Deep Brain Stimulation for Epilepsy

Deep brain stimulation (DBS) is a therapy that may help reduce seizure activity in those with certain types of epilepsy. This treatment is usually reserved for people whose seizures haven't responded to other medications or therapies. DBS is a relatively new tool for epilepsy, and further studies may reveal additional uses.

This article discusses how deep brain stimulation is used, what the DBS device does inside your brain, how it's implanted, and what to expect after starting treatment.

What Is Deep Brain Stimulation? 

Deep brain stimulation is a treatment tool for epilepsy that uses electrodes and a pacemaker implanted into the brain to help control seizures. Its goal is to interrupt the brain's abnormal electrical activity or signals that can lead to seizure activity.

The concept of deep brain stimulation goes back to the 1800s, but it was not studied and adopted in its current form until the 1970s and 80s. The Food and Drug Administration (FDA) approved deep brain stimulation as a treatment strategy for seizures in 2018, though this tool had already been used for several years in Europe and abroad.

How It Works

Deep brain stimulation works by using an implanted device to initiate a stimulating impulse in the brain. This impulse can work to fight seizure activity in two ways.

One way is by interrupting the abnormal electrical activity that triggers a seizure. The other way is to use impulses from the device to raise the overall seizure threshold, making your brain less sensitive to signals that could trigger a seizure.

The location of the deep brain stimulation device can vary. In general, the device is used to target:

• The area where seizure activity develops
• Deep cortical (areas in the brain's cerebral cortex) structures to interrupt epileptic networks
• Fiber bundles that are connected to multiple areas in the brain

Targeted areas for direct deep brain stimulation typically include the following:

• Hippocampus
• Amygdala
• Hypothalamus
• Specific cortical zones

Indirect deep brain stimulation can target areas including:

• Neuronal circuits
• Cerebellum
• Basal ganglia
• Thalamus

Conditions and Symptoms DBS Can Treat

Recent research suggests deep brain stimulation is more effective in treating generalized epilepsy than focal seizures (seizures due to abnormal electrical activity).

Beyond seizures, deep brain stimulation has been used to treat conditions including:

• Parkinson's disease
• Essential tremors
• Dystonia (muscle stiffening caused by Parkinson's disease)
• Neuropsychiatric disorders
• Obsessive-compulsive disorder (OCD)

Studies have also investigated the use of deep brain stimulation in treating Alzheimer's disease and major depressive disorder, but results in treating these conditions have been inconsistent.

Who Can Get DBS?

Deep brain stimulation is a relatively new treatment for epilepsy, but it's been used for some time to treat Parkinson's disease and other conditions. If you have epilepsy and other treatments have failed to reduce seizure activity, you may be considered for DBS therapy.

Whether you are a candidate for this treatment depends on your specific type of seizure activity, your overall health, and whether you meet other criteria your surgeon may require.

Presurgical Testing

Before you are considered for deep brain stimulation, your healthcare provider will perform several examinations and tests. These include:

• A complete physical exam
• Imaging tests, such as computed tomography (CT) scan or magnetic resonance imaging (MRI)

Your healthcare team will also review your symptoms and epilepsy history to determine if deep brain stimulation is a good fit for you.

Benefits of Deep Brain Stimulation

Generally, the benefit of deep brain stimulation is a reduction in seizure activity and an overall improvement in quality of life.

One report revealed around 69% of people who used DBS for epilepsy noticed a decrease in seizure activity five or more years after implantation of the stimulation device. About 6% said seizures had stopped entirely after DBS treatment.

Complications and Side Effects

Data regarding complications and side effects of deep brain stimulation for epilepsy is limited since it was only approved in 2018. However, it's been used longer for managing Parkinson's disease, and side effects are believed to be similar.

Adverse effects that have been noted in studies specific to deep brain stimulation for epilepsy include:

• Nerve pain or numbness from stimulation (22.7%)
• Pain at the implantation site (20.9%)
• Infection of the implantation site (12.7%)
• Bleeding around electrodes

Other possible complications observed with deep brain stimulation include:

• Wound infection
• Breaks in the extension wire
• Erosion of the electrodes or wires
• Movement of electrodes
• Interference with the neurostimulator from outside devices
• Continued, worsening, or new seizures

Other side effects that can develop not from the surgery itself but from deep brain stimulation therapy include:

• Headaches
• Dizziness
• Muscle weakness
• Nausea
• Vomiting
• Difficulty speaking
• Vision changes
• Numbness or tingling
• Pain or discomfort from equipment
• Infections

What to Expect

Deep brain stimulation devices are implanted under local or general anesthesia. A team of surgeons and epilepsy experts are involved, and the entire implantation procedure can take as long as seven hours.

Preparing for Treatment

In addition to your preoperative testing, your healthcare provider may suggest the following to you before you are approved for surgery:

• Testing for pregnancy
• Quitting smoking
• Stopping or reducing alcohol use
• Stopping blood thinners
• Reviewing your current medications and vitamins

You will be given specific preoperative instructions for the day before your surgery, including when and where to arrive. This may also include instructions such as:

• Stopping certain medications
• Not eating or drinking for eight to 12 hours before surgery
• Washing your hair with a special antibacterial cleaner

During DBS

You will first receive local or general anesthesia on the day of surgery. General anesthesia is usually used for children. If you are an adult, your healthcare provider may prefer to have you awake for at least a part of the procedure to monitor responses as electrodes are placed.

Next, your surgeon will prepare you for the procedure. They will shave and numb a section of your scalp and steady your head with a device and screws. Numbing medicine will be applied where the screws come into contact with your skin.

Stage 1

Small holes are drilled into the skull where the electrodes will be placed. As they are inserted, your surgeon may ask you to move different parts of your body, respond to questions, or even read cards. Your responses in this stage will help your surgeon confirm the appropriate location of the electrodes.

Stage 2

In this stage, you will likely be placed under general anesthesia. A small incision is made below your collarbone or in your chest or belly. The device that will generate impulses—the neurostimulator—is implanted through this incision.

Once the neurostimulator is in place, your surgeon will connect it to the implanted electrodes through a long extension wire tunneled under your skin from your brain to the neurostimulator site.

Once these devices are connected and implanted, your surgeon will close the incision, and you will be taken to a recovery area while you wake up from anesthesia.

Recovery and Outlook

After surgery, you can expect to stay in the hospital for about three days. Your stimulation device will not be activated yet.

After your discharge, you will visit the healthcare provider managing your DBS therapy. The device will be turned on and adjusted to achieve the desired number and frequency of impulses. This procedure is called programming and does not require additional surgery.

Generally, people who begin treatment report an improvement in their symptoms with the device. The use of deep brain stimulation and the surgery to implant the device is riskiest in people over age 70. If needed, the procedure can be reversed.

Talking to Your Healthcare Provider About DBS

If you are interested in exploring deep brain stimulation therapy to treat seizure activity, speak with your healthcare provider to learn whether you are a candidate for it.

Not every type of seizure responds to DBS, and your healthcare provider may want you to try additional treatments or medications before undergoing the invasive procedure for DBS placement.

Summary

Deep brain stimulation is a therapy that delivers small impulses in your brain to interrupt the abnormal electrical activity that can trigger seizures or desensitize you to seizure activity.

The device to deliver these impulses can be programmed remotely, but implantation requires extensive invasive surgery. Not everyone with epilepsy is a candidate for DBS. Speak with your healthcare provider to determine whether DBS may be a promising treatment option.