Table 4.

Typical stimulation characteristics of major electromagnetic neuromodulation modalities used in pain research and clinical practice.

Modality	Typical target/Placement	Stimulation type	Usual treatment pattern	Key caveat
SCS	Epidural space over dorsal columns	Implanted electrical stimulation	Trial stimulation followed by permanent implant if successful; can be continuous or programmed use	Parameters vary widely across tonic, burst, HF10, and other paradigms
DRG	Lead positioned near dorsal root ganglion	Implanted electrical stimulation	Trial followed by implant in selected focal pain conditions	Best considered a specialized SCS variant rather than a wholly separate platform
DBS	Intracranial pain-network targets (e.g., PAG/PVG, thalamus, ACC)	Implanted electrical stimulation	Implanted therapy, historically often intermittent daily use; modern use individualized	Highly target-dependent and heterogeneous across studies
MCS	Epidural electrodes over M1	Implanted electrical stimulation	Usually chronic implanted therapy with individualized programming	Dosing and daily use schedules are inconsistently reported
Implanted VNS	Cervical vagus nerve	Implanted electrical stimulation	Chronic implanted therapy	Pain evidence is less established than for epilepsy/depression indications
nVNS/taVNS	Cervical vagus nerve externally or auricular vagal territory	Transcutaneous electrical stimulation	Acute-use or repeated session-based protocols depending on indication	Parameters and targets vary substantially across cervical vs auricular approaches
tDCS	Scalp electrodes over M1 or DLPFC	Weak direct current	Usually repeated over 5–10 sessions	Montage and total dose vary across studies
rTMS	Superficial cortical targets, most commonly M1; also DLPFC or parietal cortex	Noninvasive magnetic stimulation	Often delivered over repeated weekday sessions, sometimes with maintenance sessions	Coil type, target, frequency, and maintenance schedule differ widely
Deep TMS	Deeper and broader cortical/subcortical targets depending on coil design	Noninvasive magnetic stimulation	Repeated session-based protocols	Potentially greater depth with reduced focality; pain evidence remains limited
TBS	Usually M1	Patterned rTMS (bursts at theta rate)	Short-session protocol, sometimes repeated over multiple visits	Pain evidence is more limited than for conventional rTMS
tACS	Scalp electrodes over cortical targets, often somatosensory/prefrontal regions	Weak alternating current	Single- or multi-session protocols	Early-stage field with limited standardization
CES	Ear-clip (earlobe) electrodes, less commonly scalp	Low-intensity pulsed cranial current	Repeated session-based use	Parameters are highly device-specific and evidence remains heterogeneous
TENS	Surface electrodes over painful region or related peripheral nerve territory	Transcutaneous pulsed electrical stimulation	Often 20–60 min/session, repeated as needed	Effectiveness is sensitive to intensity, adherence, and timing relative to pain
PNS	Lead adjacent to named peripheral nerve	Implanted/percutaneous electrical stimulation	Usually trial or staged percutaneous/implant therapy depending on system	Highly target- and system-specific
PNFS	Subcutaneous leads within painful field	Field-based electrical stimulation	Chronic implanted or percutaneous use in selected cases	Less standardized than named-nerve PNS