TMS-evoked Potentials During Repetitive Transcranial Magnetic Stimulation on the Primary Motor Cortex (rTMS-TMS-EEG)

Aalborg University

Status: Completed

Conditions: Electroencephalography; Motor Cortex; Transcranial Magnetic Stimulation; Pain Thresholds; Repetitive Transcranial Magnetic Stimulation

Treatments: Other: Sham rTMS; Other: Real rTMS

Study type: Interventional

Funder types: Other

Identifiers

NCT05714020

N-20220018-1

Details and patient eligibility

About

This study investigates the modification of the local-to-global connectivity pattern in response to a session of repetitive transcranial magnetic stimulation (rTMS) applied to the primary motor cortex. Transcranial magnetic stimulation (TMS) will be applied to elicit electroencephalography (EEG) responses in healthy volunteers. The TMS-evoked potentials (TEPs) will be recorded and serve as a reflection of cortical reactivity to TMS.

Full description

Abnormal connectivity patterns interfere with the normal function of a given neuronal network, thus leading to circuit dysfunction and, subsequently, chronic pain. In the last few years, neuroscience has been heavily influenced by network science. This synergistic association provided a new framework for understanding brain function in health and how dysfunction in specific neuronal brain circuits can lead to symptoms. A network comprises nodes (e.g., areas of the brain) and edges (functional connections between nodes). An effective network can process and share large amounts of information while maintaining specificity and not allowing noise to contaminate the flow of information across the circuits. The network approach to brain functioning has been able to integrate what has been known for several decades as spatial structural anatomy with the time-varying streaming of information (connectivity) in a dynamic perspective. In this context, symptoms of diseases are seen as being correlated with specific network abnormalities, and therapeutic interventions as being associated with the normalisation of these abnormal patterns of connection. Non-invasive neuromodulatory approaches, such as repetitive transcranial magnetic stimulation (rTMS), have entered the guidelines for the management of major depression refractory to pharmacological treatment (FDA clearance in 2008 - K061053) and several chronic pain conditions, providing low-adverse event, rapid-to-perform and safe non-pharmacological treatment possibilities for neuropsychiatric disorders. rTMS is based on the induction of a high-intensity magnetic field on the scalp and on the subsequent creation of an induced electric current that penetrates the skull and influences neuronal firing over a very restricted volume of the brain. Depending on stimulation parameters, rTMS also acts by facilitating or depressing the activity of specific brain networks non-invasively. Despite important advances in the use of rTMS, and similar to what is also obtained from pharmacological treatments, up to 40% of patients remain symptomatic after treatment. This study aims to investigate the responses of specific neuronal brain circuits to repetitive transcranial magnetic stimulation (rTMS) applied to the primary motor cortex in healthy volunteers. It has been hypothesised that the local-to-global connectivity pattern obtained by the stimulation of different cortical hubs (primary motor cortex, dorsolateral prefrontal cortex, anterior cingulate cortex and posterior insula) will be described by TMS-EEG responses in healthy individuals. The modification in cortical connectivity in response to a repetitive transcranial magnetic stimulation (rTMS) applied to the primary motor cortex will be described and compared with a sham rTMS stimulation.

Enrollment: 30 patients

Sex: All

Ages: 18 to 60 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Healthy men and women
• Speak and understand English

Exclusion criteria

• Drug addiction defined as the use of cannabis, opioids or other drugs
• Previous neurologic, musculoskeletal or mental illnesses
• Lack of ability to cooperate
• History of chronic pain or current acute pain
• Contraindications to rTMS application (history of epilepsy, metal in the head or jaw etc.).
• Failure to pass the "TASS questionnaire" (TASS = Transcranial Magnetic Stimulation Adult Safety Screen)

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Single Blind

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30 participants in 2 patient groups

Real rTMS

Active Comparator group

Description:

The active rTMS protocol is a 15-minute 10Hz stimulation, 10 seconds on, 20 seconds off, at 90% RMT, for a total of 3000 pulses using a real TMS coil. The target is the primary motor cortex.

Treatment:

Other: Real rTMS

Sham rTMS

Sham Comparator group

Description:

The sham rTMS protocol is performed by a sham coil. The sham rTMS protocol is a 15-minute 10Hz stimulation, 10 seconds on, 20 seconds off, at 90% RMT, for a total of 3000 pulses. The target is the primary motor cortex.

Treatment:

Other: Sham rTMS