Researchers Seek to Use the Brain's Own Messages to Fine-Tune DBS Surgery
CINCINNATI--The brain is a chatty entity. Its cells, alive with electrical activity, make noise day and night, in an atonal, static-y kind of way.
George Mandybur, MD, a neurosurgeon with the Mayfield Clinic, has learned to listen carefully to the sounds of brain cells. As he threads micro-electrodes through the brain of a patient with Parkinson’s disease, the sounds help him know when he has arrived at the correct spot.
Dr. Mandybur hopes to understand the sounds even better, so that deep brain stimulation (DBS) surgery can bring even greater quality of life to patients with Parkinson’s disease. "Our aim is to refine the DBS procedure," Dr. Mandybur says. "We want to be able to adjust the stimulation more effectively."
Although DBS surgery has been approved for the treatment of Parkinson’s symptoms for more than 10 years, Dr. Mandybur says, "No significant advancements have been made in its surgical implementation or in the programming paradigms that follow surgery. There is room for improvement. We want to establish best practices in probe design, electrode placement and stimulator programming."
To accomplish this goal, Dr. Mandybur and Kevin Biddell, PhD, are using a $50,000 grant from Mayfield Education & Research Foundation to record the sounds of brain cells during DBS surgery as the micro-electrodes pass slowly through the brain. Dr. Biddell, a biomedical engineer at Biosynesi LLC, is processing the vast amounts of data collected during surgery in an effort to understand the differences between the various types of cells.
Biomedical engineers have previously developed models of the brain’s workings using animal models, Dr. Mandybur says. "Those models include mathematical equations that define how certain parts of the brain interact with each other. We are going to take some of that information and translate it to the human world."
Dr. Mandybur is most interested in perfecting the entry and exit from the sub-thalamic nucleus, an area the size of a tic-tac deep inside the brain where electrodes are placed in the treatment of Parkinson’s disease. Placement of electrodes in the subthalamic nucleus can reduce tremor, slowness, rigidity, involuntary muscle contractions and wiggly movements called dyskinesias.
"Our recent understanding of signals from cells in the subthalmic nucleus suggests that an abnormal signal is generated here by the diseased circuitry," Dr. Mandybur says. "We postulate that abolishing these abnormal signals could result in improved symptoms of Parkinson’s disease."
Drs. Mandybur and Biddell are collaborating in their research with the University of Cincinnati Medical Center and the UC Department of Neurology and Rehabilitation Medicine.
Their research is in its earliest stages, Dr. Biddell says. "Our first goal is through listening to determine where we are in a more precise way. We are gathering information. Our next step will involve looking at how we can use this data to maximize DBS’s potential to improve patients’ quality of life."
Dr. Mandybur estimates that this type of work is being replicated at only a handful of centers around the world.
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The Mayfield Clinic, an independent, single-specialty academic neurosurgery group, is recognized as one of the nation's leading physician organizations for clinical care, education, and research of the spine and brain. With more than 20 specialists in neurosurgery, interventional neuroradiology, physical medicine and rehabilitation, and pain management, the Clinic treats 25,000 patients from 35 states and 13 countries in a typical year. Mayfield's physicians have pioneered surgical procedures and instrumentation that have revolutionized the medical art of neurosurgery for spinal diseases and disorders, brain tumors, and neurovascular diseases and disorders. Learn more about Mayfield at mayfieldclinic.com.
Kevin Biddell, PhD, left, and
George Mandybur, MD