An implantable neurostimulator is a small, surgically placed medical device designed to deliver mild electrical signals to specific nerves or regions within the brain. This neuromodulation technology alters nerve activity. These devices alleviate symptoms of various chronic conditions by influencing nervous system function. This targeted electrical stimulation disrupts abnormal nerve signals, offering relief when other treatments fail.
How Neurostimulators Work
The system typically consists of three main components: a pulse generator, leads, and electrodes. The pulse generator, containing a battery, is implanted under the skin, often in the abdomen or upper buttock.
Thin, insulated wires called leads extend from the pulse generator to the specific nerves or brain regions requiring stimulation. These leads have electrodes at their tips to deliver electrical impulses. The pulse generator sends these signals through the leads to the electrodes, where they then interact with the targeted neural pathways.
Conditions Addressed by Neurostimulators
Implantable neurostimulators treat medical conditions when other therapies have not provided sufficient relief. Spinal cord stimulation (SCS) is a common application, primarily used to manage chronic pain, including conditions like failed back surgery syndrome and complex regional pain syndrome. SCS works by delivering electrical signals to the epidural space near the spine, disrupting pain signals before they reach the brain.
Deep brain stimulation (DBS) is another form of neurostimulation used for movement disorders such as Parkinson’s disease, essential tremor, and dystonia. Electrodes are placed in specific brain areas to modulate abnormal neural activity responsible for tremors, rigidity, and other motor symptoms. Neurostimulators also address certain neurological conditions like epilepsy, where vagus nerve stimulation (VNS) can help reduce the frequency and intensity of seizures, particularly for individuals whose seizures are not controlled by medication.
The Implantation Process
The process begins with a pre-operative evaluation to assess a patient’s suitability for the procedure. Many neurostimulation therapies involve an initial trial period to determine if the device will effectively alleviate symptoms. During this trial, temporary leads are typically inserted through a needle and positioned near the target nerves, connecting to an external pulse generator worn by the patient for a period, often around one week.
If the trial is successful, a permanent implantation procedure is scheduled. This surgery is usually performed on an outpatient basis and generally takes about one to three hours. During the procedure, the leads are precisely placed near the spinal cord or in the brain, depending on the condition being treated, and are often anchored with sutures to minimize movement. The neurostimulator, which is about the size of a stopwatch, is then implanted under the skin, commonly in the lower back, buttock, or abdomen, and connected to the leads.
Immediately after the procedure, patients enter a recovery phase that can last several weeks. During this time, activities involving lifting, bending, and twisting may be limited, and some discomfort at the implant site is possible. The neurostimulation system is typically not activated immediately after surgery; it is turned on once the initial recovery is complete. Initial programming of the device occurs shortly after implantation, with doctors adjusting settings for optimal symptom management.
Life with a Neurostimulator
Living with an implanted neurostimulator involves ongoing management and adjustments to integrate the device into daily life. Device programming is a continuous process, with initial settings fine-tuned during follow-up appointments to optimize symptom relief. These adjustments can involve altering the intensity, frequency, and location of the electrical pulses. Patients often receive a handheld remote control, allowing them to adjust the stimulation within physician-prescribed limits, or to turn the device on and off as needed throughout the day.
Battery life varies depending on the type of neurostimulator and its usage. Non-rechargeable devices may require surgical replacement of the pulse generator every two to five years, while rechargeable models can last ten years or more, provided they are regularly charged. Recharging typically involves placing a charging device over the skin where the pulse generator is implanted, often daily or weekly depending on usage. Regular check-ups with a healthcare provider help monitor battery status and plan for timely replacements.
Safety precautions are also part of living with a neurostimulator. Patients are typically advised to avoid operating vehicles or potentially dangerous machinery while the stimulation is active, as sudden changes in sensation could be distracting. It is also important to be aware of electromagnetic fields, as certain medical procedures like MRIs may require specific device settings or may be contraindicated depending on the neurostimulator model. Patients are provided with a medical ID card to inform healthcare professionals about their implanted device.