Introduction The purpose of this study was to characterize resting‐state cortical networks in chronic stroke survivors using electroencephalography (EEG). Methods Electroencephalography data were collected from 14 chronic stroke and 11 neurologically intact participants while they were in a relaxed, resting state. EEG power was normalized to reduce bias and used as an indicator of network activity. Correlations of orthogonalized EEG activity were used as a measure of functional connectivity between cortical regions. Results We found reduced cortical activity and connectivity in the alpha (p < .05; p = .05) and beta (p < .05; p = .03) bands after stroke while connectivity in the gamma (p = .031) band increased. Asymmetries, driven by a reduction in the lesioned hemisphere, were also noted in cortical activity (p = .001) after stroke. Conclusion These findings suggest that stroke lesions cause a network alteration to more local (higher frequency), asymmetric networks. Understanding changes in cortical networks after stroke could be combined with controllability models to identify (and target) alternate brain network states that reduce functional impairment.

Whereas numerous motor control theories describe the control of arm trajectory during reach, the control of stabilization in a constant arm position (i.e., visuomotor control of arm posture) is less clear. Three potential mechanisms have been proposed for visuomotor control of arm posture: 1) increased impedance of the arm through co-contraction of antagonistic muscles, 2) corrective muscle activity via spinal/supraspinal reflex circuits, and/or 3) intermittent voluntary corrections to errors in position. We examined the cortical mechanisms of visuomotor control of arm posture and tested the hypothesis that cortical error networks contribute to arm stabilization. We collected electroencephalography (EEG) data from 10 young healthy participants across four experimental planar movement tasks. We examined brain activity associated with intermittent voluntary corrections of position error and antagonist co-contraction during stabilization. EEG beta-band (13–26 Hz) power fluctuations were used as indicators of brain activity, and coherence between EEG electrodes was used as a measure of functional connectivity between brain regions. Cortical activity in the sensory, motor, and visual areas during arm stabilization was similar to activity during volitional arm movements and was larger than activity during co-contraction of the arm. However, cortical connectivity between the sensorimotor and visual regions was higher during arm stabilization compared with volitional arm movements and co-contraction of the arm. The difference in cortical activity and connectivity between tasks might be attributed to an underlying visuomotor error network used to update motor commands for visuomotor control of arm posture. NEW & NOTEWORTHY We examined cortical activity and connectivity during control of stabilization in a constant arm position (i.e., visuomotor control of arm posture). Our findings provide evidence for cortical involvement during control of stabilization in a constant arm position. A visuomotor error network appears to be active and may update motor commands for visuomotor control of arm posture.

Purpose/Hypothesis: The purposes of this study were to compare gait and balance performance of a patient with chronic lower extremity spasticity and other motor deficits secondary to stroke prior to botulinum toxin, following botulinum toxin, and with combined botulinum toxin and body weight supported treadmill training (BWSTT), and to determine if those outcomes were maintained across time. Number of Subjects: A single-subject design (A/B1/B2/Delayed Post-Test) was used. Materials/Methods: Four weeks following lower extremity botulinum toxin injections (B1), intense BWSTT three sessions per week for eight weeks was added to the intervention (B2). The dependent variables, measured weekly, included: Berg balance scale, timed-up-and-go, 10-meter walk test and 6-minute walk test. The stroke impact scale (SIS) was measured one time during A and the Delayed Post-Test. Results: Each dependent variable showed significant improvement from A to B1, and performance remained improved through B2 phase and at the time of the Delayed Post-Test. Clinically significant differences were found in the mobility and handicap dimensions of the SIS. Conclusions: For this participant, BWSTT did not enhance outcomes beyond those observed with botulinum toxin injections alone. Improvements that were made during intervention were maintained at the Delayed Post-Test. Clinical Relevance: Previous literature has indicated limited functional carryover following botulinum toxin injections to reduce spasticity. The participant in this study enhanced functional outcomes following botulinum toxin injections only and was able to maintain those improvements during and after intense task-specific gait training.Purpose/Hypothesis: The two studies reported here evaluate the effectiveness of electrical stimulation in the management of long standing stroke impairments in a home-based exercise program. The two targeted impairments are chronic shoulder subluxation and wrist/finger contractures. Both studies compared exercise through implanted microstimulators (BIONs) with a standard surface stimulation program. Number of Subjects: Fourteen individuals with chronic shoulder subluxation due to stroke and 16 persons with wrist or finger contractures following stroke have participated in a 6 week stimulation program, either using surface electrodes or implanted microstimulators (BIONs). The average time from the stroke was 35 months. Materials/Methods: Following consent, subjects were randomized into either surface or implant stimulation groups. Following instruction regarding the appropriate equipment, subjects exercised daily at home for two or three 30 minute stimulation sessions. The exercise program continued for 6 weeks. Assessments of passive wrist and finger range of motion, or shoulder subluxation through xray, were done before and after the exercise programs. After 6 weeks of follow-up, individuals with implants were provided support for continued use. Individuals who had been compliant with surface stimulation were offered the continued use of the s...