Deep brain stimulation offers hope to those with Parkinson's and other neurological disorders
Neurosurgeon Michael C. Park, MD, PhD, has very little room for error—only a half-millimeter, in fact.
Park oversees and conducts a procedure called deep brain stimulation, also known as neuromodulation. During the procedure, surgeons implant an electrode inside the brain of patients with Parkinson’s disease, essential tremor, dystonia, or other neurological disorders such as epilepsy and obsessive-compulsive disorder (OCD). The electrode is connected by wire to a pacemaker-like device implanted in the patient’s chest. This device can then deliver electrical stimulation to regulate abnormal electrical signals originating in the brain.
The procedure is effective at relieving the debilitating tremors, slowed movement, and other symptoms of Parkinson’s disease. But only if that electrode is placed in exactly the right spot—within a half-millimeter of a pea-sized target within the brain.
Advanced imaging helps doctors see inside the brain
Park considers himself fortunate to practice within M Health Fairview, which has access to one of the world’s most advanced magnetic resonance imaging (MRI) devices at the University of Minnesota. Stationed at the Center for Magnetic Resonance Research, the MRI device is powered by a 7-tesla and now 10.5-tesla magnet that weighs 110 tons.
The higher the magnet strength (tesla), the better the image quality. Park says it’s common for hospitals to have 1.5- to 3-tesla MRIs. He compares using a 7-tesla MRI machine to switching from a regular television to a 4K high-definition TV.
The advanced MRI and the image processing technology can define the tiniest structures in the brain with high definition, Park said. This helps Park place his deep brain stimulation electrodes in the brain with a high degree of accuracy.
Of course, detailed imaging doesn’t guarantee success. For that reason, Park actually uses microelectrodes to listen to the electrical signature of the brain during placement of the DBS electrode.
“Different parts of the brain have a certain signature, a firing characteristic,” Park said. “It all sounds like static, but to a trained ear, it can serve as a guide.”
Deep brain stimulation has long been recognized as an effective treatment for Parkinson’s. Research keeps finding new applications for the electrodes. Essential tremor, dystonia, epilepsy and obsessive-compulsive disorder can all be treated by the procedure, Park said. There are indications it may also prove to be helpful in relieving the symptoms of depression, treating certain pain conditions and restoring memory in patients with Alzheimer’s disease.
The minimally invasive procedure carries relatively little risk, Park said. There are no pain receptors in the brain, so general anesthesia isn’t required when inserting the electrodes, and the opening surgeons make into the skull is tiny. During parts of the procedure, the patient is awake so the electrical activity of the brain can be recorded and mapped.
Learn more about M Health Fairview’s neurosurgical services.
New methods target individual symptoms
Deep brain stimulation has advanced significantly in recent years. Doctors and researchers have found ways to get even more exact with the stimulation, tailoring the procedure to each patient’s symptoms. Two new techniques – directional electrodes and multiple independent current control – allow surgeons to better direct the electrical stimulation in a patient’s brain.
Directional deep brain stimulation allows surgeons to point the current in the direction of their choice. Instead of a candle, the stimulation turns into a targeted flashlight, Park explained. Multiple independent current control allows doctors to distribute electrical current to different electrode contacts simultaneously and control them independently. Park compares this to having individual light dimmers in every room of a house. Doctors can increase and decrease stimulation in different parts of the electrode as needed.
“In the end, we can customize stimulation to better fit each patient,” said Park. “People with Parkinson’s disease experience a whole range of symptoms. Some may struggle more with tremors. Some may struggle more with stiffness. New technologies allow us to better single out and address patients’ primary concerns.”
Many of the new pacemaker-like devices that are implanted during deep brain stimulation can also connect to the programmer using Bluetooth. Certain devices also have remote access capability so for those that live far from the hospital may not need to come in as much for maintenance or small adjustments.
Learn more about Parkinson's disease care at M Health Fairview.
Growing our team of dedicated specialists
M Health Fairview has grown to include more neurosurgeons who are able to perform deep brain stimulation. Park sees patients in addition to Robert McGovern, MD, and David Darrow, MD.
“There aren’t many places that have three neurosurgeons who can perform this procedure,” said Park. “Our deep brain stimulation team is growing, along with the range of device options we’re able to offer patients.”
Deep brain stimulation patients also have access to a multidisciplinary team of M Health Fairview experts, including renowned neurologists treating movement disorders, Park said.
“Patients who see me actually get access to a whole team working behind the scenes—neurophysiologists, imaging center researchers and specialists, biomedical engineers, and scientists developing new advances,” said Park. “All of us are working for the same goal: making this operation safer and more effective for our patients.”
“There’s a large group of University of Minnesota scientists looking into the field of deep brain stimulation and neuromodulation,” Park added. “There are some exciting possibilities on the horizon.”
