Abstract P219: Somatosensory Impairments at Baseline Limit Motor Recovery in Stroke Survivors Using a BCI

Abstract

Objective: This study is part of a clinical trial designed to test the efficacy of an EEG-based BCI intervention for upper extremity motor rehabilitation in stroke survivors. The analyses presented here focus on the effectiveness of BCI intervention as a function of somatosensory integrity. Introduction: Human motor control requires integration of sensory and motor signals in the generation of motor commands. Stroke lesions often result in sensorimotor impairments and survivors may require rehabilitation to regain motor function and capacity. Stroke affects individuals differentially, based on a range of factors, including, but not limited to, lesion location and volume. Such factors may restrain recovery potential. Hypothesis: We tested the hypothesis that stroke survivors with measurable somatosensory impairments realize the same amount of motor recovery as those participants without somatosensory impairments. Methods: N= 23 stroke survivors participated in up to 30 hours of BCI intervention (13.8 ±1.3, mean + SD) for upper extremity rehabilitation, as measured by the ARAT. Participants were grouped post-hoc on presence or absence of somatosensory impairments, as measured by the NIHSS subdomains of Sensory (i.e. cutaneous), and Motor Arm (i.e. proprioceptive) and their group means compared. Results: The hypothesis was not confirmed. Mean ARAT scores at completion and follow up differed between groups (Cutaneous loss: ARAT mean change at completion: 0.9 ± 2.23, p= 0.234; ARAT mean change at follow-up: 1.20 ± 2.860, p = 0.217), (No Cutaneous loss: ARAT mean change at completion: 2.15 ± 6.34, p= 0.244; ARAT mean change at follow-up: 4.39 ± 6.41, p= 0.0297) (Proprioceptive loss: ARAT mean change at completion: 0.867 ± 3.66, p= 0.375, ARAT mean change at follow-up: 2.47 ± 5.38, p= 0.097), (No Proprioceptive loss: ARAT mean change at completion: 3 ± 6.80, p= 0.252, ARAT mean change at follow-up: 4 ± 5.42, p= 0.075). Conclusions: These results suggest that BCI intervention is more effective at delivering motor improvements in participants with less somatosensory impairments. These results are consistent with the view that somatosensory system integrity may be key to BCI motor rehabilitation of brain injuries following stroke.