Welcome from Michael Bottros, MD
Chronic pain is a common problem in the community and major source of healthcare utilization in the United States. In one study, the reported prevalence of chronic pain in the general population was as high as 46.5% (Elliott AM, Smith BH, Penny KI et al. The epidemiology of chronic pain in the community. Lancet 1999; 354: 1248-52). Discussion of chronic pain can be quite complex, but one simplified approach is to classify it into three categories: pain from tissue damage (nociceptive pain), pain from somatosensory damage (neuropathic pain), or a mix of the two. The term "neuropathic pain" has come into common use only in the last 25 years and is frequently cited as a common cause of chronic pain.
In this issue of PainScan, we aim to educate healthcare providers with a better understanding of neuropathic pain. For review, we have selected six papers published recently that provide important information in answering questions that general practitioners may be faced with when seeing these patients.
The articles may be grouped into four major categories:
Group 1: Introduction
Clifford Woolf is a pioneer in advancing our knowledge of neuropathic pain and its associated conditions. We hope this article from him and his colleagues presents a good introduction to the causes of neuropathic pain, the mechanisms involved (including genetics), and the effect of treatment.
Group 2: Specific Neuropathic Conditions
While the number of neuropathic conditions are long and numerous, we chose articles that look at two specific conditions:
First, we look at complex regional pain syndrome (CRPS). CRPS was previously called reflex sympathetic dystrophy (RSD) or causalgia but was recently revised in 2007 with guidelines commonly referred to as the "Budapest criteria." To make the clinical diagnosis, the following criteria must be met:
- Continuing pain disproportionate to any inciting event
- Must report at least one symptom in three of the four following categories and must display at least one symptom in two of the four categories:
While the exact mechanisms are still not fully understood, this article presents our current understanding of the mechanisms involved.
Next, diabetic neuropathy is discussed. We hope this presents a relatively concise description of the clinical manifestations and current treatment considerations.
Group 3: Assessment
In this article, we take an extensive look at what tools are available to clinicians to screen for and assess the severity of neuropathic pain based on a revision of guidelines by the Neuropathic Pain Special Interest Group (NeuPSIG) of the IASP. Outside of physical examination, several validated screening tools are discussed, as well as quantitative sensory testing and psychological and disability assessments.
Group 4: Treatment
The last two articles come from leaders in the field of pain pharmacology, O'Connor and Dworkin. The first paper discusses the foundation of pharmacological treatments used in neuropathic conditions, while the second delves into an update on the status of newer treatments such as lacosamide, botulinum toxin, and the high-concentration capsaicin patch.