Neurorehabilitation and Neural Repair RSS feed -- OnlineFirst Articles

Controlling Memory Impairment in Elderly Adults Using Virtual Reality Memory Training: A Randomized Controlled Pilot Study

Tue, 24 Nov 2009 14:15:23 PST

Background. Memory decline is a prevalent aspect of aging but may also be the first sign of cognitive pathology. Virtual reality (VR) using immersion and interaction may provide new approaches to the treatment of memory deficits in elderly individuals. Objective. The authors implemented a VR training intervention to try to lessen cognitive decline and improve memory functions. Methods. The authors randomly assigned 36 elderly residents of a rest care facility (median age 80 years) who were impaired on the Verbal Story Recall Test either to the experimental group (EG) or the control group (CG). The EG underwent 6 months of VR memory training (VRMT) that involved auditory stimulation and VR experiences in path finding. The initial training phase lasted 3 months (3 auditory and 3 VR sessions every 2 weeks), and there was a booster training phase during the following 3 months (1 auditory and 1VR session per week). The CG underwent equivalent face-to-face training sessions using music therapy. Both groups participated in social and creative and assisted-mobility activities. Neuropsychological and functional evaluations were performed at baseline, after the initial training phase, and after the booster training phase. Results. The EG showed significant improvements in memory tests, especially in long-term recall with an effect size of 0.7 and in several other aspects of cognition. In contrast, the CG showed progressive decline. Conclusions. The authors suggest that VRMT may improve memory function in elderly adults by enhancing focused attention.

Gabapentin Therapy for Ocular Opsoclonus-Myoclonus Restores Eye Movement Communication in a Patient With a Locked-In Syndrome

Pistoia, F., Sara, M. — Fri, 20 Nov 2009 09:57:34 PST

The experience with a patient with locked-in syndrome suffering from opsoclonus–myoclonus symptoms is described: gabapentin successfully reversed the symptoms, just favoring the regaining of eye-dependent communication strategies.

Semantic Event-Related Potential Components Reflect Severity of Comprehension Deficits in Aphasia

Kawohl, W., Bunse, S., Willmes, K., Hoffrogge, A., Buchner, H., Huber, W. — Wed, 18 Nov 2009 17:35:59 PST

Background and objectives. Several cognitive event-related potential (ERP) components such as mismatch negativity, P300, N400, and the late positive component (LPC) have been studied in aphasia. The aim of this study was to determine whether a modified semantic incongruity paradigm can serve as a more graded differentiation of ERP changes in patients with mild versus severe comprehension deficits. Methods. A total of 20 aphasic patients with minor and severe comprehension deficits and 20 young and elder healthy controls were examined while reading 4-word sentences ending in a semantically congruent or noncongruent word. Results. In contrast to young controls and to patients with mild comprehension deficits, aphasic patients with severe comprehension deficits exhibit an early positivity in the time window from 200 to 400 milliseconds and no N400 after the presentation of nonrecurrent semantically incongruent words. Patients with mild comprehension deficits were found to have an N400 with prolonged latency in comparison with the controls. An age effect in the control groups was detected as well. Discussion. Semantic access and integration are performed differently in aphasic subjects with severe comprehension deficits. These differences in lexical–semantic processing must be taken into account in rehabilitation approaches that aim to improve comprehension deficits. Moreover, the findings may contribute to the design of therapy studies by employing a physiological measure that can discriminate among patients at baseline and at the end of an intervention.

Reducing the Energy Cost Of Hemiparetic Gait Using Center of Mass Feedback: A Pilot Study

Massaad, F., Lejeune, T. M., Detrembleur, C. — Wed, 04 Nov 2009 10:37:26 PST

Background. Hemiparetic gait following stroke requires substantial energy consumption, which would promote deconditioning and disability. Optimal modalities for decreasing this energy cost remain challenging. Excessive energy consumption, however, seems to be mainly due to extra positive muscle work to substantially lift the body’s center of mass (CM) against gravity during the paretic limb swing. Objective. The authors tested a new rehabilitation strategy in a pilot study to specifically reduce the energy cost in hemiparetic gait. Methods. Six chronic hemiparetic patients underwent a 6-week gait training program on a treadmill with real-time feedback of their CM and were asked to reduce its increased vertical displacement. The authors assessed the walking energy cost, vertical CM displacement, kinematics, and electromyogram activity without feedback before and after treatment. Results. After treatment, the vertical CM displacement decreased by 10% (P = .005), particularly when the CM vaulted over the nonparetic limb in stance, and the energy cost decreased markedly by 30% (P = .009). The paretic knee flexion in swing increased concomitantly by 45% and muscle co-contraction decreased significantly in both thigh muscles by 15%. Conclusions. The rehabilitation approach followed in this study seems remarkably effective in decreasing the walking energy cost. By treating the compensatory strategy (ie, the increased CM displacement), we also appear to treat primary deviations such as poststroke knee impairments, which is novel and complementary to current concepts in rehabilitation. This new approach is promising and merits further investigation.

Effects of Somatosensory Stimulation on Motor Function After Subacute Stroke

Mon, 02 Nov 2009 14:19:52 PST

Background. Previous works showed potentially beneficial effects of a single session of peripheral nerve sensory stimulation (PSS) on motor function of a paretic hand in patients with subacute and chronic stroke. Objective. To investigate the influence of the use of different stimulus intensities over multiple sessions (repetitive PSS [RPSS]) paired with motor training. Methods. To address this question, 22 patients were randomized within the second month after a single hemispheric stroke in a parallel design to application of 2-hour RPSS at 1 of 2 stimulus intensities immediately preceding motor training, 3 times a week, for 1 month. Jebsen–Taylor test (JTT, primary endpoint measure), pinch force, Functional Independence Measure (FIM), and corticomotor excitability to transcranial magnetic stimulation were measured before and after the end of the treatment month. JTT, FIM scores, and pinch force were reevaluated 2 to 3 months after the end of the treatment. Results. Baseline motor function tests were comparable across the 2 RPSS intensity groups. JTT improved significantly in the lower intensity RPSS group but not in the higher intensity RPSS group at month 1. This difference between the 2 groups reduced by months 2 to 3. Conclusions. These results indicate that multiple sessions of RPSS could facilitate training effects on motor function after subacute stroke depending on the intensity of stimulation. It is proposed that careful dose–response studies are needed to optimize parameters of RPSS stimulation before designing costly, larger, double-blind, multicenter clinical trials.

Does Functional Electrical Stimulation for Foot Drop Strengthen Corticospinal Connections?

Everaert, D. G., Thompson, A. K., Chong, S. L., Stein, R. B. — Tue, 27 Oct 2009 15:31:31 PDT

Background. Long-term use of a foot-drop stimulator applying functional electrical stimulation (FES) to the common peroneal nerve improves walking performance even when the stimulator is off. This "therapeutic" effect might result from neuroplastic changes. Objective. To determine the effect of long-term use of a foot-drop stimulator on residual corticospinal connections in people with central nervous system disorders. Methods. Ten people with nonprogressive disorders (eg, stroke) and 26 with progressive disorders (eg, multiple sclerosis) used a foot-drop stimulator for 3 to 12 months while walking in the community. Walking performance and electrophysiological variables were measured before and after FES use. From the surface electromyogram of the tibialis anterior muscle, we measured the following: (1) motor-evoked potential (MEP) from transcranial magnetic stimulation over the motor cortex, (2) maximum voluntary contraction (MVC), and (3) maximum motor wave (M_max) from stimulating the common peroneal nerve. Results. After using FES, MEP and MVC increased significantly by comparable amounts, 50% and 48%, respectively, in the nonprogressive group and 27% and 17% in the progressive group; the changes were positively correlated (R² = .35; P < .001). Walking speed increased with the stimulator off (therapeutic effect) by 24% (P = .008) and 7% (P = .014) in the nonprogressive and progressive groups, respectively. The changes in M_max were small and not correlated with changes in MEP. Conclusions. The large increases in MVC and MEP suggest that regular use of a foot-drop stimulator strengthens activation of motor cortical areas and their residual descending connections, which may explain the therapeutic effect on walking speed.

Does Provision of Extrinsic Feedback Result in Improved Motor Learning in the Upper Limb Poststroke? A Systematic Review of the Evidence

Subramanian, S. K., Massie, C. L., Malcolm, M. P., Levin, M. F. — Tue, 27 Oct 2009 15:31:31 PDT

Background. Recovery of the upper limb (UL) after a stroke occurs well into the chronic stage. Stroke survivors can benefit from adaptive plasticity to improve UL movement through motor relearning. The provision of feedback has been shown to decrease the use of compensatory UL movement patterns. However, the effectiveness of feedback in improving UL motor recovery after a stroke has not yet been systematically reviewed. Objective. The objective of this review was to systematically examine the role of extrinsic feedback on implicit motor learning after stroke, focusing on UL movement and functional recovery. Results. The authors retrieved 9 studies that examined the role of feedback on UL motor recovery. Of these, 6 were randomized controlled trials (RCTs), 1 was a single-subject design, 1 was a pre–post design, and 1 was a cohort study. The studies were rated on the basis of Sackett’s levels of evidence and PEDro (Physiotherapy Evidence Database) scores for RCTs. Levels of evidence were limited (level 2b) for UL motor learning of the less-affected extremity and strong (level 1a) for the more-affected extremity. Discussion and conclusions. The results suggest that people with stroke may be capable of using extrinsic feedback for implicit motor learning and improving UL motor recovery. Emergent questions regarding the advantages of using different media for feedback delivery and the optimal type and schedule of feedback to enhance motor learning in patient populations still need to be addressed.

Segmental Muscle Vibration Improves Walking in Chronic Stroke Patients With Foot Drop: A Randomized Controlled Trial

Fri, 23 Oct 2009 12:25:31 PDT

Background. Studies have described the effects of segmental muscle vibration (SMV) on brain plasticity and corticomotor excitability. Information on the treatment-induced effects of SMV in stroke patients is, however, still limited. Objectives. To assess whether the application of SMV to ankle dorsiflexor muscles of chronic stroke patients can improve walking. Methods. Forty-four patients were randomly assigned to either an experimental group (EG) or a control group (CG) and underwent 12 sessions over 4 weeks of general physical therapy. Patients in the EG also received SMV at 120 Hz over the peroneus longus and tibialis anterior for 30 minutes at the end of each session. All the participants underwent pretreatment and posttreatment gait analysis assessments. Time-distance, kinematic, and surface electromyography (EMG) data were used as outcome measures. Results. A moderate improvement in mean gait speed, normal-side swing velocity, bilateral stride length, and normal-side toe-off percentage was observed only in the EG. A significant increase in bilateral ankle dorsiflexion angle at heel contact was associated with increased maximum ankle dorsiflexion and plantarflexion degrees during the swing phase on the paretic side after treatment in EG. Surface EMG during the swing phase revealed a significant increase in the activation of the tibialis anterior muscle on the paretic side in the posttreatment assessment in the EG. Conclusions. SMV added to general physical therapy may improve gait performance in patients with foot drop secondary to chronic stroke. The authors hypothesize that this may be due to the mechanical vibration stimulation, probably as a consequence of effective brain reorganization.

Long-Term Therapeutic and Orthotic Effects of a Foot Drop Stimulator on Walking Performance in Progressive and Nonprogressive Neurological Disorders

Wed, 21 Oct 2009 11:55:33 PDT

Background. Stimulators applying functional electrical stimulation (FES) to the common peroneal nerve improve walking with a foot drop, which occurs in several disorders. Objective.To compare the orthotic and therapeutic effects of a foot drop stimulator on walking performance of subjects with chronic nonprogressive (eg, stroke) and progressive (eg, multiple sclerosis) disorders.Methods. Subjects with nonprogressive (41) and progressive (32) conditions used a foot drop stimulator for 3 to 12 months while walking in the community.Walking speed was measured with a 10-m test and a 4-minute figure-8 test; physiological cost index (PCI) and device usage were also measured.The subjects were tested with FES on and off (orthotic effect) before and after (therapeutic effect) stimulator use. Results. After 3 months of FES use, the nonprogressive and progressive groups had a similar, significant orthotic effect (5.0% and 5.7%, respectively, P < .003; percentage change in mean values) and therapeutic effect with FES off (17.8% and 9.1%, respectively, P < .005) on figure-8 walking speed. Overall, PCI showed a decreasing trend (P = .031).The therapeutic effect on figure-8 speed diverged later between both groups to 28.0% (P < .001) and 7.9% at 11 months.The combined therapeutic plus orthotic effect on figure-8 speed at 11 months was, respectively, 37.8% (P < .001) and 13.1% (P = .012); PCI decreased 18.2% (P = .038) and 6.5%, respectively. Conclusions. Subjects with progressive and nonprogressive disorders had an orthotic benefit from FES up to 11 months.The therapeutic effect increased for 11 months in nonprogressive disorders but only for 3 months in progressive disorders.The combined effect remained significant and clinically relevant.

Vitamin E Protects Against Oxidative Damage and Learning Disability After Mild Traumatic Brain Injury in Rats

Wu, A., Ying, Z., Gomez-Pinilla, F. — Mon, 19 Oct 2009 14:03:17 PDT

Background. Reactive oxygen species induce neuronal damage, and their role in reducing synaptic plasticity and function is beginning to be understood. Vitamin E is a potent reactive oxygen species scavenger, which has the potential to reduce oxidative damage encountered after traumatic brain injury (TBI). Brain-derived neurotrophic factor (BDNF) can facilitate synaptic function and support learning by modulating the CaMKII system, synapsin I, and cAMP-response element-binding protein (CREB). The elevation of superoxide dismutase (SOD) and Sir2 (silent information regulator 2) play an important role in resistance to oxidative stress. Objective. We examined the possibility that vitamin E supplemented in the diet may help counteract the effects of TBI on the molecular substrates underlying synaptic plasticity and cognitive function in the hippocampus. Methods. Rats were fed a regular diet with or without 500 IU/kg of vitamin E for 4 weeks (n = 6-8 per group) before a mild fluid percussion injury (FPI) was performed. Results. FPI increased protein oxidation as evidenced by elevated levels of protein carbonyls and reduced levels of SOD and Sir2. In addition, FPI resulted in poor performance in the Morris water maze, which was accompanied by reduced levels of BDNF and its downstream effectors on synaptic plasticity, synapsin I, CREB, and CaMKII. Supplementation of vitamin E in the diet counteracted all the observed effects of FPI. Conclusions. These results suggest that vitamin E dietary supplementation can protect the brain against the effects of mild TBI on synaptic plasticity and cognition, using molecular systems associated with the maintenance of long-term plasticity, such as BDNF and Sir2.

Dermatomal Somatosensory Evoked Potentials and Electrical Perception Thresholds During Recovery From Cervical Spinal Cord Injury

Kramer, J. K., Taylor, P., Steeves, J. D., Curt, A. — Mon, 19 Oct 2009 14:03:17 PDT

Background.Dermatomal somatosensory evoked potentials (dSSEPs) not only provide a neurophysiological readout comparable with conventional SSEPs but also provide an opportunity to track changes in sensory function corresponding to individual dermatomes (ie, a single spinal segment) above, at, and below the level of spinal cord injury (SCI). Objectives.This study aimed to determine the reliability and responsiveness of dSSEPs and electrical perception thresholds (EPTs) to monitor changes in sensory function after cervical SCI. Methods. Initial and follow-up dSSEPs and EPTs were recorded from cervical dermatomes (C4-C8) of patients with traumatic tetraplegia (C3-C8; ASIA Impairment Scale A-D) during recovery after SCI (n = 18). Results. Follow-up examination of 74 initial dSSEPs unaffected by SCI (n = 18) revealed no significant change in latency ( = 0.0 ± 1.4 ms; P = .9) or EPT sensitivity ( = 0.1 ± 0.8 mA; P = .3). In 41 dSSEPs initially delayed after SCI (n = 14), latencies significantly decreased on follow-up examination ( = -3.1 ± 2.9 ms; P < .01) without a corresponding increase in sensitivity of the EPT ( = 0.2 ± 3.4 mA; P = .7). dSSEPs that were not measurable initially were subsequently recorded in 11 dermatomes (n = 5) on follow-up examination.This conversion of abolished-to-recordable dSSEPs was often preceded by the perception of an initial EPT and associated with a concomitant recovery of EPT at follow-up.Conclusion. dSSEPs and EPT can be reliably recorded to monitor changes in sensory function for each individual spinal segment after cervical SCI. dSSEPs may be potentially useful to monitor the safety of a therapeutic drug or cell transplant in early-phase (I/II) clinical trials as well as document the potential efficacy of interventions where the standard neurological assessment might not detect subtle therapeutic effects.

Olfactory Mucosal Autografts and Rehabilitation for Chronic Traumatic Spinal Cord Injury

Mon, 19 Oct 2009 14:03:17 PDT

Background/objective. Basic science advances in spinal cord injury (SCI) are leading to novel clinical approaches.The authors report a prospective, uncontrolled pilot study of the safety and outcomes of implanting olfactory mucosal autografts (OMA) in 20 patients with chronic,sensorimotor complete or motor complete SCI. Methods.Seven paraplegic and 13 tetraplegic subjects (17 men and 3 women; 19-37 years old) who sustained a traumatic SCI 18 to 189 months previously (mean = 49 months) were enrolled. Preoperative rehabilitation that emphasized lower extremity stepping using either overground walking training or a robotic weight-supported treadmill training was provided for 25 to 39 hours per week for a median of 4 months at 3 sites. No change in ASIA Impairment Scale (AIS) motor scores for the lower extremities or AIS grades of completeness was found. OMAs were transplanted into 1.3-to 4-cm lesions at C4-T12 neurological levels after partial scar removal.Therapy was continued postoperatively.Preoperative and postoperative assessments includedAIS scores and classification, electromyography (EMG) of attempted voluntary contractions, somatosensory evoked potentials (SSEP),urodynamic studies with sphincter EMG, spinal cord magnetic resonance imaging (MRI), and otolaryngology and psychology evaluations.The Functional Independence Measure (FIM) and Walking Index for Spinal Cord Injury (WISCI) were obtained in 13 patients. Results. All patients survived and recovered olfaction.One patient was rehospitalized for aseptic meningitis.Minor adverse events occurred in 4 others.The mean duration of follow-up was 27.7 months (range = 12-45 months). By MRI, the lesion site was filled in all patients with no neoplastic overgrowth or syringomyelia.AIS grades improved in 11 of 20 patients, 6 (A -> C),3 (B -> C),and 2 (A -> B), and declined in 1 (B -> A). Improvements included new voluntary EMG responses (15 patients) and SSEPs (4 patients). Scores improved in the FIM and WISCI (13/13 tested), and urodynamic responses improved in 5 patients. Conclusion. OMA is feasible, relatively safe, and possibly beneficial in people with chronic SCI when combined with postoperative rehabilitation. Future controlled trials may need to include a lengthy and intensive rehabilitation arm as a control.

Kinematics of Turning 180{degrees} During the Timed Up and Go in Stroke Survivors With and Without Falls History

Mon, 12 Oct 2009 10:46:38 PDT

Background. Community-dwelling, chronic stroke survivors are at risk of falling during turning and are more likely to sustain a hip fracture when they fall. Objective. This study quantifies kinematic differences between stroke survivors (mean ±SD:38.3 ±31.3 months poststroke,59.9 ±10.1 years of age),with (n =9) and without a falls history (n =9),and age-matched healthy counterparts (n =18) in turning coordination during the 180 ° turn around in the Timed "Up & Go" (TUG) test. Methods. Full-body kinematics were recorded while participants performed the 180° turn around in the TUG.Dependent measures were time to turn, number of steps to turn, and measures of axial segment coordination. Result. Although participants who had a stroke and falls history took significantly longer to turn (mean ±SD: 4.4 ±1.7 seconds) than age-matched controls (2.5 ±0.6 seconds), no kinematic differences were found in performance or in the axial segment coordination during turning that could contribute to falls history or falls risk. Conclusions. These results indicate incidences of falls during turning following stroke may not be due to impaired movement patterns but due to the many other factors that are associated with falls, such as deficits in cognitive processes—attention or central integration—and/or sensory deficits.

Toward a Better Understanding of Coordination in Healthy and Poststroke Gait

Krasovsky, T., Levin, M. F. — Mon, 12 Oct 2009 10:46:37 PDT

Locomotor coordination characterizes healthy gait and rehabilitation effectiveness in poststroke individuals. However, despite a large number of clinic-based and laboratory-based measurement options, to date there is no gold standard for measurement of locomotor coordination. A lack of a common definition for locomotor coordination may be a cause of this confusion. Coordination during gait includes both spatial and temporal components that may be measured in extrinsic or intrinsic reference frames. Measurement tools have been used to evaluate one or both aspects of coordination. The authors suggest an operational definition of locomotor coordination and describe how current measures in healthy and poststroke individuals fit with this definition. They define locomotor coordination as an ability to maintain a context-dependent and phase-dependent cyclical relationship between different body segments or joints in both spatial and temporal domains. Advantages and disadvantages of laboratory-based measures, such as cyclograms, discrete and continuous relative phase, power spectral density, and others are summarized and discussed. In addition to the definition, the authors propose a clinically feasible measurement paradigm that accentuates the adaptive component of coordination and that may be useful in merging the clinical and laboratory-based approaches to locomotor coordination.

Seated Bilateral Leg Exercise Effects on Hemiparetic Lower Extremity Function in Chronic Stroke

Mon, 12 Oct 2009 10:46:37 PDT

Background. Bilateral arm training with rhythmic auditory cueing (BATRAC) improves hemiparetic upper extremity (UE) function in stroke. It is unknown whether a similar exercise for the hemiparetic lower extremity (LE) is effective. Objective. The authors sought to test whether the BATRAC strategy would transfer to the legs by improving LE motor function following ten 30-minute sessions of bilateral leg training with rhythmic auditory cueing (BLETRAC). Methods. Twenty-four chronic stroke participants, recruited from the community, were randomized to either the BLETRAC or the BATRAC intervention. Assessments were performed before (week 0) and after (week 6) training as well as 3 months later (week 18). Change in the Fugl-Meyer LE and UE subscales served as primary outcomes. Timed 10-m walk, movement parameters during treadmill walking, and a repetitive aiming task for both feet and hands were the secondary outcomes. Results. Following an intention-to-treat approach, data from 21 subjects were analyzed. After training, improvements in the Fugl-Meyer LE and UE subscales tended to be better for the corresponding intervention group. The BLETRAC group also showed increases in step length during treadmill walking and performance in the repetitive foot and hand aiming tasks. No differences between the intervention groups were found at follow-up. Conclusions. This exploratory trial demonstrates that transfer of the BATRAC approach to the legs is feasible. Transient improvements of limb motor function in chronic stroke participants were induced by targeted exercise (BATRAC for the UE and BLETRAC for the LE). It may be that further periods of training would increase and maintain effects.

Sensorimotor Cortical Activation in Patients With Cervical Spinal Cord Injury With Persisting Paralysis

Jurkiewicz, M. T., Mikulis, D. J., Fehlings, M. G., Verrier, M. C. — Tue, 06 Oct 2009 14:34:53 PDT

Background. It is well documented that cortical sensorimotor representations are altered following nervous system pathology. However, little is known about these representations over time and, more specifically, in paralyzed individuals. Objective.To investigate the temporal changes in sensorimotor cortical activation in paralyzed individuals following spinal cord injury (SCI). Methods. Functional MRI (fMRI) was used to study 4 tetraplegic individuals repeatedly over the first year following traumatic SCI as well as 7 healthy individuals, 3 repeatedly. During fMRI, controls performed ankle movements, and patients attempted them. Standard clinical measures of SCI were used to assess movement ability. Results. Shortly after SCI, activation within the primary motor cortex (M1) was present at levels similar to those in controls. Extensive associated cortical sensorimotor activation, not seen in controls, was present. Over time, as paralysis persisted, activation in M1 was significantly reduced and progressively decreased in associated cortical sensorimotor areas. No session-specific dependence in M1 or associated sensorimotor cortical activation was found in healthy individuals. Conclusions. These findings provide the first report of the temporal evolution of cortical sensorimotor fMRI activation following traumatic SCI in humans who do not recover movement. Coupled with findings in patients who recover post-SCI, our results suggest an association between motor task–related fMRI activation and degree of motor function postinjury. Understanding the time course of plasticity and the relationship between cortical sensorimotor activation and motor ability following SCI could allow assessment of rehabilitation potential, monitoring of therapeutic efficacy, and improvement in therapeutic intervention along the course of recovery.

Quantitative Assessment of Limb Position Sense Following Stroke

Wed, 30 Sep 2009 13:13:07 PDT

Background. Impairment of position sense of the upper extremity (UE) may impede activities of daily living and limit motor gains after stroke. Most clinical assessments of position sense rely on categorical or ordinal ratings by clinicians that lack sensitivity to change or the ability to discriminate subtle deficits. Objective. Use robotic technology to develop a reliable, quantitative technique with a continuous scale to assess UE position sense following stroke. Methods. Forty-five patients recruited from an inpatient stroke rehabilitation service and 65 age-matched healthy controls performed an arm position matching task. Each UE was fitted in the exoskeleton of a KINARM device. One UE was passively placed in one of 9 positions, and the subject was told to match his or her position with the other UE. Patients were compared with statistical distributions of control data to identify those with deficits in UE position sense. Test–retest sessions using 2 raters established interrater reliability. Results. Two thirds of left hemiparetic and one third of right hemiparetic patients had deficits in limb position sense. Left-affected stroke subjects demonstrated significantly more trial-to-trial variability than right-affected or control subjects. The robotic assessment technique demonstrated good interrater reliability but limited agreement with the clinical thumb localizing test. Conclusions. Robotic technology can provide a reliable quantitative means to assess deficits in limb position sense following stroke.

Evaluation of Abnormal Synergy Patterns Poststroke: Relationship of the Fugl-Meyer Assessment to Hemiparetic Locomotion

Bowden, M. G., Clark, D. J., Kautz, S. A. — Wed, 30 Sep 2009 13:13:09 PDT

Background. Assessment of poststroke motor impairment has historically focused on the ability to move within and outside of abnormal synergistic motor patterns and is typically quantified by the Fugl-Meyer Assessment (FMA). However, it is unclear if the voluntary, isolated movement tasks of the FMA are appropriate for evaluating walking task-specific motor control requirements because walking is cyclical and involves considerable sensorimotor integration. Objective. The purpose of this study is to test whether the motor impairment measured by the FMA is indicative of motor dysfunction during walking in poststroke adults. Methods. Thirty-four individuals with chronic poststroke hemiparesis and 17 healthy controls walked for 60 seconds on an instrumented treadmill while recording electromyographic activity (EMG) from 8 lower extremity muscles. EMG recordings were also obtained during the FMA for those with hemiparesis to examine muscle activation patterns. Each participant was examined with a battery of walking-specific clinical and biomechanical assessment tools and stratified based on the FMA synergy (FMS) score. To further quantify muscle activation patterns during walking, a nonnegative matrix factorization (NNMF) determined the number of independent modules required to describe 90% of the total variance in the EMG patterns. Results. Stratification poorly differentiated motor activation across FMA tasks as well as EMG patterns during walking. While FMS correlated with 2 of 6 walking assessments, the number of EMG modules significantly correlated with all 6 walking performance measures. Conclusions. Voluntary, discrete activities as performed in the FMA may be inadequate to capture the complex motor behavior in walking. Conversely, walking-specific evaluations such as NNMF appear more appropriate.

Botulinum Toxin to Treat Upper-Limb Spasticity in Hemiparetic Patients: Grasp Strategies and Kinematics of Reach-to-Grasp Movements

Bensmail, D., Robertson, J., Fermanian, C., Roby-Brami, A. — Mon, 28 Sep 2009 14:41:35 PDT

Background. Poor control of grasping in spastic,hemiparetic patients could be because of a combination of poor individuation of joints, weakness, spasticity, and sensory loss. Objective. To investigate the effect of botulinum toxin injections (BTIs) on grasping objects of different shapes and to assess the effect on upper-limb function, reach-to-grasp kinematics, and hand position and orientation at the time of grasp. Methods. We included 15 patients with spastic hemiparesis and 9 healthy controls in this open labeled study, in which the patients were assessed before (M0), 1 month after a first (M1), and 1 month after a second BTI (M4, at 4 months). A motion capture system recorded movements. Kinematic variables were computed as well as hand position and orientation at the time of grasping, and finger configurations were coded from video recordings. Results. In contrast with healthy participants, hemiparetic patients rarely used multipulpar grasps but used specific strategies combined with various directions of approach to the object. BTIs did not alter finger configuration but improved the final direction of the approach and the hand posture during the grasp. No significant changes in kinematic parameters were found using post hoc analysis,although a session effect was found for peak hand velocity.Individual analysis showed that the patients with the best potential for functional improvement are those with good proximal and moderate distal motor command. Conclusions. BTIs can modify hand kinematics as well as the approach and posture of reach-to-grasp movements. Function and grasping strategies are probably more dependent on motor recovery.

Contribution of Transcranial Magnetic Stimulation to the Understanding of Functional Recovery Mechanisms After Stroke

Dimyan, M. A., Cohen, L. G. — Fri, 18 Sep 2009 17:06:30 PDT

Motor impairments are a major cause of morbidity and disability after stroke. This article reviews evidence obtained using transcranial magnetic stimulation (TMS) that provides new insight into mechanisms of impaired motor control and disability.They briefly discuss the use of TMS in the diagnosis, prognosis, and therapy of poststroke motor disability. Particular emphasis is placed on TMS as a tool to explore mechanisms of neuroplasticity during spontaneous and treatment-induced recovery of motor function to develop more rational and clinically useful interventions for stroke rehabilitation.

Greater Activation of Secondary Motor Areas Is Related to Less Arm Use After Stroke

Kokotilo, K. J., Eng, J. J., McKeown, M. J., Boyd, L. A. — Tue, 08 Sep 2009 08:17:47 PDT

Background. Past studies have identified reorganization of brain activity in relation to motor outcome through standardized laboratory measures, which are quantifiable surrogates for arm use in real life. In contrast, accelerometers can provide a real-life estimate of arm and hand usage. Methods. Ten persons with chronic, subcortical stroke and 10 healthy controls of similar age performed a squeeze motor task at 40% maximum voluntary contraction during functional magnetic resonance imaging (fMRI). Use of the upper extremity was quantified over 3 consecutive days using wrist accelerometers. Correlations were performed between arm use and peak percent signal change (PSC) during grasp force production in 6 regions of interest (ROIs): bilateral primary motor cortex (M1), supplementary motor area (SMA), and premotor cortex (PM). Results. Results demonstrate that in healthy controls, PSC across all ROIs did not show a relationship between arm use and brain activation during force production. In contrast, after stroke, contralesional PM and M1 showed a significant (P ≤.05) correlation between increasing activation and decreasing paretic arm use, whereas ipsilesional PM showed a significant correlation (P ≤ .05) between increasing activation and decreasing nonparetic arm use. Conclusions. The results of this pilot study demonstrate a negative relationship between brain activation and actual arm use after stroke. Larger studies using accelerometers that can detect amount and types of movement may offer further insight into brain reorganization and rehabilitation interventions.

The Effects of Bilateral Arm Training on Motor Control and Functional Performance in Chronic Stroke: A Randomized Controlled Study

Lin, K.-c., Chen, Y.-a., Chen, C.-l., Wu, C.-y., Chang, Y.-f. — Thu, 03 Sep 2009 11:56:47 PDT

Background. Most studies of bilateral arm training (BAT) did not employ a randomized controlled trial design and involved very limited functional training tasks.Objective. Compare the effects of BAT with control intervention (CI) on motor control and motor performance of the upper extremity and also functional gains in patients with chronic stroke. Methods. This 2-group randomized controlled trial with pretreatment and posttreatment measures enrolled 33 stroke patients (mean age = 53.85 years) 6 to 67 months after onset of a first stroke. They received either a BAT program concentrating on both upper extremities moving simultaneously in functional tasks by symmetric patterns or CI (control treatment) for 2 hours on weekdays for 3 weeks. Outcome measures included kinematic analyses assessing motor control strategies for unilateral and bimanual reaching and clinical measures involving the Fugl-Meyer Assessment (FMA) of motor-impairment severity and the Functional Independence Measure (FIM) and the Motor Activity Log (MAL) evaluating functional ability. Results. After treatment, the BAT group showed better temporal and spatial efficiency during unilateral and bilateral tasks and less online error correction only during the bilateral task than the control group.The BAT group showed a significantly greater improvement in the FMA than the control group but not in the FIM and MAL. Conclusions. Relative to CI, BAT improved the spatiotemporal control of the affected arm in both bilateral and unilateral tasks, decreased online corrections to perform bilateral tasks,and reduced motor impairment. These findings support the use of BAT to improve motor control and motor function of the affected upper limb in stroke patients.

Combined Botulinum Toxin Type A With Modified Constraint-Induced Movement Therapy for Chronic Stroke Patients With Upper Extremity Spasticity: A Randomized Controlled Study

Sun, S.-F., Hsu, C.-W., Sun, H.-P., Hwang, C.-W., Yang, C.-L., Wang, J.-L. — Thu, 03 Sep 2009 11:56:47 PDT

Background and objective. Botulinum toxin type A (BtxA) injection and modified constraint-induced movement therapy (mCIMT) are both promising approaches to enhance recovery after stroke. The combined application of these 2 promising modalities has rarely been studied. The aim was to investigate whether combined BtxA and mCIMT would improve spasticity and upper extremity motor function more than BtxA plus conventional rehabilitation in chronic stroke patients with upper extremity spasticity. Methods. In a prospective, randomized controlled, observer-blinded trial with 6-month follow-up, 32 patients (≥1 year after stroke) with ability to actively extend >10° at metacarpophalangeal and interphalangeal joints and 20° at wrist of the affected upper limb were randomized to receive BtxA + mCIMT (combination group) or BtxA + conventional rehabilitation (control group) for 2 hours/day, 3 days/week for 3 months. The primary outcome assessed spasticity on the Modified Ashworth Scale. Secondary outcomes assessed real-world arm function (Motor Activity Log), laboratory motor activity (Action Research Arm Test), and patients’ global satisfaction. Results. A total of 32 stroke patients were recruited, and 29 completed the study. Spasticity significantly improved in all subjects at 4 weeks and 3 months postinjection without between-group differences. The combination group showed significantly greater improvements in elbow, wrist, and finger spasticity (P = .019, P = .019, and P < .001, respectively), affected upper extremity real-world arm function (P < .001) and laboratory motor activity (P < .001) than the control group at 6-month postinjection. Patients reported considerable satisfaction and no serious adverse events occurred. Conclusions. Combining BtxA and mCIMT is an effective and safe intervention for improving spasticity and motor function in chronic stroke patients. The results are promising enough to justify further studies. We recommend future research to address the likely need for including rehabilitation with BtxA to improve function in patients with poststroke spasticity.

Management of Spasticity After Spinal Cord Injury: Current Techniques and Future Directions

Elbasiouny, S. M., Moroz, D., Bakr, M. M., Mushahwar, V. K. — Tue, 01 Sep 2009 09:21:56 PDT

Spasticity, resulting in involuntary and sustained contractions of muscles, may evolve in patients with stroke, cerebral palsy, multiple sclerosis, brain injury, and spinal cord injury (SCI). The authors critically review the neural mechanisms that may contribute to spasticity after SCI and assess their likely degree of involvement and relative significance to its pathophysiology. Experimental data from patients and animal models of spasticity as well as computer simulations are evaluated. The current clinical methods used for the management of spasticity and the pharmacological actions of drugs are discussed in relation to their effects on spinal mechanisms. Critical assessment of experimental findings indicates that increased excitability of both motoneurons and interneurons plays a crucial role in pathophysiology of spasticity. New interventions, including forms of spinal electrical stimulation to suppress increased neuronal excitability, may reduce the severity of spasticity and its complications.

Visuomotor Training Improves Stroke-Related Ipsilesional Upper Extremity Impairments

Quaney, B. M., He, J., Timberlake, G., Dodd, K., Carr, C. — Wed, 26 Aug 2009 09:14:59 PDT

Background. Unilateral middle cerebral artery infarction has been reported to impair bilateral hand grasp. Methods. Individuals (5 males and 5 females; age 33-86 years) with chronic unilateral middle cerebral artery stroke (4 right lesions and 6 left lesions) repeatedly lifted a 260-g object. Participants were then trained to lift the object using visuomotor feedback via an oscilloscope that displayed their actual grip force (GF) and a target GF, which roughly matched the physical properties of the object. Results. The subjects failed to accurately modulate the predictive GF when relying on somatosensory information from the previous lifts. Instead, for all the lifts, they programmed excessive GF equivalent to the force used for the first lift. The predictive GF was lowered for lifts following the removal of the visual feedback. The mean difference in predictive GF between the lifts before and after visual training was significant (4.35 ± 0.027 N; P ≤ .001;95% confidence interval [CI] = 3.80-4.88). After removal of visual feedback, there was also a significant mean difference in the applied predictive GF between the "early" and "late" lifts (0.78 ± 0.029 N; P ≤ .006; 95% CI = 0.22-1.35), demonstrating continued increase in predictive GF accuracy. Conclusion. Predictive or feedforward fingertip force generation is impaired in the ipsilesional hand when lifting a novel object with precision grip. Reacquisition of the motor forces for the grasp of objects is possible after stroke. Potentially, retraining grasp control for the ipsilesional hand may translate to improved function and motor learning within the contralesional hand.

Efficacy of Functional Strength Training on Restoration of Lower-Limb Motor Function Early After Stroke: Phase I Randomized Controlled Trial

Cooke, E. V., Tallis, R. C., Clark, A., Pomeroy, V. M. — Mon, 24 Aug 2009 15:31:29 PDT

After stroke, physiotherapy can promote brain reorganization and motor recovery. Combining muscle strength and functional training (functional strength training, FST) may be beneficial. The aim of the authors was to compare FST with conventional physiotherapy (CPT) while controlling for the potential confounder of therapy intensity in a multicenter,randomized controlled observer-blind trial. The mean age of the participants was 68.3 (standard deviation [SD] = 12.03) years at a mean of 34 (SD = 20) days after stroke, with mean peak paretic knee extension torque (torque) of 22 (SD = 25) Nm. The estimated sample size was 102 to detect a between-group difference of 0.2 m/s in walking speed.After baseline measures, participants were allocated randomly to CPT or CPT + CPT or CPT + FST for 6 weeks. Additional experimental therapy was provided for up to 1 hour a day, 4 times each week. Outcomes were measured 6 weeks after baseline and at follow-up 12 weeks thereafter. Measures included walking speed, knee extensor torque, and functional mobility (Rivermead). At outcome, both extraintensity groups showed greater increases in walking speed than the CPT group, but this reached significance only for the CPT + CPT group (P = .031). The CPT + CPT group also had a greater number of participants who walked at 0.8 m/s or above. No significant differences were observed for torque about the knee or for the Rivermead score. At follow-up,no significant differences were observed. These phase I results justify a subsequent trial of CPT + CPT versus CPT + FST.

Kinematic Robot-Based Evaluation Scales and Clinical Counterparts to Measure Upper Limb Motor Performance in Patients With Chronic Stroke

Bosecker, C., Dipietro, L., Volpe, B., Krebs, H. I. — Fri, 14 Aug 2009 13:31:58 PDT

Background. Human-administered clinical scales are the accepted standard for quantifying motor performance of stroke subjects. Although they are widely accepted, these measurement tools are limited by interrater and intrarater reliability and are time-consuming to apply. In contrast, robot-based measures are highly repeatable, have high resolution, and could potentially reduce assessment time. Although robotic and other objective metrics have proliferated in the literature, they are not as well established as clinical scales and their relationship to clinical scales is mostly unknown. Objective. To test the performance of linear regression models to estimate clinical scores for the upper extremity from systematic robot-based metrics. Methods. Twenty kinematic and kinetic metrics were derived from movement data recorded with the shoulder-and-elbow InMotion2 robot (Interactive Motion Technologies, Inc), a commercial version of the MIT-Manus. Kinematic metrics were aggregated into macro-metrics and micro-metrics and collected from 111 chronic stroke subjects. Multiple linear regression models were developed to calculate Fugl-Meyer Assessment, Motor Status Score, Motor Power, and Modified Ashworth Scale from these robot-based metrics. Results. Best performance–complexity trade-off was achieved by the Motor Status Score model with 8 kinematic macro-metrics (R = .71 for training; R = .72 for validation). Models including kinematic micro-metrics did not achieve significantly higher performance. Performances of the Modified Ashworth Scale models were consistently low (R = .35-.42 for training; R = .08-.17 for validation). Conclusions. The authors identified a set of kinetic and kinematic macro-metrics that may be used for fast outcome evaluations. These metrics represent a first step toward the development of unified, automated measures of therapy outcome.

Evaluation of Tooth-Click Triggering and Speech Recognition in Assistive Technology for Computer Access

Simpson, T., Gauthier, M., Prochazka, A. — Thu, 13 Aug 2009 07:14:39 PDT

Background. Computer access can play an important role in employment and leisure activities following spinal cord injury. The authors’ prior work has shown that a tooth-click detecting device, when paired with an optical head mouse, may be used by people with tetraplegia for controlling cursor movement and mouse button clicks. Objective. To compare the efficacy of tooth clicks to speech recognition and that of an optical head mouse to a gyrometer head mouse for cursor and mouse button control of a computer. Methods. Six able-bodied and 3 tetraplegic subjects used the devices listed above to produce cursor movements and mouse clicks in response to a series of prompts displayed on a computer.The time taken to move to and click on each target was recorded. Results. The use of tooth clicks in combination with either an optical head mouse or a gyrometer head mouse can provide hands-free cursor movement and mouse button control at a speed of up to 22% of that of a standard mouse. Tooth clicks were significantly faster at generating mouse button clicks than speech recognition when paired with either type of head mouse device. Conclusions. Tooth-click detection performed better than speech recognition when paired with both the optical head mouse and the gyrometer head mouse. Such a system may improve computer access for people with tetraplegia.

The Effects of a Secondary Task on Forward and Backward Walking in Parkinson's Disease

Hackney, M. E., Earhart, G. M. — Wed, 12 Aug 2009 07:29:27 PDT

Background. People with Parkinson’s disease (PD) often fall while multitasking or walking backward, unavoidable activities in daily living. Dual tasks involving cognitive demand during gait and unfamiliar motor skills, such as backward walking, could identify those with fall risk, but dual tasking while walking backward has not been examined in those with PD, those who experience freezing of gait (FOG), or healthy older controls. Methods. A total of 78 people with PD (mean age = 65.1 ±9.5 years; female, 28%) and 74 age-matched and sex-matched controls (mean age = 65.0 ±10.0 years; female, 23%) participated. A computerized walkway measured gait velocity, stride length, swing percent, stance percent, cadence, heel to heel base of support, functional ambulation profile, and gait asymmetry during forward and backward walking with and without a secondary cognitive task. Results. Direction and task effects on walking performance were similar between healthy controls and those with PD. However, those with PD were more affected than controls, and freezers were more affected than nonfreezers, by backward walking and dual tasking. Walking backward seemed to affect gait more than dual tasking in those with PD,although the subset of freezers appeared particularly affected by both challenges. Conclusion. People with PD are impaired while performing complex motor and mental tasks simultaneously,which may put them at risk for falling. Those with FOG are more adversely affected by both motor and mental challenges than those without. Evaluation of backward walking while performing a secondary task might be an effective clinical tool to identify locomotor difficulties.

Falls in Persons With Spinal Cord Injury: Validity and Reliability of the Berg Balance Scale

Wirz, M., Muller, R., Bastiaenen, C. — Wed, 12 Aug 2009 07:29:26 PDT

Background.Persons with spinal cord injury who are able to walk are at risk for falls. Objective.The objectives were to investigate if the Berg Balance Scale (BBS) can discriminate those with a propensity to fall; to determine whether the BBS is associated with mobility measures, fear of falling, and muscle strength; and to assess interobserver reliability. Methods. The measurement tools used were the BBS, the Spinal Cord Independence Measure, the Falls Efficacy Scale (FES-I), the Walking Index for Spinal Cord Injury, the 10-m walk test, and the standard neurological classification including motor scores (MS). Falls were recorded retrospectively for the previous month and prospectively for the subsequent 4 months. To determine interobserver reliability, BBS performance was videotaped and analyzed by additional physical therapists. Associations between BBS and the number of falls,measures of mobility, FES-I,and MS were calculated using Spearman correlations.The interobserver reliability was quantified using Kendall’s coefficient of concordance and intraclass correlation coefficients (ICCs). Results. Forty-two participants were included of whom 26 sustained 1 or more falls. BBS performance correlated with measures of mobility, FES-I, and MS (r_s= .83 to .93; P < .001) but not with the number of falls (r_s= .17; P = .28). The interobserver reliability was excellent, both for single items (.84-.98, P < .001) and for the total score (ICC = .95; 95% confidence interval = 0.910-0.975). Conclusions.The BBS proved to be reliable and to relate well with other mobility measures, fear of falling,and muscle strength. However,it was unable discriminate between people who did fall and people who did not fall.

Rehabilitation of Gait Speed After Stroke: A Critical Review of Intervention Approaches

Dickstein, R. — Thu, 18 Sep 2008 06:48:10 PDT

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 metaanalyses, 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.