Decoding Imagined Movement in People with Multiple Sclerosis for Brain-Computer Interface Translation

TL;DR

This study demonstrates that it is feasible to decode imagined limb movements in people with Multiple Sclerosis using EEG, achieving over 70% accuracy, which could enhance BCI-based rehabilitation approaches.

Contribution

It is the first to show successful decoding of imagined movements in MS patients, expanding BCI research beyond neurotypical controls and highlighting potential for MS rehabilitation.

Findings

MS patients achieved >70% accuracy in imagined movement classification

Decodable signals were found in alpha and beta frequency bands

No significant difference between limb weakness/paralysis and controls

Abstract

Multiple Sclerosis (MS) is a heterogeneous autoimmune-mediated disorder affecting the central nervous system, commonly manifesting as fatigue and progressive limb impairment. This can significantly impact quality of life due to weakness or paralysis in the upper and lower limbs. A Brain-Computer Interface (BCI) aims to restore quality of life through control of an external device, such as a wheelchair. However, the limited BCI research in people with MS is insufficient. The current study aims to expand on the current MS-BCI literature by highlighting the feasibility of decoding MS imagined movement. We collected electroencephalography (EEG) data from eight participants with various symptoms of MS and ten neurotypical control participants. Participants made imagined movements of the hands and feet as directed by a go no-go protocol. Binary regularised linear discriminant analysis was used to classify imagined movement at individual time-frequency points. The frequency bands which provided the maximal accuracy, and the associated latency, were compared. In all MS participants, the classification algorithm achieved above 70% accuracy in at least one imagined movement vs. rest classification and most movement vs. movement classifications. There was no significant difference between classification of limbs with weakness or paralysis to neurotypical controls. Both the MS and control groups possessed decodable information within the alpha (7-13 Hz) and beta (16-30 Hz) bands at similar latency. This study is the first to demonstrate the feasibility of decoding imagined movements in people with MS. As an alternative to the P300 response, motor imagery-based control of a BCI may also be combined with existing motor imagery therapy to supplement MS rehabilitation. These promising results merit further long term BCI studies to investigate the effect of MS progression on classification performance.