Does Spasticity Correlate With Motor Impairment in the Upper and Lower Limbs in Ambulatory Chronic Stroke Survivors?

OBJECTIVE: This study aimed to explore correlations between spasticity and motor impairments in the upper and lower limbs in ambulatory chronic stroke survivors. DESIGN: We performed clinical assessments in 28 ambulatory chronic stroke survivors with spastic hemiplegia (female: 12; male: 16; mean ages = 57.8 ± 11.8 yrs; 76 ± 45 mos after stroke). RESULTS: In the upper limb, spasticity index and Fugl-Meyer Motor Assessment showed a significant correlation. Spasticity index for the upper limb showed a significant negative correlation with handgrip strength of the affected side ( r = -0.4, P = 0.035) while Fugl-Meyer Motor Assessment for the upper limb had a significant positive correlation ( r = 0.77, P < 0.001). In the LL, no correlation was found between SI_LL and FMA_LL. There was a significant and high correlation between timed up and go test and gait speed ( r = 0.93, P < 0.001). Gait speed was positively correlated with Spasticity index for the lower limb ( r = 0.48, P = 0.01), and negatively correlated with Fugl-Meyer Motor Assessment for the lower limb ( r = -0.57, P = 0.002). Age and time since stroke showed no association in analyses for both upper limb and lower limb. CONCLUSIONS: Spasticity has a negative correlation on motor impairment in the upper limb but not in the lower limb. Motor impairment was significantly correlated with grip strength in the upper limb and gait performance in the lower limb of ambulatory stroke survivors.

Vagus Nerve Stimulation Paired With Upper-Limb Rehabilitation After Stroke: 2- and 3-Year Follow-up From the Pilot Study.

OBJECTIVE: To assess whether a long-term home-based intervention using Paired VNS therapy is feasible and whether the benefits of Paired VNS therapy are maintained beyond 1 year. DESIGN: A long-term follow-up study. SETTING: Three centers in the United States and 1 in the United Kingdom. PARTICIPANTS: Adults with chronic ischemic stroke (n=15) with moderate to severe arm and hand impairment. INTERVENTIONS: Participants were implanted with a VNS device followed by 6 weeks of in-clinic therapy with Paired (Active) or control VNS followed by home-based rehabilitation through day 90 (blinded phase). The control VNS group then crossed over to receive 6 weeks of in-clinic Active VNS. Participants in both groups then continued a long-term home exercise program with self-administered Active VNS. MAIN OUTCOME MEASURES: Fugl-Meyer Assessment for Upper Extremity (FMA-UE) and Wolf Motor Function Test (WMFT) Functional scores were evaluated at the end of in-clinic therapy and day 90. Since both groups were subsequently receiving home-based rehabilitation with Active VNS during the long term, follow-up outcome assessments were pooled for the analyses at 6, 9, and 12 months, as previously reported. Here, we report pooled analysis of outcomes beyond 1 year. RESULTS: One year after Paired VNS therapy, FMA-UE improved by an average of 9.2±8.2 points, as previously reported. Overall, the 2- and 3-year FMA-UE gain from baseline was 11.4±8.7 (P<.001) and 14.8±10.2 points (P<.001), respectively. At years 2 and 3, FMA-UE improved by an additional 2.9 (P=.03 for change vs year 1, n=14) and 4.7 (P=.02 for change vs year 1, n=14) points, respectively. At year 1, 73% (11/15) of participants were responders (FMA-UE change ≥6) and by year 3, 85.7% (12/14) were responders. At years 2 and 3, the WMFT score improved by an additional 0.21 points (P=.03 for change vs year 1, n=15) and 0.42 points (P=.01 for change vs year 1, n=13), respectively. Responder rate (WMFT change ≥0.4) was 46.6% (7/15), 73.3% (11/15), and 69.2% (9/13) at years 1, 2, and 3, respectively. Long-term significant improvements were also observed for Motor Activity Log (MAL) and Stroke Impact Scale, Hand section (SIS-Hand). There were no serious long-term adverse events from the stimulation. CONCLUSIONS: Significant effects of Paired VNS therapy at 1 year were maintained at years 2 and 3, and further improvements in both impairment and function were observed in years 2 and 3. These changes were associated with improvements in measures of activity and participation.

Ultrasound Assessment of Spastic Muscles in Ambulatory Chronic Stroke Survivors Reveals Function-Dependent Changes.

OBJECTIVE: To correlate ultrasound characteristics of spastic muscles with clinical and functional measurements in chronic stroke survivors. METHODS: Ultrasound assessment and clinical and functional assessments were performed in 28 ambulatory stroke survivors (12 females, mean age 57.8 ± 11.8 years, 76 ± 45 months after stroke). RESULTS: Muscle thickness in the affected side was decreased compared with the contralateral side (p < 0.001). The decrease was more evident in the upper limb muscles. On the affected side, the modified Heckmatt scale score was lowest (closer to normal) in the rectus femoris (RF) muscle compared with other muscles (biceps brachii (BB), flexor carpi ulnaris (FCU) and medial gastrocnemius (MG)). Muscle thickness and echogenicity of spastic muscles did not correlate with spasticity, as measured with the modified Ashworth scale (MAS), Fugl-Meyer motor assessment scores, age, or time since stroke. There was a significant negative correlation between grip strength and percentage decrease in muscle thickness for the spastic FCU muscle (r = -0.49, p = 0.008). RF muscle thickness correlated with ambulatory function (Timed Up and Go test (r = 0.44, p = 0.021) and 6-metre walk test (r = 0.41, p = 0.032)). There was no significant correlation between echogenicity and functional assessments Conclusion: Ambulatory chronic stroke survivors had function-dependent changes in muscle thickness on the affected side. Muscle thickness and echogenicity of spastic muscles did not correlate with spasticity, Fugl-Meyer motor assessment scores, age, or time since stroke.

Multi-center, single-blind randomized controlled trial comparing functional electrical stimulation therapy to conventional therapy in incomplete tetraplegia.

Background: Loss of upper extremity function after tetraplegia results in significant disability. Emerging evidence from pilot studies suggests that functional electrical stimulation (FES) therapy may enhance recovery of upper extremity function after tetraplegia. The aim of this trial was to determine the effectiveness of FES therapy delivered by the Myndmove stimulator in people with tetraplegia. Methods: A multi-center, single-blind, parallel-group, two-arm, randomized controlled trial was conducted comparing FES to conventional therapy in adults (≥18 years) with C4-C7 traumatic incomplete tetraplegia between 4 and 96 months post-injury, and with a baseline spinal cord injury independence measure III -self-care (SCIM III-SC) score of ≤10. Participants were enrolled at four SCI-specialized neurorehabilitation centers in the U.S. and Canada. Participants were stratified by center and randomized in a 1:1 ratio to receive either 40 sessions of FES or conventional therapy targeting upper extremities over a 14-week period. Blinded assessors measured SCIM III, Toronto Rehabilitation Institute Hand Function Test, and Graded Redefined Assessment of Strength, Sensibility, and Prehension at baseline, after 20th session, after 40th session or 14 weeks after 1st session, and at 24 weeks after 1st session. The primary outcome measure was change in SCIM III-SC from baseline to end of the treatment. Based on the primary outcome measure, a sample size of 60 was calculated. Seventeen participants' progress in the study was interrupted due to the COVID-19 lockdown. The protocol was modified for these participants to allow them to complete the study. Results: Between June 2019 to August 2021, 51 participants were randomized to FES (n = 27) and conventional therapy (n = 24). Both groups gained a mean of 2 points in SCIM-SC scores at the end of treatment, which was a clinically meaningful change. However, there was no statistically significant difference between the groups on any outcomes. Conclusion: Forty sessions of FES therapy delivered by the MyndMove stimulator are as effective as conventional therapy in producing meaningful functional improvements that persist after therapy is completed. Limitations of this study include the impact of COVID-19 limiting the ability to recruit the target sample size and per-protocol execution of the study in one-third of the participants. Registration: This trial is registered at www.ClinicalTrials.gov, NCT03439319.

Aging after stroke: how to define post-stroke sarcopenia and what are its risk factors?

BACKGROUND: Sarcopenia, generally described as "aging-related loss of skeletal muscle mass and function", can occur secondary to a systemic disease. AIM: This project aimed to study the prevalence of sarcopenia in chronic ambulatory stroke survivors and its associated risk factors using the two most recent diagnostic criteria. DESIGN: A cross-sectional observational study. SETTING: A scientific laboratory. POPULATION: Chronic stroke. METHODS: Twenty-eight ambulatory chronic stroke survivors (12 females; mean age=57.8±11.8 years; time after stroke=76±45 months), hand-grip strength, gait speed, and appendicular skeletal muscle mass (ASM) were measured to define sarcopenia. Risk factors, including motor impairment and spasticity, were identified using regression analysis. RESULTS: The prevalence of sarcopenia varied between 18% and 25% depending on the diagnostic criteria used. A significant difference was seen in the prevalence of low hand grip strength on the affected side (96%) when compared to the contralateral side (25%). The prevalence of slow gait speed was 86% while low ASM was present in 89% of the subjects. Low ASM was marginally negatively correlated with time since stroke and gait speed, but no correlation was observed with age, motor impairment, or spasticity. ASM loss, bone loss and fat deposition were significantly greater in the affected upper limb than in the affected lower limb. Regression analyses showed that time since stroke was a factor associated with bone and muscle loss in the affected upper limb, spasticity had a protective role for muscle loss in the affected lower limb, and walking had a protective role for bone loss in the lower limb. CONCLUSIONS: The prevalence of sarcopenia in stroke survivors is high and is a multifactorial process that is not age-related. Different risk factors contribute to muscle loss in the upper and lower limbs after stroke. CLINICAL REHABILITATION IMPACT: Clinicians need to be aware of high prevalence of sarcopenia in chronic stroke survivors. Sarcopenia is more evident in the upper than lower limbs. Clinicians also need to understand potential protective roles of some factors, such as spasticity and walking for the muscles in the lower limb.

Vagus Nerve Stimulation Paired With Upper-Limb Rehabilitation After Stroke: One-Year Follow-up.

Background. Vagus nerve stimulation (VNS) paired with rehabilitation may improve upper-limb impairment and function after ischemic stroke. Objective. To report 1-year safety, feasibility, adherence, and outcome data from a home exercise program paired with VNS using long-term follow-up data from a randomized double-blind study of rehabilitation therapy paired with Active VNS (n = 8) or Control VNS (n = 9). Methods. All people were implanted with a VNS device and underwent 6 weeks in clinic therapy with Control or Active VNS followed by home exercises through day 90. Thereafter, participants and investigators were unblinded. The Control VNS group then received 6 weeks in-clinic Active VNS (Cross-VNS group). All participants then performed an individualized home exercise program with self-administered Active VNS. Data from this phase are reported here. Outcome measures were Fugl-Meyer Assessment-Upper Extremity (FMA-UE), Wolf Motor Function Test (Functional and Time), Box and Block Test, Nine-Hole Peg Test, Stroke Impact Scale, and Motor Activity Log. Results. There were no VNS treatment-related serious adverse events during the long-term therapy. Two participants discontinued prior to receiving the full crossover VNS. On average, participants performed 200 ± 63 home therapy sessions, representing device use on 57.4% of home exercise days available for each participant. Pooled analysis revealed that 1 year after randomization, the FMA-UE score increased by 9.2 points (95% CI = 4.7 to 13.7; P = .001; n = 15). Other functional measures were also improved at 1 year. Conclusions. VNS combined with rehabilitation is feasible, with good long-term adherence, and may improve arm function after ischemic stroke.

Neural activity modulations and motor recovery following brain-exoskeleton interface mediated stroke rehabilitation.

Brain-machine interfaces (BMI) based on scalp EEG have the potential to promote cortical plasticity following stroke, which has been shown to improve motor recovery outcomes. However, the efficacy of BMI enabled robotic training for upper-limb recovery is seldom quantified using clinical, EEG-based, and kinematics-based metrics. Further, a movement related neural correlate that can predict the extent of motor recovery still remains elusive, which impedes the clinical translation of BMI-based stroke rehabilitation. To address above knowledge gaps, 10 chronic stroke individuals with stable baseline clinical scores were recruited to participate in 12 therapy sessions involving a BMI enabled powered exoskeleton for elbow training. On average, 132 ± 22 repetitions were performed per participant, per session. BMI accuracy across all sessions and subjects was 79 ± 18% with a false positives rate of 23 ± 20%. Post-training clinical assessments found that FMA for upper extremity and ARAT scores significantly improved over baseline by 3.92 ± 3.73 and 5.35 ± 4.62 points, respectively. Also, 80% participants (7 with moderate-mild impairment, 1 with severe impairment) achieved minimal clinically important difference (MCID: FMA-UE >5.2 or ARAT >5.7) during the course of the study. Kinematic measures indicate that, on average, participants' movements became faster and smoother. Moreover, modulations in movement related cortical potentials, an EEG-based neural correlate measured contralateral to the impaired arm, were significantly correlated with ARAT scores (ρ = 0.72, p < 0.05) and marginally correlated with FMA-UE (ρ = 0.63, p = 0.051). This suggests higher activation of ipsi-lesional hemisphere post-intervention or inhibition of competing contra-lesional hemisphere, which may be evidence of neuroplasticity and cortical reorganization following BMI mediated rehabilitation therapy.

Robot-assisted Therapy for the Upper Limb after Cervical Spinal Cord Injury.

Tetraplegia resulting from cervical injury is the most frequent neurologic category after spinal cord injury and causes substantial disability. The residual strength of partially paralyzed muscles is an important determinant of independence and function in tetraplegia. Small improvements in upper extremity function can make a clinically significant difference in daily activities. Major advances in rehabilitation technologies over the past 2 decades have allowed testing of robotic devices in rehabilitation of motor impairments. This literature assessment provides an overview of robotic-assisted training research for improving arm and hand functions after cervical spinal cord injury.

Vagus Nerve Stimulation Paired With Upper Limb Rehabilitation After Chronic Stroke.

Background and Purpose- We assessed safety, feasibility, and potential effects of vagus nerve stimulation (VNS) paired with rehabilitation for improving arm function after chronic stroke. Methods- We performed a randomized, multisite, double-blinded, sham-controlled pilot study. All participants were implanted with a VNS device and received 6-week in-clinic rehabilitation followed by a home exercise program. Randomization was to active VNS (n=8) or control VNS (n=9) paired with rehabilitation. Outcomes were assessed at days 1, 30, and 90 post-completion of in-clinic therapy. Results- All participants completed the course of therapy. There were 3 serious adverse events related to surgery. Average FMA-UE scores increased 7.6 with active VNS and 5.3 points with control at day 1 post-in-clinic therapy (difference, 2.3 points; CI, -1.8 to 6.4; P=0.20). At day 90, mean scores increased 9.5 points from baseline with active VNS, and the control scores improved by 3.8 (difference, 5.7 points; CI, -1.4 to 11.5; P=0.055). The clinically meaningful response rate of FMA-UE at day 90 was 88% with active VNS and 33% with control VNS ( P<0.05). Conclusions- VNS paired with rehabilitation was acceptably safe and feasible in participants with upper limb motor deficit after chronic ischemic stroke. A pivotal study of this therapy is justified. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT02243020.

White matter changes in corticospinal tract associated with improvement in arm and hand functions in incomplete cervical spinal cord injury: pilot case series.

INTRODUCTION: This is a prospective clinical pilot case series. Improvement of arm and hand functions after spinal cord injury (SCI) is one of the major rehabilitation goals. Electrical stimulation of the primary motor cortex via transcranial direct current stimulation (tDCS) coupled with high-intensity repetitive motor training may have potential to facilitate improvement in motor function in chronic, incomplete cervical SCI. We investigated the relationship between motor recovery and changes in white matter integrity in response to treatment intervention. This study was conducted in The Institute for Rehabilitation and Research Memorial Hermann, Houston, USA. CASE PRESENTATION: Four right-handed adults with chronic, incomplete cervical SCI (age, 36-63 years, American Spinal Injury Association Impairment Scale grade C-D) were enrolled in 10 sessions of anodal tDCS at 2 mA versus sham tDCS followed by 1 h of robotic-assisted arm training. Changes in arm and hand function were measured with Jebsen-Taylor Hand Function Test and Motor Activity Log-Amount of Use. Diffusion tension imaging was used to measure changes in fractional anisotropy (FA) of corticospinal tracts (CSTs). DISCUSSION: After 10 sessions of treatment, we found greater improvement in hand function and hand usage in patients who received active tDCS treatment versus sham treatment. There was an overall positive change in FA values across all patients. We show changes in arm and hand function associated with changes in CST tractographic mapping to quantify the motor system components in chronic incomplete cervical SCI.

Robot-Assisted Training of Arm and Hand Movement Shows Functional Improvements for Incomplete Cervical Spinal Cord Injury.

OBJECTIVE: The aim of the study was to demonstrate the feasibility, tolerability, and effectiveness of robotic-assisted arm training in incomplete chronic tetraplegia. DESIGN: Pretest/posttest/follow-up was conducted. Ten individuals with chronic cervical spinal cord injury were enrolled. Participants performed single degree-of-freedom exercise of upper limbs at an intensity of 3-hr per session for 3 times a week for 4 wks with MAHI Exo-II. Arm and hand function tests (Jebsen-Taylor Hand Function Test, Action Research Arm Test), strength of upper limb (upper limb motor score, grip, and pinch strength), and independence in daily living activities (Spinal Cord Independence Measure II) were performed at baseline, end of training, and 6 mos later. RESULTS: After 12 sessions of training, improvements in arm and hand functions were observed. Jebsen-Taylor Hand Function Test (0.14[0.04]-0.21[0.07] items/sec, P = 0.04), Action Research Arm Test (30.7[3.8]-34.3[4], P = 0.02), American Spinal Injury Association upper limb motor score (31.5[2.3]-34[2.3], P = 0.04) grip (9.7[3.8]-12[4.3] lb, P = 0.02), and pinch strength (4.5[1.1]-5.7[1.2] lb, P = 0.01) resulted in significant increases. Some gains were maintained at 6 mos. No change in Spinal Cord Independence Measure II scores and no adverse events were observed. CONCLUSIONS: Results from this pilot study suggest that repetitive training of arm movements with MAHI Exo-II exoskeleton is safe and has potential to be an adjunct treatment modality in rehabilitation of persons with spinal cord injury with mild to moderate impaired arm functions.

Improving robotic stroke rehabilitation by incorporating neural intent detection: Preliminary results from a clinical trial.

This paper presents the preliminary findings of a multi-year clinical study evaluating the effectiveness of adding a brain-machine interface (BMI) to the MAHI-Exo II, a robotic upper limb exoskeleton, for elbow flexion/extension rehabilitation in chronic stroke survivors. The BMI was used to trigger robot motion when movement intention was detected from subjects' neural signals, thus requiring that subjects be mentally engaged during robotic therapy. The first six subjects to complete the program have shown improvements in both Fugl-Meyer Upper-Extremity scores as well as in kinematic movement quality measures that relate to movement planning, coordination, and control. These results are encouraging and suggest that increasing subject engagement during therapy through the addition of an intent-detecting BMI enhances the effectiveness of standard robotic rehabilitation.

Combined Dextroamphetamine and Transcranial Direct Current Stimulation in Poststroke Aphasia.

There is a growing need for various effective adjunctive treatment options for speech recovery after stroke. A pharmacological agent combined with noninvasive brain stimulation has not been previously reported for poststroke aphasia recovery. In this "proof of concept" study, we aimed to test the safety of a combined intervention consisting of dextroamphetamine, transcranial direct current stimulation, and speech and language therapy in subjects with nonfluent aphasia. Ten subjects with chronic nonfluent aphasia underwent two experiments where they received dextroamphetamine or placebo along with transcranial direct current stimulation and speech and language therapy on two separate days. The Western Aphasia Battery-Revised was used to monitor changes in speech performance. No serious adverse events were observed. There was no significant increase in blood pressure with amphetamine or deterioration in speech and language performance. Western Aphasia Battery-Revised aphasia quotient and language quotient showed a statistically significant increase in the active experiment. Comparison of proportional changes of aphasia quotient and language quotient in active experiment with those in placebo experiment showed significant difference. We showed that the triple combination therapy is safe and implementable and seems to induce positive changes in speech and language performance in the patients with chronic nonfluent aphasia due to stroke.

Transcranial direct current stimulation (tDCS) of the primary motor cortex and robot-assisted arm training in chronic incomplete cervical spinal cord injury: A proof of concept sham-randomized clinical study.

BACKGROUND: After cervical spinal cord injury, current options for treatment of upper extremity motor functions have been limited to traditional approaches. However, there is a substantial need to explore more rigorous alternative treatments to facilitate motor recovery. OBJECTIVE: To demonstrate whether anodal-primary motor cortex (M1) excitability enhancement (with cathodal-supra orbital area) (atDCS) combined with robot-assisted arm training (R-AAT) will provide greater improvement in contralateral arm and hand motor functions compared to sham stimulation (stDCS) and R-AAT in patients with chronic, incomplete cervical spinal cord injury (iCSCI). METHODS: In this parallel-group, double-blinded, randomized and sham-controlled trial, nine participants with chronic iCSCI (AIS C and D level) were randomized to receive 10 sessions of atDCS or stDSC combined with R-AAT. Feasibility and tolerability was assessed with attrition rate and occurrence of adverse events, Changes in arm and hand function were assessed with Jebson Taylor Hand Function Test (JTHFT). Amount of Use Scale of Motor Activity Log (AOU-MAL), American Spinal Injury Association Upper Extremity Motor Score and Modified Ashworth Scale (MAS) at baseline, after treatment, and at two-month follow-up. RESULTS: None of the participants missed a treatment session or dropped-out due to adverse events related to the treatment protocol. Participants tended to perform better in JTHFT and AOU-MAL after treatment. Active group at post-treatment and two-month follow-up demonstrated better arm and hand performance compared to sham group. CONCLUSION: These preliminary findings support that modulating excitatory input of the corticospinal tracts on spinal circuits may be a promising strategy in improving arm and hand functions in persons with incomplete tetraplegia. Further study is needed to explore the underlying mechanisms of recovery.

Design and Optimization of an EEG-Based Brain Machine Interface (BMI) to an Upper-Limb Exoskeleton for Stroke Survivors.

This study demonstrates the feasibility of detecting motor intent from brain activity of chronic stroke patients using an asynchronous electroencephalography (EEG)-based brain machine interface (BMI). Intent was inferred from movement related cortical potentials (MRCPs) measured over an optimized set of EEG electrodes. Successful intent detection triggered the motion of an upper-limb exoskeleton (MAHI Exo-II), to guide movement and to encourage active user participation by providing instantaneous sensory feedback. Several BMI design features were optimized to increase system performance in the presence of single-trial variability of MRCPs in the injured brain: (1) an adaptive time window was used for extracting features during BMI calibration; (2) training data from two consecutive days were pooled for BMI calibration to increase robustness to handle the day-to-day variations typical of EEG, and (3) BMI predictions were gated by residual electromyography (EMG) activity from the impaired arm, to reduce the number of false positives. This patient-specific BMI calibration approach can accommodate a broad spectrum of stroke patients with diverse motor capabilities. Following BMI optimization on day 3, testing of the closed-loop BMI-MAHI exoskeleton, on 4th and 5th days of the study, showed consistent BMI performance with overall mean true positive rate (TPR) = 62.7 ± 21.4% on day 4 and 67.1 ± 14.6% on day 5. The overall false positive rate (FPR) across subjects was 27.74 ± 37.46% on day 4 and 27.5 ± 35.64% on day 5; however for two subjects who had residual motor function and could benefit from the EMG-gated BMI, the mean FPR was quite low (< 10%). On average, motor intent was detected -367 ± 328 ms before movement onset during closed-loop operation. These findings provide evidence that closed-loop EEG-based BMI for stroke patients can be designed and optimized to perform well across multiple days without system recalibration.

Diffusion tensor imaging of the human cerebellar pathways and their interplay with cerebral macrostructure.

Cerebellar white matter (WM) connections to the central nervous system are classified functionally into the Spinocerebellar (SC), vestibulocerebellar (VC), and cerebrocerebellar subdivisions. The SC pathways project from spinal cord to cerebellum, whereas the VC pathways project from vestibular organs of the inner ear. Cerebrocerebellar connections are composed of feed forward and feedback connections between cerebrum and cerebellum including the cortico-ponto-cerebellar (CPC) pathways being of cortical origin and the dentate-rubro-thalamo-cortical (DRTC) pathway being of cerebellar origin. In this study we systematically quantified the whole cerebellar system connections using diffusion tensor magnetic resonance imaging (DT-MRI). Ten right-handed healthy subjects (7 males and 3 females, age range 20-51 years) were studied. DT-MRI data were acquired with a voxel size = 2 mm × 2 mm × 2 mm at a 3.0 Tesla clinical MRI scanner. The DT-MRI data were prepared and analyzed using anatomically-guided deterministic tractography methods to reconstruct the SC, DRTC, fronto-ponto-cerebellar (FPC), parieto-ponto-cerebellar (PPC), temporo-ponto-cerebellar (TPC) and occipito-ponto-cerebellar (OPC). The DTI-attributes or the cerebellar tracts along with their cortical representation (Brodmann areas) were presented in standard Montréal Neurological Institute space. All cerebellar tract volumes were quantified and correlated with volumes of cerebral cortical, subcortical gray matter (GM), cerebral WM and cerebellar GM, and cerebellar WM. On our healthy cohort, the ratio of total cerebellar GM-to-WM was ~3.29 ± 0.24, whereas the ratio of cerebral GM-to-WM was approximately 1.10 ± 0.11. The sum of all cerebellar tract volumes is ~25.8 ± 7.3 mL, or a percentage of 1.6 ± 0.45 of the total intracranial volume (ICV).

Detecting movement intent from scalp EEG in a novel upper limb robotic rehabilitation system for stroke.

Stroke can be a source of significant upper extremity dysfunction and affect the quality of life (QoL) in survivors. In this context, novel rehabilitation approaches employing robotic rehabilitation devices combined with brain-machine interfaces can greatly help in expediting functional recovery in these individuals by actively engaging the user during therapy. However, optimal training conditions and parameters for these novel therapeutic systems are still unknown. Here, we present preliminary findings demonstrating successful movement intent detection from scalp electroencephalography (EEG) during robotic rehabilitation using the MAHI Exo-II in an individual with hemiparesis following stroke. These findings have strong clinical implications for the development of closed-loop brain-machine interfaces to robotic rehabilitation systems.

Robotic training and clinical assessment of upper extremity movements after spinal cord injury: a single case report.

CASE REPORT: A 28-year-old woman, with incomplete spinal cord injury at the C2 level, classified as American Spinal Injury Impairment Scale C (AIS), participated in a robotic rehabilitation program 29 months after injury. Robotic training was provided to both upper extremities using the MAHI Exo-II, an exoskeleton device designed for rehabilitation of the upper limb, for 12 × 3-h sessions over 4 weeks. Training involved elbow flexion/extension, forearm supination/pronation, wrist flexion/extension, and radial/ulnar deviation. RESULTS: Outcome measures were Action Research Arm Test, Jebsen-Taylor Hand Function Test, and AIS-upper extremity motor score. Safety measures included fatigue, pain and discomfort level using a 5-point rating scale. Following training, improvements were observed in the left arm and hand function, whereas the right arm and hand function showed no improvement in any of the functional outcome measures. No excessive pain, discomfort or fatigue was reported. CONCLUSION: Data from one subject demonstrate valuable information on the feasibility, safety and effectiveness of robotic-assisted training of upper-extremity motor functions after incomplete spinal cord injury.

Normalized movement quality measures for therapeutic robots strongly correlate with clinical motor impairment measures.

In this paper, we analyze the correlations between four clinical measures (Fugl-Meyer upper extremity scale, Motor Activity Log, Action Research Arm Test, and Jebsen-Taylor Hand Function Test) and four robotic measures (smoothness of movement, trajectory error, average number of target hits per minute, and mean tangential speed), used to assess motor recovery. Data were gathered as part of a hybrid robotic and traditional upper extremity rehabilitation program for nine stroke patients. Smoothness of movement and trajectory error, temporally and spatially normalized measures of movement quality defined for point-to-point movements, were found to have significant moderate to strong correlations with all four of the clinical measures. The strong correlations suggest that smoothness of movement and trajectory error may be used to compare outcomes of different rehabilitation protocols and devices effectively, provide improved resolution for tracking patient progress compared to only pre- and post-treatment measurements, enable accurate adaptation of therapy based on patient progress, and deliver immediate and useful feedback to the patient and therapist.

A tele-assessment system for monitoring treatment effects in subjects with spinal cord injury.

We developed a method for remote measurement of balance and leg force in patients with spinal cord injury (SCI). In a group of 21 patients, both telemedicine and conventional clinical assessments were conducted at baseline and six months later. Telemedicine assessments were successfully acquired and transmitted at first attempt. The time required to set up the telemedicine equipment, position the subject, perform the measurements, and then send the data to the university laboratory was approximately 30 minutes. After six months, several motor and sensory functions showed significant changes. There were significant correlations between changes in remotely-measured leg force and changes in several of the American Spinal Injury Association (ASIA) sensory and motor scores. Changes in balance did not show any significant correlations with changes in the ASIA scores. Intra-rater reliability was better than inter-rater reliability. Use of telemedicine to remotely monitor changes in patients with SCI appears promising.