What is deep brain stimulation (DBS)?
Deep brain stimulation (DBS) is a type of treatment for symptoms of some movement disorders, including dystonia, essential tremor, and Parkinson's disease (PD). DBS uses a surgically implanted, battery-operated device to send electrical signals to areas in the brain that control movement. The signals from DBS control (regulate) the nerve signals that cause movement disorder symptoms. It is a safe and effective treatment for many movement disorders that are not responding to medication.
More recently, DBS was also FDA-approved to treat epilepsy. The signals from DBS deliver stimulation to a part of the brain involved in the spread of some types of seizures.
A DBS system has three main components:
- The electrode or lead is a thin, insulated wire inserted into the brain at different locations depending on what condition the DBS system will treat. Doctors insert the leads through small openings made in the skull.
- The extension wire is an insulated wire placed under the skin and links the lead at the top of the person’s head with the location near the collar bone where it connects with the battery pack.
- The battery pack, also called the implantable pulse generator (IPG), is the power source of the DBS system. Doctors usually implant the battery pack under the skin near the collarbone. In some cases, doctors position the battery back lower in the chest or under the skin over the abdomen.
The battery pack creates electrical pulses that travel through the extension wire and to the lead in the brain. These pulses change the brain's electrical activity at a target site to regulate the signals sent to muscles and reduce movement disorder symptoms. After DBS surgery, a doctor programs the signals sent by the DBS system. DBS programming fine tunes the system to be most effective for the person. Finding the right DBS setting can be a complex process and may take multiple visits with a neurologist.
DBS was first approved by the U.S. Food and Drug Administration (FDA) in 1997. NINDS-supported research on brain circuitry was critical to the development of DBS. Today, NINDS-funded researchers are continuing to study and improve DBS treatments.
In one current study at the NINDS clinical center, people with DBS for Parkinson’s, dystonia, or essential tremor receive on-going care to monitor the effects of DBS. Researchers periodically examine people in the study after DBS surgery and adjust their DBS programming. The study tests movement, thinking, and memory in DBS recipients. Several other clinical studies track people after DBS surgery to find ways that the DBS can be more effective and reduce side effects or complications.
How does deep brain stimulation treat disorders?
DBS works by regulating signals that cause movement symptoms. DBS can target different areas of the brain, depending on what condition it is used to treat. Current DBS methods typically target one of the following areas of the brain:
- Globus pallidus internus, which helps regulate intended movement (targeted in PD and dystonia treatment)
- Subthalamic nucleus, which helps direct how the body prepares to move (targeted in PD and dystonia treatment)
- Thalamus, which relays and integrates sensory and movement information (targeted in PD and essential tremor treatment)
Before DBS surgery, a neurosurgeon uses noninvasive imaging—either MRI (magnetic resonance imaging) or CT (computed tomography) scans—to find the best place in the brain to implant the DBS leads. During DBS surgery, many surgeons insert a small wire to monitor the activity of nerve cells and to identify the exact area of the brain that the DBS system will stimulate.
How do I know if deep brain stimulation is right for me?
DBS can help improve movement symptoms, such as difficulty maintaining posture or involuntary movements. It can be a powerful tool for treating movement disorders, but it is not a cure. DBS helps manage symptoms, but it doesn’t slow the progression of neurodegeneration caused by some movement disorders. DBS can help treat symptoms of many movement disorders, including PD, dystonia, essential tremor, and epilepsy. Most commonly, DBS systems are used to treat PD.
DBS is usually used for people whose symptoms do not respond to medicine. However, in the case of PD and some other conditions, only people who see some improvement after taking medicine, will benefit from DBS. Most people still need to take medicine after undergoing DBS surgery but may be able to reduce the dosage they take. Improvements in symptoms may be different depending on the person. People with signs of dementia are not good candidates for DBS.
People considering DBS surgery should work together with their doctors to carefully consider whether DBS is the right treatment for them and whether it will provide more benefit than harm. DBS requires ongoing care and maintenance, and people with DBS systems will need to have long-term relationships with their healthcare teams.
Most DBS systems only treat some of the motor symptoms caused by movement disorders like PD. However, current NINDS research on DBS targets, modifications, and adjustments may help treat additional motor symptoms, sleep disruption, and cognitive symptoms. Recent NINDS research has also made breakthroughs in understanding how DBS affects speech for people with PD, which may help prevent side effects in the future.
Additionally, NINDS research is exploring ways to use DBS to treat more neurological disorders, including Tourette syndrome, stroke, cerebral palsy, and Rett syndrome. Current clinical trials are recruiting people with Tourette syndrome and cerebral palsy to test the safety and effectiveness of DBS treatment.
Ethical considerations in DBS
Neuroethics explores the ethical, legal, and social questions surrounding brain research and treatments like DBS. While DBS can improve movement and quality of life for people with conditions like PD, it may also affect mood or personality.
Healthcare providers must carefully consider each person's needs and weigh the benefits and potential risks. Neuroethicists work with researchers to address these challenges and ensure neuroscience moves forward in a way that respects people's rights, values, and well-being.
The NIH’s Brain Research Through Advancing Innovative Neurotechnologies® Initiative, or The BRAIN Initiative®, integrates neuroethics into its work, supporting research, training, and funding opportunities to navigate complex ethical issues in neuroscience. Researchers can connect with neuroethicists, request bioethics consultations, or explore funding for neuroethics research through NIH and other organizations.
Advantages of DBS
DBS involves few permanent surgical changes to the brain. Surgeons can remove the battery pack to stop DBS treatment at any time if a person experiences side effects. The signals sent by the DBS system are also easy to adjust without needing more surgery. This allows doctors to adjust DBS programming if a person's symptoms change as the disease progresses.
People with DBS also have access to a “patient programmer,” which allows the patient to turn the device off if it interrupts their sleep—they may need to avoid certain scanners when going through security. or when going through a security scan. In some situations, doctors can also set the patient programmer so that patients can make small adjustments to their levels of stimulation themselves.
Risks associated with DBS
DBS requires an invasive surgical procedure, and surgeries always carry some risk. In rare cases, placement of the DBS system can cause bleeding or infection in the brain. Mechanical stress on the device may cause DBS complications, such as bleeding and brain tissue swelling of the brain. Other complications may include headache, seizures, and temporary pain following surgery.
The signals from DBS may affect the brain tissue surrounding the system’s intended target. This can cause side effects, including cognitive symptoms. Additional side effects of DBS may include numbness or tingling sensations, behavioral changes, balance difficulties, or worsening speech. DBS settings can usually be adjusted to reduce some of these side effects.
DBS hardware may also break down over time, and the battery pack may need to be replaced. Some DBS devices are designed with rechargeable batteries to extend the life of the battery pack. Additional surgery is required to replace broken parts of a DBS system.
NINDS funds research focusing on improving the effectiveness and longevity of DBS while minimizing side effects. Research on DBS that uses shorter pulses of signals instead of constant signals may help reduce side effects, prolong system battery life, and provide longer symptom relief.
The FDA recently approved a new, adaptive DBS system for PD. Adaptive DBS devices monitor signals in the brain to deliver targeted treatment in response to signals that are associated with symptoms, instead of delivering treatment constantly. These systems may help improve side effects and prolong battery life. In fact, a recent study supported by NIH found that people with PD whose symptoms did not respond to classic DBS experienced fewer symptoms and better quality of life in response to adaptive DBS.
What role does deep brain stimulation play in research and clinical trials?
NINDS-funded research and clinical trials studying DBS help researchers learn more about movement disorders, movement disorder treatments, and how the brain controls movement. DBS research also raises critical neuroethical considerations, particularly regarding patient consent, autonomy, and the potential long-term effects of brain modulation (making changes to the way the brain works).
Researchers studying DBS must carefully balance the promise of symptom relief with ethical concerns about unintended cognitive or emotional changes. Clinical trials exploring DBS for movement disorders provide valuable insights into treatment efficacy and the broader implications of altering brain activity. These studies help inform guidelines for responsible research and clinical applications, ensuring that DBS continues to be a safe and effective option for those who need it.
DBS surgery provides a unique opportunity for researchers to gather data on the brain. During DBS surgery, researchers can study how the brain reacts to different situations and collect data on how the brain controls movement. A person undergoing DBS surgery may be eligible for one of many clinical trials on a variety of subjects during and following their surgery.
For information about participating in clinical research visit the NINDS Clinical Trials site and NIH Clinical Research Trials and You. Learn about clinical trials involving DBS at Clinicaltrials.gov, a searchable database of current and past clinical studies and research results.
For more information about DBS research for movement disorders, visit NIH RePORTER, a searchable database of current and past research projects supported by NIH and other federal agencies. The database includes links to publications and resources from NINDS-supported projects.
For research articles and summaries on DBS, search PubMed, which contains citations from medical journals and other sites. You can also learn more about DBS at MedlinePlus.gov.
Where can I find more information about deep brain stimulation?
Information may be available from the following sources: