Contralesional Brain-Computer Interface Control of a Powered Exoskeleton for Motor Recovery in Chronic Stroke Survivors.

BACKGROUND AND PURPOSE: There are few effective therapies to achieve functional recovery from motor-related disabilities affecting the upper limb after stroke. This feasibility study tested whether a powered exoskeleton driven by a brain-computer interface (BCI), using neural activity from the unaffected cortical hemisphere, could affect motor recovery in chronic hemiparetic stroke survivors. This novel system was designed and configured for a home-based setting to test the feasibility of BCI-driven neurorehabilitation in outpatient environments. METHODS: Ten chronic hemiparetic stroke survivors with moderate-to-severe upper-limb motor impairment (mean Action Research Arm Test=13.4) used a powered exoskeleton that opened and closed the affected hand using spectral power from electroencephalographic signals from the unaffected hemisphere associated with imagined hand movements of the paretic limb. Patients used the system at home for 12 weeks. Motor function was evaluated before, during, and after the treatment. RESULTS: Across patients, our BCI-driven approach resulted in a statistically significant average increase of 6.2 points in the Action Research Arm Test. This behavioral improvement significantly correlated with improvements in BCI control. Secondary outcomes of grasp strength, Motricity Index, and the Canadian Occupational Performance Measure also significantly improved. CONCLUSIONS: The findings demonstrate the therapeutic potential of a BCI-driven neurorehabilitation approach using the unaffected hemisphere in this uncontrolled sample of chronic stroke survivors. They also demonstrate that BCI-driven neurorehabilitation can be effectively delivered in the home environment, thus increasing the probability of future clinical translation. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02552368.

Cognitive impairments and mood disruptions negatively impact instrumental activities of daily living performance in the first three months after a first stroke.

BACKGROUND: Cognition and mood play crucial roles in post-stroke recovery; however, the stroke literature is unclear as to how impairments in both domains influence performance of instrumental activities of daily living (IADL). OBJECTIVE: (1) Evaluate the extent to which mood and cognition at two weeks post-stroke predict performance three months post-stroke. (2) Assess performance differences in patients with impairments in both cognition and mood to patients with impairments in either cognition or mood. METHODS: Inpatients with a first-ever ischemic or hemorrhagic stroke were assessed at 2 weeks (n = 52) and at 3 months (n = 41) post-stroke. Patients completed a battery of neuropsychological tests, self-report measures and performance-based tests. Cognitive impairments and mood disruptions were assessed at 2 weeks and three months and IADL performance, as assessed by the Executive Function Performance Test, was evaluated at three months. RESULTS: Complete data from the 41 patients assessed at both time points were analyzed. Regression analysis showed that composite cognition and composite mood variables at two weeks post-stroke predicted 48% of the variance in IADL performance at three months (F3,37 = 12.04; adjusted R(2) = 0.48, P < 0.001). Statistically significant differences were found in performance scores for patients with a single impairment (M = 7.86, SD = 7.81) and for those with impairments in both mood and cognition (M = 19.2, SD = 13.2) (t(39) = - 3.41, P = 0.008). CONCLUSION: The results of this study suggest that cognitive and mood impairments at two weeks post-stroke are important predictors of performance in complex activities required for full independence at home and should be routinely assessed in stroke rehabilitation.

Clinician adherence to a standardized assessment battery across settings and disciplines in a poststroke rehabilitation population.

OBJECTIVES: (1) To examine clinician adherence to a standardized assessment battery across settings (acute hospital, inpatient rehabilitation facilities [IRFs], outpatient facility), professional disciplines (physical therapy [PT], occupational therapy, speech-language pathology), and time of assessment (admission, discharge/monthly), and (2) to evaluate how specific implementation events affected adherence. DESIGN: Retrospective cohort study. SETTING: Acute hospital, IRF, and outpatient facility with approximately 118 clinicians (physical therapists, occupational therapists, speech-language pathologists). PARTICIPANTS: Participants (N=2194) with stroke who were admitted to at least 1 of the above settings. All persons with stroke underwent standardized clinical assessments. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Adherence to Brain Recovery Core assessment battery across settings, professional disciplines, and time. Visual inspections of 17 months of time-series data were conducted to see if the events (eg, staff meetings) increased adherence ≥5% and if so, how long the increase lasted. RESULTS: Median adherence ranged from .52 to .88 across all settings and professional disciplines. Both the acute hospital and the IRF had higher adherence than the outpatient setting (P≤.001), with PT having the highest adherence across all 3 disciplines (P<.004). Of the 25 events conducted across the 17-month period to improve adherence, 10 (40%) resulted in a ≥5% increase in adherence the following month, with 6 services (60%) maintaining their increased level of adherence for at least 1 additional month. CONCLUSIONS: Actual adherence to a standardized assessment battery in clinical practice varied across settings, disciplines, and time. Specific events increased adherence 40% of the time with those gains maintained for >1 month 60% of the time.

Prediction of discharge walking ability from initial assessment in a stroke inpatient rehabilitation facility population.

OBJECTIVES: To (1) determine which clinical assessments at admission to an inpatient rehabilitation facility (IRF) most simply predict discharge walking ability, and (2) identify a clinical decision rule to differentiate household versus community ambulators at discharge from an IRF. DESIGN: Retrospective cohort study. SETTING: IRF. PARTICIPANTS: Two samples of participants (n=110 and 159) admitted with stroke. INTERVENTIONS: A multiple regression determined which variables obtained at admission (age, time from stroke to assessment, Motricity Index, somatosensation, Modified Ashworth Scale, FIM, Berg Balance Scale, 10-m walk speed) could most simply predict discharge walking ability (10-m walk speed). A logistic regression determined the likelihood of a participant achieving household (<0.4m/s) versus community (≥0.4-0.8m/s; >0.8m/s) ambulation at the time of discharge. Validity of the results was evaluated on a second sample of participants. MAIN OUTCOME MEASURE: Discharge 10-m walk speed. RESULTS: Admission Berg Balance Scale and FIM walk item scores explained most of the variance in discharge walk speed. The odds ratio of achieving only household ambulation at discharge was 20 (95% confidence interval [CI], 6-63) for sample 1 and 32 (95% CI, 10-96) for sample 2 when the combination of having a Berg Balance Scale score of ≤20 and a FIM walk item score of 1 or 2 was present. CONCLUSIONS: A Berg Balance Scale score of ≤20 and a FIM walk item score of 1 or 2 at admission indicates that a person with stroke is highly likely to only achieve household ambulation speeds at discharge from an IRF.

Effect of a foot-drop stimulator and ankle-foot orthosis on walking performance after stroke: a multicenter randomized controlled trial.

BACKGROUND: Studies have demonstrated the efficacy of functional electrical stimulation in the management of foot drop after stroke. OBJECTIVE: To compare changes in walking performance with the WalkAide (WA) foot-drop stimulator and a conventional ankle-foot orthosis (AFO). METHODS: Individuals with stroke within the previous 12 months and residual foot drop were enrolled in a multicenter, randomized controlled, crossover trial. Subjects were assigned to 1 of 3 parallel arms for 12 weeks (6 weeks/device): arm 1 (WA-AFO), n = 38; arm 2 (AFO-WA), n = 31; arm 3 (AFO-AFO), n = 24. Primary outcomes were walking speed and Physiological Cost Index for the Figure-of-8 walking test. Secondary measures included 10-m walking speed and perceived safety during this test, general mobility, and device preference for arms 1 and 2 for continued use. Walking tests were performed with (On) and without a device (Off) at 0, 3, 6, 9, and 12 weeks. RESULTS: Both WA and AFO had significant orthotic (On-Off difference), therapeutic (change over time when Off), and combined (change over time On vs baseline Off) effects on walking speed. An AFO also had a significant orthotic effect on Physiological Cost Index. The WA had a higher, but not significantly different therapeutic effect on speed than an AFO, whereas an AFO had a greater orthotic effect than the WA (significant at 12 weeks). Combined effects on speed after 6 weeks did not differ between devices. Users felt as safe with the WA as with an AFO, but significantly more users preferred the WA. CONCLUSIONS: Both devices produce equivalent functional gains.