Table 2:
Parameters of tES dose and related factors (adapted from [3]).
| Stimulation Waveform Parameters‡ |
Examples* | Section |
|---|---|---|
| For transcranial Direct Current Stimulation (tDCS): current amplitude, duration, and details of ramp up/down. | Amplitude of 2 mA applied for 20 minutes duration, with 30 second linear ramp up/down. | 3.1 |
| For transcranial Alternating Current Stimulation (tACS): current amplitude, frequency, and offset (dc bias) or details of ramp up/down. | 10 Hz sinusoidal current with peak amplitude of 1 mA (peak to baseline), applied for 30 minutes, with no dc bias and a linear ramp up/down over 15 seconds. | 3.4, 2.11 |
| For transcranial Pulsed Current Stimulation: pulse shape, amplitude, duration, polarity, inter-pulse-interval (pulse repetition frequency), intertrain interval (duration between pulse trains), total number of pulses. | Monophasic rectangular pulse, 4 mA peak current, 1 ms pulse width, train of 100 pulses at 100 Hz frequency, 10 seconds between pulse trains, 2000 total pulses (20 pulse trains). | 3.2, 2.11 |
| For Electroconvulsive Therapy (ECT): pulse shape, directionality, amplitude, width, train frequency, train duration, number of sessions, and interval between sessions. | Rectangular current pulses with 800 mA amplitude, 1.0 ms width, and alternating polarity, delivered at 40 Hz (pulse-pairs per second) for 4 s. | 3.2.3 |
| For repeated sessions, duration of all sessions, interval between sessions and total number of sessions. | 20 minutes daily, 5 days per week (weekdays only), for 4 weeks. OR Repeated within 18–26 hours with 5 sessions completed in 5 days |
2 |
| If the dose is individually titrated for efficacy or safety: Describe the titration procedure method (formula) and how the final dose is determined. Ideally, report dose per subject, but at a minimum descriptive statistics on the dose across the whole population of subjects/patients participating in the study should be provided. Optionally, the dose applied at each iteration and the final dose applied may be reported. | Subject 1: 2.0 mA amplitude Subject 2: 1.5 mA amplitude OR Increase amplitude by 0.5 mA increments every 30 seconds until subject reports sensation. Experimentally resulting in amplitude range of 1.0 to 2.0 mA with an average amplitude of 1.5 mA and a SD of 0.5 mA. |
2 |
| Montage and Electrode Assembly (including conductive solution) | ||
| All electrode assembly components including electrode, conductive solution (electrolyte), and any supporting materials (e.g. sponge). If a well-defined manufacturer/model is used, it may be sufficient to report it, but to reduce ambiguity key features should be specified. The reporting of a unique product model may allow collection of manufacturing details not apparent to the researcher (e.g. product materials); however, basic electrode assembly description should still be provided to minimize ambiguity. | 7×5 cm sponge; sponge material – e.g. cellulose pocket area, 2 cm thick per sponge; 3×5 cm area conductive rubber electrode centered inside sponge pocket with 0.9% isotonic saline. Electrode Model Z and Gel Model Y by Company X. | 2.2, 2.3 |
| Electrode position on the scalp relative to a clearly defined (reproducible) system (e.g. 10–10, landmarks, imaging, or evoked neurophysiology). This must be specified for all electrodes. | Pad centered on F4 (EEG 10-10) and oriented orthogonal to vertex, OR The position labeled “F4” on Company X, Cap Y, OR Centered on motor “hot spot” as identified by TMS, OR Positioned on forehead with the bottom center of the pad directly above the eyebrow and centered on the eye. |
2.1 |
| Electrode composition, headgear, equipment, and subject preparation | ||
| Skin preparation techniques. | Gentle alcohol wipe, OR Abrasion, OR None. |
- |
| Head gear | Two 5.1 cm wide elastic fasteners made with hypoallergic rubber, affixed with 2 plastic joints.@ | 2.6 |
‡
Complete characterization of waveform of electrode voltage (for voltage-controlled devices) or current (for current-controlled devices).
*
Examples are intended to illustrate how to apply/report parameters and are not intended to prescribe any specific or preferred implementation.
@
Researchers apply different forms of head-gear which may vary outcomes even if dose is maintained; for example, variations in pressure on scalp can influence adverse events such as pressure headache or erythema [8].