The sweet spot? UF doctors test targets for Parkinson surgery

March 16, 2009

GAINESVILLE, Fla. - Doctors may be able to tailor a specialized form of brain surgery to more closely match the needs of Parkinson patients, according to results from the first large-scale effort to compare the two current target areas of deep brain stimulation surgery, or DBS.

Called the COMPARE Trial, the National Institutes of Health-funded study conducted at the University of Florida evaluated 45 patients for mood and cognitive changes related to DBS.

UF investigators found that DBS in either brain target effectively treated motor symptoms such as tremors, stiffness and slowness.

However, DBS also produced unique effects depending on the target location, especially in patients' moods and mental sharpness.

The discoveries, in today's (March 13, 2009) Annals of Neurology, may have an impact on the selection of DBS patients, especially those with pre-existing memory, cognitive or mood disabilities.

"Both targets are FDA-approved and provide excellent outcomes for motor function in Parkinson patients," said Michael S. Okun, M.D., the principal investigator of the study and a co-director of the Movement Disorders Center at UF's McKnight Brain Institute. "But there were differences in cognitive function and verbal fluency seven months after the surgery, and that is something that should be considered when trying to tailor therapy to an individual patient's condition."

DBS received Food and Drug Administration approval in 2002 as a therapy for movement-related problems associated with essential tremor and Parkinson's disease. It uses a medical device surgically implanted in a patient's brain and connected to a power pack in the shoulder region. DBS delivers electrical pulses to targeted areas of the brain via very thin wires, known as "leads." Each lead ends with four distinct electrical "contacts."

Currently, in almost all cases worldwide, the leads are implanted in a brain region known as the subthalamic nucleus. But the nearby globus pallidus interna, or GPi, may again emerge as a viable target, especially for patients with mood and cognitive issues, researchers say.

Forty-five volunteers with moderate to advanced Parkinson's disease completed the prospective, randomized study. Twenty-three received leads to the GPi and 22 to the subthalamic nucleus.

Before surgery, scientists at UF's Cognitive Neuroscience Laboratory evaluated the patients' verbal fluency, memory, attention and cognitive processing. Patients were retested about seven months later during four conditions - with stimulation at the optimal contact point on the lead as determined during previous programming sessions, with stimulation at contact points adjacent to the optimal one, and with stimulation turned off. Examiners and patients were blind to the conditions as well as to the brain target.

Generally, the target choice produced no major differences in motor function, mood or cognition in the patients. However, patients whose leads were implanted in the subthalamic nucleus, the most common surgery target, did have increased problems with verbal fluency and mood - and they tended to be more angry and irritable.

"We think it will be important to tailor the therapy to the patient," said Kelly D. Foote, M.D., an associate professor of neurosurgery at the College of Medicine and a co-director of the UF Movement Disorders Center. "Targeting the traditional location - the subthalamic nucleus - might be better for someone who is younger and healthier. But for someone who is older with memory problems, or perhaps in the early stages of dementia, it would be important to consider the alternative."

The traditional target does have unique advantages, Foote said. It seems to be more effective at reducing a patient's medications, which may lead to an improved quality of life and cost savings. In addition, because it is relatively smaller - about a third the size of a pea - less electricity was required to stimulate this area, which is an important consideration because more surgery is required to replace DBS batteries.

More study will be necessary to determine whether DBS target choice can be tailored to meet individual patient needs. However, in considering the surgery, potential patients need to weigh the benefits of DBS against risks such as mild cognitive decline.

"It is unclear whether these mild cognitive changes are clinically significant in terms of the patient's everyday life," said Dawn Bowers, Ph.D., a professor in the department of clinical and health psychology in the College of Public Health and Health Professions and the director of the Cognitive Neuroscience Laboratory where the patients were assessed. "Though important, they pale in comparison to the tremendous boost these patients receive in motor behavior."

In the meantime, scientists say uses for DBS technology will continue to move beyond the movements disorders field.

"It is vitally important that we take the opportunities afforded to us by deep brain stimulation technology to better understand what underpins mood and cognitive circuitry in the brain," said Okun, who is also an associate professor of neurology and neurosurgery at the UF College of Medicine and the national medical director of the National Parkinson Foundation. "What we have learned from Parkinson's disease we are now taking into other areas, and as we unlock the circuitry, we can apply new technologies to ultimately improve quality of life."

University of Florida

---

---

	Deep Brain Stimulation: A New Life for People with Parkinson's, Dystonia and Essential Tremor by Kelvin L. Chou (Author), Susan Grube (Author), Parag Patil (Author) In the United States, an estimated 42 million people suffer from some form of movement disorder, including Parkinson’s disease (PD), essential tremor (ET), and dystonia. Although medications may be helpful for these conditions, in many patients, symptoms cannot be controlled with medications alone. In such situations, their physicians may recommend a surgical procedure known as Deep Brain Stimulation (DBS). DBS is a revolutionary technology using an implanted device to deliver electrical stimulation to the brain to help symptoms, alleviate suffering, and improve quality of life. Deep brain stimulation has dramatically changed the lives of many patients with uncontrollable tremors. Patients often can resume normal activities, such as feeding and dressing themselves, and can...
	Deep Brain Stimulation Programming: Principles and Practice by Erwin B. Montgomery Jr. MD (Author) Deep Brain Stimulation (DBS) is a remarkable therapy for an expanding range of neurological and psychiatric disorders. In many cases it is better than best medical therapy and succeeds even when brain transplants fail. Yet despite the remarkable benefits, many physicians and healthcare professionals seem hesitant to embrace this therapy. Post-operative programming of the DBS systems seems unfamiliar, even mysterious, and is viewed as difficult and time consuming. However, DBS programming is rational and can be efficient and effective if one understands the basing underlying concepts of electronics, electrophysiology, and the relevant regional anatomy. Even these principles can be relatively easy to grasp. The book helps the reader to obtain an intuitive understanding of the...
	Deep Brain Stimulation Management (Cambridge Medicine) by William J. Marks Jr. (Editor) Deep Brain Stimulation Management is a practical guide to the use of this paradigm-shifting therapy for movement disorders, including Parkinson's disease, essential tremor, and dystonia. This title is an essential resource for clinicians who wish to begin utilizing DBS, as well as current practitioners seeking to improve their understanding and application of the technique. Highly illustrated and in full color throughout, this comprehensive book covers the key aspects of DBS practice, including patient selection, device programming and activation to achieve optimum symptom control, long-term management, and trouble-shooting. With contributions from some of the most experienced clinical leaders in the field of DBS and extremely practical content, this is an essential reference text for any...
	Life With a Battery-Operated Brain - A Patient's Guide to Deep Brain Stimulation Surgery for Parkinson's Disease by Jackie Hunt Christensen (Author) Why would anyone say ''Let's stick wires into someone's brain, run voltage through it, and see what happens!'' So asks Jackie Hunt Christensen in Life With a Battery-Operated Brain: A Patient's Guide to Deep Brain Stimulation Surgery for Parkinson s Disease. Author Christensen answers this question -- and more -- in her unique and comprehensive book, as she has first-hand knowledge of the procedure commonly referred to as DBS. She herself lived with Parkinson's disease for more than seven years before electing to be evaluated for DBS surgery. It was not a fast and easy choice. For Christensen, a fear of DBS surgery -- which involves placing one or two electrical wires inside the brain -- and its potential complications had to be weighed against quality of life without the surgery, a life...
	Deep Brain Stimulation: A New Treatment Shows Promise in the Most Difficult Cases by Jamie Talan (Author) There are disorders that defy treatment with prescribed pharmaceuticals: a man’s hands shake so hard that he cannot hold anything; a woman is mired in severe inescapable depression. For these patients and others, an alternative is emerging: deep brain stimulation. In this fascinating and timely investigation, well-known science writer Jamie Talan explains a cutting-edge medical development that is surprising and impressing researchers around the world. More than 40,000 people worldwide have undergone deep brain stimulation, which involves implanting electrodes in the brain that are connected to a device similar to a pacemaker. With compelling profiles of patients and an introduction to doctors and scientists who are pioneering the research, Talan describes the ways in which deep brain...
	Deep Brain Stimulation in Neurological and Psychiatric Disorders (Current Clinical Neurology) by Daniel Tarsy (Editor), Jerrold Lee Vitek (Editor), Philip Starr (Editor), Michael Okun (Editor) Written by renowned authorities in the field, Deep Brain Stimulation in Neurological and Psychiatric Disorders discusses today s most current and cutting-edge applications of DBS. Initially used to treat Parkinson s disease and essential tremor, DBS now has new clinical indications, new anatomic targets, and new technologies that enable an expanded role for DBS in the treatment of other movement disorders such as dystonia, and for other neurologic disorders such as epilepsy, Tourette syndrome and cluster headache. Early experience has also been reported for psychiatric syndromes, such as obsessive-compulsive disorder and depression. This important book begins with reviews of the functional anatomy and physiology of motor and nonmotor aspects of the basal ganglia and their connections...
	Deep Brain Stimulation by Peter Bain (Author), Tipu Aziz (Author), Xuguang Liu (Author), Dipankar Nandi (Author) Deep brain stimulation (DBS) is increasingly used for the treatment of patients with severe Parkinson's disease and other movement disorders, but the technique and science behind it is still poorly understood by most clinicians. This book is intended to provide an overview of the use of deep brain stimulation for movement disorders and to provide an introduction to the developing areas of DBS for psychiatric disease. The first part of the book covers the varying surgical techniques involved in implanting electrodes into various deep nuclei within the brain. The neurophysiological techniques involved in this process and the complex issue of programming the implanted stimulator in order to optimize therapeutic efficacy and minimize stimulation induced adverse effects. The second part of the...
	Deep Brain Stimulation shows promise for Alzheimer's, depression treatment: doctors also now have more options in how DBS is used to treat Parkinson's ... An article from: Duke Medicine Health News by Sarah H. Lisanby (Author) This digital document is an article from Duke Medicine Health News, published by Belvoir Media Group, LLC on August 1, 2011. The length of the article is 944 words. The page length shown above is based on a typical 300-word page. The article is delivered in HTML format and is available immediately after purchase. You can view it with any web browser. Citation Details Title: Deep Brain Stimulation shows promise for Alzheimer's, depression treatment: doctors also now have more options in how DBS is used to treat Parkinson's disease. Author: Sarah H. Lisanby Publication: Duke Medicine Health News (Newsletter) Date: August 1, 2011 Publisher: Belvoir Media Group, LLC Volume: 17 Issue: 8 Page: S1(2) Distributed by Gale, a part of Cengage...
	Deep Brain Stimulation: New Developments, Procedures and Applications by Alden G. Sloan (Editor), Andrea I. Montes Villarreal (Editor) In this book, the authors present current research in the study of the new developments, procedures and applications in the field of deep brain stimulation. Topics discussed in this compilation include deep brain stimulation for Gilles de Tourette syndrome; the impact of subthalamic stimulation on autonomic dysfunction in Parkinson's disease; deep brain stimulation in treatment-resistant depressive disorders; and gamma knife thalamotomy for disabling tremors as an alternative to DBS.
	Deep Brain Stimulation for Parkinson's Disease (Neurological Disease and Therapy) by Gordon H. Baltuch (Editor), Matthew B. Stern (Editor) Considered the largest breakthrough in the treatment of Parkinson's disease in the past 40 years, Deep Brain Stimulation (DBS) is a pioneering procedure of neurology and functional neurosurgery, forging enormous change and growth within the field. The first comprehensive text devoted to this surgical therapy, this source expertly examines all aspects of DBS from history and theory to patient evaluation, recovery, and rehabilitation. Edited by specialists in the top-tiers of the discipline, including contributors from the pioneering Movement Disorder Group at the University of Pennsylvania, this text will be an indispensable companion for the entire neurological and neurosurgical community.