Subcutaneous Target Stimulation (STS) in Chronic Noncancer Pain: A Nationwide Retrospective Study

Stimulation of primary afferent neurons offers a new approach for the control of localized chronic pain. We describe the results with a new neurostimulation technique, subcutaneous target stimulation (STS), for the treatment of chronic focal noncancer pain. STS applies permanent electrical stimulation directly at the painful area via a percutaneous‐placed subcutaneous lead. We reported the clinical outcomes of 111 patients with focal chronic, noncancer pain treated with STS in this first nationwide, multicenter retrospective analysis. The indications for STS were low back pain (n = 29) and failed back surgery syndrome (back pain with leg pain) (n = 37), cervical neck pain (n = 15), and postherpetic neuralgia (n = 12). Pain intensity was measured on a numerical rating scale (NRS) before and after implantation. Data on analgesic medication, stimulation systems, position, and type of leads and complications were obtained from the patients' records. After implantation, the mean pain intensity improved by more than 50% (mean NRS reduction from 8.2 to 4.0) in the entire patient group (P = 0.0009). This was accompanied by a sustained reduction in demand for analgesics. In all the patients, the STS leads were positioned directly at the site of maximum pain. Lead dislocation occurred in 14 patients (13%), infections in 7 (6%), and in 6 cases (5%), lead fractures were observed. The retrospective data analysis revealed that STS effectively provided pain relief in patients suffering from refractory focal chronic noncancer pain and that STS is an alternative treatment option. Prospective controlled studies are required to confirm these retrospective findings. This article presents a new minimally invasive technique for therapy‐resistant focal pain.     

Demographic Characteristics of Patients with Severe Neuropathic Pain Secondary to Failed Back Surgery Syndrome

Background: Neuropathic pain commonly affects the back and legs and is associated with severe disability and psychological illness. It is unclear how patients with predominantly neuropathic pain due to failed back surgery syndrome (FBSS) compare with patients with other chronic pain conditions. Aims: To present data on characteristics associated with FBSS patients compared with those with complex regional pain syndrome, rheumatoid and osteoarthritis, and fibromyalgia. Methods: The PROCESS (Prospective Randomized Controlled Multicenter Trial of the Effectiveness of Spinal Cord Stimulation, ISRCTN 77527324) trial randomized 100 patients to spinal cord stimulation (n = 52) plus conventional medical management (CMM) or CMM alone (n = 48). Baseline patient parameters included age, sex, time since last surgery, employment status, pain location and severity (visual analogue scale), health‐related quality of life (HRQoL), level of disability, medication, and nondrug therapies. Reference population data was drawn from the literature. Results: At baseline, patients in the PROCESS study had a similar age and gender profile compared with other conditions. PROCESS patients suffered from greater leg pain and had lower HRQoL. PROCESS patients treatment cost was higher and they commonly took opioids, while antidepressants and nonsteroidal anti‐inflammatory drugs were more often used for other conditions. Prior to baseline, 87% of patients had tried at least 4 different treatment modalities. Conclusions: Patients suffering from chronic pain of neuropathic origin following FBSS often fail to obtain adequate relief with conventional therapies (eg, medication, nondrug therapies) and suffer greater pain and lower HRQoL compared with patients with other chronic pain conditions. Neuropathic FBSS patients may require alternative and possibly more (cost‐) effective treatments, which should be considered earlier in their therapeutic management.     

Facial Pain Update: Advances in Neurostimulation for the Treatment of Facial Pain

Craniofacial pain, including trigeminal neuralgia, trigeminal neuropathic pain, and persistent idiopathic facial pain, is difficult to treat and can have severe implications for suffering in patients afflicted with these conditions. In recent years, clinicians have moved beyond treating solely with pharmacological therapies, which are generally not very effective, and focused on new interventional pain procedures. These procedures have evolved as technology has advanced, and thus far, early results have demonstrated efficacy in small patient cohorts with a variety of craniofacial pain states. Some of the most promising interventional pain procedures include peripheral nerve field stimulation, high-frequency spinal cord stimulation, sphenopalatine ganglion stimulation, and deep brain stimulation. This review focuses on a better understanding of craniofacial pain and emerging interventional pain therapies. With the advent of newer miniature wireless devices and less invasive implantation techniques, this should allow for more widespread use of neurostimulation as a therapeutic modality for treating craniofacial pain. Larger studies should assist in best practice strategies vis-à-vis traditional pharmacological therapies and emerging interventional pain techniques.     

Neurostimulation for Neck Pain and Headache

Patients with medically refractory headache disorders are a rare and challenging‐to‐treat group. The introduction of peripheral neurostimulation (PNS) has offered a new avenue of treatment for patients who are appropriate surgical candidates. The utility of PNS for headache management is actively debated. Preliminary reports suggested that 60‐80% of patients with chronic headache who have failed maximum medical therapy respond to PNS. However, complications rates for PNS are high. Recent publication of 2 large randomized clinical trials with conflicting results has underscored the need for further research and careful patient counseling. In this review, we summarize the current evidence for PNS in treatment of chronic migraine, trigeminal autonomic cephalagias and occipital neuralgia, and other secondary headache disorders.     

“The failed back surgery syndrome”: Definition and therapeutic algorithms – An update

Approximately 30% of patients experience persistent or recurrent low back and/or pain projecting into the legs following technically adequate lumbosacral surgery. Such pain conditions are often alluded to as the failed back surgery syndrome (FBSS). FBSS represents a significant clinical and economic concern. The treatment of FBSS presents a challenge to physicians, as conservative therapies and spinal reoperations are often unsuccessful – if not a significant cause (besides fibrosis) of the persistent pain syndrome is found at the post-operative examinations. Neuropathic pain radiating into the leg(s) is often the main component of this persistent and disabling syndrome. In this case, spinal cord stimulation (SCS) has been shown to be a successful therapeutic option. Studies have demonstrated that up to 60% of implanted patients experience 50% or more pain relief following SCS. Moreover, SCS has been shown to improve both quality of life and functional status in a significant number of patients. In order to address the challenge of managing both chronic back and leg pain, a multidisciplinary group of physicians experienced in pain management and spinal surgery assembled to discuss and formulate a treatment strategy for FBSS, based on a systematic review of the literature that focused on the role of SCS. The outcome of these discussions however remained unpublished why an update, taking into account also the moderns technologies has been performed.The development of new treatment algorithms should allow, easier, more rational and effective management of this common and clinically – as well as economically – important problem.     

Stimulation methods for neuropathic pain control

Neurostimulation methods for control of chronic neuropathic pain have recently gained in popularity. The reasons for this are mutifactorial. As opposed to nerve ablation, these methods are minimally invasive and reversible. The improvements in hardware design simplified implantation techniques and prolonged equipment longevity. Stimulation trials have become less invasive, allowing patients to test its effects before final implantation. Finally, the scientific evidence has shown good outcomes of neurostimulation methods for chronic neuropathic pain control. Recent research efforts have revealed new potential mechanisms of action of neurostimulation. Whereas its action was widely explained by gate control theory in the past, it seems that neuromodulation acts also by modulation of neurotransmitters in the central nervous system. Three neurostimulation methods are currently used in clinical practice: spinal cord stimulation (SCS), peripheral nerve stimulation (PNS), and deep brain stimulation (DBS). The SCS and PNS are excellent treatment choices for certain forms of neuropathic pain. The new indications for SCS are end-stage peripheral vascular disease and ischemic heart disease, whereas PNS is used for the treatment of occipital neuralgia and chronic pelvic pain. DBS is reserved for carefully selected patients in whom the other treatment modalities have failed. In a minority of patients the "tolerance" to neurostimulation develops after long-term use. Further research is needed to establish better outcome predictors to neurostimulation and possibly improve patient selection criteria.     

Retrospective Review of 707 Cases of Spinal Cord Stimulation: Indications and Complications

Appropriate patient selection and minimizing complications are critical for successful spinal cord stimulation (SCS) therapy in managing intractable pain. We thus reviewed electronic medical records of 707 consecutive cases of patients who received SCS therapy in the Cleveland Clinic from 2000 to 2005 with an emphasis on indications and complications. SCS was used to treat complex regional pain syndrome (CRPS) (345 cases), failed back surgery syndrome (235 cases), peripheral vascular disease (20 cases), visceral pain in the chest, abdomen, and pelvis (37 cases), and peripheral neuropathy (70 cases). CRPS and failed back surgery syndrome accounted for 82% of the cases. The implant‐to‐trial ratio was 75% on average, with the highest for CRPS type 2 (83%) and the lowest for peripheral vascular diseases (65%). The only documented complication associated with SCS trials was lead migration in 5 of 707 patients (0.7%). There were no permanent neurological deficits or deaths as a result of SCS implant or its complications. Hardware‐related complications were common (38%) and included lead migration (22.6%), lead connection failure (9.5%), and lead breakage (6%). Revisions or replacements were required in these cases. Biologically related complications included pain at the generator site (12%) and clinical infection (4.5%; 2.5% with positive culture). The rates of infection varied among the different diagnoses with the highest in failed back surgery syndrome (6.3%). Patients with diabetes had an infection rate of 9%, over the 4% in non‐diabetics. Infections were managed successfully with explantation and antibiotic therapy without permanent sequela.     

Safety and Efficacy of Percutaneous Neuromodulation Therapy in the Management of Subacute Radiating Low Back Pain

Objective: Percutaneous neuromodulation therapy (PNT) is a new minimally invasive, office‐based treatment for low back pain in which electrical stimulation is delivered to the paraspinal peripheral nerves. The purpose of this study was to determine the safety, tolerability, and clinical efficacy of PNT in a population of patients with subacute low back pain with radiation to the lower extremity. Design: Open label prospective clinical trial. Setting: Multi‐center outpatient setting. Participants: We enrolled 83 patients who had radiating low back pain for 4 weeks to 6 months with a pain intensity of at least 4 on a visual analog scale of 0–10. Interventions: Subjects were treated with PNT 1 to 2 times per week for at least 4 weeks. Based on clinical response patients were treated up to an additional 8 weeks. Main Outcome Measures: We recorded baseline visual analog scale (VAS) scores of radiating pain, low back pain, physical activity, and sleep, as well as the Oswestry Disability Questionnaire. Follow‐up assessments were performed at each session, and at 5 and 12 weeks. Patients benefiting from treatments at 12 weeks were followed‐up at 6 months. Results: Fifty‐nine patients completed the study protocol. Mean VAS scores improved as follows: leg/buttock pain decreased by 37% to 4.0 ± 2.6 from a baseline of 6.6 ± 1.7 (P < 0.001); low back pain decreased by 26% to 3.9 ± 2.4 from a baseline of 5.5 ± 2.2 (P < 0.001); activity levels improved by 38% to 3.6 ± 2.2 from a baseline of 6.0 ± 2.2 (P < 0.001); and sleep improved by 27% to 3.1 ± 2.5 from a baseline of 4.8 ± 3.0 (P < 0.001). The Oswestry Low Back Pain Disability scores improved by 24% to 32 ± 16 from a baseline of 43 ± 15 (P < 0.001). Pain relief was sustained over a 3‐month observation period. Conclusion: For many patients with subacute radiating low back pain, PNT significantly reduced pain and self‐rated disability, and improved sleep quality and activity level. PNT is safe and generally well tolerated.     

A Review of Duloxetine 60 mg Once‐Daily Dosing for the Management of Diabetic Peripheral Neuropathic Pain,Fibromyalgia, and Chronic Musculoskeletal Pain Due to Chronic Osteoarthritis Pain and Low Back Pain

Background: Duloxetine is a selective dual neuronal serotonin (5‐Hydroxytryptamine, 5‐HT) and norepinephrine reuptake inhibitor (SSNRI). It is indicated in the United States for treatment of major depressive disorder (MDD), generalized anxiety disorder (GAD), and several chronic pain conditions, including management of diabetic peripheral neuropathic pain, fibromyalgia, and chronic musculoskeletal pain due to chronic osteoarthritis (OA) pain and chronic low back pain (LBP). Its use for antidepressant and anxiolytic actions has been extensively reviewed previously. We here review the evidence for the efficacy of 60 mg once‐daily dosing of duloxetine for chronic pain conditions. Method: The literature was searched for clinical trials in humans conducted in the past 10 years involving duloxetine. Results: There were 199 results in the initial search. Studies not in the English language were excluded. We then included only studies of diabetic peripheral neuropathic pain, fibromyalgia, and chronic musculoskeletal pain (OA and LBP). Studies of painful symptoms reported in mental health studies were excluded. This resulted in 32 studies. Articles that did not include a 60 mg/day daily dose as a study arm were excluded. This resulted in 30 studies, broken down as follows: 12 for diabetic peripheral neuropathy, 9 for fibromyalgia, 6 for LBP, and 3 for OA pain. Conclusions: The studies reviewed report that duloxetine 60 mg once‐daily dosing is an effective option for the management of diabetic peripheral neuropathic pain, fibromyalgia, and chronic musculoskeletal pain due to chronic OA pain and chronic LBP. As these pains are often comorbid with MDD or GAD, duloxetine might possess the pharmacologic properties to be a versatile agent able to address several symptoms in these patients. With adequate attention to FDA prescribing guidance regarding safety and drug–drug interactions, duloxetine 60 mg once‐daily dosing appears to be an effective option in the appropriate pain patient population.     

Minimally invasive interventional therapy for pain

Pain interventional therapy, known as the most promising medical technology in the 21st century, refers to clinical treatment technology based on neuroanatomy, neuroimaging, and nerve block technology to treat pain diseases. Compared with traditional destructive surgery, interventional pain therapy is considered a better and more economical choice of treatment. In recent years, a variety of minimally invasive pain interventional therapy techniques, such as neuroregulation, spinal cord electrical stimulation, intervertebral disc ablation, and intrasheath drug infusion systems, have provided effective solutions for the treatment of patients with post-herpetic neuralgia, complex regional pain syndrome, cervical/lumbar disc herniation, and refractory cancer pain.     

On the Therapeutic Viability of Peripheral Nerve Stimulation for Ilioinguinal Neuralgia: Putative Mechanisms and Possible Utility

▪ Abstract:   Injury to the ilioinguinal nerve commonly follows during lower abdominal and pelvic surgery, especially with inguinal hernia repair, appendectomy, and hysterectomy. Other potential causes include low abdominal blunt trauma, iliac crest bone graft, psoas abscess, Pott's disease, and prolonged wearing of abdominally constrictive clothing. The actual incidence of ilioinguinal neuralgia is uncertain, as reported percentage ranges between 12% and 62%. Prompt and accurate diagnosis is critical, and appropritate treatments range from conservative pharmacologic management with nonopioid (eg, gabapentin, topiramate) as well as opioid agents, to surgical neurectomy of the proximal portion of the ilioinguinal nerve. Pharmacological treatment is frequently unsuccessful (particularly if delayed) and while surgery is successful in approximately 73% of cases, it can result in problematic paresthesias, and pain may continue to persist in some patients. Thus, minimally invasive techniques, such as peripheral nerve stimulation, may be viable in those patients who are refractory to pharmacological management, as an option to surgery, and who have not gained satisfactory pain relief through surgical intervention. We present three cases of successful pain control of ilioinguinal neuralgia with peripheral nerve stimulation. These cases demonstrate the potential benefits of neurostimulation including durable effective pain relief and decreased use of medication. Putative mechanisms of effect(s) and caveats for continued research to inform prudent employment of this technique are presented. ▪     

Is Spinal Cord Stimulation an Effective Treatment Option for Discogenic Pain?

Introduction: In a prospective observational study conducted in an urban pain management center, we evaluated whether spinal cord stimulation (SCS) is effective in relieving discogenic pain of IDD origin. Methods: Thirteen patients with intractable discogenic low back pain were enrolled. Four patients never underwent permanent implantation due to insurance denial, medical reasons or failed trial and served as a control group. Nine patients underwent SCS implantation (treatment group). All patients were followed for 12 months and assessed at each interval for pain (NRS), disability (ODI), and opioid use. Results: Nine patients completed the SCS trial with > 50% pain relief. The pretrial NRS score was 7.8 ± 0.5 mm in treated patients vs. 6.5 ± 1.7 mm in control patients. At 3, 6 and 12 months, the NRS was reduced to 2.9 ± 0.7 mm, 1.7 ± 0.5 mm, and 2.9 ± 0.5 mm, respectively in treated patients. NRS was unchanged in the control patients (6.5 ± 1.9 mm). The ODI score prior to the SCS trial in treated patients was 53.1 ± 3.4% vs. 54.0 ± 20.5 in control patients. At 3, 6 and 12 months the ODI scores were 39.0 ± 8.0%, 38.7 ± 4.6%, and 41.1 ± 3.9%, respectively in the treated patients, and 48.5 ± 29.5 at 12 months in control patients. In 6 patients receiving opioids prior to the SCS trial, average consumption was reduced by 69% (P = 0.036) over 12 months of therapy as compared with a 54% increase in the control patients. SCS usage was stable over the 12‐month study. Conclusions: The current study indicates that SCS may provide effective pain relief, improve disability, and reduce opioid usage in patients with discogenic pain.     

Interventional management of neuropathic pain: NeuPSIG recommendations

Neuropathic pain (NP) is often refractory to pharmacologic and noninterventional treatment. On behalf of the International Association for the Study of Pain Neuropathic Pain Special Interest Group, the authors evaluated systematic reviews, clinical trials, and existing guidelines for the interventional management of NP. Evidence is summarized and presented for neural blockade, spinal cord stimulation (SCS), intrathecal medication, and neurosurgical interventions in patients with the following peripheral and central NP conditions: herpes zoster and postherpetic neuralgia (PHN); painful diabetic and other peripheral neuropathies; spinal cord injury NP; central poststroke pain; radiculopathy and failed back surgery syndrome (FBSS); complex regional pain syndrome (CRPS); and trigeminal neuralgia and neuropathy. Due to the paucity of high-quality clinical trials, no strong recommendations can be made. Four weak recommendations based on the amount and consistency of evidence, including degree of efficacy and safety, are: 1) epidural injections for herpes zoster; 2) steroid injections for radiculopathy; 3) SCS for FBSS; and 4) SCS for CRPS type 1. Based on the available data, we recommend not to use sympathetic blocks for PHN nor radiofrequency lesions for radiculopathy. No other conclusive recommendations can be made due to the poor quality of available data. Whenever possible, these interventions should either be part of randomized clinical trials or documented in pain registries. Priorities for future research include randomized clinical trials, long-term studies, and head-to-head comparisons among different interventional and noninterventional treatments.     

Cervicomedullary junction spinal cord stimulation for head and facial pain

Objective.— To review our experience with cervicomedullary junction spinal cord stimulation (SCS), to alleviate head and facial pain. Background.— There is a dearth of literature regarding the use of spinal cord stimulation for treating head and facial pain. Design.— We performed a Boolean search of the electronic medical record (1990‐2009) and identified 35 patients (9 men, 26 women) for whom the senior author (J.J.M) trialed paddle lead cervicomedullary junction stimulation (CMJ‐S) for intractable head or facial pain. Twenty‐five patients (71.4%) had a successful trial with subsequent implantation of SCS hardware and 10 patients (28.6%) experienced a failed trial. Pain syndromes were categorized into diagnostic groups: trigeminal deafferentation pain (TDP), trigeminal neuropathic pain (TNP), occipital pain/neuralgia, post‐herpetic neuralgia (PHN), and post‐stroke facial pain. Follow‐up via structured telephone interview was obtained in 25 patients (71.4%). Results.— Among the 25 patients available for follow‐up, 16 patients (64%) underwent implantation and 9 patients (36%) had a failed trial of CMJ‐S. The mean patient age and length of follow‐up was 47.3 years old (20‐78 years old) and 53.4 months (2‐120 months), respectively. On a 0‐10 pain intensity scale (0 being no pain and 10 being the worst degree of pain), a mean pretrial pain level of 9.6 (range 7‐10) had been reduced to a mean of 4.8 (0‐10) at follow‐up. Successful trial and subsequent implantation occurred in 7 patients with TDP (70%), 4 patients with TNP (80%), both patients with PHN (100%), and in the single patient with post‐stroke facial pain (100%) but in only 2 patients (28.6%) with occipital neuralgia/pain. At the time of telephone interview, 4 of the implanted patents (25%) had their hardware removed because of loss of effectiveness (3) and infection (1). The other 12 implanted patients (75%) continue to use CMJ‐S on a daily basis and insist that it has improved their quality of life. Six current users (50%) of CMJ‐S have been able to decrease their use of oral pain medications. Complications in the implanted group included infection (1), uncomfortable paresthesias from breakdown of connecting wire insulation (1), and gradual loss of effectiveness (3). Conclusions.— Our preliminary experience suggests that patients suffering from TDP, TNP, and PHN may respond favorably to CMJ‐S whereas patients with occipital neuralgia/pain are rarely palliated by this neuromodulatory approach.     

神经阻滞技术与周围神经痛

介绍三叉神经痛、舌咽神经痛、枕神经痛、颈椎性神经根痛、肋间神经痛、坐骨神经痛、股神经痛、股外侧皮神经痛、髂腹股沟及髂腹下神经痛等10种周围神经痛的病因和发病机制、临床症状、诊断以及治疗方法。神经阻滞(nerveblock,NB)技术治疗这些疾病是来源于麻醉学的一种独特的方法。当药物疗法或其他方法不见效时改用这种技术可获显著效果,于是详述眶上NB,眶下NB,上颌NB,下颌NB,颏NB,半月神经节乙醇、甘油、热凝NB,舌咽NB,枕NB,肋间NB,腰大肌肌沟阻滞,股NB,股外侧皮NB,髂腹股沟及髂腹下NB等18种NB技术的实施方法。     

Clinical presentation and manual therapy for lower quadrant musculoskeletal conditions

Chronic lower quadrant injuries constitute a significant percentage of the musculoskeletal cases seen by clinicians. While impairments may vary, pain is often the factor that compels the patient to seek medical attention. Traumatic injury from sport is one cause of progressive chronic joint pain, particularly in the lower quarter. Recent studies have demonstrated the presence of peripheral and central sensitization mechanisms in different lower quadrant pain syndromes, such as lumbar spine related leg pain, osteoarthritis of the knee, and following acute injuries such as lateral ankle sprain and anterior cruciate ligament rupture. Proper management of lower quarter conditions should include assessment of balance and gait as increasing pain and chronicity may lead to altered gait patterns and falls. In addition, quantitative sensory testing may provide insight into pain mechanisms which affect management and prognosis of musculoskeletal conditions. Studies have demonstrated analgesic effects and modulation of spinal excitability with use of manual therapy techniques, with clinical outcomes of improved gait and functional ability. This paper will discuss the evidence which supports the use of manual therapy for lower quarter musculoskeletal dysfunction.     

Efficacy of spinal cord stimulation: 10 years of experience in a pain centre in Belgium.

Spinal cord stimulation is a minimally invasive mode of treatment in the management of certain forms of chronic pain that do not respond to conventional pain therapy. Several authors have reported encouraging findings with this technique. Over a 10-year period in a single centre, 254 patients were subjected to a trial period of spinal cord stimulation with an externalized pulse generator. Two hundred and seventeen of the patients showed satisfactory results justifying permanent implantation of a spinal cord stimulation system. In 1998, an independent physician invited 153 patients (155 pain cases), who still had the system in place and who could be contacted, for an interview. The aim of this study was to evaluate the efficacy of an implanted spinal cord stimulation system in terms of pain relief and quality of life and to assess the accuracy of the patient selection criteria. The results of this study demonstrate a high success rate as evaluated by the patients' own assessments--68% of the patients rated the result of the treatment as excellent to good after an average follow-up of almost 4 years. The resumption of work by 31% of patients who had been working before the onset of pain supports these positive findings.     

Postherpetic Neuralgia: The Never-Ending Challenge

Abstract: Postherpetic neuralgia (PHN) is defined as pain that persists 1 to 3 months following the rash of herpes zoster (HZ). PHN affects about 50% of patients over 60 years of age and 15% of all HZ patients. Patients with PHN may experience two types of pain: a steady, aching, boring pain and a paroxysmal lancinating pain, usually exacerbated by contact with the involved skin. Herpes zoster is initially a clinical diagnosis, based on the observation of a typical dermatomal distribution of rash and radicular pain. HZ is pathologically characterized by inflammatory necrosis of dorsal root ganglia, occasionally associated with evidence of neuritis, leptomeningitis, and segmental unilateral degeneration of related motor and sensory roots. Although acyclovir has been used successfully as standard therapy for varicella zoster virus (VZV) infection in the past decade, resistant strains of VZV are often recognized in immunocompromised patients. Therapy with acyclovir and the use of corticosteroids have been reported to prevent PHN in up to 60% of HZ patients. Management of chronic pain in PHN is more problematic. The only therapy proven effective for PHN in controlled study is the use of tricyclic antidepressants, including amitriptyline and desipramine. There is good evidence of efficacy from randomized trials that gabapentin and pregabalin (new anticonvulsant drugs) are of benefit in the reduction of pain from PHN. As alternative therapies, topical agents such as capsaicin, lidocaine or opioid analgesic treatment may give satisfactory results. Interventions with low risk, such as transcutaneous electrical nerve stimulation (TENS), are appropriate. Evidence is scant for the value of surgical and procedural interventions in general, although there are numerous, small studies supporting the use of specific interventions such as nerve blocks, neurosurgical procedures, and neuroaugmentation. Although antiviral agents are appropriate for acute HZ, and the use of neural blockade and sympathetic blockade may be helpful in reducing pain in selected patients with HZ, there is little evidence that these interventions will reduce the likelihood of developing PHN. Postherpetic neuralgia remains a difficult pain problem. This review describes the epidemiology and pathophysiology of PHN and discusses proposed mechanisms of pain generation with emphasis on the various pharmacological treatments and invasive modalities currently available.     

Percutaneous Peripheral Nerve Stimulation for the Treatment of Chronic Low Back Pain: Two Clinical Case Reports of Sustained Pain Relief

As the leading cause of disability among U.S. adults, chronic low back pain (LBP) is one of the most prevalent and challenging musculoskeletal conditions. Neuromodulation provides an opportunity to reduce or eliminate the use of opioids to treat chronic LBP, but the cost and invasiveness of existing methods have limited its broad adoption, especially earlier in the treatment continuum. The present case report details the results of a novel method of short‐term percutaneous peripheral nerve stimulation (PNS) in 2 subjects with chronic LBP. At the end of the 1‐month therapy, stimulation was discontinued and the leads were withdrawn. PNS produced clinically significant improvements in pain (62% average reduction in Brief Pain Inventory Question #5, average pain), and functional outcomes (73% reduction in disability, Oswestry Disability Index; 83% reduction in pain interference, Brief Pain Inventory). Both subjects reduced nonopioid analgesic use by 83%, on average, and the one subject taking opioids ceased using all opioids. The only adverse event was minor skin irritation caused by a topical dressing. The clinically significant improvements were sustained at least 4 months after start of therapy (79% average reduction in pain; both reported minimal disability; 100% reduction in opioids; 74% reduction nonopioids). The results reveal the utility of this novel, short‐term approach and its potential as a minimally invasive neuromodulation therapy for use earlier in the treatment continuum to produce sustained pain relief and reduce or eliminate the need for analgesic medications, including opioids, as well as more expensive and invasive surgical or therapeutic alternatives.     

Herpes zoster in older adults. (Duke University Medical Center, Durham, NC) Clinical Infectious Diseases. 2001;32:1481–1486.

Herpes zoster (HZ) strikes millions of older adults annually worldwide and disables a substantial number of them via postherpetic neuralgia (PHN). Key aged‐related clinical, epidemiological, and treatment features of zoster and PHN are reviewed in this article. HZ is caused by renewed replication and spread of the varicella‐zoster virus (VZV) in sensory ganglia and afferent peripheral nerves in the setting of age‐related, disease‐related, and drug‐related decline in cellular immunity to VZV. VZV‐induced neuronal destruction and inflammation causes the principal problems of pain, interference with activities in daily living, and reduced quality of life in elderly patients. Recently, attempts to reduce or eliminate HZ pain have been bolstered by the findings of clinical trials that antiviral agents and corticosteroids are effective treatment for HZ and that tricyclic antidepressants, topical lidocaine, gabapentin, and opiates are effective treatment for PHN. Although these advances have helped, PHN remains a difficult condition to prevent and treat in many elderly patients. Comment by Miles Day, M.D. This article reviews the epidemiology clinical features diagnosis and treatment of acute herpes zoster. It also describes the treatment of postherpetic neuralgia. While this is a good review for the primary care physician, the discussion for the treatment for both acute herpes zoster and postherpetic neuralgia do not mention invasive therapy. It is well documented in pain literature that sympathetic blocks with local anesthetic and steroid as well as subcutaneous infiltration of active zoster lesions not only facilitate the healing of acute herpes zoster but also prevents or helps decrease the incidence of postherpetic neuralgia. All patients who present to the primary care physician with acute herpes zoster should have an immediate referral to a pain management physician for invasive therapy. The treatment of postherpetic neuralgia is a challenging experience both for the patient and the physician. While the treatments that have been discussed in this article are important, other treatments are also available. Regional nerve blocks including intercostal nerve blocks, root sleeve injections, and sympathetic blocks have been used in the past to treat postherpetic neuralgia. If these blocks are helpful, one can proceed with doing crynourlysis of the affected nerves or also radio‐frequency lesioning. Spinal cord stimulation has also been used for those patients who are refractory to noninvasive and invasive therapy. While intrathecal methylprednisolone was shown to be effective in the study quoted in this article one must be cautious not to do multiple intrathecal steroid injections in these patients. Multilple intrathecal steroid injections can lead to archnoiditis secondary to the accumulation of the steroid on the nerve roots and in turn causing worsening pain.