Neurotechnologic devices are proving themselves in clinical medicine. Many of these devices offer several distinct advantages over traditional pharmaceutical-based therapies: their effects are reversible, they are often cheaper than pharmaceuticals, and they solve therapy adherence issues. "If a problem occurs, you can turn off the device; or if the disease evolves over time, you can dynamically adjust the device," explained Ali R. Rezai, MD, chairman of the Center for Neurological Restoration at the Cleveland Clinic.
Neurotechnologic devices are proving themselves in clinical medicine. Many of these devices offer several distinct advantages over traditional pharmaceutical-based therapies: their effects are reversible, they are often cheaper than pharmaceuticals, and they solve therapy adherence issues. "If a problem occurs, you can turn off the device; or if the disease evolves over time, you can dynamically adjust the device," explained Ali R. Rezai, MD, chairman of the Center for Neurological Restoration at the Cleveland Clinic.Perhaps most important is that many of these devices are associated with fewer side effects than pharmaceutical therapies. "Having dealt with epilepsy for the past 20 years, I have seen pretty much all of the side effects you can get from the drugs," said Ingela Danielsson, MD, PhD, a medical director at Cyberonics, a medical device manufacturer based in Houston. She took part in clinical trials of the Vagus Nerve Stimulator (VNS) System, conducted at the University of Maryland in Baltimore in the late 1990s. "The Vagus Nerve Stimulator did not have any of those side effects, and I thought it was a much safer and natural alternative."Neurodevices aren't completely without pitfalls and risks. "There can be erosion and infection, and wires can break, and we can have device malfunctions, although such occurrences are rare," commented Rezai, who has implanted 1000 deep brain stimulators (DBSs) within the past decade. "Use of these treatments requires an active dialogue with all the physicians on the team and proper follow-up maintenance."A NEW PARADIGM"For a patient with a neurologic disease, just taking a pill was the old school, now considering surgical treatments of any kind may be the new paradigm, and I think we'll be seeing more of this type of intervention," said Brett Kissela, MD, associate professor and director of the Neurology Residency Program at the University of Cincinnati and participant in Northstar Neuroscience's clinical trial on cortical stimulation for stroke recovery. In fact, the number of persons in whom a neurodevice has been implanted is increasing daily. Worldwide, there are approximately 97,000 persons who have cochlear implants.1 More than 32,000 persons have VNS devices, according to Reese Terry, CEO of Cyberonics.In the United States, more than 150,000 Medtronic-type neurostimulators have been implanted, according to Joseph McGrath, director of public relations and corporate communications for Medtronic's Neurological Division. More than 110,000 of these neurostimulators were implanted to manage chronic pain and more than 30,000 to treat movement disorders such as Parkinson disease, essential tremor, and dystonia."Right now you're talking about tens of thousands of patients, and in the next few years, it will be hundreds of thousands of patients," predicted Rezai. "In 1997 and 1998, when I was first learning how to do this in New York, there was a handful of centers in the United States doing it. Now more than 200 centers in United States and 500 centers worldwide are implanting DBSs."To date, the vast majority of patients who have received implants failed all other conventional treatment modalities. It may not be long, however, before some of these devices are used routinely. "Over the next decade, medical technology innovations will fundamentally transform the health care delivery system, providing new solutions with medical devices that will challenge existing paradigms and revolutionize the way treatments are administered," said Scott Gottlieb, MD, the FDA's deputy commissioner for medical and scientific affairs. This past January he announced the agency's new postmarket program to "transform and strengthen medical device safety."As with any new technology, there has been some resistance both on the part of neurologists and patients. "If you go back to the early 1980s and the early days of cochlear implants, there was militant resistance-especially when implants began to be used in children-from patient groups, deaf advocacy groups, and to some degree, from the medical community. Today you don't see any of that," said Paul Stypulkowski, PhD, research director of Medtronic Neurological in Minneapolis. "Now you see cochlear implants being placed in children as young as age 18 months who then mainstream through school as if they were normal hearing individuals. The best analogy is to cardiac pacemakers. When pacemakers were first developed, people asked, 'How can you stick a wire in the heart-the seat of the soul? Here we're talking about sticking a wire in the brain."Many patients have been self-referred to these new technologies. Those who spoke with Applied Neurology said that patients who became informed about neurodevices usually did so through the Internet. "It's more of an urgency for the patients than it may be for neurologists, and it's a more personal issue," said Stypulkowski. "But it's a mixed bag," added Rezai, who has encountered his fair share of patients with Munchausen syndrome. "We screen every patient carefully. Before we implant, we conduct a detailed neuropsychologic study or psychiatric evaluation. It's an important issue that cannot be overlooked."CELEBRITY ADVOCATEOther patients are introduced to neurodevices by their physicians-including comedian Jerry Lewis, who suffered from severe back pain for 37 years as a result of a pratfall in 1965. Having tried virtually every pain medication available, he agreed to try neurostimulation on the advice of his pain specialist/anesthesiologist Joseph Schifini, MD, of Las Vegas.At that time, Lewis was unable to walk more than a few steps. To make matters worse, he just received a diagnosis of lung disease."I had every shot, every dimension of pain management. I was ready to walk into an 18-wheeler or blow my brains out. I didn't think I'd make it another day," Lewis confided. Neurostimulation, however, achieved what none of the drug therapies could. "Jerry had 100% pain relief," reported Schifini."I was reborn," said Lewis, who was so elated with his new pain-free life that he began providing testimonials at Medtronic seminars and conferences. To date, Lewis has not experienced adverse effects from his implant and is currently free of pain medication.Before the availability of neurotechnologic devices, "many neurologists accepted a lower standard of care for certain patients than they might have accepted for themselves or for their loved ones and many of our patients," said James W. Wheless, MD, professor and chief of pediatric neurology at the University of Tennessee Health Science Center in Memphis. "The nice thing about these devices is that they allow us to offer hope to patients we couldn't offer hope to before."REFERENCE1. The National Institute on Deafness and Other Communication Disorders (NIDCD) Fact Sheet. Available at: www.nidcd.nih.gov/ health/hearing/coch.htm. Accessed May 4, 2006.This 3-part series explores the boom of neurodevices within the neurotechnology revolution now under way. Part I looked at the evolution and current market. In Part II, acceptance and clinical applications are explored. Part III will look at the future.AJS RAYL is a freelance writer in Malibu, California.