Neurostimulation Devices for Postoperative Pain: Peripheral and Spinal Approaches

Introduction:

Healthcare professionals have prescribed painkillers (analgesics) for the past many years to alleviate pain in chronic cases after a surgical procedure or even for body aches and severe headaches. These are pharmacological medications that have side effects. Nowadays, a newer and safer technique has been introduced that uses an implantable device through which mild electrical impulses are delivered to the diseased nerves to restrict the passage of pain signals to the brain. These devices help in treating chronic pain. It is a non-invasive technique.

What Is Neurostimulation?

Neurostimulation is a scientific technique in which the peripheral nervous system (nerves present outside the brain and spinal cord) is electrically stimulated to treat chronic pain conditions. This technique uses ultrasound, electric, and magnetic fields to treat chronic pain in injuries like spinal cord injuries or neural disorders.

What Is a Neurotransmitter Device?

A neurotransmitter is a surgical device that is implanted in the patient’s body. It is approximately the size of a stopwatch. The main function of a neurotransmitter is to transmit electrical signals that are usually mild in nature to the epidural space near the spinal cord through one or more leads (thin wires).

Principle of Working- Neurotransmitters relieve pain that disrupts the pain signals between the brain and spinal cord. Pain can intensify or move according to the change in position. So, the intensity, location, and strength of the stimulus can be altered depending on the preference of a handheld programmer.

What Are the Components of a Neurostimulator Device?

There are several components in an implantable neurostimulator device, including:

• Neurostimulator - It is responsible for generating electrical impulses. The device is usually implanted under the skin in the abdomen or buttock region.

• Leads - They are thin medical wires that are insulated and deliver the impulses into the epidural space of the spinal cord.

• Doctor’s Programmer - This device is available at the doctor’s clinic, where they can adjust the device settings.

• Patient’s Programmer - It is a handheld device that the patient uses to customize their settings accordingly. It does not make any noise.

What Are the Different Types of Neurostimulation Devices Used for Postoperative Pain Relief?

A variety of neurostimulation devices have been developed to target different areas of chronic pain.

• Transcutaneous Electrical Nerve Stimulation - It is also known as TENS. It is a portable device that is noninvasive and delivers electrical impulses (electric current) to the skin through the electrodes. These electrical impulses stimulate the nerves. These stimulated nerves then disrupt the pain signals from reaching the brain. They stimulate the release of endorphins (natural painkillers of the body). This device is easy to use and accessible.

• Percutaneous Electrical Nerve Stimulation - Also referred to as PENS, it is similar to TENS in delivering electrical impulses. However, the thin electrodes are inserted through the skin to target specific clusters of nerves. The pain relief is more precise and targeted in this case. This treatment approach opts for patients who do not respond well to TENS therapy.

• Deep Brain Stimulation - It is a neurostimulation device that sends electrical signals to the deeper parts of the brain. The electrodes are surgically placed, and the pulse generator is placed near the collarbone under the skin. This therapy is used for seizures and Parkinson’s disease.

• Peripheral Nerve Stimulation - This device targets the peripheral nerves outside the spinal cord and brain. The electrodes are implanted into the skin near the pathologic nerves. It blocks the pain signals from delivering to the brain. It is used for treating peripheral nerve conditions.

• Spinal Cord Stimulation - A small device is implanted near the spinal cord. Here, the electrical impulses are directly transmitted to the spinal cord. These impulses help in blocking the pain signals along the spinal cord. This type of device is used to relieve pain in chronic spinal cord injuries, complex regional pain syndrome, back surgery syndrome that has failed, diabetes-related neuropathy, postherpetic neuralgia, and neurological pain. The spinal stimulation provides a transient or trial period, after which the patient can decide whether they want to go for permanent installation of the neurostimulation device. The spinal cord stimulators aid in alleviating various types of chronic pain.

• Vagus Nerve Stimulation - A small neurostimulator device is implanted to stimulate the vagus nerve by electrical stimulation. The vagus nerve passes through the neck, chest, and abdomen from the brainstem. It can be used to cure fibromyalgia, migraine, and epilepsy.

What Are the Factors Influencing the Choice of a Neurostimulator Device?

• Type and Location of Chronic Pain - TENS is used to relieve localized pain, whereas spinal cord stimulation is used to treat generalized and widespread pain such as that in neuropathy. Therefore, the specific condition of pain will determine the appropriate neurostimulator device.

• Pain Severity and Duration - The intensity and duration of pain determine the type of device that needs to be installed.

• Prior Therapy - The patient's previous medications, physical therapy, and other pain management techniques help to determine the appropriate neurostimulator device.

• Preferences of the Patients - Some patients prefer noninvasive devices, whereas others opt for implantable devices if these devices offer better pain relief.

What Are the Advantages of a Neurostimulator Device?

• They are found to be effective in minimizing pain for various chronic pain conditions.

• They can be customized according to the needs of the patients and the healthcare professional.

• They are noninvasive (require no surgery) and, in some cases, minimally invasive devices.

• They greatly reduce the dependence of the patient on pharmacological medications.

• They help improve patients' quality of life by reducing their chronic pain.

Conclusion:

Neurostimulation devices are innovative devices used to alleviate pain in chronic conditions. They are noninvasive and can be tailored according to the needs of the doctor and the patients. People struggling with chronic pain can benefit from these neurostimulation devices. More research is needed to explore their role in enhancing the patient’s well-being to relieve pain.