The Red Flags of Neuropathic Pain

Contents

• Introduction
• Neuropathic Pain: An Overview
• The Impact of Neuropathic Pain*
• Abnormal Pain Transmission: The Pathophysiology of Neuropathic Pain*
• The Presentation of Neuropathic Pain*
• Red Flags: When Symptoms Signal Trouble*
• Serious Etiologies of Neuropathic Pain*
• Diagnosis and Assessment*
• Patient History*
• Physical and Neurological Examination*
• Ancillary Studies*
• To Whom to Refer: The Treatment Team*
• Recognizing the Red Flags of Neuropathic Pain: Case Studies*
• Case Study 1*
• Case Study 2*
• Case Study 3*
• Summary*
• References*
• Additional Information*

* Requires registration. Registration is free and allows you access to all content on PainAwareness.org.
Click here to register.

Target Audience

This continuing medical education activity has been developed for physicians and pharmacists treating neuropathic pain.

Purpose Statement

The purpose of this newsletter is to identify the appropriate time to refer patients to neurologists for neuropathic pain.

Learning Objectives

After completing this activity, participants will be able to:

• Identify patients appropriate for referral to neurologists for neuropathic pain symptoms
• Understand classic and nonclassic clinical “red flags” of neuropathic pain
• Apply an understanding of neuropathic pain to reinforce diagnosis and promote therapeutic selections for patients presenting with both common and challenging neuropathic pain conditions

Introduction

Neuropathic pain is the result of abnormal transmission of pain signals by the central or peripheral nervous system.¹ This aberrant pain signaling differentiates neuropathic pain from other pain types. Indeed, neuropathic pain often produces distinct symptoms, may occur in the absence of tissue injury or persist after an injury has healed, and often does not respond to traditional analgesic drugs.^1,2 An expanding array of adjuvant analgesic agents, including certain antidepressants and anticonvulsants, has demonstrated efficacy for neuropathic pain in clinical studies. For most patients with neuropathic pain, careful application of evidencebased treatment with these nontraditional agents can provide relief. However, a minority of patients presenting with neuropathic pain may have serious, complicated, or even life-threatening conditions. Certain key features may indicate the need for immediate and meticulous assessment and referral to specialists for further investigation and treatment. These “red flags” include the pattern of presentation, the types of functions affected, the time course of illness, and association with certain diseases. This tutorial describes the presentation and mechanisms of neuropathic pain and highlights features of these disorders that indicate the need for referral to specialists for diagnosis and treatment.

Neuropathic Pain: An Overview

Neuropathic pain is common in both primary care and specialist settings, affecting as many as 4 million individuals in the United States.^2,3 Neuropathic pain is heterogeneous in presentation, etiology, pathophysiology, and response to treatment, making it a particular challenge for clinicians.¹ Traditional analgesics, such as the nonsteroidal antiinflammatory drugs (NSAIDs), are generally ineffective in neuropathic pain states.² Despite the availability of other, nontraditional treatments, current strategies fail to produce adequate pain relief in a substantial proportion of patients, suggesting an unmet medical need.^4–6

Neuropathic pain represents a wide range of pain syndromes that together share an underlying nerve injury or dysfunction.¹ Numerous conditions are associated with neuropathic pain (Table 1); common conditions include diabetic peripheral neuropathic pain (DPNP) and postherpetic neuralgia (PHN).

A full discussion of the treatment of neuropathic pain is beyond the scope of this review. Due to its heterogeneity, neuropathic pain must be managed on an individual basis. Pharmaceutical options for treatment include antidepressants, anticonvulsants, topical anesthetics, and, as a second-line option, opioids. Evidence-based recommendations for first-line pharmacologic treatment are summarized in Table 2.⁷

To access the full version of this Case & Commentary, please register.
Registration is free and allows you access to all content on PainAwareness.org.