In our last two updates to highlight NINDS contributions to therapies for neurological disorders, we focused on a recombinant clot-busting protein for acute stroke, enzyme replacement therapies for lysosomal storage disorders, and an RNA-targeting treatment for spinal muscular atrophy (SMA). All of these are examples of biologics, or products produced from or containing components of living organisms, and they represent a growing and exciting area of research and development for a range of clinical applications. This week, we turn our attention to medical devices, another growing area where scientific and technological advances are fueling opportunities to treat neurological disorders by modulating the activity of neural circuits in the brain, spinal cord, and peripheral nervous system.
The first of two new entries on our website describes the development of deep brain stimulation (DBS) to treat movement disorders, including Parkinson’s disease, essential tremor, and dystonia. The second outlines the development of two devices approved for the treatment of epilepsy in people who have not achieved adequate benefits from other available therapies. One of these is a DBS device that delivers constant stimulation intended to alter brain activity just enough to prevent or limit the initiation or spread of a seizure. The other is a responsive, or “closed loop,” device that delivers stimulation to the site of seizure onset, but only when continuously monitored brain activity suggests a seizure is beginning or likely to occur. The paths leading to these devices for movement disorders and epilepsy show how basic neuroscience research and advances in medical device technology built on decades of neurosurgical experience to drive new therapeutic approaches. NINDS and NIH supported or conducted research at important steps along the way, including studies to map brain circuits involved in movement coordination and seizure spread and to design algorithms for automated seizure detection. In recognition of their pioneering work to develop DBS for Parkinson’s disease, NIH-supported neuroscientist Mahlon DeLong and French neurosurgeon Alim-Louis Benabid received the 2014 Lasker-Debakey Clinical Medical Research Award.
These stories form part of a long history of NINDS and NIH investments in pioneering research on neural interfaces. The NINDS Neural Prosthesis Program, which began in the 1970s, laid the groundwork through support for research in applied engineering, materials science, and neuroscience, including long term safety studies of electrical stimulation and implanted devices. An early success of this program was the cochlear implant, a device that stimulates the auditory nerve to provide sound sensation in people who are deaf or hard-of hearing.
Today, NINDS and NIH continue to foster innovative research toward the next generation of neuromodulatory devices. Currently available devices provide sometimes dramatic benefits, but open questions remain regarding the underlying mechanisms of these benefits as well as the optimal sites and parameters for stimulation. The NIH BRAIN Initiative established a Public-Private Partnership program to facilitate clinical research using industry-supplied devices. One study supported through this program recently described a closed-loop DBS system for Parkinson’s disease that fine-tunes stimulation based on movement-related brain activity. In addition, researchers supported through the BRAIN Initiative® and other programs are revealing ever finer details of the structure and function of neural circuits, understanding how these circuits are affected by disease, and developing new ways to monitor and modulate circuit activity, including methods that are more precise or less invasive. With these advances, we can hope for even more effective devices for a broader range of neurological disorders.