Electroencephalography as a Biomarker for Functional Recovery in Spinal Cord Injury Patients

• Published in: Frontiers in human neuroscience 2021-04, Vol.15, p.548558-548558
• Main Authors: Simis, Marcel, Doruk Camsari, Deniz, Imamura, Marta, Filippo, Thais Raquel Martins, Rubio De Souza, Daniel, Battistella, Linamara Rizzo, Fregni, Felipe
• Format: Article
• Language: English
• Subjects: Balance; Biomarkers; EEG; Electroencephalography; Gait; Medical imaging; Neuroplasticity; Neuroscience; Ostomy; Patients; Recovery of function; Rehabilitation; Spinal cord injuries; spinal cord injury
• ISSN: 1662-5161; 1662-5161
• DOI: 10.3389/fnhum.2021.548558

Functional changes after spinal cord injury (SCI) are related to changes in cortical plasticity. These changes can be measured with electroencephalography (EEG) and has potential to be used as a clinical biomarker. In this longitudinal study participants underwent a total of 30 sessions of robotic-assisted gait training (RAGT) over a course of 6 weeks. The duration of each session was 30 min. Resting state EEG was recorded before and after 30-session rehabilitation therapy. To measure gait, we used the Walking Index for Spinal Cord Injury Scale, 10-Meter- Walking Test, Timed-Up-and-Go, and 6-Min-Walking Test. Balance was measured using Berg Balance Scale. Fifteen participants with incomplete SCI who had AIS C or D injuries based on American Spinal Cord Injury Association Impairment Scale classification were included in this study. Mean age was 35.7 years (range 17-51) and the mean time since injury was 17.08 (range 4-37) months. All participants showed clinical improvement with the rehabilitation program. EEG data revealed that high beta EEG activity in the central area had a negative correlation with gait ( = 0.049; β coefficient: -0.351; and adj- : 0.23) and balance ( = 0.043; β coefficient: -0.158; and adj- :0.24) measured at baseline, in a way that greater high beta EEG power was related to worse clinical function at baseline. Moreover, improvement in gait and balance had negative correlations with the change in alpha/theta ratio in the parietal area (Gait: = 0.049; β coefficient: -0.351; adj- : 0.23; Balance: = 0.043; β coefficient: -0.158; and adj- : 0.24). In SCI, functional impairment and subsequent improvement following rehabilitation therapy with RAGT correlated with the change in cortical activity measured by EEG. Our results suggest that EEG alpha/theta ratio may be a potential surrogate marker of functional improvement during rehabilitation. Future studies are necessary to improve and validate these findings as a neurophysiological biomarker for SCI rehabilitation.