Deep brain stimulation (DBS) is a neurosurgical procedure that uses implanted electrodes to deliver electrical stimulation to specific areas of the brain. It is most often used to treat movement disorders like Parkinson’s disease, essential tremor, and dystonia when medications are no longer effective. Following the surgical implantation of the DBS system, a process known as programming begins. This personalized step involves adjusting the electrical impulses to manage a patient’s specific symptoms and is necessary for the therapy to be effective.
Defining DBS Programming
DBS programming is the process of adjusting the electrical stimulation parameters of the implanted device. This is necessary because every patient’s brain anatomy and response to stimulation are different, making the process highly individualized. The primary goals are to achieve the best therapeutic benefit for a patient’s symptoms while minimizing potential side effects. For instance, the aim might be to reduce tremors or improve motor function without causing issues like speech changes.
The effectiveness of DBS depends on this careful and precise programming. In people with movement disorders, the brain’s electrical signals are often disorganized. DBS works by interrupting these irregular signals, and programming fine-tunes this interruption. This provides a more constant and steady source of therapy compared to medications, which can cause fluctuating effects, leading to more stable symptom control.
The Programming Process and Team
DBS programming is performed by a neurologist, a movement disorder specialist, or a specially trained nurse or physician assistant. The initial session takes place a few weeks after surgery, allowing the brain time to heal. During this appointment, the clinician uses a handheld device that communicates wirelessly with the patient’s implanted neurostimulator, allowing for real-time adjustments.
The patient is awake and plays an active part in the process. The programmer systematically tests different electrode contacts and stimulation settings. The patient provides feedback on how their symptoms are improving and reports any sensations or side effects they experience, making it a collaborative process.
Follow-up programming sessions are common and are used for fine-tuning the stimulation as needed. It can take several appointments to find the optimal settings, as the process is often iterative. These sessions occur in a clinic or hospital outpatient setting and can last from 30 minutes to an hour.
Adjustable Stimulation Settings
Several electrical parameters are manipulated during DBS programming to tailor the therapy. Programmers must find a balance that provides symptom relief without causing unwanted effects by adjusting the following:
- Electrode contacts: The implanted lead has multiple points, and the programmer can select which ones are active. This directs the electrical current to a very specific area of the brain to maximize benefits and avoid areas that might cause side effects.
- Amplitude: This is the strength or intensity of the stimulation, measured in volts or milliamps. Increasing the amplitude can lead to greater symptom improvement, but it can also increase the risk of side effects if the electrical field affects nearby brain structures.
- Pulse width: This refers to the duration of each electrical pulse. Altering the pulse width can change which neuronal elements are affected by the stimulation.
- Frequency: This is the rate that determines how many electrical pulses are delivered per second. Different frequencies can have varying effects on symptoms, and the optimal frequency can differ from person to person.
Patient Participation and Ongoing Adjustments
A patient’s participation is a large part of successful programming. Providing clear and honest feedback to the clinician about symptom changes and any side effects is necessary. Some patients may be asked to keep a symptom diary to track their responses between programming sessions, which helps the clinician make more informed adjustments.
Patients should also have realistic expectations. Programming is a process, and finding the optimal settings may not happen immediately. It can take time and multiple sessions to achieve the best possible outcome through a series of small adjustments.
DBS is a long-term treatment, and programming is an ongoing aspect of it. Settings may need adjustments over the years due to disease progression, medication changes, or tolerance to the stimulation. Patients receive a programmer for limited control, like turning the device on or off or switching between pre-set programs. If symptoms return or new side effects appear, contacting the medical team for reprogramming is recommended.