Spinal Cord Stimulation
Learn More About Common Pain Conditions, Their Origins, and Mechanisms
What is a "Pain Pacemaker" or How Does Neuromodulation Work?
The goal of neuromodulative pain treatments is to influence and suppress pain signals at the level of the spinal cord. This is achieved through electrical impulses delivered via “lead electrodes” – less commonly “paddle electrodes” – that are placed in the spinal canal at the level of the spinal cord. These impulses directly stimulate the spinal cord. With various stimulation programs, pain signals entering the spinal cord via the nerve roots can be counteracted and suppressed. In classic low-frequency stimulation, patients experience a fine, pleasant tingling sensation (called “paresthesia”) in the pain area, which covers the pain. In high-frequency neurostimulation, no paresthesia is felt.
Indications for Neurostimulation
The following pain conditions can be treated with spinal neurostimulation, known as Spinal Cord Stimulation (SCS):
- Therapy-refractory back pain
- Pain after back surgery (PSPS Type 2/FBSS)
- Complex Regional Pain Syndrome (CRPS)
- Peripheral and central neuropathic pain (nerve pain)
- Peripheral arterial occlusive disease (PAOD)
Requirements for SCS
All eligible patients are evaluated interdisciplinarily by us and together with colleagues from neurosurgery, psychosomatics/psychiatry, neurology, and pain therapy. The discussion takes place regularly, either bilaterally, or at the interdisciplinary neuromodulation board at USZ. The process, including surgical procedures, is carried out in collaboration with the Department of Neurosurgery at the University Hospital Zurich, the Institute for Interventional Pain Medicine Zurich (IISZ), and the USZ Pain Ambulatory Clinic, led by Dr. D. Friis. If the conditions (indication present and no contraindication) are met, a trial, known as SCS Trial, is performed after obtaining cost approval from the health or accident insurance agency.
Procedure of an SCS Treatment
The process consists of two steps. In the first step, electrodes are placed in the spinal canal under X-ray guidance in the operating room under local anesthesia and mild sedation. Test stimulation is then performed while the patient is awake to provide feedback. Based on this feedback, the optimal electrode position is determined to cover the painful area completely. Once this is achieved, the electrode wires are brought out through the skin and connected to an external stimulator. Patients stay overnight in the hospital and are then discharged for a “test phase,” the so-called SCS Trial, which lasts from 1 to a maximum of 4 weeks. During this time, patients regularly come in for dressing changes and adjustments to the stimulation parameters.
If there is a clear positive response to neurostimulation (pain reduction, improved mobility, better quality of life), a decision is made with the patient on whether to proceed with the definitive implantation. This involves a second short surgery where the “neurostimulator” with a battery is implanted under the skin. This part, also known as the pulse generator, resembles a pacemaker. However, if it becomes clear during the test phase that the therapy is not significantly beneficial, the electrodes are removed in a short procedure under local anesthesia. The trial is therefore reversible, which is a major advantage over many surgeries.
Side Effects and Complications
Every procedure and treatment has risks, but overall, these are relatively manageable compared to many other therapies.
- Bleeding
- Electrode displacement
- Connection problems between electrodes and battery
- Battery malfunctions
- Loss of stimulation effect
- Infections
- Electrode breakage
- Cable breakage
- Battery malfunctions
- Pain in the area of the battery pocket
