Guidelines for the diagnosis and management of neuropathic pain: consensus of a group of Latin American experts

Small Fiber Neuropathy

PURPOSE OF REVIEW

This narrative review aims to summarize advances in the field of small fiber neuropathy made over the last decade, with emphasis on novel research highlighting the distinctive features of SFN.

RECENT FINDINGS

While the management of SFNs is ideally aimed at treating the underlying cause, most patients will require pain control via multiple, concurrent therapies. Herein, we highlight the most up-to-date information for diagnosis, medication management, interventional management, and novel therapies on the horizon. Despite the prevalence of small fiber neuropathies, there is no clear consensus on guidelines specific for the treatment of SFN. Despite the lack of specific guidelines for SFN treatment, the most recent general neuropathic pain guidelines are based on Cochrane studies and randomized controlled trials (RCTs) which have individually examined therapies used for the more commonly studied SFNs, such as painful diabetic neuropathy and HIV neuropathy. The recommendations from current guidelines are based on variables such as number needed to treat (NNT), safety, ease of use, and effect on quality of life.

Small Fiber Neuropathy in the Elderly

Small fiber neuropathy is common and prevalent in the elderly. The disease can be associated with many medical conditions. It often has a negative impact on quality of life due to painful paresthesia, dizziness, and sedative side effects of pain medications. Skin biopsy is the gold standard diagnostic test. Screening for associated conditions is important, because etiology-specific treatment can slow down disease progression and ameliorate symptoms. Adequate pain control can be challenging due to safety and tolerability of pain medications in the elderly. Treatment should be individualized with the goals of controlling underlying causes, alleviating pain, and optimizing daily function.

Medical Cannabis for Chronic Noncancer Pain: A Systematic Review of Health Care Recommendations

Purpose

Medical cannabis for patients with chronic noncancer pain (CNCP) has been the focus of numerous health care recommendations. We conducted a systematic review to identify and summarize the currently available evidence-based recommendations.

Methods

We searched MEDLINE, EMBASE, PsycINFO, the Cochrane database of systematic reviews, and websites for clinical guidelines and recommendations. We summarized the type of the publications, developers, approach of health care recommendation development, year and country of publication, and conditions that were addressed. We categorized the direction and strength of each recommendation.

Results

We identified 12 eligible publications. Publication years ranged from 2007 to 2019; four (33.3%) of them were published in 2018. Canada ranked first for the number of publications (n = 4, 33.3%). Most (n = 11, 92%) of the included recommendations were based on both a systematic review of the best evidence and expert consensus. All the included publications provided a recommendation supporting medical cannabis for CNCP in general and for the specific conditions of neuropathic pain, chronic pain in people living with Human Immunodeficiency Virus (HIV), and chronic abdominal pain, with detailed information sharing and comprehensive consideration of a patient's own values and preferences.

Conclusion

Clinicians can attend to the guidance currently offered, being aware that only weak recommendations are available for medical cannabis in patients with CNCP, as a third- or fourth-line therapy. Detailed discussions with patients regarding the benefits in reducing pain and potential adverse effects are required before its prescription.

Neuropathic Pain and Rehabilitation: A Systematic Review of International Guidelines

Background: Neuropathic pain is an injury or disease of the central and/or peripheral somatosensory nervous system, and it has a significant impact on quality of life, especially since it is often refractory to treatment. Rehabilitative intervention is considered in various guidelines on neuropathic pain treatment, although not in an organic nor detailed way. The aim of this systematic review was to analyze the most indicated therapeutic strategies, providing rehabilitative recommendations in the management of neuropathic pain. Methods: A systematic review was performed according to PRISMA guidelines. The scientific search, carried out until July 2020, considered guidelines in English language of the last thirteen years. Results: Six guidelines were analyzed, from which emerges that a multidisciplinary approach, comprehensive of pharmacologic and nonpharmacologic interventions, should drive neuropathic pain management. A relevant role in non-pharmacological intervention is played by rehabilitation, through an adequate tailored rehabilitation program and physical therapies. Conclusion: This analysis highlights the importance of rehabilitation but also the lack of evidence on various rehabilitative practices. Arises hence the need for further studies in this field to better define a rehabilitative treatment strategy.

Medical cannabis for orthopaedic patients with chronic musculoskeletal pain: does evidence support its use?

The treatment of chronic, non-cancer musculoskeletal pain has become a topic growing interest as it is believed to be one of the reasons for the current opioid epidemic. The medicinal use of cannabis has a long history as a number of active compounds in cannabis have been shown to interact with the body's endocannabinoid system to reduce pain. This position paper provides a history on the evolution of cannabis, the science behind its therapeutic effects, and review of the evidence and current guideline recommendations on its use as a treatment for patients with chronic, non-cancer musculoskeletal pain. Results from systematic reviews have demonstrated a statistically significant reduction in chronic pain conditions with cannabinoids, compared with placebo, although the effects might be considered small and did not reach the minimally important difference. More adverse events were reported in the cannabinoid group than in the placebo group with longer than 2 weeks of treatment. There is a lack of evidence on dependence. With changes to policies, patients' perception has changed to be more positive toward the use of medical cannabis. Current recommendations from North America, Latin America, Europe, Australia and Iran support the use of medical cannabis for chronic, non-cancer pain. Based on the current evidence, it is our position that cannabinoids may be considered as an adjunctive therapy after recommended first- and second-line therapies have failed to provide sufficient efficacy or tolerability. Patients should consider the balance between the desirable and undesirable effects of taking cannabis for chronic pain, and comprehensively consider their own values and preferences, as well as cost-effectiveness factors, based on the information provided by their physician.

Small fiber neuropathy: Getting bigger!

Etiological and clinical heterogeneity of small fiber neuropathy (SFN) precludes a unifying approach and necessitates reliance on recognizable clinical syndromes. Symptoms of SFN arise from dysfunction in nociception, temperature, and autonomic modalities. This review focuses on SFN involving nociception and temperature, examining epidemiology, etiology, clinical presentation, diagnosis, pathophysiology, and management. Prevalence of SFN is 52.95 per 100,000 population, and diabetes and idiopathic are the most common etiologies. Dysesthesia, allodynia, pain, burning, and coldness sensations frequently present in a length-dependent pattern. Additional autonomic features in gastrointestinal, urinary, or cardiovascular systems are frequent but poorly objectified. SFN is diagnosed by intraepidermal nerve fiber density and quantitative sensory and autonomic tests in combination with normal nerve conduction. Pathophysiological understanding centers on sodium channel dysfunction, and genetic forms are beginning to be understood. Treatment is directed at the underlying etiology supported by symptomatic treatment using antidepressants and anticonvulsants. Little is known about long-term outcomes, and systematic cohort studies are needed.

Clinical practice guidelines for the management of neuropathic pain: a systematic review

BACKGROUND

The management of neuropathic pain (NP) is challenging despite it being the recent focus of extensive research. A number of clinical practice guidelines (CPGs) for the management of NP have been published worldwide over the past 2 decades. This study aimed to assess the quality of these CPGs.

METHODS

We performed a systematic review of published CPGs for the management of NP. Three reviewers independently assessed the quality of the CPGs using the Appraisal of Guidelines Research and Evaluation II (AGREE-II) instrument, and recommendations of CPGs were also appraised.

RESULTS

A total of 16 CPGs were included. Thirteen CPGs were developed using an evidence-based approach, and the remaining CPGs were produced by consensus panels. None of CPGs obtained a score greater than 50% in all six AGREE II instrument domains mainly owing to poor performance in the "Applicability" domain. The highest score of the CPGs was achieved in "Clarity and Presentation" domain, followed by "Scope and Purpose" and "Editorial Independence" domains, and the lowest scores were found the in "Applicability" domain. The majority of the CPG recommendations on the management of patients with NP were relatively consistent, especially regarding the recommendation of stepwise treatment with medication.

CONCLUSIONS

Greater efforts are needed not only to improve the quality of development and presentation of the CPGs, but also to provide more efficacy evidence for the management of patients with NP.

The topical 5% lidocaine medicated plaster in localized neuropathic pain: a reappraisal of the clinical evidence

Topical 5% lidocaine medicated plasters represent a well-established first-line option for the treatment of peripheral localized neuropathic pain (LNP). This review provides an updated overview of the clinical evidence (randomized, controlled, and open-label clinical studies, real-life daily clinical practice, and case series). The 5% lidocaine medicated plaster effectively provides pain relief in postherpetic neuralgia, and data from a large open-label controlled study indicate that the 5% lidocaine medicated plaster is as effective as systemic pregabalin in postherpetic neuralgia and painful diabetic polyneuropathy but with an improved tolerability profile. Additionally, improved analgesia and fewer side effects were experienced by patients treated synchronously with the 5% lidocaine medicated plaster, further demonstrating the value of multimodal analgesia in LNP. The 5% lidocaine medicated plaster provides continued benefit after long-term (≤7 years) use and is also effective in various other LNP conditions. Minor application-site reactions are the most common adverse events associated with the 5% lidocaine medicated plaster; there is minimal risk of systemic adverse events and drug–drug interactions. Although further well-controlled studies are warranted, the 5% lidocaine medicated plaster is efficacious and safe in LNP and may have particular clinical benefit in elderly and/or medically compromised patients because of the low incidence of adverse events.

Chronic abdominal syndrome due to nervous compression. Study of 100 cases and proposed diagnostic-therapeutic algorithm

OBJECTIVE

In the medical literature, thoracic disc protrusion has traditionally been considered a rare occurrence. We hypothesise that the incidence of such protrusions and their abdominal symptoms is higher than is generally believed and that their presence may account for a significant proportion of chronic non-visceral abdominal pains. Accordingly, the present study was designed to identify and quantify the symptoms experienced by patients with thoracic disc protrusion and to assess the relative risk of these symptoms being presented, compared to the general population.

DESIGN

We conducted a cross-sectional study with a control group. The following comparison groups were analysed: case group, consisting of 100 patients diagnosed with thoracic disc protrusion in our hospital between February 2007 and October 2012, and control group consisting of 100 subjects from the general population, chosen at random. To compare the symptoms observed in each group, the following tests were applied to all study subjects: clinical examination, gastrointestinal-related quality of life (GIQLI) questionnaire and DN4 questionnaire. We also reviewed the subjects' medical records for the previous 3 years.

RESULTS

The subjects in the case group had a significantly higher incidence of digestive-urologic symptoms, a poorer gastrointestinal quality of life and greater need of medical care than those in the control group. The differences were statistically significant for all the parameters studied. Almost all the case group subjects suffered chronic abdominal pain and/or digestive-urologic symptoms. We term this group of symptoms "chronic abdominal syndrome due to nervous compression". Nevertheless, in most cases, no neurologic aetiology was suspected, and therefore the treatment given was ineffective. In view of the results obtained, we propose a diagnostic-therapeutic algorithm for such patients.

CONCLUSION

Thoracic disc protrusion, as well as having a non-negligible incidence, is often associated with a digestive-urologic clinical syndrome, and this factor should be taken into account in all cases of chronic abdominal pain and other digestive-urologic symptoms when standard tests are negative, so that appropriate treatment may be given.

A patient and physician survey of fibromyalgia across Latin America and Europe

Background

Patients and physicians from three Latin American (LA) and six European countries were surveyed in order to describe differences in journey to diagnosis, impact, and management of fibromyalgia (FM).

Methods

900 patients (300 LA; 600 Europe) and 1824 physicians (604 LA; 1220 Europe) were surveyed between October-December 2010 (LA) and February-April 2008 (Europe). Patients and physicians (GP or specialists) completed separate questionnaires, on symptoms, impact, and FM management. Interviews were conducted in local languages. Appropriate rating scales were used throughout. Data were analyzed using cross-tabulations and descriptive statistics. Significance was determined at P < 0.05 (indicated by *).

Results

In LA versus Europe, patients reported having FM symptoms for longer (100.8 vs. 83.7* months), and taking longer to be diagnosed (42.3 vs. 31.1* months). FM was characterized by multiple symptoms (11.2 vs. 6.9), but more LA patients reported 14 common symptoms*, and rated pain higher on 11-point scale (8.0 vs. 7.2*). LA patients were taking fewer medications (3.3 vs. 4.0). Patients from both regions found common symptoms very/extremely disruptive to their quality of life, but symptoms impacted daily living and ability to work more significantly in LA. Physicians (GPs or specialists) from LA more often considered problems sleeping*, difficulty concentrating*, anxiety*, depression*, numbness/tingling*, and leg cramps* very/extremely disruptive vs. European physicians. Despite headache, heightened sensitivity to touch, difficulty concentrating, and joint pain being experienced by ≥50% of patients from both regions, <15% of PCPs or specialists considered these typical FM symptoms. Patients also considered 12/14 symptoms more disruptive than PCPs or specialists in the same region. However, a higher proportion of PCPs or specialists considered FM to have a strong/very strong impact on aspects of daily living vs. patients within the same region.

Conclusions

Patient- and physician-rated disease perception and impact was often higher in LA than in Europe. Patient and physician perspective concerning FM impact and disruption were often misaligned within the same region. Our observations may be representative of cultural differences in stoicism, expression, beliefs, and attitudes to pain perception and management. Better understanding of these complexities could help targeted educational/training programs incorporating cultural differences, to improve chronic care.

Prevalence, characteristics, and factors associated with chronic pain with and without neuropathic characteristics in São Luís, Brazil

CONTEXT

Chronic pain (CP) with and without neuropathic characteristics is a public health problem. This is the first population-based study in South America, and the third in the world, to use the Douleur Neuropathique 4 Questions (DN4) tool in epidemiologic studies.

OBJECTIVES

The objectives were to estimate the prevalence and associated factors of CP with and without neuropathic characteristics in São Luís, Brazil.

METHODS

We surveyed 1597 people. The DN4 questionnaire was applied. Poisson regression was used to analyze the risk factors.

RESULTS

The prevalence of CP was 42%, and 10% had CP with neuropathic characteristics (CPNC). The results showed that female sex and age ≥30 years were associated with an increased prevalence of CP (P<0.001) and education ≥12 years with a reduction in the prevalence of CP. The sensations listed in the DN4 were more common in people with CPNC and most frequent were pins and needles (87.9%). The cephalic region (36%) and limbs (51%) were the locations most affected. Most respondents felt pain between six months and four years (51.6%), with daily frequency (45%). Pain intensity, the impediments caused by pain, and sadness were more prevalent in people who had CPNC (P<0.001). Health status was regular for most, 50.9% did not know the cause of their pain, 64.1% used drugs, and only 7% had consulted with a pain specialist. Dissatisfaction with treatment was reported by 55%.

CONCLUSION

CP with and without neuropathic characteristics is a public health problem in Brazil, with high prevalence and great influence on people's daily lives.

Diagnosis and treatment of pain in small-fiber neuropathy

Small-fiber neuropathy manifests in a variety of different diseases and often results in symptoms of burning pain, shooting pain, allodynia, and hyperesthesia. Diagnosis of small-fiber neuropathy is determined primarily by the history and physical exam, but functional neurophysiologic testing and skin biopsy evaluation of intraepidermal nerve-fiber density can provide diagnostic confirmation. Management of small-fiber neuropathy depends on the underlying etiology with concurrent treatment of associated neuropathic pain. A variety of recent guidelines proposes the use of antidepressants, anticonvulsants, opioids, topical therapies, and nonpharmacologic treatments as part of the overall management of neuropathic pain. Unfortunately, little data about the treatment of pain specifically in small-fiber neuropathy exist because most studies combine mixed neuropathic pain syndromes in the analysis. Additional studies targeting the treatment of pain in small-fiber neuropathy are needed to guide decision making.

New developments in the treatment algorithm for peripheral neuropathic pain

Neuropathic pain often imposes a substantial and unrelenting burden on those individuals who have it; single-agent analgesics typically only reduce pain at best. Worldwide, five sets of treatment recommendations offer insight into managing neuropathic pain, including two European guidelines, one Canadian, one Latin American, and another constructed under the auspices of the International Association for the Study of Pain (IASP). The analgesics common to these guidelines are topical lidocaine, secondary amine tricyclic antidepressants, serotonin and norepinephrine dual reuptake inhibitors, calcium channel α(2)-δ ligands, tramadol, and opioid antagonists. Still, significant knowledge gaps in the treatment of neuropathic pain conditions have hampered the development of algorithms and multimodal approaches. As the evidence base expands, the addition of new comparative trial data will further refine the development of new guidance for clinical management of neuropathic pain. New alternatives for managing neuropathic pain, such as the high-concentration capsaicin patch, will enlarge the treatment armamentarium and potentially impact therapeutic guidelines.

Guidelines for the Pharmacological Treatment of Peripheral Neuropathic Pain: Expert Panel Recommendations for the Middle East Region

Neuropathic pain (NeP) has been the focus of extensive basic and clinical research over the past 20 years. This has led to an increased understanding of underlying pathophysiological mechanisms and the development of new therapeutic agents, as well as a clearer definition of the role of established medications. To date there are no published treatment guidelines for NeP in the Middle East. A multidisciplinary panel of Middle East and international experts met to review critically and reach a consensus on how best to apply evidence-based guidelines for the treatment of NeP (mainly peripheral NeP) in the Middle East. The expert panel recommended pregabalin, gabapentin and secondary amine tricyclic antidepressants (nortriptyline and desipramine) as first-line treatments for peripheral NeP. Serotonin-norepinephrine reuptake inhibitor antidepressants, tramadol and controlled-release opioid analgesics were recommended as second-line treatments. There is a need to increase diagnostic awareness of NeP, use validated screening questionnaires and undertake more treatment research in the Middle East region.