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Background.: Altered dynamic functional connectivity has been associated with motor impairments in the acute phase post-stroke. Its association with somatosensory impairments in the early sub-acute phase remains unexplored., Objective.: To investigate altered dynamic functional connectivity associated with somatosensory impairments in the early sub-acute phase post-stroke., Methods.: We collected resting state magnetic resonance imaging and clinical somatosensory function of the upper limb of 20 subacute stroke patients and 16 healthy controls (HC). A sliding-window approach was used to identify 3 connectivity states based on the estimated dynamic functional connectivity of sensorimotor related networks. Network components were subdivided into 3 domains: cortical and subcortical sensorimotor, as well as cognitive control network. Between-group differences were investigated using independent t -tests and Mann-Whitney- U tests. Analyzes were performed with correction for age, head motion and time post-stroke and corrected for multiple comparisons., Results.: Stroke patients spent significantly less time in a weakly connected network state (state 3; dwell time: p state3  = 0.003, mean stroke  = 53.02, SD stroke  = 53.13; mean HC  = 118.92, SD HC  = 72.84), and stayed shorter but more time intervals in a highly connected intra-domain network state (state 1; fraction time: p state 1  < 0.001, mean stroke  = 0.46, SD stroke  = 0.26; mean HC  = 0.26, SD HC  = 0.21) compared to HC. After 8 weeks of therapy, improvements in wrist proprioception were moderately associated with decreases in dwell and fraction times toward a more normalized pattern., Conclusion.: Changes in temporal properties of large-scale network interactions are present in the early rehabilitation phase post-stroke and could indicate enhanced neural plasticity. These findings could augment the understanding of cerebral reorganization after loss of neural tissue specialized in somatosensory functions.

Abstract Purpose Methods and materials Results Conclusions \nIMPLICATIONS FOR REHABILITATION After stroke, upper limb somatosensation can be impaired which affects motor control. Vision is often used to compensate for this. A clinical assessment which assesses the combined sensorimotor function in the absence of vision would be beneficial in studies targeting sensorimotor improvement.We adapted the Action Research Arm Test (ARAT) to be performed without vision and called this modified version the sensorimotor ARAT (sARAT). Sixty healthy participants and 22 participants with chronic stroke performed the ARAT, sARAT, Fugl-Meyer upper extremity assessment (FM-UE) and Erasmus modified Nottingham sensory assessment (EmNSA). Discriminative validity of sARAT was evaluated by comparing performance between healthy participants and participants with chronic stroke. Convergent validity was evaluated by correlating sARAT with FM-UE and EmNSA.Participants with stroke performed worse on the sARAT compared to healthy participants (p < 0.001), with median scores of 52 (IQR 32-57) and 57 (IQR 57-57), respectively. The sARAT showed high correlations with FM-UE and EmNSA (r = 0.80-0.90).The sARAT shows good discriminative and convergent validity in people with chronic stroke. It allows a quick assessment of the combined upper limb sensorimotor function, by performing the well-known ARAT with the eyes closed. The sensorimotor adaptation of the Action Research Arm Test (sARAT) is a clinical assessment of upper limb activity which is performed with the eyes closed. Combining the gold standard ARAT with the sensorimotor adaptation sARAT can inform about the influence of somatosensory impairments on upper limb activity in stroke survivors when vision is blocked. The sARAT shows good discriminative and convergent validity in persons with chronic stroke. The sensorimotor adaptation of the Action Research Arm Test (sARAT) is a clinical assessment of upper limb activity which is performed with the eyes closed.Combining the gold standard ARAT with the sensorimotor adaptation sARAT can inform about the influence of somatosensory impairments on upper limb activity in stroke survivors when vision is blocked.The sARAT shows good discriminative and convergent validity in persons with chronic stroke. [ABSTRACT FROM AUTHOR]

Upper limb sensory processing deficits are common in the chronic phase after stroke and are associated with decreased functional performance. Yet, current clinical assessments show suboptimal psychometric properties. Our aim was to develop and validate a novel robot-based assessment of sensory processing. We assessed 60 healthy participants and 20 participants with chronic stroke using existing clinical and robot-based assessments of sensorimotor function. In addition, sensory processing was evaluated with a new evaluation protocol, using a bimanual planar robot, through passive or active exploration, reproduction and identification of 15 geometrical shapes. The discriminative validity of this novel assessment was evaluated by comparing the performance between healthy participants and participants with stroke, and the convergent validity was evaluated by calculating the correlation coefficients with existing assessments for people with stroke. The results showed that participants with stroke showed a significantly worse sensory processing ability than healthy participants (passive condition: p = 0.028, Hedges' g = 0.58; active condition: p = 0.012, Hedges' g = 0.73), as shown by the less accurate reproduction and identification of shapes. The novel assessment showed moderate to high correlations with the tactile discrimination test: a sensitive clinical assessment of sensory processing (r = 0.52–0.71). We conclude that the novel robot-based sensory processing assessment shows good discriminant and convergent validity for use in participants with chronic stroke. [ABSTRACT FROM AUTHOR]

Background: Somatosensory function plays an important role in motor learning. More than half of the stroke patients have somatosensory impairments in the upper limb, which could hamper recovery. Question: Is sensorimotor upper limb (UL) therapy of more benefit for motor and somatosensory outcome than motor therapy? Design: Randomized assessor- blinded multicenter controlled trial with block randomization stratified for neglect, severity of motor impairment, and type of stroke. Participants: 40 first-ever stroke patients with UL sensorimotor impairments admitted to the rehabilitation center. Intervention: Both groups received 16 h of additional therapy over 4 weeks consisting of sensorimotor (N = 22) or motor (N = 18) UL therapy. Outcome measures: Action Research Arm test (ARAT) as primary outcome, and other motor and somatosensory measures were assessed at baseline, post-intervention and after 4 weeks follow-up. Results: No significant between-group differences were found for change scores in ARAT or any somatosensory measure between the three time points. For UL impairment (Fugl-Meyer assessment), a significant greater improvement was found for the motor group compared to the sensorimotor group from baseline to post-intervention [mean (SD) improvement 14.65 (2.19) vs. 5.99 (2.06); p = 0.01] and from baseline to follow-up [17.38 (2.37) vs. 6.75 (2.29); p = 0.003]. Conclusion: UL motor therapy may improve motor impairment more than UL sensorimotor therapy in patients with sensorimotor impairments in the early rehabilitation phase post stroke. For these patients, integrated sensorimotor therapy may not improve somatosensory function and may be less effective for motor recovery. Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT03236376. [ABSTRACT FROM AUTHOR]