Spinal Cord Stimulation

What is it?

Spinal cord stimulation (SCS) is a form of neuromodulation, a treatment that aims to change how the nervous system processes pain signals. Thin electrodes (leads) placed in the epidural space around the spinal cord deliver mild electrical pulses. The leads are connected to a small pulse generator (battery) implanted under the skin, and a remote control lets you switch stimulation on or off and adjust its strength within set limits.

The technique is also known by its older name, dorsal column stimulation, because the stimulation targets nerve fibres in the back part of the spinal cord (the dorsal columns). It is used for certain types of neuropathic pain, meaning pain caused by nerve damage or nerve dysfunction. It does not remove the cause of the pain; it aims to reduce pain by changing the way it is perceived.

When is it considered?

SCS is considered for carefully selected people whose pain has not eased enough with medication, physiotherapy and less invasive procedures such as an epidural steroid injection or radiofrequency treatment. Its main uses are nerve pain that persists in an arm or leg after back or neck surgery, and complex regional pain syndrome. It may also be used for some peripheral nerve conditions, such as painful diabetic neuropathy. In spinal stenosis, it is usually discussed for selected people whose leg pain continues after surgery or who are not suitable for surgery.

The UK's National Institute for Health and Care Excellence (NICE) recommends SCS as an option for adults with neuropathic pain that has lasted at least six months despite appropriate conventional treatment, and who have benefited from a trial of stimulation. It also states that the assessment should be carried out by an experienced multidisciplinary team. For pain caused by poor blood flow (ischaemic pain), NICE recommends SCS only within research.

The strength of the evidence varies. In a randomised trial of people with persistent, mainly leg pain after back surgery, adding SCS to conventional treatment led to greater improvements in pain and quality of life at six months. By contrast, a Cochrane review of studies in low back pain concluded that current evidence does not show sustained benefits that would outweigh the risks of the procedure. Careful patient selection therefore matters a great deal.

How does it work?

The exact mechanism is not fully understood. The classic explanation, known as the gate control theory, is that stimulating large nerve fibres in the spinal cord reduces the transmission of pain signals to the brain. With traditional programmes, you feel a mild tingling over the painful area. Some newer programmes deliver stimulation without causing any tingling.

Settings are tailored to you and can be changed over time. The aim of SCS is not to eliminate pain entirely, but to reduce it enough to improve sleep, movement and daily function, and to lower the need for painkillers.

Before the procedure

The source of the pain is clarified through examination and imaging, and any problem that surgery could correct is looked for. Because long-lasting pain affects mood and sleep, a psychological assessment is also part of the process. It helps set realistic expectations and allows the benefit of treatment to be judged fairly.

Blood thinners are planned for, and anything that could raise the risk of infection is treated beforehand. How the device works, how the trial will be assessed, the possible risks and the alternatives are explained before you give written consent.

What happens during the procedure?

For the trial, you lie face down. The skin is numbed with local anaesthetic, with light sedation if needed. The leads are inserted through a needle into the epidural space under fluoroscopy (live X-ray). If traditional stimulation is to be used, you will be asked whether the tingling covers your painful area. The leads are then connected to a temporary stimulator outside the body and tested in your daily life, usually for several days to a week, and sometimes a little longer.

During the trial, changes in your pain, sleep, activity and medicine use are assessed together. If the benefit is sufficient, the system is implanted in a separate operation in an operating theatre. The leads are secured and the pulse generator is placed under the skin, usually in the buttock or abdomen. In some people, the leads need to be placed through a small surgical incision.

After the procedure

For the first 6-8 weeks after the device is implanted, you are usually advised to avoid bending, sudden twisting, heavy lifting and raising your arms above your head, so that the leads can settle in place. The wounds may be sore and tender for a few days. Many people can return to desk work within one to two weeks.

You will be given a device identification card. Always mention the device before an MRI scan, another operation or certain heat treatments used in physiotherapy (diathermy). Whether an MRI scan is possible depends on the system implanted. Depending on the battery type, regular recharging or, after some years, a battery replacement may be needed.

When might you notice results?

The trial lets you see in advance whether the treatment suits you. Once the device is implanted, the effect usually begins when it is switched on, although finding the right settings may take several follow-up visits.

Results vary from person to person. In some people, the effect fades over time and the settings need to be changed. SCS is one part of a broader pain management plan that includes exercise, medicine adjustment and, where helpful, psychological support. To find out whether this option suits your pain, you can request a consultation.