Neuromodulation consists of a wide variety of therapies utilized across a wide variety of different medical specialties. Most frequently, neuromodulation is associated with stimulation. Analogous to the use of a pace-maker, stimulation refers to stimulating a nerve or set of nerves using controlled electrical impulses to try and improve their overall functionality and restore movement or alleviate pain.
Targets for stimulation usually include the brain and spinal cord, but can also include the peripheral and autonomic nerves as well. Examples include spinal cord stimulation, vagal nerve stimulation, deep brain stimulation, and peripheral nerve stimulation.
Please see below for additional information on each of these therapies.
DEEP BRAIN STIMULATION
Deep brain stimulation (DBS) uses implanted wires to deliver small electrical pulses to specific parts of the brain. It is used in the treatment of movement disorders including Parkinson’s disease, dystonia, and tremor, as well as chronic severe pain. DBS leads are placed in precise brain locations that are chosen according to the type of symptoms to be addressed.
What is a deep brain stimulation system made up of?
The deep brain stimulation system consists of three components:
depth leads that are inserted into the brain
an implanted pulse generator (IPG) which is a small box that contains a battery and circuitry to produce the stimulus current pulses
extension leads that connect the electrode leads to the IPG
SPINAL CORD STIMULATION
Spinal cord stimulation (SCS) is a treatment for chronic severe neuropathic pain. Electrodes are implanted into the spine, just behind the spinal cord. They stimulate the back of the spinal cord where the nerve fibres that carry sensation run upwards towards the head. Stimulating these fibres aims to mask painful signals with other less unpleasant sensations, often described as being like a buzzing feeling.
What is a spinal cord stimulation system made up of?
The spinal cord stimulation system consists of two components:
PERIPHERAL NERVE STIMULATION
Peripheral nerve stimulation (PNS) is a treatment for severe pain in a fairly small and well defined body area. An example is pain in the groin after hernia repair. Electrodes placed under the skin are used to stimulate sensory nerves in the area which can block the pain signals or mask them with other less unpleasant feelings such as a buzzing.
What is a PNS system made up of?
The system consists of two components:
Electrode wires that are inserted underneath the skin in the painful area
An implanted pulse generator (IPG), which is a small box that contains a battery and circuitry to produce the stimulus current
DORSAL ROOT GANGLION STIMULATION
On each side of the spine along its length from the top of the neck to the bottom of the back, there are almost 30 "nerve roots" that connect the spinal cord to different parts of the arms, body, and legs. These nerve roots carry signals coming down from the brain that control your muscles, and they also carry sensory signals back in the other direction. The sensory signals convey the sense of touch but also include pain signals.
At the point where each nerve root enters the spine it has a bulge called the "dorsal root ganglion" or DRG. This is a key part of the pathways that carry the sensory and pain signals from the periphery to the spinal cord and onward to the brain. It has been found that electrical stimulation applied to the DRG can block the transmission of pain signals from the specific area of the body that the nerve root is running to.
What is a DRGS system made up of?
The system consists of two components:
Intrathecal Drug Delivery (ITDD) systems are used for the treatment of spasm and spasticity, and chronic severe malignant and non-malignant pain. There is a small space around the spinal cord called the 'intrathecal space' which is normally filled with a watery fluid called cerebrospinal fluid (CSF). ITDD systems deliver medication into the CSF surrounding the spinal cord. Because the medication is being delivered directly to the site of action only very small doses are required. This means that side-effects are minimised as there is very little medication elsewhere in the body.
What is an ITDD system made up of?
An ITDD system consists of two components:
An external programmer is used to adjust pump settings wirelessly.