The Core Principle Behind Spinal Cord Stimulation
A spinal cord stimulator (SCS) is an implanted medical device designed to manage chronic pain by sending mild electrical impulses to the spinal cord. These electrical signals intercept or modify the pain signals traveling to the brain, essentially replacing the sensation of pain with a different feeling or, in some cases, no sensation at all. The system consists of a small, battery-powered pulse generator, similar to a pacemaker, and thin wires called leads with electrodes on the ends. The generator is typically implanted under the skin in the abdomen or buttocks, while the leads are placed in the epidural space near the spinal cord.
The Traditional Sensation: Paresthesia
For many years, the primary goal of spinal cord stimulation was to replace the painful sensation with a different, more tolerable one known as paresthesia.
What is paresthesia?
Paresthesia is the light, tingling, or buzzing sensation that some people with a spinal cord stimulator feel when the device is active. It is not painful but serves as a constant reminder that the device is working. The level of this tingling is customizable and can be adjusted by the patient using a handheld remote control. The intensity and coverage area of the paresthesia are fine-tuned during the trial period to ensure it effectively masks the patient's specific pain points.
Living with paresthesia-based stimulation
While effective for many, paresthesia-based stimulation isn't for everyone. Some patients find the constant tingling sensation uncomfortable or distracting, especially in certain positions or at specific intensity levels. The brain and body can also become sensitized to the sensation over time, but it remains a noticeable feeling. For those who find the paresthesia bothersome, newer technologies offer alternative solutions.
Sub-Perception Stimulation: Feeling Nothing at All
Recent advancements in neuromodulation technology have introduced spinal cord stimulators that work without producing the tingling sensation of paresthesia. These are often referred to as sub-perception, high-frequency, or burst stimulation devices.
How sub-perception stimulation works
Instead of a continuous, tingling sensation, sub-perception stimulators deliver electrical pulses at much higher frequencies or in short, rapid bursts. This approach is designed to disrupt pain signals in a different way, targeting specific pain pathways without creating a sensation that the patient can consciously feel.
Benefits of sensation-free therapy
For patients who find paresthesia unpleasant or distracting, sub-perception stimulation offers a significant advantage. The goal is to provide profound pain relief without the trade-off of a constant, engineered sensation. This allows for a more natural feeling and can be especially beneficial for those who are sensitive to the traditional paresthesia. The result is pain relief that feels more subtle, allowing the patient to go about their daily life with less distraction.
Feeling the Implanted Hardware
Beyond the electrical impulses, some patients wonder if they will physically feel the stimulator hardware itself. The device is a small, flat component placed directly under the skin, often in an area with some fatty tissue, like the abdomen or buttocks.
What to expect with the implant
- Initial soreness: Immediately following the implantation surgery, some soreness and discomfort at the incision sites are common. This is a normal part of the healing process and typically subsides within a few days or weeks.
- Feeling the device: The profile of stimulators has become smaller, but it's still possible to feel the pulse generator under the skin, especially if you press on the area. Most patients report that they quickly become accustomed to its presence. The device is not usually visible during casual observation.
- Potential for migration: Though rare, the implanted leads can sometimes shift or break, which may result in changes to the stimulation sensation or reduced pain relief. Avoiding excessive bending, twisting, and strenuous activity during the initial recovery period can help the leads settle properly.
Comparison of Spinal Cord Stimulator Sensations
| Feature | Traditional SCS (Paresthesia-Based) | Modern SCS (Sub-Perception/High-Frequency) |
|---|---|---|
| Electrical Sensation | A mild, constant tingling, buzzing, or "pins and needles" sensation. | No perceptible sensation during stimulation. |
| Mechanism | Electrical pulses interfere with pain signals and replace them with paresthesia. | Higher-frequency or burst pulses block pain signals without creating a new feeling. |
| Perceived Outcome | Pain relief is experienced by feeling the tingling sensation instead of the pain. | Pain relief is experienced as the pain simply diminishes or disappears. |
| Customization | Amplitude and frequency can be adjusted to cover different pain areas. | Settings can be adjusted to maintain pain relief with no tingling. |
| Patient Suitability | Suitable for patients who are comfortable with the paresthesia sensation. | A good option for patients who find paresthesia distracting or uncomfortable. |
| Notable Effects | Some patients find the tingling distracting, especially when changing positions. | Offers a more discreet therapy experience, which some patients prefer. |
Conclusion
To answer the question, "Do you feel a spinal cord stimulator?", the response is that it depends. You might feel a gentle tingling or nothing at all, based on the type of stimulator and personal settings chosen with your doctor. The trial period is a crucial step in this process, allowing you to experience the different sensations and determine which type of SCS provides the best pain relief with the most comfort. While you may be able to feel the implanted hardware under your skin, most people quickly acclimate to its presence. The technology has evolved significantly, offering a personalized approach to chronic pain management that can substantially improve a patient's quality of life.
Further Reading
For more in-depth information on spinal cord stimulation and living with the device, you can explore resources from the American Association of Neurological Surgeons (AANS).(https://www.aans.org/patients/conditions-treatments/spinal-cord-stimulation)
