Optimizing the montage for cerebellar transcranial alternating current stimulation (tACS): a combined computational and experimental study

TY - JOUR

T1 - Optimizing the montage for cerebellar transcranial alternating current stimulation (tACS): a combined computational and experimental study

AU - Sadeghihassanabadi, Fatemeh

AU - Misselhorn, Jonas

AU - Gerloff, Christian

AU - Zittel, Simone

N1 - Creative Commons Attribution license.

PY - 2022/5/4

Y1 - 2022/5/4

N2 - Objective. The application of cerebellar transcranial alternating current stimulation (tACS) is limited by the absence of commonly agreed montages and also the presence of unpleasant side effects. We aimed to find the most effective cerebellar tACS montage with minimum side effects (skin sensations and phosphenes).Approach. We first simulated cerebellar tACS with five montages (return electrode on forehead, buccinator, jaw, and neck positions, additionally focal montage with high-definition ring electrodes) to compare induced cerebellar current, then stimulated healthy participants and evaluated side effects for different montages and varying stimulation frequencies.Main results. The simulation revealed a descending order of current density in the cerebellum from forehead to buccinator, jaw, neck and ring montage respectively. Montages inducing higher current intensity in the eyeballs during the simulation resulted in stronger and broader phosphenes during tACS sessions. Strong co-stimulation of the brainstem was observed for the neck. Skin sensations did not differ between montages or frequencies. We propose the jaw montage as an optimal choice for maximizing cerebellar stimulation while minimizing unwanted side effects.Significance. These findings contribute to adopting a standard cerebellar tACS protocol. The combination of computational modelling and experimental data offers improved experimental control, safety, effectiveness, and reproducibility to all brain stimulation practices.

AB - Objective. The application of cerebellar transcranial alternating current stimulation (tACS) is limited by the absence of commonly agreed montages and also the presence of unpleasant side effects. We aimed to find the most effective cerebellar tACS montage with minimum side effects (skin sensations and phosphenes).Approach. We first simulated cerebellar tACS with five montages (return electrode on forehead, buccinator, jaw, and neck positions, additionally focal montage with high-definition ring electrodes) to compare induced cerebellar current, then stimulated healthy participants and evaluated side effects for different montages and varying stimulation frequencies.Main results. The simulation revealed a descending order of current density in the cerebellum from forehead to buccinator, jaw, neck and ring montage respectively. Montages inducing higher current intensity in the eyeballs during the simulation resulted in stronger and broader phosphenes during tACS sessions. Strong co-stimulation of the brainstem was observed for the neck. Skin sensations did not differ between montages or frequencies. We propose the jaw montage as an optimal choice for maximizing cerebellar stimulation while minimizing unwanted side effects.Significance. These findings contribute to adopting a standard cerebellar tACS protocol. The combination of computational modelling and experimental data offers improved experimental control, safety, effectiveness, and reproducibility to all brain stimulation practices.

KW - Cerebellum

KW - Humans

KW - Phosphenes

KW - Reproducibility of Results

KW - Sensation/physiology

KW - Transcranial Direct Current Stimulation/methods

U2 - 10.1088/1741-2552/ac676f

DO - 10.1088/1741-2552/ac676f

M3 - SCORING: Journal article

C2 - 35421852

VL - 19

JO - J NEURAL ENG

JF - J NEURAL ENG

SN - 1741-2560

IS - 2

M1 - 026060

ER -