Dynamic Causal Modeling of Neuromodulation of Action Speed Via Targeted TMS-EEG

Overview

Stroke is a major cause of long-term disability, with cognitive and motor deficits-especially action slowing and executive dysfunction-being strong predictors of poor recovery outcomes. Recent advances in network neuroscience suggest that action speed is governed by interactions between specific prefrontal and premotor regions. However, the precise neural mechanisms underlying action slowing in stroke remain unclear, limiting the efficacy of current rehabilitation approaches. This study integrates high-density EEG, fNIRS and dynamic causal modeling (DCM), and rTMS to map and modulate the neural circuits involved in action speed. In the first phase, we will assess the role of seven key brain regions in action speed modulation by applying virtual lesions using single-pulse TMS in 60 healthy individuals. In the second phase, we will apply offline intermittent theta burst stimulation (iTBS) to the most relevant regions and evaluate its impact on action speed. Finally, in the clinical phase, we will administer individualized iTBS to 20 stroke patients to enhance action speed. Patients will be assessed at baseline, immediately post-treatment, and after one and three months to track improvements in action speed using DCM and behavioral tests. Changes in connectivity and action speed performance will be compared to healthy controls to refine treatment parameters. Secondary outcomes include executive function and daily life motor performance. Longitudinal follow-up will determine the persistence of improvements, informing future personalized rehabilitation strategies. By characterizing effective connectivity changes post-stroke, we aim to refine neuromodulation strategies and develop a personalized rTMS approach. Our hypothesis is that targeting specific regions identified through integration of EEG, fNIRS and DCM can enhance action speed, ultimately improving functional recovery. This personalized approach could lead to more effective rehabilitation protocols, tailored to individual brain damage patterns.

Interventions

• Other Phase 1 functional MRI (fMRI)
  3D T1-weighted imaging (T1w) and (10 min) resting-state functional MRI (fMRI) will be acquired for each healthy subject to identify target regions for TMS interventions. Phase 1 aims to assess the impact of temporary disruption (caused by virtual lesions (VL)) on action speed, measured by reaction time (RT) using a simple reaction time (SRT) task in healthy subjects
• Other Phase 2 functional MRI (fMRI)
  Phase 2 will assess the effects of intermittent theta burst stimulation (iTBS) on improving action speed in healthy individuals.
• Other Phase 3 functional MRI (fMRI)
  Phase 3 administers iTBS to enhance action speed in stroke patients within the first six months post-stroke, leveraging individualized action speed models to tailor interventions.

Primary outcome measures

• variations in action speed is the reaction time [Time frame: day 0]

Secondary outcome measures (1)

• variation between both groups of brain connectivity values [Time frame: day 0]

Eligibility criteria

Inclusion criteria

• The control group consists of individuals who are :
• neurologically healthy,
• meaning they do not have any medical conditions that could interfere with cognitive performance or its measurement.
• not have any contraindications for undergoing MRI scans or TMS, such as epilepsy, which could be triggered by magnetic stimulation.
• The patient group will include :
• individuals who have experienced a hemispheric stroke but with specific criteria ( stroke must not have affected key prefrontal regions that are targeted in the study, ensuring that the observed motor slowing is due to network dysfunction rather than direct structural damage to these regions)
• be free of other cognitive impairments or medical conditions that could confound the study's results.

Exclusion criteria

• participants with neurological,
• psychiatric, or general conditions known to alter test performance or cognitive function, according to a previously validated method will be excluded.
• any contraindication to MRI and TMS (e.g., epilepsy).
• For stroke patients, the lesion delineated on MRI must spare the prefrontal target structures.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

Non-randomized

Model

Parallel assignment

Masking

Open label

Primary purpose

Other

Study locations

France · 1 center

• CHU Amiens — Amiens

Identifiers

NCT: NCT07468032 · PI2025_843_0195

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗