Stroke & recovery
Does motor-imagery-contingent BCI feedback help chronic stroke?
Open access · cc by · source: Europe PMC
In 25 people with chronic stroke, 4 weeks of BCI-FES with MI-contingent feedback improved wrist extensor strength more than matched MI-independent (sham-like) feedback.
How this study connects
Role on claims
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The primary composite outcome did not move even though the targeted measure and connectivity did.
Behavioural gains are narrower than the connectivity changes accompanying them. Motor-imagery-contingent BCI feedback improved wrist extension strength (adjusted mean difference 0.52, 95% CI 0.03–1.00) and raised affected-hemisphere connectivity correlating with that measure, but did not improve the total Fugl-Meyer score over the control arm.
Evidence for the claim as stated.
The mechanistic account and the human evidence sit at levels that cannot confirm one another. Pericyte PDGFRβ signalling was necessary for astrogliosis, remyelination and functional recovery in mice after permanent occlusion, whereas the human trials measure connectivity, force and clinical scales and identify no cellular mechanism at all.
Evidence for the claim as stated.
Open questions
Tensions this paper is part of
From concept pages' “where studies disagree.” Disagreement means the same question; scope means different assays, populations, or outcomes.
The mechanistic account and the human evidence sit at levels that cannot confirm one another. Pericyte PDGFRβ signalling was necessary for astrogliosis, remyelination and functional recovery in mice after permanent occlusion, whereas the human trials measure connectivity, force and clinical scales and identify no cellular mechanism at all.
Study at a glance
- Design
- RCT — Double-blinded, parallel-group RCT; 1:1 MI-contingent vs MI-independent BCI-FES; assessors and participants blinded.
- N
- N=25 · 27 chronic-stroke participants enrolled; 2 dropouts; 12 contingent vs 13 independent analyzed.
- Population
- Adults with first-ever chronic hemiplegic stroke (≥6 months), wrist extensor MRC ≤2.
- Outcome
- MRC-WE and AROM-WE plus resting-state EEG connectivity after 20 sessions over 4 weeks.
Structured fields used in claim comparison tables when every cited study has a complete layer.
Inspect source passages
Does motor-imagery-contingent BCI feedback help chronic stroke?
These passages occur verbatim in the stored paper text. They support the points listed below; they do not verify every statement in the explanation.
27 enrolled; 25 analyzed (12 vs 13).
This study included a total of 27 participants with chronic stroke.
MRC-WE mean difference 0.52 (95% CI 0.03–1.00, p=0.036).
mean difference = 0.52, 95% CI = 0.03–1.00, p = 0.036
Key findings
MRC-WE improved more with contingent feedback (adjusted mean difference 0.52, 95% CI 0.03–1.00, p=0.036). Within contingent, AROM-WE rose by week 4 (p=0.019). Affected-hemisphere connectivity increased and correlated with MRC-WE and FMA-distal. FMA-total did not favor contingent.
Methodology
Double-blind RCT at one rehab hospital (2020–2022). recoveriX-PRO delivered 20 × 60-min sessions, 5 days/week for 4 weeks. Contingent group got FES/avatar only when EEG detected the correct-hand motor imagery; independent group got three calibration runs with FES regardless of MI.
Limitations
Pilot n=25, single center, no long-term follow-up after W4; FMA-total was not superior, so gains are mainly wrist-level and may not generalize to all upper-limb function or acute stroke.
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