Deep Brain Stimulation

OVERVIEW

Deep brain stimulation (DBS) is an elective surgical procedure in which electrodes are implanted into certain brain areas. These electrodes, or leads, generate electrical impulses that control abnormal brain activity. The electrical impulses can also adjust for the chemical imbalances within the brain that cause various conditions. Stimulation of brain areas is controlled by a programmable generator that is placed under the skin in the upper chest.

The DBS system involves three distinct components:

• The electrode, or lead, is a thin, insulated wire inserted through a small opening in the skull and implanted into a specific brain area.
• The extension wire is also insulated and passed under the skin of the head, neck and shoulder, connecting the electrode to the internal pulse generator (IPG).
• The IPG is the third piece of the system and is usually implanted under the skin in the upper chest.

Conditions that are treated using DBS are:

• Dystonia
• Epilepsy
• Essential tremor
• Obsessive-compulsive disorder
• Parkinson’s disease

Causes

DBS is a surgical intervention used to treat patients with movement disorders such as essential tremor, Parkinson’s disease and dystonia. It can also be used to control symptoms of obsessive-compulsive disorder and epilepsy. This procedure is utilized when medications are no longer effective for patients maintaining good quality of life.

These diseases affect hundreds of thousands of people worldwide. DBS has been used to treat over 160,000 people for various neurological conditions.

Symptoms

Each disease type has a variety of symptoms that patients may experience. Common ones are:

Dystonia

• Involuntary muscle contractions occurring during specific actions (e.g. writing)
• Muscle contractions worsen with stress, fatigue or anxiety

Epilepsy

• Temporary confusion
• A staring spell
• Loss of consciousness
• Uncontrollable jerking movements of arms or legs
• Emotional responses such as fear, anxiety or déjà vu

Essential Tremor

• Tremor occurring during daily activities like writing or drinking

Obsessive-compulsive Disorder

• Fear of germs or contamination
• Aggressive thoughts towards others or one’s self
• Having things in symmetrical or in perfect order
• Excessive cleaning or handwashing
• Compulsive counting
• Checking things repeatedly (e.g. oven is off, door is locked, etc.)

Parkinson’s Disease

• Tremor
• Bradykinesia – slowing down of movement
• Stiffness
• Abnormal walking

When & How to Seek Medical Care

DBS is used when medications are no longer effective for patients maintaining good quality of life. See your doctor if any of the above symptoms are persistent for an extended period to discuss if DBS is the right treatment.

TESTING + DIAGNOSIS

There is a multidisciplinary team of professionals including a neurologist, neurosurgeon, neuropsychologist and psychiatrist that may care for patients. Often patients with Parkinson’s disease or tremor may undergo testing of motor symptoms on and off medications to assess the severity of the disease. Epilepsy testing may include electroencephalography, including more advanced testing. Certain patients may undergo neuro-psychological evaluation during evaluation. Obsessive-compulsive disorder patients must complete Yale-Brown Obsessive Compulsive scale (YBOCs) testing.

Prior to surgery, patients undergo:

• Blood and urine tests
  • This helps identify toxins and abnormalities
• MRI and/or CT scans
  • Imaging can help doctors target the right area of the brain for symptom relief.
• Medical Clearance

Candidates for DBS meet these criteria:

• Symptoms are substantially reducing quality of life.
• Symptoms are uncontrolled despite receiving the suitable dose of medications.
• Side effects stemming from current medications cannot be tolerated

Treatment + Care

Non-Surgical Treatments

Before being considered for surgical interventions such as DBS, doctors may consider any of the following treatments.

• Medications
• Physical Therapy

Surgery

Advantages

• Can be performed on one or both sides of the brain, depending on symptoms.
• The effects are reversible and can be customized individually for each patient’s clinical status.
• Stimulation settings can be modified to diminish potential side effects and improve effectiveness over time.
• The device can provide continuous symptom control 24 hours a day.
• Patients who have undergone DBS can participate in other treatments, such as stem cell or gene therapy, when they become available.

Risks

In patients who are properly selected, DBS is safe and effective. Risks and potential side effects do exist, but they are generally mild and reversible.

Risks may include:

• 1% risk of brain hemorrhage, including stroke
• Infection
• Device malfunction
• Lack of benefit for certain symptoms
• Headache
• Worsening mental or emotional status

During stimulation, side effects may include:

• Temporary tingling in the face or limbs
• A feeling of pulling in muscles
• Speech or vision problems
• Loss of balance

Resources

• Surgical option a potential life-changer for patients with OCD: Read and watch Erin’s story as she, a lively 21-year-old woman, fought her battle with OCD. This article explores how deep brain stimulation gave Erin her life back. The procedure was the first of its kind performed at Albany Medical Center – the only facility offering this treatment between New York and Boston. In Erin’s own words, “Now, I can be who I really am and tell people my story and hopefully inspire people and help people along the way.”
• Karen and Jim’s Story: A Shared Journey of Life, Love and DBS: Read about Karen and Jim. They were each diagnosed with Parkinson’s before they met. Follow them on their journey as they fall in love after meeting each other from an online support group. See how they embraced each other and DBS.
• Kay’s Story – A Parkinson’s Disease Patient: Read about Kay, a 68-year-old woman suffering from Parkinson’s disease. The article and video explore how DBS helped her regain her life. In Kay’s own words, “It’s like I had been turned on again. It was like a miracle.”

The electrodes and electrical systems that provide stimulation are generally very well tolerated with no significant changes in surrounding brain tissue. Migration of the electrode from the original implantation site may occur. There also may be temporary rebound worsening of the tremor when stimulation is stopped. Surgery risks increase in people age 70 and older, and in those with other health conditions such as cerebrovascular disease and high blood pressure. The benefits of surgery should always be weighed carefully against its risks. Although a large percentage of patients report significant improvement after DBS surgery, there is no guarantee that surgery will help every individual.

Sources

• Charles, D., Tolleson, C., Davis, T. L., Gill, C. E., Molinari, A. L., Bliton, M. J., … Konrad, P. E. (2012). Pilot study assessing the feasibility of applying bilateral subthalamic nucleus deep brain stimulation in very early stage Parkinson’s disease: study design and rationale. Journal of Parkinson’s disease, 2(3), 215–223. doi:10.3233/JPD-2012-012095. This pilot study conducted at Vanderbilt University explores the application of DBS in patients with early stage Parkinson’s disease. They hope to utilize this dataset in order to support and design a Phase III, multicenter trial.
• Hamani, C., Pilitsis, J., Rughani, A. I., Rosenow, J. M., Patil, P. G., Slavin, K. S., … Kalkanis, S. (2014). Deep Brain Stimulation for Obsessive-Compulsive Disorder. Neurosurgery, 75(4), 327–333. doi: 10.1227/neu.0000000000000499 This article established evidence-based guidelines on DBS when used to treat patients with OCD. The authors conclude that of the existing studies, in one class I and two class II double-blind, randomized, controlled trials it was reported that bilateral DBS is more effective in improving OCD symptoms than sham treatment.
• Salanova, V., Witt, T., Worth, R., Henry, T. R., Gross, R. E., Nazzaro, J. M., … SANTE Study Group (2015). Long-term efficacy and safety of thalamic stimulation for drug-resistant partial epilepsy. Neurology, 84(10), 1017–1025. doi:10.1212/WNL.0000000000001334. This study aimed to report long term efficacy and results of the SANTE trial that explored DBS of the anterior nucleus of the thalamus for treatment of epilepsy. They found that long-term follow up of the ANT DBS sustained efficacy and safety in patients that resisted prior treatment.
• Follett, K. A., Weaver, F. M., Stern, M., Hur, K., Harris, C. L., Luo, P., … Reda, D. J. (2010). Pallidal versus Subthalamic Deep-Brain Stimulation for Parkinsons Disease. New England Journal of Medicine, 362(22), 2077–2091. doi: 10.1056/nejmoa0907083. This study was conducted as a multi-center clinical trial for patients with idiopathic Parkinson’s disease. Patients were randomly assigned to have either the globus pallidus interna or subthalamic nucleus stimulated. The authors concluded that all patients had comparable improvement in their motor function after either type of stimulation.
• Weaver, F. M., Follett, K. A., Stern, M., Luo, P., Harris, C. L., Hur, K., … Reda, D. J. (2012). Randomized trial of deep brain stimulation for Parkinson disease: thirty-six-month outcomes. Neurology, 79(1), 55–65. doi:10.1212/WNL.0b013e31825dcdc1. This study was conducted to compare long term outcomes of patients receiving DBS targeting either the globus pallidus interna or subthalamic nucleus. The authors concluded that the study provided Class III evidence that, over the course of three years, the improvement of motor symptoms of PD remains stable and does not vary based on the surgical target.