Peripheral Nerve Stimulation

K. V. Slavin

• Éditeur: S. Karger
• Année: 2011
• ISBN:
  9783805594899
• Sujet: Medicine
• Sous-sujet: Neurosurgery

In a rapidly growing field of neuromodulation against pain, this excellent publication presents a unique compilation of the latest theoretical and practical information for electrical stimulation of the peripheral nerves. Chapters cover the use of peripheral nerve stimulation in particular indications such as migraine, cluster headache, pain in Chiari malformation and fibromyalgia, as well as in specific body parts such as head and neck, trunk, and extremities. Furthermore, chapters on history, technical aspects, mechanism of action, terminology, complications and other important aspects of this pain-relieving modality give you a full overview of the field. Written by leading experts, this publication provides a comprehensive and updated summary of the currently available scientific information on peripheral nerve stimulation. All chapters contain original information making this book an invaluable reference for all who deal with the management of severe and chronic pain - including neurosurgeons and neurosurgical trainees, pain specialists and practitioners, anesthesiologists and neurologists.

Slavin KV (ed): Peripheral Nerve Stimulation.
Prog Neurol Surg. Basel, Karger, 2011, vol 24, pp 1–15

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History of Peripheral Nerve Stimulation

Konstantin V. Slavin

Department of Neurosurgery, University of Illinois at Chicago, Chicago, Ill., USA

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Abstract

Peripheral nerve stimulation (PNS) is an established neuromodulation approach that has been successfully used for the treatment of various painful conditions since the early 1960s. This review provides a comprehensive summary of relevant publications on PNS dividing its history into three distinct periods. The milestones of the field are related to the development of procedures, equipment and indications. As the most rapidly growing segment of operative neuromodulation, PNS continues to evolve as current and emerging clinical indications become matched by basic and clinical research, technological developments and procedural refinements.

Copyright © 2011 S. Karger AG, Basel

Whenever a new patient in my practice is considered for a peripheral nerve stimulation (PNS) procedure, the same questions inevitably come up in conversation with the patient and family, and then again with the referring/primary physician, and finally with the insurance company where the procedure is reviewed – how new and experimental PNS is and how different it is from other neuromodulation approaches. This situation reflects the current state of PNS and indicates several important issues. First of all, there is a significant shortage of information regarding this approach, partly due to lack of awareness in the medical community at large, and, to a major degree, to lack of commercial support from the device- manufacturing companies – in stark contrast with an abundance of educational materials for more established neuromodulation approaches of spinal cord stimulation and intrathecal drug delivery. Second, and probably just as important, is the paucity of scientific clinical and basic research work in support of the PNS approach, its safety, efficacy, and cost- effectiveness. Last and probably intimately related to the first two issues, is the lack of regulatory approval for PNS as a technical application for existing devices that are used for it in routine practice.

Unfortunately, this situation represents a somewhat vicious cycle – there are no marketing efforts from device manufacturers and distributors due to the lack of regulatory approval, and this approval will never be given unless the manufacturers apply for it. Lack of marketing efforts, low awareness and lack of educational materials have, for a long time, resulted in a low volume for this particular device application – and its off- label status and unlikely chance of getting insurance approval made the situation worse since low volumes translate into lack of clinical experience and difficulty in collecting sufficient clinical data to come up with any scientific information that would be needed to get the regulatory approval.

Despite all these hurdles, the field is developing rapidly, and the increasing number of publication regarding the use of the PNS approach supports its gradual acceptance by the neuromodulation community. The goal of this chapter is to briefly review the PNS history and to track the 40 some year long path from the original introduction to clinical practice to its current state.

Invention of PNS

For many centuries electricity has been used to treat a variety of human ailments. Therapeutic effects of electric shocks from torpedo fish were known in antiquity, and pain relief from electrical discharges of this Mediterranean ray was described by Scribonius Largus in patients with gout and headaches. The pain would get better when these patients touched the electric fish or when they put their feet into a pool with torpedo fish [1]. This approach to pain control apparently persisted for a very long time – and there is mention of the electric fish being used for pain control in early American plantations [2].

A more modern approach to peripheral electrical stimulation was introduced at the beginning of the 20th century when a consumer electrical device called Electreat was introduced for the treatment of pain and many other conditions [3]. This technology was later translated into a transcutaneous electrical nerve stimulation (TENS) that continues to be widely available today.

Before this, however, there was a very interesting description of electricity being used for pain control when directly applied to the peripheral sensory (‘sentient’) nerve. In 1859, Julius Althaus wrote the following [4]:

. . .‘a direct reduction of sensibility in a nerve can be accomplished in the following way: if a continuous, or a rapidly interrupted induced current of medium intensity is sent through the trunk of a nerve – say the ulnar, or the sciatic. . . and the action of the current be kept up for a quarter of an hour or more, the pain which is excited by this proceeding becomes much less, after a certain time, than it was at the beginning of the operation, and a feeling of numbness is produced in the limb. I do not mean to say that sensibility can be entirely destroyed by this local application of electricity, but I am quite satisfied that it is notably diminished by it. The result is much more striking if there is a morbid increase in sensibility in a nerve, as in the case in neuralgia, than if a nerve in its normal state is acted upon.’

He then went on to describe differential effects of cathodal and anodal stimulation on patients’ perception, as well as the effect of increasing the frequency of stimulation, up to a certain limit, that produces a stronger decrease in nerve sensitivity – a surprising depth of observations with mid- 19th century technology.

The true beginning of clinical PNS application or treatment of pain started in the 1960s. The creators of the ‘gate control’ theory of pain, Drs. Melzack and Wall, postulated in their article published in Science in 1965 that innocuous sensory information may suppress the transmission of pain [5]. Nonpainful information is delivered to a secondary afferent neuron (or the first central transmission cell) that also receives information from nociceptive afferents. The same large fibers that carry non-nociceptive information excite cells in the substantia gelatinosa that inhibit transmission of painful signals from the periphery.

Although this theory was based on serious experimental findings, clinical confirmation was needed to check its validity. In a follow- up paper called ‘Temporary abolition of pain in man’ published in 1967, Wall and Sweet demonstrated that nonpainful electrical stimulation of the peripheral nerve does indeed suppress pain perception in the area that it innervates. In a true spirit of science, they did it by inserting electrodes into their own infraorbital foramina [6].

Later, this was described in a book ‘Pain and the Neurosurgeon’ [7]:

‘Turning from their animal studies to man, Wall and one of us (WHS) asked ourselves if artificially intense stimulation confined to the low- threshold A fibers could produce a clinically demonstrable reduction of pain. We first tested ourselves, using 0.1- ms square waves at 100 cps, sticking into our own infraorbital nerves needle electrodes insulated except for the tip. Tingling, buzzing or vibrating sensations were evoked in some portion of the sensory domain of our nerves at a voltage near the threshold. These were not unpleasant feelings and were always tolerable for an indefinite period. Moreover, we each had analgesia to pinprick in this area of paresthesia during the stimulation. But both the objective sensory loss and our subjective sensations returned rapidly to normal when the stimulus stopped.’

Soon thereafter, an implantable device was created and used in patients with chronic pain [8]. The first PNS surgery was done on a 26- year- old woman with clinical presentation consistent with a complex regional pain syndrome (CRPS) [7]:

‘On October 9, 1965, Dr. Wall and one of us (Dr. W.H. Sweet) implanted a pair of silastic splitring platinum electrodes around the ulnar and another pair around the median nerve in the arm carrying the wires out of the skin at the mid- forearm. On the median nerve 0.1- ms pulses at 100/s and 0.6 V provoked a pleasant tingling in the lateral three fingers and corresponding hand and stopped the pain in the medial three fingers and hand as well as tenderness in the third finger and palm.’

This quote clearly breaks the myth of PNS being a ‘novel’ modality as its clinical application for treatment of pain preceded, albeit by only a year or two, the introduction of spinal cord stimulation (SCS) by Shealy et al. [9].

PNS Progress: Early Years

The 50- year history of the clinical use of PNS may be divided into several distinct periods. The first period, a period of semi- experimental PNS use, started with the pioneering experience of Wall, Sweet, and others, and lasted for 15– 20 years. That was a time when PNS surgery could be d...