Is Resting-State EEG Longitudinally Associated With Recovery of Clinical Neurological Impairments Early Poststroke? A Prospective Cohort Study.

Background. The time course of cortical activation and its relation with clinical measures may elucidate mechanisms underlying spontaneous neurobiological recovery after stroke. Objective. We aimed to investigate (1) the time course of cortical activation as revealed by EEG-based spectral characteristics during awake rest and (2) the development of these spectral characteristics in relation to global neurological and upper-limb motor recovery in the first 6 months poststroke. Methods. Resting-state EEG was measured serially in 41 patients after a first-ever ischemic stroke, within 3 and at 5, 12, and 26 weeks poststroke. We computed the brain symmetry index (BSI) and directional BSI (BSIdir) over different frequency bands (1-25 Hz, delta, theta) and delta/alpha ratio (DAR). The National Institutes of Health Stroke Scale (NIHSS) and Fugl-Meyer motor assessment of the upper extremity (FM-UE) were determined as clinical reflections of spontaneous neurobiological recovery. Longitudinal changes in spectral characteristics and within- and between-subject associations with NIHSS and FM-UE were analyzed with linear mixed models. Results. Spectral characteristics showed a gradual normalization over time, within and beyond 12 weeks poststroke. Significant within- and between-subject associations with NIHSS were found for DAR of the affected hemisphere (DARAH) and BSIdirdelta. BSIdirdelta also demonstrated significant within- and between-subject associations with FM-UE. Conclusions. Changes in spectral characteristics are not restricted to the time window of recovery of clinical neurological impairments. The present study suggests that decreasing DARAH and BSIdirdelta reflect improvement of global neurological impairments, whereas BSIdirdelta was also specifically associated with upper-limb motor recovery early poststroke.

Tolerance and effectiveness of a new dynamic hand-wrist orthosis in chronic stroke patients.

PURPOSE: To evaluate tolerance of a new dynamic hand-wrist orthosis and effectiveness on the prevention of progressive wrist contracture and spasticity after stroke. METHOD: Chronic stroke patients (N = 6) with upper limb spasticity, who had not been able to endure a static orthosis, were provided with a custom-made dynamic orthosis. Tolerance of the orthosis was evaluated by the daily wearing time, and self-reported pain and spasticity. Effectiveness was measured by contracture of wrist and finger flexor muscles, upper limb spasticity and use of spasticity treatment. Outcome measures were collected at time of fitting of the dynamic orthosis (baseline) and after three and six months. RESULTS: Five patients could endure the dynamic orthosis without discomfort for 6 hours daily during the 6-month period. Self-reported spasticity and pain decreased significantly (p < 0.05) compared to wearing the static orthosis. In comparison to baseline, the maximum passive wrist extension increased significantly from -29° to -12° (p < 0.05). Although, no significant change in spasticity was measured, the use of Botulinum Toxin injections decreased for two patients. CONCLUSIONS: The majority of the included chronic stroke patients tolerated the new dynamic orthosis for at least 6 hours daily and the use significantly reduced wrist contractures in a 6-month period.