Hand In Chronic Stroke Patients Research Articles

Real time motion intention recognition method with limited number of surface electromyography sensors for A 7-DOF hand/wrist rehabilitation exoskeleton

The functions of human hand are rich, and the motor dysfunction of hand of chronic stroke patients can be alleviated to some extent through active rehabilitation training. Hand rehabilitation exoskeleton can assist patients to do active rehabilitation training. However, how to realize more motion with less surface electromyogrphy (sEMG) sensors, and how to realize the real-time motion intention recognition are two important issues. This paper introduces real-time motion intention recognition method with limited number of sEMG sensors for a 7-DOF wearable hand/wrist rehabilitation exoskeleton to realize the real-time motion intention recognition and rehabilitation training. Root mean square (RMS) and Bens Spiker Algorithm (BSA) features of three-channel sEMG signals are extracted, and they are mapped to seven different intention movements by combining the Bagging method. The finger structure part of the exoskeleton is composed of a rotary-spatial-spatial-rotary (RSSR) mechanism and a double-parallelogram mechanism, which makes the projection center of exoskeleton coincide with the rotation center of the hand joint. The average real-time motion intention recognition accuracy is 95.37 ± 0.97%.

Decoding Finger Tapping With the Affected Hand in Chronic Stroke Patients During Motor Imagery and Execution.

In stroke rehabilitation, motor imagery based on a brain-computer interface is an extremely useful method to control an external device and utilize neurofeedback. Many studies have reported on the classification performance of motor imagery to decode individual fingers in stroke patients compared with healthy controls. However, classification performance for a given limb is still low because the differences between patients owing to brain reorganization after stroke are not considered. We used electroencephalography signals from eleven healthy controls and eleven stroke patients in this study. The subjects performed a finger tapping task during motor execution, and motor imagery was performed with the dominant and affected hands in the healthy controls and stroke patients, respectively. All fingers except for the thumb were classified using the proposed framework based on a voting module. The averaged four-class accuracies during motor execution and motor imagery were 53.16 ± 8.42% and 46.94 ± 5.99% for the healthy controls and 53.17 ± 14.09% and 66.00 ± 14.96% for the stroke patients, respectively. Importantly, the classification accuracies in the stroke patients were statistically higher than those in healthy controls during motor imagery. However, there was no significant difference between the accuracies of motor execution and motor imagery. These findings show the potential for high classification performance for a given limb during motor imagery in stroke patients. These results can also provide insights into controlling an external device on the basis of a brain-computer interface.

Timing-dependent effects of transcranial direct current stimulation with mirror therapy on daily function and motor control in chronic stroke: a randomized controlled pilot study

BackgroundThe timing of transcranial direct current stimulation (tDCS) with neurorehabilitation interventions may affect its modulatory effects. Motor function has been reported to be modulated by the timing of tDCS; however, whether the timing of tDCS would also affect restoration of daily function and upper extremity motor control with neurorehabilitation in stroke patients remains largely unexplored. Mirror therapy (MT) is a potentially effective neurorehabilitation approach for improving paretic arm function in stroke patients. This study aimed to determine whether the timing of tDCS with MT would influence treatment effects on daily function, motor function and motor control in individuals with chronic stroke.MethodsThis study was a double-blinded randomized controlled trial. Twenty-eight individuals with chronic stroke received one of the following three interventions: (1) sequentially combined tDCS with MT (SEQ), (2) concurrently combined tDCS with MT (CON), and (3) sham tDCS with MT (SHAM). Participants received interventions for 90 min/day, 5 days/week for 4 weeks. Daily function was assessed using the Nottingham Extended Activities of Daily Living Scale. Upper extremity motor function was assessed using the Fugl-Meyer Assessment Scale. Upper extremity motor control was evaluated using movement kinematic assessments.ResultsThere were significant differences in daily function between the three groups. The SEQ group had greater improvement in daily function than the CON and SHAM groups. Kinematic analyses showed that movement time of the paretic hand significantly reduced in the SEQ group after interventions. All three groups had significant improvement in motor function from pre-intervention to post-intervention.ConclusionThe timing of tDCS with MT may influence restoration of daily function and movement efficiency of the paretic hand in chronic stroke patients. Sequentially applying tDCS prior to MT seems to be advantageous for enhancing daily function and hand movement control, and may be considered as a potentially useful strategy in future clinical application.Trial registrationClinicalTrials.gov Identifier: NCT02827864. Registered on 29th June, 2016.

The effects of neuromuscular electrical stimulation during repetitive transcranial magnetic stimulation before repetitive facilitation exercise on the hemiparetic hand in chronic stroke patients

The effects of neuromuscular electrical stimulation during repetitive transcranial magnetic stimulation before repetitive facilitation exercise on the hemiparetic hand in chronic stroke patients

Effects of repetitive facilitative exercise with neuromuscular electrical stimulation, vibratory stimulation and repetitive transcranial magnetic stimulation of the hemiplegic hand in chronic stroke patients

Aim: Repetitive facilitative exercise (RFE) is a developed approach to the rehabilitation of hemiplegia. RFE can be integrated with neuromuscular electrical stimulation (NMES), direct application of vibratory stimulation (DAVS) and repetitive transcranial magnetic stimulation (rTMS). The aims of the present study were to retrospectively compare the effects of RFE and NMES, DAVS with those of RFE and rTMS, and to determine the maximal effect of the combination of RFE with NMES, DAVS, rTMS and pharmacological treatments in stroke patients. Subjects and methods: Thirty-three stroke patients were enrolled and divided into three groups: 15 who received RFE with rTMS (4 min) (TMS4 alone), 9 who received RFE with NMES, DAVS (NMES, DAVS alone) and 9 who received RFE with NMES, DAVS and rTMS (10 min) (rTMS10 + NMES, DAVS). The subjects performed the Fugl-Meyer Assessment (FMA) and Action Research Arm Test (ARAT) before and after the 2-week session. The 18 patients in the NMES, DAVS alone and rTMS10 + NMES, DAVS group underwent the intervention for 4 weeks. Result: There were no significant differences in the increases in the FMA, ARAT scores in the three groups. The FMA or ARAT scores in the NMES, DAVS alone and the rTMS10 + NMES, DAVS group were increased significantly. The FMA and ARAT scores were significantly improved after 4 weeks in the NMES, DAVS alone group. Discussion: RFE with NMES, DAVS may be more effective than RFE with rTMS for the recovery of upper-limb function. Patients who received RFE with NMES, DAVS and pharmacological treatments showed significant functional recovery.

Sensory deficits in ipsilesional upper-extremity in chronic stroke patients

Objective To investigate somatosensory deficits in the ipsilesional wrist and hand in chronic stroke patients and correlate these deficits with contralesional sensorimotor dysfunctions, functional testing, laterality and handedness.Methods Fifty subjects (twenty-two healthy volunteers and twenty-eight stroke patients) underwent evaluation with Semmes-Weinstein monofilaments, the sensory and motor Fugl-Meyer Assessment, the Nottingham Sensory Assessment in both wrists and hands and functional tests.Results Twenty-five patients had sensory changes in the wrist and hand contralateral to the stroke, and eighteen patients (64%) had sensory deficits in the ipsilesional wrist and hand. The most significant ipsilesional sensory loss was observed in the left-handed patients. We found that the patients with brain damage in the right hemisphere had better scores for ipsilesional tactile sensation.Conclusions A reduction in ipsilesional conscious proprioception, tactile or thermal sensation was found in stroke subjects. Right hemisphere damage and right-handed subjects had better scores in ipsilesional tactile sensation.

1-A-D-4. Effects of repetitive facilitative exercise with neuromuscular electrical stimulation, direct application of vibratory stimulation and repetitive transcranial stimulation of the hemiplegic hand in chronic stroke patients

Repetitive facilitative exercise (RFE) is a recently developed approach to the rehabilitation of hemiplegia. RFE can be integrated with neuromuscular electrical stimulation (NMES), direct application of vibratory stimulation (DAVS), and repetitive transcranial magnetic stimulation (rTMS) to achieve further improvement. The aims of the present study were to retrospectively compare the effects of RFE and NMES + DAVS with those of RFE and rTMS and to determine the maximal effect of the combination of RFE with NMES, DAVS, rTMS and pharmacological treatments in chronic stroke patients. Fifty-three stroke patients were enrolled and divided into three groups: 15 who received RFE with rTMS (NMES(−), rTMS(+) group), 19 who received RFE with NMES + DAVS (NMES(+), rTMS(−) group), and 19 who received RFE with NMES + DAVS and rTMS (NMES(+), rTMS(+) group). The increase in the Fugl-Meyer Assessment (FMA) score in the NMES(+), rTMS(−) group was significantly better than that in the NMES(−), rTMS(+) group after 2 weeks. RFE with NMES + DAVS may be more effective than RFE with rTMS for the recovery of upper-limb function. The FMA scores were significantly improved after 4 weeks in the 38 patients of the NMES(+), rTMS(−) and NMES(+) rTMS(+) groups who received RFE with NMES, DAVS, rTMS and pharmacological treatments.

Effectiveness of temporary deafferentation of the arm on somatosensory and motor functions following stroke: a systematic review protocol

Effectiveness of temporary deafferentation of the arm on somatosensory and motor functions following stroke: a systematic review protocol

P 128. Predicting behavioural response to TDCS in chronic motor stroke

Transcranial direct current stimulation (TDCS) of primary motor cortex (M1) can transiently improve paretic hand function in chronic stroke. However, responses are variable so there is incentive to try to improve efficacy or to predict response in individual patients. Both excitatory (Anodal) stimulation of ipsilesional M1 and inhibitory (Cathodal) stimulation of contralesional M1 can speed simple reaction time. Here we tested whether combining these two effects simultaneously, by using a bilateral M1–M1 electrode montage, would improve efficacy. We tested the physiological efficacy of Bilateral, Anodal or Cathodal TDCS in changing motor evoked potentials (MEPs) in the healthy brain and their behavioural efficacy in changing reaction times with the paretic hand in chronic stroke. In addition, we aimed to identify clinical or neurochemical predictors of patients’ behavioural response to TDCS. There were three main findings: (1) Unlike Anodal and Cathodal TDCS, Bilateral M1–M1 TDCS (1 mA, 20 min) had no significant effect on MEPs in the healthy brain or on reaction time with the paretic hand in chronic stroke patients; (2) GABA levels in ipsilesional M1 predicted patients’ behavioural gains from Anodal TDCS; (3) Although patients were in the chronic phase, time since stroke (and its combination with Fugl-Meyer score) was a positive predictor of behavioural gain from Cathodal TDCS. These findings indicate the superiority of Anodal or Cathodal over Bilateral TDCS in changing motor corticospinal excitability in the healthy brain and in speeding reaction time in chronic stroke. The identified clinical and neurochemical markers of behavioural response should help to inform the optimization of TDCS delivery and to predict patient outcome variability in future TDCS intervention studies in chronic motor stroke.

S5-2. HANDS therapy – Functional recovery and neurophysiological reorganization

Hybrid assistive neuromuscular dynamic stimulation (HANDS) is a therapeutic approach to facilitate the use of the paretic upper extremity in daily living by combining assistive neuromuscular electrical stimulation with a wrist-hand splint for patients with moderate to severe hemiparesis. Usually in HANDS therapy, patients use these devices eight hours a day and perform intensive hand rehabilitation for three weeks. We examined the change of short intracortical inhibition (SICI) and reciprocal inhibition (RI) to examine the effects of the HANDS therapy to the cortico-spinal systems in chronic stroke patients. In many patients, the SICI in an affected hemisphere was decreased, and RI of a paretic arm was increased after HANDS therapy. It means the excitability of an affected cortex was increased and reciprocal inhibition of a paretic arm was enhanced in spinal level. These changes were correlated with improvement of motor function after treatment. Furthermore, in HANDS therapy, the change of neurophysiological factor and motor function was seen in stroke patients with chronic phase more than a few years from the onset of stroke. HANDS therapy might be considered a useful choice as a therapeutic approach to paretic hand of chronic stroke patients.

Predicting behavioural response to TDCS in chronic motor stroke

Transcranial direct current stimulation (TDCS) of primary motor cortex (M1) can transiently improve paretic hand function in chronic stroke. However, responses are variable so there is incentive to try to improve efficacy and or to predict response in individual patients. Both excitatory (Anodal) stimulation of ipsilesional M1 and inhibitory (Cathodal) stimulation of contralesional M1 can speed simple reaction time. Here we tested whether combining these two effects simultaneously, by using a bilateral M1–M1 electrode montage, would improve efficacy. We tested the physiological efficacy of Bilateral, Anodal or Cathodal TDCS in changing motor evoked potentials (MEPs) in the healthy brain and their behavioural efficacy in changing reaction times with the paretic hand in chronic stroke. In addition, we aimed to identify clinical or neurochemical predictors of patients' behavioural response to TDCS. There were three main findings: 1) unlike Anodal and Cathodal TDCS, Bilateral M1–M1 TDCS (1mA, 20min) had no significant effect on MEPs in the healthy brain or on reaction time with the paretic hand in chronic stroke patients; 2) GABA levels in ipsilesional M1 predicted patients' behavioural gains from Anodal TDCS; and 3) although patients were in the chronic phase, time since stroke (and its combination with Fugl–Meyer score) was a positive predictor of behavioural gain from Cathodal TDCS. These findings indicate the superiority of Anodal or Cathodal over Bilateral TDCS in changing motor cortico-spinal excitability in the healthy brain and in speeding reaction time in chronic stroke. The identified clinical and neurochemical markers of behavioural response should help to inform the optimization of TDCS delivery and to predict patient outcome variability in future TDCS intervention studies in chronic motor stroke.

Effects of repetitive trascranial magnetic stimulation on repetitive facilitation exercises of the hemiplegic hand in chronic stroke patients

To investigate whether multiple sessions of 1-Hz repetitive transcranial magnetic stimulation (rTMS) facilitates the effect of repetitive facilitation exercises on hemiplegic upper-limb function in chronic stroke patients. Randomized double-blinded crossover study. Eighteen patients with hemiplegia of the upper limb. Patients were assigned to 2 groups: a motor-before-sham rTMS group, which performed motor rTMS sessions for 2 weeks followed by sham rTMS sessions for 2 weeks; or a motor-following-sham rTMS group, which performed sham rTMS sessions for 2 weeks followed by motor rTMS sessions for 2 weeks. Patients received 1-Hz rTMS to the unaffected motor cortex for 4 min and performed repetitive facilitation exercises for 40 min during motor rTMS sessions. The Fugl-Meyer Assessment, Action Research Arm Test (ARAT) and Simple Test for Evaluating Hand Function were used to evaluate upper-limb function. The Modified Ashworth Scale and F-wave were measured to evaluate spasticity. Motor function improved significantly during the motor, but not sham, rTMS sessions. ARAT score gains were 1.5 (0-4.0) (median, interquartile range) during the motor rTMS session, and 0 (-0.8-1.8) during the sham rTMS session (p = 0.04). Spasticity did not significantly change during either session. Multiple sessions of 1-Hz rTMS facilitated the effects of repetitive facilitation exercises in improving motor function of the affected upper limb, but did not change spasticity.

Cutaneous anesthesia of the forearm enhances sensorimotor function of the hand

Temporary deafferentation of the upper limb, with ischemic or anesthetic nerve block, has rapid effects on sensorimotor cortex. Cutaneous anesthesia of the forearm has recently been found to improve sensory and motor function of the paretic hand in chronic stroke patients. However, the neurophysiological mechanisms are unknown. The aim of this study was to investigate the behavioral and neurophysiological effects of cutaneous forearm anesthesia. Twenty-five healthy right-handed adults participated in this double-blind, randomized study. Participants completed two sessions, with either a topical anesthesia cream (EMLA) or placebo applied to their left forearm in each session. Thresholds for cutaneous sensation and spatial acuity of the left hand were measured before and after the intervention. Transcranial magnetic stimulation was used to measure corticomotor excitability and short-interval intracortical inhibition in the left first dorsal interosseous and abductor digiti minimi muscles before and after the intervention. Manual dexterity was assessed with the grooved pegboard task after the intervention in each session. Left-hand dexterity improved to a greater extent after treatment with EMLA than placebo, and this was related to improved spatial acuity at the fingertips. Corticomotor excitability remained stable, and short-interval intracortical inhibition increased after EMLA treatment. We have confirmed and extended previous reports that cutaneous forearm anesthesia results in improved spatial acuity and manual dexterity of the ipsilateral hand. The neurophysiological mechanisms involve an increase in intracortical inhibition, which may improve the precision of voluntary movement. These results lend support to the therapeutic application of EMLA in movement rehabilitation.

P11-10 Effect of rTMS over unaffected M1 on motor performance and motor skill learning with affected hand of chronic stroke patients

P11-10 Effect of rTMS over unaffected M1 on motor performance and motor skill learning with affected hand of chronic stroke patients

Cortical effect and functional recovery by the electromyography-triggered neuromuscular stimulation in chronic stroke patients

We investigated the effect of electromyography (EMG)-triggered neuromuscular electrical stimulation (NMES; EMG-stim) on functional recovery of the hemiparetic hand and the related cortical activation pattern in chronic stroke patients. We enrolled 14 stroke patients, who were randomly assigned to the EMG-stim (n=7) or the control groups (n=7). The EMG-stim was applied to the wrist extensor of the EMG-stim group for two sessions (30 min/session) a day, five times per week for 10 weeks. Four functional tests (box and block, strength, the accuracy index, and the on/offset time of muscle contraction) and functional MRI (fMRI) were performed before and after treatment. fMRI was measured at 1.5 T in parallel with timed finger flexion-extension movements at a fixed rate. Following treatment, the EMG-stim group showed a significant improvement in all functional tests. The main cortical activation change with such functional improvement was shifted from the ipsilateral sensorimotor cortex (SMC) to the contralateral SMC. We demonstrated that 10-week EMG-stim can induce functional recovery and change of cortical activation pattern in the hemiparetic hand of chronic stroke patients.

Functional changes in the primary motor cortex ipsilateral (M1ipsi) to an active hand in chronic stroke patients

After stroke, force production by the non-paretic hand does not lead to the same facilitation in excitability of the affected M1ipsi [1,2] as that seen in healthy individuals [3-8]. We hypothesized that a disproportionate increase in interhemispheric inhibition (IHI) from the unaffected to the affected M1 may underlie the lack of facilitation in the affected M1ipsi. One method of testing IHI at 10ms is to test without controlling for the size of the conditioning stimulus motor evoked potential (CS-MEP) [8-10].

Strategies in Motor Stroke Rehabilitation

To the Editor: We read with interest the report by Woldag et al about increased corticomotoneuronal excitability targeting muscles in the paretic hand of chronic stroke patients during voluntary contraction of the healthy hand.1 The authors interpreted their results as supportive of the concept that use of the unaffected hand may exert a beneficial effect on paretic hand function. We raise your attention to 2 issues that impact on this interpretation. First, measurements of corticomotoneuronal excitability provide mechanistic information on brain activity but do not represent a surrogate marker of paretic hand function. This report carefully describes changes in excitability. In the absence of measures of motor function, it is difficult to assess the functional relevance of these results on neurorehabilitation. For example, …