Closed-loop rTMS-EEG During Visuomotor Integration.

State-dependent Entrainment of Intrinsic Brain Rhythms to Improve Interregional Functional Coupling.

This pilot study aims at establishing personalized state-based rTMS for precision neurorehabilitation, we designed a within-subject cross-over study to test closed-loop repetitive transcranial magnetic stimulation and electroencephalography (rTMS-EEG) comparing the targeting of two key nodes in the frontoparietal network during bimanual visuomotor force tracking in persons with upper extremity sensorimotor impairment affecting eye-hand control.

There is a need for oscillatory or repetitive neuromodulatory tools and methods that are effective in entraining intrinsic neural rhythms to improve inefficient functional coupling within neural circuits. The goal of the proposed study is to develop a closed-loop application of repetitive transcranial magnetic stimulation (rTMS) and electroencephalography (EEG) suitable for use in multidomain precision neural-circuit based rehabilitation studies that permits the time-locked application of rTMS pulses to the phase of the intrinsic neural oscillation (personalized state-based application) in a defined behavioral context (e.g., goal-directed eye-hand control).

Inclusion Criteria:

• adult volunteers (age ≥18 years)
• right-hand dominance (defined with the Edinburg Handedness Scale)
• voluntary whole-hand grip force (Medical Research Council scale for muscle force ≥2)
• capable of repeated grasp and release with 5% of maximum voluntary contraction (standardized with an in-house computer-based assessment involving whole-hand grip force tracking upon visual cues with a digital dynamometer).

Exclusion Criteria:

• presence of any MRI risk factors (such as an electrically, magnetically, mechanically activated metal or nonmetal implant including cardiac pacemaker, intracerebral vascular clips, any other electrically sensitive support system, or claustrophobia)
• presence of any contraindications to repetitive transcranial magnetic stimulation, rTMS (e.g., history of seizures or epileptic activity, currently taking medications that lower seizure thresholds)
• any neurological or psychiatric disorders affecting cognitive function (e.g., established dementia) affecting the ability to understand the purpose of the study and give informed consent or ability to complete cognitive testing
• substance use disorder
• visual impairment that precludes completion of scanner tasks
• uncontrolled hypertension despite treatment
• intake of tricyclic anti-depressants
• musculoskeletal disorders affecting bimanual grasp- and release
• pregnancy (or suspected/possible pregnancy or plan to become pregnant in the short term). If the participant is a woman of childbearing potential, a urine pregnancy test will be performed on a standard basis.
• severe aphasia affecting particularly of receptive nature (NIH Stroke Scale, NIHSS Language subsection ≥2) affecting the ability to understand the purpose of the study and give informed consent
• pregnancy