Physical Address

304 North Cardinal St.
Dorchester Center, MA 02124

Paradigm shifts and the future of neuromodulation

Introduction To address the future of neuromodulation, it is first important to recognize that I believe that evolutionary changes in neuromodulation devices do not play a critical role in this future. In the past, the field has identified that changes in the number of contacts per lead, the length of each lead, or the number of leads defined its future. Later, expanded stimulation parameters alone, such…

Expectations and outcomes

Since the resurgence of neurostimulation technologies in the 1990s, promising advances have been made in this field by altering nervous system function for relief of pain and other symptoms in select patients. Combined with a better understanding of the disease process, the use of electrical stimulation and lesioning of specific targets in the brain or spinal cord has provided many patients with the amelioration of symptoms…

Programming—SCS

Introduction Spinal cord stimulation (SCS), a treatment for chronic intractable pain, was founded on the gate control theory of pain, which proposes that pain transmission is inhibited by activity in sensory afferent fibers, specifically Aβ fibers [ ]. SCS was first developed to increase Aβ fiber activity, and thus decrease pain transmission, by stimulating the dorsal columns whose inputs are primarily Aβ fibers [ ]. Since…

Programming—DBS programming

Introduction One of the greatest advantages of neuromodulation therapies, and in contrast to ablative procedures of the past, is that the anatomical and physiological substrate of the therapy may continue to be manipulated long after the implant surgery is accomplished. The adjustment of stimulation parameters postoperatively is called programming and allows the clinician to modify the effect of the implanted device. It is the goal of…

Troubleshooting of neuromodulatory devices: case examples

Conflicts of interest Dr. Pilitsis is a consultant for Boston Scientific, Nevro, TerSera, and Abbott and receives grant support from Medtronic, Boston Scientific, Abbott, Nevro, TerSera, GE Global Research, SBIR 1R43NS107076-01A1, NIH 2R01CA166379-06 and NIH U44NS115111. She is medical advisor for Aim Medical Robotics and Karuna and has stock equity. Introduction The use of various neuromodulation therapies for the treatment of neurological conditions has rapidly expanded…

Intraoperative evaluation

Introduction As neuromodulation therapies become a treatment standard for a variety of disorders including medically refractory Parkinson's disease (PD), essential tremor, dystonia, pain syndromes, epilepsy, psychiatric disorders, and other future indications, more is being learned about the longevity and function of the implantable stimulator and its components. A literature review describes a 15%–30% failure rate that includes both infection and device failure [ ]. As neuromodulation…

Limiting morbidity in neuromodulation

Disclosures Dr. Pilitsis is a consultant for Boston Scientific, Nevro, TerSera, and Abbott and receives grant support from Medtronic, Boston Scientific, Abbott, Nevro, TerSera, NIH 2R01CA166379-06 and NIH U44NS115111. She is medical advisor for Aim Medical Robotics and Karuna and has stock equity. Introduction All surgeries carry a risk of complications, and it is the goal of the surgeon to prepare the patient for the possibility…

Intraoperative physiology techniques to inform targeting

Background Spinal cord stimulation (SCS) has been employed for the treatment of intractable pain most commonly for failed back surgery syndrome and complex regional pain syndromes. It is generally accepted that for successful SCS treatment there is the superposition of SCS-induced paresthesias overlapping the regions of perceived pain. This has become true for both paresthesia-based and paresthesia-free stimulation as physiologic placement is paramount. This is especially…

Trials and their applicability

Introduction Implantable Devices have seen major increases in technology and complexity over the past decade. Fortunately, this has not changed our ability to “Test Drive” our devices. Unlike other interventional or minimally invasive procedures, our patients have the advantage of trialing our devices for an average of 3–7 days. We are able to apply a technology that is both safe and testable. After the trial period, the…

Surgical techniques

Introduction Paying proper attention to all technical aspects of neurostimulation device implantation makes all the difference in the long-term patient outcome with these devices. If these are truly going to be less invasive therapies, then the experience of undergoing implantation and ongoing maintenance and interaction with the devices needs to be as seamless as possible. Problems are often encountered when implanting physicians feel that these are…

Power use in neurostimulators

Overview All neurostimulators require an energy source to generate the electric fields which modulate the nervous system. The choice of technologies to power neurostimulators has a greater impact on the device design than any other choice. The use of an implanted battery and type of battery (rechargeable or nonrechargeable) can not only impact the volume of the device but also how the patient uses it. Inductively…

Electronics

Introduction Neurostimulators can be generally categorized as either external or fully implantable. The former has a longer history because external neurostimulators do not have the design and operational challenges of limited power sources, convenient size, hermeticity, and control interfaces among other details [ ]. Fully implantable neurostimulators, however, have inherited much from pacemaker technology development, though in recent years, as the neurostimulator market has seen higher…

Device materials, handling, and upgradability

Introduction A neuromodulation system may consist of two or more components, including the implantable pulse generator (IPG) and a therapy lead which delivers stimulation to the underlying neural tissue. The leads direct energy from the pulse generator to the target and provide key differentiation between device manufacturers. Some device variations include an external power source and a battery-free implantable pulse generator. It is important to understand…

The electrode—principles of the neural interface and materials

Introduction Neuromodulation requires a means of affecting the function of neurons and/or axons. This can be achieved by physical means such as changing temperature or mechanical pressure. Manipulation of the chemical environment by changing pH, ionic concentration, or the release of specific chemicals can also influence neuronal activity. However, the application of electrical fields, either directly or through electromagnetic induction, may be the simplest and most…

Waveforms and mechanisms in neuromodulation

Introduction All of neuromodulation is dependent on the delivery of a waveform comprised of electromagnetic fields to nervous system tissues in the human body. We are setting aside for now the types of neuromodulation working within the realm of light, ultrasonics, or any other forms of manipulating the function of a nervous system. Because the nervous system is generally thought to rely on information transfer to…

Peripheral nerve stimulation

Introduction One of the less commonly discussed areas of neuromodulation, peripheral nerve stimulation (PNS) is nonetheless probably its fastest growing direction, at least in the field of pain treatment. The approach, which is still considered novel and experimental by many, is in fact neither—PNS was introduced before the much more accepted modality of spinal cord stimulation (SCS) and there are devices on the market today that…

Spinal—extradural neuromodulation

Introduction Neuromodulation and specifically epidural spinal cord stimulation (SCS) represented a fundamental change in the thought process behind pain control given that primarily irreversible ablative procedures had been used historically. The benefits of SCS include being reversible and adjustable. Advances in technology over the prior 2 decades have led to significant improvements in device design, overall effectiveness, and a broadening of its indications. The most common…

Cerebral—deep

Introduction The notion that functional brain disorders can be treated by modulating the activity of subcortical brain regions is nearly a century old. Meyers is credited with performing the first transventricular lesions of the basal ganglia [ ], but it was not until the introduction of ventriculography and the human stereotactic frame that surgical approaches to deep brain targets became routine. Ablation represents the most straightforward…

Cerebral: surface

Chapter 2 Stimulation of the brain cortex has emerged as one of the most promising avenues for palliation of neurological and psychiatric conditions. Cortical stimulation (CS) can be administered either noninvasively (NICS) ( Box 2.1 ) or invasively (ICS) [ , ]. Box 2.1 Common modalities of CS [ , ]. 1 Transcranial Magnetic Stimulation (TMS) : TMS in a repetitive mode (rTMS) is a noninvasive technique with…

The neuromodulation approach

Introduction Neuromodulation means many things to many people—but essential to any point of view is that the term implies some type of intervention that interfaces on some level with the nervous system of the patient and modifies function with the goal of giving benefit to the patient. What remains important to the definition, however, is a deeper belief that this therapeutic approach itself has greater merit…