We aim to show a larger increase in the excitability of the motor cortical representation of the right FDI muscle when using new model-based optimized electrode configurations than when using the commonly used standard configuration. This study can…
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Brief title
Condition
- Other condition
Synonym
Health condition
n.a.
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
This study will examine the changes in motor cortical excitability, defined as
the size of MEPs measured via TMS and EMG, induced by anodal tDCS using
different electrode configurations. Specifically, we predict that the
model-based optimized configurations will lead to a larger increase in MEP size
than the standard configuration from literature.
Secondary outcome
Furthermore, we expect that optimization based on both electric field strength
and direction will lead to a larger increase in MEP size than optimization
based on electric field strength alone.
Background summary
Transcranial direct current stimulation (tDCS) is a promising tool to study
human brain function and improve function in certain tasks in both healthy
subjects and patients with neurological diseases. As the effects are currently
promising, but small and short-lived, this study aims to improve the technique.
Using a highly detailed volume conduction model of the human head, it was found
that with the commonly used electrode configurations stimulation is not
optimal, and new optimized configurations were determined. The proposed study
aims to test these optimized configurations experimentally and compare the
results to the standard configuration.
Study objective
We aim to show a larger increase in the excitability of the motor cortical
representation of the right FDI muscle when using new model-based optimized
electrode configurations than when using the commonly used standard
configuration. This study can lead to new tDCS configurations that have bigger
effects and can be used in many other studies and applications. Also, this
study can give new insights into the mechanisms behind tDCS.
Study design
Experimental within-subject design with healthy volunteers.
Intervention
tDCS (anodal, 2 mA, 15 minutes, three sessions) will be applied with three
different tDCS configurations targeting the motor cortical representation of
the right FDI muscle. Excitability is measured via EMG as so-called motor
evoked potentials (MEPs) of the FDI muscle (an intrinsic hand muscle) induced
by single pulses of transcranial magnetic stimulation (TMS).
Study burden and risks
Participants will not directly benefit from their participation in the study,
except for a compensatory (financial) incentive. Transcranial current
stimulation (tCS) is a widely used non-invasive brain stimulation technique,
applying weak direct/alternating currents (tDCS/tACS) via conductive
rubber/sponge electrodes to the scalp. These weak currents can slightly shift
the neurons* membrane potential and thereby increase or decrease spontaneous
neuronal activity in the stimulated cortex, but (unlike TMS) they do not evoke
action potentials. During the stimulation, participants may transiently
experience light tingling, itching or burning sensations on the skin underlying
the electrodes, which can be unpleasant. The most common side effects are a
light transient headache and a feeling of fatigue. In the current study,
healthy participants will be stimulated with a protocol that is considered safe
with respect to the latest published safety guidelines. Transcranial magnetic
stimulation (TMS) is a widely used non-invasive brain stimulation technique,
based on the principle of electromagnetic induction. During stimulation, the
participant will likely hear the clicks of the TMS pulses and experience
stimulation of nerves and muscles of the head. The most common side effect is a
light transient headache (2-4% occurrence). A severe headache is uncommon
(0.3-0.5% occurrence). In TMS studies of patient populations (e.g. epilepsy) or
those exceeding the standard protocols (e.g. in intensity or frequency)
epileptic seizures have been reported in rare cases. In the current study
healthy participants will be stimulated with a protocol that falls within the
safety guidelines. All subjects are screened for their relevant medical history
and other tCS and TMS safety aspects (e.g. metal parts in the head). In
summary, because the risk and burden associated with participation can be
considered negligible-to-minimal, we do not expect serious adverse events
during the project.
Reinier Postlaan 4
Nijmegen 6525 GC
NL
Reinier Postlaan 4
Nijmegen 6525 GC
NL
Listed location countries
Age
Inclusion criteria
Age 18-45 years
Righthanded
Exclusion criteria
• Epilepsy, convulsion or seizure (TMS)
• Serious head trauma or brain surgery
• Large or ferromagnetic metal parts in the head (except for a dental wire)
• Implanted cardiac pacemaker or neurostimulator
• Pregnancy
• Skin diseases at intended electrode sites (EMG, tDCS)
• History or current presence of any neurologic or psychiatric disease
• Any prescribed medication that can alter cortical excitability (e.g. antiepileptics, tricyclic anti-depressives or benzodiazepines) or can have an influence on the participant*s vigilance or cognitive performance within two weeks prior to participation
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL43188.091.13 |