl—Meyer scores, and Upper Extremity Chedoke—McMaster Stages of Motor Recovery. The chronic stroke subjects demonstrated improvements in most categories, but the changes were not statistically significant. Conclusions. FES therapy with upper extremity training may be an efficacious intervention in the rehabilitation of reaching and grasping function during acute stroke rehabilitation.

Background. In hemiparetic individuals, sit-to-stand (STS) transfer is characterized by asymmetric weight-bearing and altered trunk kinematics that can be improved by positioning the affected foot behind the nonaffected one. Objective. To examine the influence of frontal trunk kinematics on medio-lateral displacements of the center of pressure (CP) during STS performed with the feet placed in 2 different positions, as well as relationships between these parameters, medio-lateral stability, and clinical scores of the participants. Methods. Eighteen patients with chronic stroke and 15 control individuals were evaluated during sit-to-stand transfers either in spontaneous foot position or with their affected or dominant foot placed behind, respectively. Medio-lateral CP, pelvis, and shoulder displacement were analyzed using 3D kinematic and kinetic data recordings of the whole task. Motor and sensory impairment, spasticity, muscle strength, and equilibrium were evaluated by standard scales. The possible time during which a participant could prevent a fall (minimal time-to-contact) was used as a stability index. Results. Spontaneously, the deviation of the CP of stroke participants paralleled the tilt of the trunk toward the nonaffected side, as early as the first third of the task. With the affected foot placed behind, trunk position did not differ from those of control participants who executed the transfer spontaneously. Hemiparetic participants were less stable than control participants. Placement of the feet had no significant effect on the stability of either group. Stability was strongly associated with better motor scores on the Chedoke-McMaster Stroke Assessment. Conclusions. In hemiparetic individuals, improving STS symmetry by positioning the affected foot behind the nonaffected one did not decrease medio-lateral stability, which was associated with the level of stroke-related motor impairments.

Background. The minimal clinically important difference (MCID) of the Stroke Rehabilitation Assessment of Movement (STREAM) measure is unknown, which limits the application and interpretation of change scores. Objective. To estimate the MCID of the 3 subscales (ie, lower extremity, upper extremity, and mobility subscales) of the STREAM using the method of patients' global ratings of change. Methods. Eighty-one stroke patients participated in this study. The patients' global ratings of change were used to rate their changes of limb movements and basic mobility skills on the 15-point Likert scale. The mean change scores on the 3 subscales of STREAM of the MCID group (ie, scored on +2 to +3 or —2 to —3) served as the estimates of the MCID. Results. There were 42, 38, and 43 patients in the MCID group, and the estimates of the MCID were 2.2, 1.9, and 4.8 points for the upper-extremity subscale, lower-extremity subscale, and mobility subscale, respectively. Conclusions. These findings suggest that if the mean change scores on the 3 subscales of the STREAM within a stroke group have reached 2.2, 1.9, and 4.8 points, the change scores on the 3 subscales of the STREAM can be perceived by patients as clinically important.

Background. Functional magnetic resonance imaging (fMRI) appears to be useful for investigating motor recovery after stroke. Some of the potential confounders of brain activation studies, however, could be mitigated through complementary physiological monitoring. Objective. To investigate a sensorimotor fMRI battery that included simultaneous measurement of electrodermal activity in subjects with hemiparetic stroke to provide a measure related to the sense of effort during motor performance. Methods. Bilateral hand and ankle tasks were performed by 6 patients with stroke (2 subacute, 4 chronic) during imaging with blood oxygen level-dependent (BOLD) fMRI using an event-related design. BOLD percent changes, peak activation, and laterality index values were calculated in the sensorimotor cortex. Electrodermal recordings were made concurrently and used as a regressor. Results. Sensorimotor BOLD time series and percent change values provided evidence of an intact motor network in each of these well-recovered patients. During tasks involving the hemiparetic limb, electrodermal activity changes were variable in amplitude, and electrodermal activity time-series data showed significant correlations with fMRI in 3 of 6 patients. No such correlations were observed for control tasks involving the unaffected lower limb. Conclusions. Electrodermal activity activation maps implicated the contralesional over the ipsilesional hemisphere, supporting the notion that stroke patients may require higher order motor processing to perform simple tasks. Electrodermal activity recordings may be useful as a physiological marker of differences in effort required during movements of a subject's hemiparetic compared with the unaffected limb during fMRI studies.

Objective. To provide empirical justification for selecting motor scales for stroke patients, the authors compared the psychometric properties (validity, responsiveness, test-retest reliability, and smallest real difference [SRD]) of the Fugl-Meyer Motor Scale (FM), the simplified FM (S-FM), the Stroke Rehabilitation Assessment of Movement instrument (STREAM), and the simplified STREAM (S-STREAM). Methods. For the validity and responsiveness study, 50 inpatients were assessed with the FM and the STREAM at admission and discharge to a rehabilitation department. The scores of the S-FM and the S-STREAM were retrieved from their corresponding scales. For the test-retest reliability study, a therapist administered both scales on a different sample of 60 chronic patients on 2 occasions. Results. Only the S-STREAM had no notable floor or ceiling effects at admission and discharge. The 4 motor scales had good concurrent validity (rho ≥ .91) and satisfactory predictive validity (rho = .72-.77). The scales showed responsiveness (effect size d ≥ 0.34; standardized response mean ≥ 0.95; P < .0001), with the S-STREAM most responsive. The test-retest agreements of the scales were excellent (intraclass correlation coefficients ≥ .96). The SRD of the 4 scales was 10% of their corresponding highest score, indicating acceptable level of measurement error. The upper extremity and the lower extremity subscales of the 4 showed similar results. Conclusions. The 4 motor scales showed acceptable levels of reliability, validity, and responsiveness in stroke patients. The S-STREAM is recommended because it is short, responsive to change, and able to discriminate patients with severe or mild stroke.

Background. Children with cerebral palsy often suffer from a lack of balance compared with typically developing children. Because balance capacity is relevant to functional activities, reliable and valid functional balance measures are crucial for the pediatric clinical setting. Objective. This study examined the reliability and validity of 3 functional balance measures. Methods. Thirty children aged 60 to 142 months with Gross Motor Function Classification System (GMFCS) levels of I to IV were recruited. For test-retest reliability, the same physical therapist administered the Functional Reach Test (FRT), Berg Balance Scale (BBS), and Timed Up and Go (TUG) twice. For interrater reliability, the testing processes were video recorded and later scored by another therapist. For convergent validity, children with cerebral palsy received the Gross Motor Function Measures (GMFM), walking speed, and 10-second sit-to-stand test within 1 week and the results evaluated. Results. The 3 functional balance measures had excellent test-retest reliability (intraclass correlation coefficient [ICC] >0.95) and interrater reliability (ICC = 0.98-1.00). With regard to convergent validity, the BBS and the TUG were highly correlated with GMFM total score, walking speed, and the 10-second sit-to-stand test. The discriminate validity indicates that the FRT can distinguish children with cerebral palsy with different GMFCS levels, whereas the BBS total score and TUG failed to distinguish between children with cerebral palsy with GMFCS levels of I and II. Conclusion. The 3 functional balance measures are simple, valid, and reliable for examining children with cerebral palsy and are thus suitable for clinical practice.

Background. Using the rat facial nerve axotomy model, the authors recently showed that manual stimulation of denervated whiskerpad muscles reduced the posttransectional polyinnervation at the neuromuscular junctions and promoted full recovery of vibrissal whisking. Objective. Prompted by implications for rehabilitation therapy, the authors examined whether manual stimulation of denervated supra- and infrahyoid muscles would also improve recovery after unilateral lesion on the hypoglossal nerve. Methods. Adult rats underwent transection of the right hypoglossal nerve. Half of the animals received no postoperative treatment, and the other half were subjected to daily manual stimulation of the suprahyoid/sublingual region for 2 months. Recovery was assessed by measuring the angle of tongue-tip deviation from the midline, degree of collateral axonal branching at the lesion site (counts after retrograde labeling with 2 fluorescent dyes), synaptic input to the hypoglossal motoneurons using synaptophysin immunocytochemistry, tongue-muscles motor representation in the cerebral cortex after c-Fos immunocytochemistry, and portion of polyinnervated neuromuscular junctions. Results. In animals receiving manual stimulation, the tongue-tip deviation was 37.0 ± 49.37°, whereas values in control nonstimulated rats were significantly higher (50.1 ± 9.01°; P < .05; mean ± SD). Improved recovery was not associated with reduced collateral axonal branching; there were also no differences in tongue-muscles representation in the motor cortex. However, manual stimulation restored the total synaptic input to levels in intact animals and reduced the proportion of polyinnervated neuromuscular junctions compared with nonstimulated animals. Conclusion. The data show that manual stimulation of denervated muscles improves functional outcome following peripheral nerve injury. This suggests immediate potential for enhancing clinical rehabilitation strategies.