Tremor, Limb
Conditions
Brief summary
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. While tACS applied over the motor cortex at the general applied amplitude (1 mA) and using patch electrodes has been shown to entrain physiological tremor in healthy volunteers, the aim of this study is to test the feasibility of using high-amplitude tACS and to assess the effect of different electrode montages and stimulation sites in entraining physiological tremor. First, 10 subjects (arm 1) will be stimulated with 2 mA current amplitude applied between saline soaked patch square electrodes and comparison will be done between motor cortex stimulation and peripheral cortex stimulation. Then, 10 subjects (arm 2) will be stimulated using focused 4x1 montage with gel-filled cup-electrodes and 5 mA amplitude and comparison will be made between motor cortex and occipital cortex stimulation. Three outcome measurements will be measured during the experiments which are: tremor entrainment, phosphene intensity and phosphene threshold.
Interventions
DEVICEtACS at tremor frequency
tACS applied between the stimulation electrodes at tremor frequency
Sponsors
KU Leuven
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* Above 18 * signed informed written consent
Exclusion criteria
* Pregnancy * History of Epilepsy * Family history of Epilepsy
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Tremor-stimulation phase entrainment | During the 36 minutes of all sessions (3 sessions each of is 12 minutes) | phase locking value was calculated between the tremor signal measured using accelerometer and the stimulation signal |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Phosphene rating | Measured up to 5 minutes before the start of the stimulation sessions and lasts for 10 seconds of stimulation after which the subject gives the rating | The subject is asked to rate the phosphene intensity during the stimulation using a visual analog scale from 0 to 10. Zero means no phosphene is perceived and the number starts to increase as the phosphene perception intensity increases to reach 10 if the subject observe only a white view |
| Phosphene threshold | Measured 3 minutes before the start of the stimulation sessions and lasts up to 2 minutes. Stimulation at each amplitude lasts for 10 sec. | Stimulation amplitude at which the subject starts to perceive phosphene. Stimulation starts with 0 mA amplitude and then increased gradually until phosphene is perceived (or reaching maximum amplitude). |
Outcome results
None listed