Learn about Deep Brain Stimulation (DBS)
This is intended to provide a summary of the procedure, risks and benefits of deep brain stimulation surgery. It is not a substitute for a complete discussion of the procedure with your neurologist and neurosurgeon.
If you have questions about surgery or want to know more, please feel free to e-mail us at firstname.lastname@example.org.
Most people diagnosed with certain neurological disorders or diseases find relief through drug treatment. However, in some cases, medications fail to control the symptoms. For these patients, the Functional Neurosurgery Program at Northwestern Memorial Hospital offers hope by combining advanced technology and innovative surgical techniques to relieve the symptoms and provide patients with an increased quality of life.
In the past, surgeons would create lesions in the brain, destroying the areas that were causing the disabling symptoms that were caused by neurological disorders. More recently, deep brain stimulation (DBS) has proven to be a safe and effective treatment. Conditions that may respond to this type of surgery include:
- Parkinson’s disease (PD)
- Essential tremor
Medically intractable epilepsy
- Central Pain Syndrome
- Complex Regional Pain Syndrome 1 (CRPS/RSD)
- Failed Back Surgery Syndrome (FBSS)
DBS can be compared to a cardiac pacemaker. Similar to the way the pacemaker regulates and maintains an appropriate heart rhythm, DBS maintains appropriate electrical signaling in the brain. This is done by sending continuous electrical signals to the parts of the brain where the disturbance originates, which blocks the abnormal nerve signals and alleviates the symptoms of neurological disorders.
The DBS system consists of three components: the electrode (also called a lead), the extension and the neurostimulator.
The electrode is a thin, insulated wire that is inserted through a small opening in the skull and implanted in the brain. The tip of the electrode is positioned in the area of the brain that has been identified as causing the symptoms.
The extension is an insulated wire that is passed under the skin of the head, neck and shoulder, connecting the lead to the neurostimulater.
The battery-operated neurostimulator is usually implanted under the skin near the collarbone. Sometimes it may be implanted lower in the chest or under the skin over the abdomen.
Northwestern Memorial Hospital’s Functional Neurosurgery Program is one of the leading programs in the Midwest and the first center in the Chicagoland area to use frameless technology to place deep brain stimulating electrodes without the use of the traditional confining and anchored stereotactic frame.
In the past, patients would undergo the procedure by having a stereotactic frame attached to their skull with four pins. This would ensure the patient’s head was immobilized and the placement of the electrodes was accurate. Today, nearly all patients undergo DBS using stereotactic frameless technology. Instead of having a frame attached directly to their heads, 5 small markers are attached to the skull through small incisions. With the use of a computer, CT and MRI images of the patient’s head are merged together. This gives the surgeon the ability to locate the targeted areas of the brain relative to the markers placed on the patient’s head. During the procedure, the patient’s head remains unrestrained with the head and neck supported by a soft cradle. This innovative technology makes the surgery more comfortable, allowing the patient to move around a bit, if needed, to relieve stiffness or spasm.
The actual operation to implant the DBS system is only the beginning of a process to improve the quality of life of a patient. Some of the beneficial effects of stimulation may take hours or even a few days to become fully apparent. There may be side effects from the stimulation, the medication or a combination of the two that can be inconvenient for the patient. Optimizing the balance between the stimulation and medications takes several visits over a few months. It often requires about 6 months before a comfortable balance is reached and the patient can go many months between needing follow up appointments.
Risks of Deep Brain Stimulation
Any operation carries certain risks, and it is important to know these before undergoing the DBS procedure.
Variable results in DBS relief
Not all people get as much relief as others, due to a variety of reasons:
- Each person’s brain anatomy is different
- Type of neurological disorder or disease varies
- Progression of the disorder or disease varies
Bleeding in the brain
Approximately 1 to 2 percent of patients experience bleeding in the brain, usually asymptomatic, but it can lead to:
Temporary or permanent weakness
Breakage of the device
About 1 percent experience breakage of the DBS device.
Infection of the DBS hardware
About 5 percent of patients who undergo deep brain stimulation operations get an infection of the hardware; in almost all of these cases, it is necessary to remove the hardware to fully treat the infection.
A very small percentage of patients experience cognitive decline after surgery. These patients are typically elderly and have pre-existing dementia or decline in critical thinking skills. Neuropsychological testing before the procedure usually helps identify those patients at high risk for cognitive decline so they may be counseled before surgery. The presence of dementia at preoperative testing does not completely disqualify a patient for DBS if they have tremor and other symptoms that would otherwise benefit from the procedure. It is important to fully understand these risks before the procedure, and it is necessary to discuss the neuropsychological test results with the neurologist and neurosurgeon.
Neurostimulator-induced side effects
Some patients can experience problems due to the stimulation itself, which may include:
Problems with balance
Difficulty with speech
Vague sensation of "not feeling right”
Feelings of depression or despair (a rare occurrence)
All deep brain stimulator-induced effects are temporary and reverse promptly when the stimulator is reprogrammed. After a programming session, patients should wait at the center for an hour or so before returning home to make sure the new stimulator settings are well-tolerated and do not cause side effects.
Living with DBS
Once the programming settings are stable, patients with implanted deep brain stimulators are free to participate in nearly any physical activity they choose. However, it is important to use common sense and not engage in activities that could cause direct physical trauma to the device or wires, such as:
Chiropractic neck manipulation
Repeated trauma to the wires or device
All of the above physical traumas may cause the connecting lead wire or the battery to erode through the skin, which will necessitate battery replacement.
Accidental DBS Shut Off
Deep brain stimulators may switch off by accident if patients linger in a magnetic field, such as a store security device or theft detector. Symptoms can immediately return when the stimulator switches off. If this happens, the patient may reactivate the stimulator using the handheld device. Accidental shut off of the stimulator is simply an inconvenience and carries no permanent risk to the patient or stimulator device.
Please note: microwave ovens do not pose this risk.
Situations to Avoid or Approach with Caution
Patients with implanted DBS systems may have MRI scans of the brain if performed under strict conditions to ensure the patients safety.
Check with your neurosurgeon or neurologist at your DBS center before having an MRI.
MRI scans of the brain should be performed at a center that also performs DBS procedures.
- MRI scans of other body areas, such as the neck, back, knees and hips, are not allowed under any circumstances. Diathermy (shortwave, microwave or therapeutic ultrasound)
Patients should not undergo diathermy treatment.
- Diathermy involves applying a heating coil to the skin that will interfere with the DBS hardware and device.
X-rays and CT scans are completely safe.
Patients should always contact their DBS neurologist if they have any questions about their deep brain stimulator.
Determining Candidates for Deep Brain Stimulation at Northwestern Memorial
There are no standardized criteria for patient selection, and criteria are dependent upon the symptoms or disorder.
All patients must undergo an evaluation here at Northwestern Memorial prior to being deemed a surgical candidate. This evaluation includes:
Review of records from your current neurologist that document past treatment efforts.
Thorough examinations by our neurologists and neurosurgeon to determine if your symptoms will respond well to surgery. As part of this, you will have an examination both off all medications and then after your medications are taken so that we may determine the maximal difference between your most severe off state and your best on state.
MRI of the brain within the last year to make sure there are no other factors that could account for the symptoms, as well as to insure there are no anatomic hindrances to surgery.
Detailed neuropsychological evaluation to make sure there is no dementia or other cognitive disorders. It is also intended to screen for untreated anxiety or depression. These problems do not completely prevent a person from having surgery. People with anxiety or depression just need to be under treatment so that the disorders do not interfere with the surgery or postoperative period. People with severe dementia, however, are not candidates since the operation can worsen this condition.
Detailed medical evaluation to medically optimize patients before surgery. This is usually performed by the Preoperative Service at Northwestern Memorial Hospital.
For more information about Deep Brain Stimulation you may e-mail us at email@example.com or call the Functional Neurosurgery Program at 312-695-8143.