Spinal cord stimulation (SCS)

Implantation of electrodes in the epidural space at the level of the posterior columns of the spinal cord

Invasive; outpatient surgical procedure; mid level of burden to patients

Modulation of pain signals at the level of the spinal cord and central modulation of the pain response

Transcutaneous electrical stimulation (TENS)

Electrodes are placed at the level of the painful region and stimulate the underlying area

Non-invasive; low level of burden to patients

Based on the ‘gate theory’ by Melzack and Wolf in which vibration closes the gate for pain information at the spinal cord level; also evidence for supraspinal mechanisms

Peripheral nerve stimulation (PNS)

Implantation of electrodes in the subcutaneous tissue over the peripheral nerve that innervates the affected area

Invasive; outpatient surgical procedure; intermediate level of burden to patients

Impulse interruption by collision; gate control within the spinal cord or supraspinal locations; inhibition of neuroma spontaneous activity

Transcranial direct current stimulation (tDCS)

Placement of electrodes on the scalp and forehead creating an electrical field between the two electrodes

Non-invasive; minimal burden to patients

Subthreshold modulation of neuronal resting membrane potential with subsequent changes of N-methyl-D-aspartate receptor

Transcranial magnetic stimulation (TMS)

Magnet placed on the scalp and stimulate the underlying brain tissue

Non-invasive; delivery can be painful; low burden to patients.

Modulation of brain neuronal excitability under the magnet and connections to other parts of the brain

Deep brain stimulation (DBS)

Leads placed in deep brain structures

Invasive; inpatient surgical intervention; high level of burden to patients

Modulates the activities of certain brain areas like the hypothalamus, thalamus, periaqueductal grey area

Motor cortex stimulation (MCS)

Grid placed on the motor cortex

Invasive; inpatient procedure; high level of burden to patients

Modulates the activity of the underlying cortex and connections to other brain areas