1
|
Du J, Morales A. Electrical Stimulation Induced Current Distribution in Peripheral Nerves Varies Significantly with the Extent of Nerve Damage: A Computational Study Utilizing Convolutional Neural Network and Realistic Nerve Models. Int J Neural Syst 2023; 33:2350022. [PMID: 36916993 PMCID: PMC10561898 DOI: 10.1142/s0129065723500223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Electrical stimulation of the peripheral nervous system is a promising therapeutic option for several conditions; however, its effects on tissue and the safety of the stimulation remain poorly understood. In order to devise stimulation protocols that enhance therapeutic efficacy without the risk of causing tissue damage, we constructed computational models of peripheral nerve and stimulation cuffs based on extremely high-resolution cross-sectional images of the nerves using the most recent advances in computing power and machine learning techniques. We developed nerve models using nonstimulated (healthy) and over-stimulated (damaged) rat sciatic nerves to explore how nerve damage affects the induced current density distribution. Using our in-house computational, quasi-static, platform, and the Admittance Method (AM), we estimated the induced current distribution within the nerves and compared it for healthy and damaged nerves. We also estimated the extent of localized cell damage in both healthy and damaged nerve samples. When the nerve is damaged, as demonstrated principally by the decreased nerve fiber packing, the current penetrates deeper into the over-stimulated nerve than in the healthy sample. As safety limits for electrical stimulation of peripheral nerves still refer to the Shannon criterion to distinguish between safe and unsafe stimulation, the capability this work demonstrated is an important step toward the development of safety criteria that are specific to peripheral nerve and make use of the latest advances in computational bioelectromagnetics and machine learning, such as Python-based AM and CNN-based nerve image segmentation.
Collapse
|
2
|
Du J, Morales A, Kosta P, Bouteiller JMC, Martinez G, Warren D, Fernandez E, Lazzi G. Electrical Stimulation Induced Current Distribution in Peripheral Nerves Varies Significantly with the Extent of Nerve Damage: A Computational Study Utilizing Convolutional Neural Network and Realistic Nerve Models. INTERNATIONAL WORK-CONFERENCE ON THE INTERPLAY BETWEEN NATURAL AND ARTIFICIAL COMPUTATION 2022; 13258:526-535. [PMID: 37846407 PMCID: PMC10578432 DOI: 10.1007/978-3-031-06242-1_52] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2023]
Abstract
Although electrical stimulation is an established treatment option for multiple central nervous and peripheral nervous system diseases, its effects on the tissue and subsequent safety of the stimulation are not well understood. Therefore, it is crucial to design stimulation protocols that maximize therapeutic efficacy while avoiding any potential tissue damage. Further, the stimulation levels need to be adjusted regularly to ensure that they are safe even with the changes to the nerve due to long-term stimulation. Using the latest advances in computing capabilities and machine learning approaches, we developed computational models of peripheral nerve stimulation based on very high-resolution cross-sectional images of the nerves. We generated nerve models constructed from non-stimulated (healthy) and over-stimulated (damaged) rat sciatic nerves to examine how the current density distribution is affected by nerve damage. Using our in-house numerical solver, the Admittance Method (AM), we computed the induced current distribution inside the nerves and compared the current penetration for healthy and damaged nerves. Our computational results indicate that when the nerve is damaged, primarily evidenced by the decreased nerve fiber packing, the current penetrates deeper inside the nerve than in the healthy case. As safety limits for electrical stimulation of biological tissue are still debated, we ultimately aim to utilize our computational models to determine refined safety criteria and help design safer and more efficacious electrical stimulation protocols.
Collapse
Affiliation(s)
- Jinze Du
- Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- Institute for Technology and Medical Systems Innovation (ITEMS), Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Andres Morales
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- Institute for Technology and Medical Systems Innovation (ITEMS), Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Pragya Kosta
- Institute for Technology and Medical Systems Innovation (ITEMS), Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Jean-Marie C Bouteiller
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- Institute for Technology and Medical Systems Innovation (ITEMS), Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Gema Martinez
- Institute of Bioengineering, University Miguel Hernandez, Elche and CIBER-BBN, Madrid, Spain
| | - David Warren
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT 84112, USA
| | - Eduardo Fernandez
- Institute of Bioengineering, University Miguel Hernandez, Elche and CIBER-BBN, Madrid, Spain
| | - Gianluca Lazzi
- Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- Institute for Technology and Medical Systems Innovation (ITEMS), Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| |
Collapse
|
3
|
Du J, Morales A, Paknahad J, Kosta P, Bouteiller JMC, Fernandez E, Lazzi G. Electrode Spacing and Current Distribution in Electrical Stimulation of Peripheral Nerve: A Computational Modeling Study using Realistic Nerve Models. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2021; 2021:4416-4419. [PMID: 34892199 PMCID: PMC10072138 DOI: 10.1109/embc46164.2021.9631068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Electrical stimulation of peripheral nerves has long been used and proven effective in restoring function caused by disease or injury. Accurate placement of electrodes is often critical to properly excite the nerve and yield the desired outcome. Computational modeling is becoming an important tool that can guide the rapid development and optimization of such implantable neural stimulation devices. Here, we developed a heterogeneous very high-resolution computational model of a realistic peripheral nerve stimulated by a current source through cuff electrodes. We then calculated the current distribution inside the nerve and investigated the effect of electrodes spacing on current penetration. In the present study, we first describe model implementation and calibration; we then detail the methodology we use to calculate current distribution and apply it to characterize the effect of electrodes distance on current penetration. Our computational results indicate that when the source and return cuff electrodes are placed close to each other, the penetration depth in the nerve is shallower than the cases in which the electrode distance is larger. This study outlines the utility of the proposed computational methods and anatomically correct high-resolution models in guiding and optimizing experimental nerve stimulation protocols.
Collapse
|
4
|
Banks GP, Winfree CJ. Evolving Techniques and Indications in Peripheral Nerve Stimulation for Pain. Neurosurg Clin N Am 2019; 30:265-273. [PMID: 30898277 DOI: 10.1016/j.nec.2018.12.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Peripheral nerve stimulation is the direct electrical stimulation of named nerves outside the central neuraxis to alleviate pain in the distribution of the targeted peripheral nerve. These treatments have shown efficacy in treating a variety of neuropathic, musculoskeletal, and visceral refractory pain pathologies; although not first line, these therapies are an important part of the treatment repertoire for chronic pain. With careful patient selection and judicious choice of stimulation technique, excellent results can be achieved for a variety of pain etiologies and distributions. This article reviews current and past practices of peripheral nerve stimulation and upcoming advancements in the field.
Collapse
Affiliation(s)
- Garrett P Banks
- Department of Neurosurgery, Columbia University, 710 West 168 Street, 4th Floor, New York, NY 10032, USA.
| | - Christopher J Winfree
- Department of Neurosurgery, Columbia University, 710 West 168 Street, 4th Floor, New York, NY 10032, USA
| |
Collapse
|
5
|
Abstract
Although the first publications on clinical use of peripheral nerve stimulation for the treatment of chronic pain came out in the mid-1960s, it took 10 years before this approach was used to stimulate the occipital nerves. The future for occipital nerve stimulation is likely to bring new indications, devices, stimulation paradigms, and a decrease in invasiveness. As experience increases, one may expect that occipital nerve stimulation will eventually gain regulatory approval for more indications, most likely for occipital neuralgia, migraines and cluster headaches. This process may require additional studies, at least for approval from the US Food and Drug Administration.
Collapse
|
6
|
Doran J, Ward M, Ward B, Paskhover B, Umanoff M, Mammis A. Investigating Complications Associated With Occipital Nerve Stimulation: A MAUDE Study. Neuromodulation 2018; 21:296-301. [DOI: 10.1111/ner.12750] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 10/31/2017] [Accepted: 11/21/2017] [Indexed: 11/29/2022]
Affiliation(s)
- Joseph Doran
- Department of Neurological Surgery; Rutgers New Jersey Medical School; Newark NJ USA
| | - Max Ward
- Department of Neurological Surgery; Rutgers New Jersey Medical School; Newark NJ USA
| | | | - Boris Paskhover
- Department of Otolaryngology Facial Plastics and Reconstruction; Rutgers New Jersey Medical School; Newark NJ USA
| | - Michael Umanoff
- Department of Anesthesiology; St. Joseph's University Medical Center; Paterson NJ USA
| | - Antonios Mammis
- Department of Neurological Surgery; Rutgers New Jersey Medical School; Newark NJ USA
| |
Collapse
|
7
|
Abstract
We report on the use of a new percutaneous technique for peripheral nerve stimulation (PNS) treatment of chronic pain. A 56-year-old woman was diagnosed with algodystrophic syndrome, now called Complex Regional Pain Syndrome, type 2 (CRPS2), due to a lesion of the right medial nerve despite surgical revascularization, angioplasty and stent insertion. After a successful 10-day trial of PNS via a percutaneous quadripolar lead in the interscaline space, an implantable pulse generator was implanted in the abdominal subcutaneous tissue and connected to the subcutaneous lead via an extension. After one year of follow-up, the patient was still experiencing good pain relief. We conclude that this novel percutaneous PNS technique offers the advantage of being a minimally invasive approach that can be easily adopted for the management of chronic pain.
Collapse
Affiliation(s)
- Enrico Monti
- Centro di Terapia Antalgica, Ospedale di Imola, Imola, Italy
| |
Collapse
|
8
|
Slavin KV, Vannemreddy PSSV. Repositioning of supraorbital nerve stimulation electrode using retrograde needle insertion: a technical note. Neuromodulation 2010; 14:160-3; discussion 163-4. [PMID: 21992205 DOI: 10.1111/j.1525-1403.2010.00315.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
INTRODUCTION With growing interest and acceptance of peripheral nerve stimulation (PNS) approach, there is now an increasing need in developing clear procedural details to resolve frequent complications and minimize associated tissue injury. Migration and suboptimal positioning of PNS electrodes are one of the most commonly observed complications of PNS approach. MATERIALS AND METHODS We present a simple technique for repositioning a supraorbital electrode using retrograde insertion of introducer needle that allows one to place percutaneous (cylindrical) PNS electrode into appropriate anatomical location with minimal additional injury to surrounding tissues. RESULTS This approach has been successfully used in multiple cases. An illustrative case of electrode revision with proposed technique is described in detail. CONCLUSION This technically simple approach to repositioning of cylindrical supraorbital electrodes using retrograde needle insertion eliminates the need for a more elaborate and invasive procedure. The technique can be used for electrode repositioning in most PNS applications.
Collapse
Affiliation(s)
- Konstantin V Slavin
- Department of Neurosurgery, University of Illinois at Chicago, Chicago, IL 60612, USA.
| | | |
Collapse
|
9
|
Grill WM, Norman SE, Bellamkonda RV. Implanted Neural Interfaces: Biochallenges and Engineered Solutions. Annu Rev Biomed Eng 2009; 11:1-24. [DOI: 10.1146/annurev-bioeng-061008-124927] [Citation(s) in RCA: 368] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Warren M. Grill
- Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708-0281;
| | - Sharon E. Norman
- Bioengineering Program Department of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332
| | - Ravi V. Bellamkonda
- Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, Atlanta, Georgia 30332
| |
Collapse
|
10
|
|
11
|
|
12
|
Weiner RL, Alo’ KM. Occipital Neurostimulation for Treatment of Intractable Headache Syndromes. Neuromodulation 2009. [DOI: 10.1016/b978-0-12-374248-3.00031-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
13
|
Peripheral Nerve Stimulation for Pain Peripheral Neuralgia and Complex Regional Pain Syndrome. Neuromodulation 2009. [DOI: 10.1016/b978-0-12-374248-3.00030-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|
14
|
Feasibility of Ultrasound-Guided Percutaneous Placement of Peripheral Nerve Stimulation Electrodes in a Cadaver Model. Reg Anesth Pain Med 2008. [DOI: 10.1097/00115550-200811000-00007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
15
|
Oberoi J, Sampson C, Ross E. Head and Neck Peripheral Stimulation for Chronic Pain Report of Three Cases. Neuromodulation 2008; 11:272-6. [DOI: 10.1111/j.1525-1403.2008.00175.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
16
|
Abstract
Peripheral nerve stimulation (PNS) has been used for treatment of neuropathic pain for more than 40 years. Recent resurgence of interest to this elegant surgical modality came from the introduction of less invasive implantation techniques and the wider acceptance of neuromodulation as a treatment of medically refractory cases. This article reviews the literature on the use of PNS for neuropathic pain and describes current indications and hardware choices in frequent use. Published experience indicates that neuropathic pain responds to PNS in many patients. PNS works well in both established indications, such as post-traumatic and postsurgical neuropathy, occipital neuralgia, and complex regional pain syndromes, and in relatively new indications for neuromodulation, such as migraines and daily headaches, cluster headaches, and fibromyalgia. Future research and growing clinical experience will help in identifying the best candidates for PNS, choosing the best procedure and best hardware for each individual patient, and defining adequate expectations for patients and pain specialists.
Collapse
Affiliation(s)
- Konstantin V Slavin
- Department of Neurosurgery, University of Illinois at Chicago, Chicago, Illinois 60612, USA.
| |
Collapse
|
17
|
Rogers LL, Swidan S. Stimulation of the occipital nerve for the treatment of migraine: current state and future prospects. ACTA NEUROCHIRURGICA. SUPPLEMENT 2007; 97:121-8. [PMID: 17691367 DOI: 10.1007/978-3-211-33079-1_17] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Migraine is a common disabling malady. Despite the development of therapeutic agents such as the triptans, a significant number of patients continue to suffer. The evolution of peripheral nerve stimulation for headache management, may significantly improve the management of those who suffer from moderate to refractory migraine symptoms.
Collapse
Affiliation(s)
- L L Rogers
- Division Chronic Pain Management, Department of Anesthesiology, Duke University, USA.
| | | |
Collapse
|
18
|
Slavin KV. Peripheral nerve stimulation for the treatment of neuropathic craniofacial pain. ACTA NEUROCHIRURGICA. SUPPLEMENT 2007; 97:115-20. [PMID: 17691366 DOI: 10.1007/978-3-211-33079-1_16] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Treatment of neuropathic pain in the region of head and face presents a challenging problem for pain specialists. In particular, those patients who do not respond to conventional treatment modalities usually continue to suffer from pain due to lack of reliable medical and surgical approaches. Peripheral nerve stimulation (PNS) has been used for treatment of neuropathic pain for many decades, but only recently it has been systematically applied to the craniofacial region. Here we summarize published experience with PNS in treatment of craniofacial pain and discuss some technical details of the craniofacial PNS procedure.
Collapse
Affiliation(s)
- K V Slavin
- Department of Neurosurgery, University of Illinois, Chicago 60612, USA.
| |
Collapse
|
19
|
Weiner RL. Occipital neurostimulation for treatment of intractable headache syndromes. ACTA NEUROCHIRURGICA. SUPPLEMENT 2007; 97:129-33. [PMID: 17691368 DOI: 10.1007/978-3-211-33079-1_18] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Intractable migraine and other headache syndromes affect almost 40 million Americans and many more millions worldwide. Although many treatment protocols exist, mainly designed around medication regimens, there are estimated to be at least 3-5% of these headache sufferers that do not respond in a meaningful way to medications and whose lives can be severely restricted to darkened, quiet rooms, heavy doses of narcotics, failed personal relationships and an overwhelming sense of hopelessness. In this article, we describe current neuromodulation-based approach to the management of intractable headache.
Collapse
Affiliation(s)
- R L Weiner
- Department of Neurosurgery, Presbyterian Hospital of Dallas, Dallas, Texas, USA.
| |
Collapse
|
20
|
Weiner RL. Occipital Neurostimulation (ONS) for Treatment of Intractable Headache Disorders. PAIN MEDICINE 2006. [DOI: 10.1111/j.1526-4637.2006.00129.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
21
|
Ellrich J, Lamp S. Peripheral Nerve Stimulation Inhibits Nociceptive Processing: An Electrophysiological Study in Healthy Volunteers. Neuromodulation 2005; 8:225-32. [DOI: 10.1111/j.1525-1403.2005.00029.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
22
|
Abstract
Suboccipital stimulation is a relatively new method of neuromodulation for treatment of intractable occipital headache and occipital neuralgia. The most common complication besides an infection is a lead displacement. Anchoring of a lead at the entry place partially solves the problem. Migration of electrode's tip is a major problem so far. A case report of electrode migration and a technique of retrograde lead insertion and subcutaneous anchoring of the tip by means of contralateral incision and suturing of lead is described.
Collapse
Affiliation(s)
- Michael Gofeld
- Center for Pain Medicine, Tel-Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel.
| |
Collapse
|
23
|
Nambi-Joseph P, Stanton-Hicks M, Sferra JJ. Interventional modalities in the treatment of complex regional pain syndrome. Foot Ankle Clin 2004; 9:405-17. [PMID: 15165590 DOI: 10.1016/j.fcl.2004.03.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Complex regional pain syndrome (CRPS) applies to a variety of conditions in which symptoms such as allodynia and hyperalgesia predominate along with hyperpathia and vasomotor/sudomotor disturbances. The incidence of CRPS in the chronic pain population varies and is difficult to determine, though it appears to affect women more than men. Treatment is multidisciplinary, and recovery of function and the reduction of pain are the main goals of treatment;this article addresses some of the interventional modalities that are used.
Collapse
Affiliation(s)
- Pushpa Nambi-Joseph
- Section of Foot & Ankle Surgery, Department of Pain Management, The Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA.
| | | | | |
Collapse
|
24
|
Oh MY, Ortega J, Bellotte JB, Whiting DM, Aló K. Peripheral Nerve Stimulation for the Treatment of Occipital Neuralgia and Transformed Migraine Using a C1-2-3 Subcutaneous Paddle Style Electrode: A Technical Report. Neuromodulation 2004; 7:103-12. [DOI: 10.1111/j.1094-7159.2004.04014.x] [Citation(s) in RCA: 148] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
25
|
Somers DL, Clemente FR. The relationship between dorsal horn neurotransmitter content and allodynia in neuropathic rats treated with high-frequency transcutaneous electric nerve stimulation. Arch Phys Med Rehabil 2003; 84:1575-83. [PMID: 14639554 DOI: 10.1053/s0003-9993(03)00290-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To examine the relation between axon terminal neurotransmitter content in the dorsal horn and allodynia in neuropathic rats treated with high-frequency transcutaneous electric nerve stimulation (TENS). DESIGN A completely randomized experimental design. Two groups of rats received a chronic constriction injury to the right sciatic nerve, and 2 groups did not. The rats were either treated or not treated with TENS. SETTING Research laboratory. ANIMALS Adult male Sprague-Dawley rats (150-165g). INTERVENTIONS TENS was delivered daily for 1 hour to the chronic constriction injury rats or to the uninjured rats through self-adhesive electrodes applied to the skin innervated by the right dorsal rami of lumbar spinal nerves 1 to 6. MAIN OUTCOME MEASURES Thermal and mechanical pain thresholds were assessed bilaterally in the hind paws of all rats twice before the chronic constriction injury surgery (baseline) and then 12 days after the surgery. An analogous time frame of assessment was used for rats that did not have chronic constriction injury surgery. Thermal and mechanical allodynia were expressed as difference scores between the pain thresholds of the right and left hind paws. These values were normalized to differences that existed between the 2 paws at baseline. The amino acid content of dorsal horn axon terminals was assessed bilaterally with high-pressure liquid chromatography, and values were normalized to wet weight. RESULTS The mean level of thermal and mechanical allodynia did not differ between the TENS-treated and untreated rats with chronic constriction injury. However, there was a significant relation between the dorsal horn, axon terminal content of glutamate (adjusted R(2)=.45, P<.01) and glycine (adjusted R(2)=.51, P<.005) and the magnitude of mechanical allodynia present in TENS-treated chronic constriction injury rats, but not in any other group. As axon terminal glutamate and glycine decreased in the right dorsal horn and increased in the left, mechanical allodynia was reduced or absent. When this trend was reversed, mechanical allodynia was more severe. Daily TENS also reduced the mean axon terminal content of aspartate, glutamate, and glycine bilaterally in the chronic constriction injury rats from the level observed in untreated neuropathic rats (P<.05). CONCLUSION The variability in responsiveness of mechanical allodynia to daily TENS treatment in neuropathic rats is related to the axon terminal content of glutamate and glycine in the dorsal horn. These findings may help explain a similar variability in humans when TENS is used to treat neuropathic pain.
Collapse
Affiliation(s)
- David L Somers
- Department of Physical Therapy, John G. Rangos Sr. School of Health Sciences, Duquesne University, Pittsburgh, PA 15282-0011, USA.
| | | |
Collapse
|
26
|
Abstract
There is a renewed interest in the use of PNS for the control of intractable pain caused by peripheral mononeuropathies and sympathetically mediated chronic pain syndromes. Technical advances in neurostimulation hardware, specifically lead design and surgical advancements with percutaneous and subcutaneous techniques, fuel this interest in part. The use of multipolar electrode arrays placed percutaneously in the region of peripheral nerves or in their dermatomal distribution without the need for extensive surgical dissection should help to support the use of PNS as a reasonable alternative to potentially destructive surgical procedures for chronic pain control.
Collapse
Affiliation(s)
- Richard L Weiner
- Department of Neurosurgery, Presbyterian Hospital of Dallas, University of Texas Southwestern Medical School, Dallas, TX, USA.
| |
Collapse
|
27
|
Abstract
Spinal cord stimulation, as with neuromodulation procedures in general, is a nondestructive, screenable, and reversible treatment option. Because there are no long-term side effects that have been reported; spinal cord stimulation is generally preferable as a first step when other less invasive treatments have failed to produce acceptable control of the pain.
Collapse
Affiliation(s)
- John C Oakley
- Northern Rockies Pain and Palliative Rehabilitation Center, Yellowstone Neurosurgical Associates, PC, 2900 North 12th, Suite 501 Billings, MT 59101, USA.
| |
Collapse
|
28
|
Coggeshall RE, Lekan HA, White FA, Woolf CJ. A-fiber sensory input induces neuronal cell death in the dorsal horn of the adult rat spinal cord. J Comp Neurol 2001; 435:276-82. [PMID: 11406811 DOI: 10.1002/cne.1029] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Excitotoxicity due to excessive synaptic glutamate release is featured in many neurological conditions in which neuronal death occurs. Whether activation of primary sensory pathways can ever produce sufficient over-activity in secondary sensory neurons in the dorsal horn of the spinal cord to induce cell death, however, has not been determined. In this study, we asked whether activity in myelinated afferents (A fibers), which use glutamate as a transmitter, can induce cell death in the dorsal horn. Using stereological estimates of neuron numbers from electron microscopic sections, we found that stimulation of A-fibers in an intact sciatic nerve at 10 Hz, 20 Hz, and 50 Hz in 10-minute intervals at a stimulus strength that activates both Abeta and Adelta fibers resulted in the loss of 25% of neurons in lamina III, the major site of termination of large Abeta fibers, but not in lamina I, where Adelta fibers terminate. Furthermore, sciatic nerve lesions did not result in detectable neuron loss, but activation of A fibers in a previously sectioned sciatic nerve did cause substantial cell death not only in lamina III but also in laminae I and II. The expansion of the territory of A-fiber afferent-evoked cell death is likely to reflect the sprouting of the fibers into these laminae after peripheral nerve injury. The data show, therefore, that primary afferent A-fiber activity can cause neuronal cell death in the dorsal horn with an anatomical distribution that depends on whether intact or injured fibers are activated. Stimulation-induced cell death potentially may contribute to the development of persistent pain.
Collapse
Affiliation(s)
- R E Coggeshall
- Department of Anatomy and Neuroscience, University of Texas Medical Branch, Galveston, Texas 77555-1069, USA.
| | | | | | | |
Collapse
|