Painful small fiber neuropathies.
PURPOSE OF REVIEW:
This article reviews the clinical features, pathophysiology, and treatment of small fiber sensory neuropathy.
Neuropathic pain is prevalent among patients with peripheral neuropathies of diverse etiologies. For example, in one recent study using the sensitive Neuropathic Pain Symptom Inventory as a screening tool, neuropathic pain was reported in 94% of patients with different peripheral nervous system diseases. Neuropathic pain is frequently underrecognized or inadequately treated. Furthermore, the paucity of clinical signs with small fiber neuropathy may delay recognition of an organic process. Pain, or uncomfortable symptoms, typically results from damage to small unmyelinated nerve fibers (C fibers) or thinly myelinated nerve fibers (A delta fibers). Recent research has helped discover the location of the “pain generators” within the injured peripheral nerves. Small fiber neuropathies are relatively common in clinical practice, but until recently most of the available neurodiagnostic tests focused on large caliber nerve fibers. In the past two decades, the widespread use of quantitative sensory testing and punch skin biopsies to evaluate small caliber nerve fibers has substantially changed the neurologist’s ability to diagnose and manage small fiber sensory neuropathy.
Neuropathic pain from small fiber neuropathy is prevalent and is caused by a wide variety of disorders, many of which are treatable, especially if recognized early in the process
Interventional management of neuropathic pain: NeuPSIG recommendations.
Dworkin RH, O’Connor AB, Kent J, Mackey SC, Raja SN, Stacey BR, Levy RM, Backonja M, Baron R, Harke H, Loeser JD, Treede RD, Turk DC, Wells CD.
Neuropathic pain (NP) is often refractory to pharmacologic and non-interventional treatment. On behalf of the International Association for the Study of Pain Neuropathic Pain Special Interest Group (NeuPSIG), 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 post-stroke 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 RF lesions for radiculopathy. No other conclusive recommendations can be made due to the poor quality of available of 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 non-interventional treatments.
Pain Res Manag. 2012 May-Jun;17(3):150-8. – FULL ARTICLE HERE
Evidence-based guideline for neuropathic pain interventional treatments: spinal cord stimulation, intravenous infusions, epidural injections and nerve blocks.
Mailis A, Taenzer P.
Department of Medicine, University of Toronto, Toronto, Canada. firstname.lastname@example.org
The Special Interest Group of the Canadian Pain Society has produced consensus-based guidelines for the pharmacological management of neuropathic pain. The society aimed to generate an additional guideline for other forms of neuropathic pain treatments.
To develop evidence-based recommendations for neuropathic pain interventional treatments.
A task force was created and engaged the Institute of Health Economics in Edmonton, Alberta, to survey the literature pertaining to multiple treatments. Sufficient literature existed on four interventions only: spinal cord stimulation; epidural injections; intravenous infusions; and nerve blocks. A comprehensive search was conducted for systematic reviews, randomized controlled trials and evidence-based clinical practice guidelines; a critical review was generated on each topic. A modified United States Preventive Services Task Force tool was used for quality rating and grading of recommendations.
Investigators reviewed four studies of spinal cord stimulation, 19 studies of intravenous infusions, 14 studies of epidural injections and 16 studies of nerve blocks that met the inclusion criteria. The task force chairs rated the quality of evidence and graded the recommendations. Feedback was solicited from the members of the task force.
There is sufficient evidence to support recommendations for some of these interventions for selected neuropathic pain conditions. This evidence is, at best, moderate and is often limited or conflicting. Pain practitioners are encouraged to explore evidence-based treatment options before considering unproven treatments. Full disclosure of risks and benefits of the available options is necessary for shared decision making and informed consent.
Here is the conclusion from the paper: Available data support some evidence-based recommendations for SCS, epidural injections, certain nerve blocks and IV injections for selected neuropathic pain conditions. However, the evidence for most interventions is weak/limited or insufficient. Many nonpharmacological treatment options currently in use for neuropathic pain, including many forms of interventional therapy, have not been investigated using high-quality clinical trial methods. The CPS NePSIG encourages practitioners to explore evidence-based treatment options before considering unproven treatments. Full and careful disclosure of the known and unknown risks and benefits of available options is necessary for shared decision making and truly informed consent.