Brain-controlled functional electrical stimulation for lower-limb motor recovery in stroke survivors

Abstract

Despite the prevalence of stroke-induced gait impairment due to foot drop, current rehabilitative practices to improve gait function are limited, and orthoses can be uncomfortable and do not provide long-lasting benefits. Therefore, novel modalities that may facilitate lasting neurological and functional improvements, such as brain-computer interfaces (BCIs), have been explored. In this article, we assess the feasibility of BCI-controlled functional electrical stimulation (FES) as a novel physiotherapy for post-stroke foot drop. Three chronic stroke survivors with foot drop received three, 1-hour sessions of therapy during 1 week. All subjects were able to purposefully operate the BCI-FES system in real time. Furthermore, the salient electroencephalographic (EEG) features used for classification by the data-driven methodology were determined to be physiologically relevant. Over the course of this short therapy, the subjects’ dorsiflexion active range of motion (AROM) improved by 3°, 4°, and 8°, respectively. These results indicate that chronic stroke survivors can operate the BCI-FES system, and that BCI-FES intervention may promote functional improvements.

Brain-controlled functional electrical stimulation therapy for gait rehabilitation after stroke: a safety study

“…The subjects averaged 8.4 BCI-FES runs per session. Almost 95 % of the total number of BCI-FES runs across all subjects and sessions were at a significant performance level (α = 0.01) compared to Monte-Carlo simulation (details in [ 24 ]; see Table 1 ).…”

“…However, compliance with these instructions was not formally measured. The training data were recorded at 256 Hz with a NeXus-32 bioamplifier (Mind Media, Herten, Netherlands) to generate a session-specific decoding model for online operation (methods in [ 24 – 26 ]). This model could distinguish idling from dorsiflexion using EEG.…”

“…Each run consisted of 10 alternating, contiguous 10-s-long dorsiflex/relax cues, during which the BCI-FES system detected the subjects’ intention to dorsiflex (or relax) from EEG and correspondingly provided (or withheld) stimulation. The accuracy of BCI operation was calculated as the percentage of correctly determined BCI-states at a rate of four decisions per second (decisions were calculated every 0.25 s based on the most recent 0.75 s of EEG data [ 24 ]).…”

Therapeutic effects of brain-computer interface-controlled functional electrical stimulation training on balance and gait performance for stroke

“…They suggested that the BCI-FES therapy is a safe and new gait rehabilitation option for stroke patients with severe impairments. [ 32 , 33 ] Young and colleagues also reported real-time feedback provided by using a BCI device that can be used to reward the production of certain patterns of neural activity over others. [ 8 ] The BCI-FES treatment also involves repeated attempts at functional activities to actively modulate brain activity during imagined movement, resulting in reward-based and use-dependent reinforcements and induction of neuroplastic change in the disrupted motor system.…”

Brain imaging of locomotion in neurological conditions

“…These results are summarized in Table 2b. There are few studies investigating EEG in post-stroke patients, most of them aiming to evaluate EEG-based brain-computer interfaces (BCIs) in rehabilitation, for example detection of movement intention or stopping [131,179]. Other studies aimed to determine the best algorithms to detect FOG for example are excluded from this review.…”