The Trans-cutaneous Effects on Physiological Tremor Entertainment During tACS

Catholic University (KU) of Leuven

Status: Completed

Conditions: Tremor, Limb

Treatments: Device: tACS at tremor frequency

Study type: Interventional

Funder types: Other

Identifiers

NCT04065022

S57869-1

Details and patient eligibility

About

Transcranial alternating current stimulation (tACS) is a noninvasive neuromodulation method that works by passing alternating electric current between electrodes where at least one of them is attached to the head. This has been shown to have effects on the motor system, cognition and behavior. The exact mechanism by which tACS causes such effects is not fully understood. Some studies suggests a contribution from the stimulated peripheral nerves present in the scalp rather than direct brain effects. To test this hypothesis two arms will be done. First, 12 subjects (arm 1) will be stimulated using focused 4x1 montage with gel-filled cup-electrodes over the motor cortex and the effects will be compared between anesthetized and non-anesthetized scalp. The effects of anesthetizing the scalp will be tested on three different stimulation amplitudes off (0 mA), low (0.5 mA) and high (2.5 mA). Then, 10 subjects (arm 2) will be stimulated over the contralateral arm to exclude any direct brain stimulation effects and to test if peripheral nerve stimulation can entrain the tremor. Three outcome measurements will be measured during the experiments which are: tremor entrainment, sensation intensity and sensation threshold.

Enrollment: 22 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Above 18
• Signed informed consents

Exclusion criteria

• Pregnancy
• History of Epilepsy
• Family history of Epilepsy

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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22 participants in 2 patient groups

Head stimulation

Experimental group

Description:

Each subject will be stimulated at two different days. One day with the presence of topical anesthetic cream on the scalp above the MC and in the other day with absence of the anesthetic cream. Stimulation frequency is set similar to that of the tremor. Three stimulation amplitudes will be tested (0 mA, 0.5 mA and 2.5 mA -reduced if not uncomfortable). A set of 4\*1 gel-filled cup-electrodes is placed over each of motor cortex. Each subject follows three sessions of 12 min length each day. During each session the tremor is measured while interleaving between low amplitude stimulation, high amplitude stimulation and No stimulation. By the end of each session we get 3 min of Low amplitude stimulation, 3 min of high amplitude stimulation and 6 min of No stimulation.

Treatment:

Device: tACS at tremor frequency

Arm stimulation

Experimental group

Description:

Each subject will be stimulated on only one day. Stimulation frequency is set similar to that of the tremor. Three stimulation amplitudes will be tested (0 mA, 0.5 mA and 2.5 mA -reduced if not uncomfortable). A set of 2\*1 gel-filled cup-electrodes is placed over the contralateral arm. Each subject follows three sessions of 12 min length. During each session the tremor is measured while interleaving between low amplitude stimulation, high amplitude stimulation and No stimulation. By the end of each session we get 3 min of Low amplitude stimulation, 3 min of high amplitude stimulation and 6 min of No stimulation.

Treatment:

Device: tACS at tremor frequency