A spinal cord stimulator (SCS) is an implanted electronic device that delivers low-level electrical impulses to the spinal cord to interrupt pain signals before they reach the brain. This neurostimulation therapy is a common treatment for chronic pain when other therapies have failed. Because the SCS system consists of an internal pulse generator and electrode leads placed near the spinal cord, certain activities and environments must be avoided or modified. These precautions are necessary to prevent harm to the patient and protect the device’s sensitive electronics. Understanding these constraints is fundamental to safely managing life with an SCS.
Restrictions Related to Medical Procedures and Diagnostics
Magnetic Resonance Imaging (MRI)
The most significant constraint for an SCS recipient is the use of Magnetic Resonance Imaging (MRI) technology, which utilizes extremely powerful magnetic fields. Older SCS models are generally considered “MRI Unsafe” because magnetic forces can dislodge the leads, and radiofrequency energy can heat the metal electrodes, potentially causing severe tissue damage. The strong fields can also permanently damage the pulse generator’s electronic components.
Modern SCS systems are often “MRI Conditional,” meaning a scan can be performed safely only if strict guidelines are followed. These conditions typically include scanning only at a specific magnetic field strength (e.g., 1.5 or 3.0 Tesla), restricting the area of the body being scanned, and placing the device into a specialized “MRI mode” or turning it off entirely.
High-Frequency Electrical Procedures
Procedures that use high-frequency electrical energy are largely prohibited due to the risk of transferring energy to the implanted leads. Diathermy, which uses shortwave, microwave, or ultrasound energy for deep tissue heating, is strictly contraindicated because the energy can be focused by the metal leads, leading to severe internal burns or tissue damage.
Electrocautery, which uses high-frequency currents to cut or coagulate tissue, requires the neurostimulator to be temporarily placed into a “surgery mode” or turned off completely. Only bipolar electrosurgery is generally recommended, and the current path must be kept as far as possible from the SCS components. Radiation therapy for cancer also requires careful planning, as the high-energy radiation can cause the electronic circuitry within the implantable pulse generator to malfunction.
Environmental Hazards and External Interference
Patients must avoid exposure to strong external magnetic fields, as these can interfere with the SCS operation or cause permanent damage. Common items containing powerful magnets, such as large stereo speakers, industrial motors, and high-power tools, should be kept at a safe distance. Magnets can inadvertently switch the stimulator on or off, or corrupt the programmed settings.
Security screening systems present a different type of risk due to their electromagnetic fields. Walking through metal detectors at airports or Electronic Article Surveillance (EAS) gates can cause a sudden, uncomfortable burst of stimulation or potentially damage the internal circuitry. Individuals with an SCS are instructed to carry a device identification card and request a manual search instead of passing through these scanners.
Environments with high-voltage or high-frequency energy can also cause interference. Working near arc welding equipment, powerful radio frequency (RF) transmitters, or large power generators can result in unexpected changes in stimulation intensity. These sources can temporarily disrupt the electrical function of the SCS, causing uncomfortable sensations or a temporary loss of therapy.
Limitations on Physical Activities and Movement
Driving and Operating Machinery
Driving and operating heavy machinery require specific behavioral modifications to ensure safety. If the SCS is generating paresthesia, a sudden change in stimulation intensity could occur, which may be distracting. Manufacturers recommend turning the stimulator off entirely or to a low, non-paresthesia setting before operating equipment.
Physical Strain and Impact
Physical activities that place excessive strain on the body must be limited, especially following implantation, to prevent component failure. Repetitive or extreme movements like heavy lifting, twisting, or bending can cause the electrode leads to migrate away from their optimal position. Lead migration reduces pain relief effectiveness and often requires subsequent surgery to reposition the electrodes.
High-impact activities and contact sports are restricted indefinitely to protect the implanted hardware. Activities like football, martial arts, or riding roller coasters carry a significant risk of a direct blow to the pulse generator. Such impacts can lead to severe device damage, lead breakage, or internal injury.
Environmental Extremes
Certain environmental extremes can affect the device’s function or battery life. These activities should be discussed with a physician:
- Prolonged exposure to extreme heat, such as in saunas or hot tubs, which can prematurely deplete the battery.
- Deep-sea scuba diving.
- Travel in unpressurized aircraft.
- Rapid and significant changes in atmospheric pressure, which can affect the hermetic seal of the device.