Cathodal High-Definition Transcranial Direct Current Stimulation Primed Intermittent Theta-Burst Stimulation for Upper Limb Motor Recovery in Stroke: A secondary analysis.

Objective: To identify baseline factors linked to a positive response to intermittent theta-burst stimulation (iTBS) in individuals with stroke.

Design: Secondary analysis of a randomized controlled trial.

Setting: A single rehabilitation hospital.

Participants: Sixty stroke patients (mean age 61.48±8.91 years; 48 males), including both ischemic and hemorrhagic stroke types.

Interventions: iTBS combined with routine rehabilitation MAIN OUTCOME MEASURES: Responders were defined as patients with a ≥7-point improvement in the Fugl-Meyer Assessment of the Upper Extremity (FMA-UE). Baseline variables included demographics, stroke-related factors, and initial motor assessments. Uni- and multivariate logistic regression analyses were conducted to identify predictors of treatment response. A receiver operating characteristic (ROC) curve was used to determine the optimal time window post-stroke for intervention.

Results: Among the 60 patients, 34 (56.7%) were classified as responders. Univariate analyses identified several baseline predictors of treatment response, including time since stroke onset, intervention type, FMA-UE, Motricity Index-Upper Extremity, and Shoulder Abduction and Finger Extension score. In the whole sample, multivariate logistic regression identified time since stroke onset as an independent predictor (odds ratio [OR] 0.963, p = 0.042). Notably, time since onset remained significant in the iTBS group (OR = 0.920, p = 0.016). Patients treated within the first month post-stroke were more likely to respond (x = 4.884, p = 0.027). Receiver operating characteristic analysis identified an optimal cut-off of 37.5 days post-stroke (area under the curve = 0.734).

Conclusions: Earlier post-stroke administration of the iTBS intervention yielded greater improvements in upper limb motor function. Incorporating a preconditioning iTBS protocol may enhance treatment outcomes, guiding clinicians in optimizing stroke rehabilitation strategies.

Trial Registration: Chinese Clinical Trial Registry, ChiCTR2200063397 DEVICE STATUS: The device(s) that is/are the subject of this manuscript is/are not FDA approved and is/are not-commercially available in the United States.