Spinal Cord Stimulation (SCS)

What is spinal cord stimulation (SCS)?

An implantable, adjustable “pain-control system” acting at the level of the spinal cord.

Spinal cord stimulation (SCS) is a minimally invasive method for the management of chronic neuropathic pain. One or more thin electrodes are placed in the epidural space over the dorsal columns of the spinal cord. These electrodes are connected to a small pulse generator (battery) implanted typically in the lateral abdominal wall or the buttock.

The generator delivers electrical impulses that modulate pain signals before they reach the brain. In collaboration with the pain team, the patient can adjust the stimulation parameters to achieve maximal pain relief with minimal side effects.

Who is it for?

Patients with chronic, predominantly neuropathic pain when conservative measures have been exhausted.

Spinal cord stimulation is not a first-line therapy, nor a simple alternative to medication. It is intended for patients with chronic pain—usually lasting longer than 6–12 months—in whom:

• pharmacologic and other conservative treatments (physical therapy, injections, re-operation when appropriate) have been adequately attempted without satisfactory benefit, and
• pain is predominantly neuropathic or mixed, with significant functional impairment.

Classic indications include:

• Failed Back Surgery Syndrome (FBSS) — persistent pain after spinal surgery, typically with leg pain exceeding low-back pain.
• Complex Regional Pain Syndrome type I (CRPS I) — severe, disproportionate pain with swelling and skin or temperature changes in a limb.
• Chronic ischemic lower-limb pain due to peripheral vascular disease when revascularization is not feasible or insufficient.
• Medication-refractory angina in selected centers.
• Other chronic neuropathic pain syndromes after careful multidisciplinary evaluation.

What patient profile may benefit from SCS?

Chronic pain that persists despite treatment, limits mobility, and significantly impairs daily life.

Patients who most often benefit from SCS describe:

• persistent or frequent leg pain or pain in a defined region, often burning or “electric” in character
• worsening with standing or walking, requiring frequent rest
• difficulty sleeping because of severe pain
• restriction of daily activities (work, errands, social life)
• psychological burden, anxiety, or depression

A primary goal of SCS therapy is not only reduction in medication burden, but more importantly the restoration of function—improved walking tolerance, better sleep, improved mood, and enhanced social participation.

How does spinal cord stimulation work?

From the “gate-control” theory of pain to modern concepts of neuromodulation.

SCS was originally based on the gate-control theory of pain (Melzack & Wall), whereby stimulation of large, fast-conducting fibers in the dorsal columns can “close the gate” to pain signals transmitted by smaller fibers.

Current evidence shows that SCS:

• modulates neuronal activity in the dorsal horn, reducing central sensitization
• activates inhibitory circuits and descending pathways that suppress pain perception
• can influence the autonomic nervous system, improving blood flow in ischemic tissues

Clinically, patients often experience a mild sensation of tingling or paresthesia (with modern systems, often no perceptible sensation), replacing intense pain with a more tolerable sensory experience.

How are diagnosis and patient selection performed?

Careful screening—SCS is for a limited number of patients, but when appropriately selected, outcomes are meaningful.

Before recommending implantation, we require:

• Neurological and orthopedic evaluation to exclude conditions better treated by revision surgery or other interventions.
• Imaging (MRI, CT) of the spine or relevant region to rule out surgically correctable pathology.
• Comprehensive review of previous treatments (medications, injections, physical therapy, sympathetic blocks, etc.).
• Psychological/psychiatric assessment to identify untreated depression, anxiety, somatization, secondary gain issues, and the ability to participate in therapy.
• Evaluation of social support, realistic expectations, and willingness to actively engage in device programming.

Only when these criteria are met do we proceed to the trial phase, an essential step in the overall process.

How does SCS differ from other chronic pain therapies?

SCS is neither conventional surgery nor simply another medication—it is an implantable, externally programmable system.

Compared with:

• Traditional spine surgery: SCS does not correct mechanical pathology but instead modulates pain when structural causes have been addressed or are no longer surgically amenable.
• Opioids & strong analgesics: SCS may allow dose reduction, limiting side effects and dependence risks.
• Ablative procedures (e.g., cordotomy, DREZ): SCS is reversible and adjustable, without permanently destroying neural tissue.

It may be combined with rehabilitation, psychotherapy, and pharmacologic therapy within a comprehensive pain-management strategy.

When should I consider spinal cord stimulation?

When pain remains substantial despite optimal therapy and significantly limits daily functioning.

You may wish to discuss SCS if:

• your pain has persisted for more than 6–12 months at a moderate or severe level,
• you have tried multiple medication regimens at adequate doses,
• you have undergone re-evaluation for possible surgical or vascular intervention when appropriate,
• your pain substantially interferes with work, walking, or sleep,
• you are willing to actively participate in device management and follow-up.

The final decision is always made following specialized assessment in a pain and neurosurgical center.

What is the SCS trial?

A temporary “test” using an external stimulator before deciding on permanent implantation.

The trial phase usually lasts 4–7 days and includes:

• percutaneous placement of one or two thin electrodes into the epidural space,
• connection to an external stimulator worn on a belt,
• testing different programs during normal daily activities.

At the end of the trial:

• electrodes are removed in the clinic,
• outcomes are reviewed in detail: pain reduction, functional improvement,
• the benefit is weighed against inconvenience and long-term device considerations.

A trial is typically considered successful when pain is reduced by ≥ 50% with clear improvement in function and quality of life. Only then is permanent implantation recommended.

How is permanent SCS implantation performed?

A targeted procedure with a small spinal incision and a second incision for the generator.

Permanent implantation is performed in the operating room, usually under general anesthesia:

• the patient is positioned prone on a dedicated frame (e.g., Wilson frame),
• under fluoroscopic guidance, a limited posterior spinal approach is made at the appropriate level,
• the electrode is advanced into the epidural space to the target level (e.g., T8–T10 for lower-limb pain),
• coverage is verified using intraoperative neuromonitoring,
• the lead is anchored and a pocket is created for the generator (buttock or lateral abdomen),
• connections are secured, impedances checked, and initial programming performed.

Hospital stay is typically 1–2 days. The patient receives instruction on use of the external controller, activity restrictions during early recovery, and incision care.

What outcomes can be expected?

Significant pain reduction in selected patients, though not complete elimination in all.

Studies demonstrate that in well-selected patients:

• a substantial proportion (approximately half) achieve ≥ 50% pain reduction,
• functional capacity improves (walking, sleep, daily activities),
• dependence on strong analgesics and opioids decreases,
• quality-of-life and treatment satisfaction scores increase.

However, 30–40% of patients may not achieve the desired benefit, underscoring the importance of realistic expectations and careful selection.

What are the risks and limitations of SCS?

As with any implantable therapy, SCS carries technical and medical risks that must be understood.

Potential complications include:

• Infection at the generator or lead site, possibly requiring system removal.
• Lead migration or fracture, reducing efficacy and necessitating revision.
• Rarely, hematoma or injury to the spinal cord or nerve roots with neurologic deficit.
• Cerebrospinal fluid leak.
• Pain or discomfort at the generator site.
• Device malfunction or battery replacement after several years.

Additional limitations:

• older systems may not be MRI-compatible (newer systems are MRI-conditional),
• caution is required with pacemakers/defibrillators (cardiology coordination necessary),
• ongoing follow-up and reprogramming may be required.

At Neuroknife, all these factors are discussed in detail so that the decision to proceed is informed and deliberate.

Living with an SCS system—what should I expect?

Therapy continues after surgery: regular adjustments, follow-up, and patient support are essential.

After implantation:

• regular visits are needed for programming optimization,
• medication doses may be gradually reduced,
• you will learn to use the external controller to activate/deactivate and change programs,
• you will receive guidance regarding early activity restrictions (bending, twisting).