Chronic neuropathic pain, caused by lesions in the peripheral or central nervous system, comes in many forms. We describe current approaches to the diagnosis and assessment of neuropathic pain and discuss the results of recent research on its pathophysiologic mechanisms. Randomized controlled clinical trials of gabapentin, the 5% lidocaine patch, opioid analgesics, tramadol hydrochloride, and tricyclic antidepressants provide an evidence-based approach to the treatment of neuropathic pain, and specific recommendations are presented for use of these medications. Continued progress in basic and clinical research on the pathophysiologic mechanisms of neuropathic pain may make it possible to predict effective treatments for individual patients by application of a pain mechanism–based approach.

Chronic neuropathic pain is common in clinical practice. Patients with conditions as diverse as diabetic polyneuropathy, human immunodeficiency virus (HIV) sensory neuropathy, poststroke syndromes, and multiple sclerosis frequently experience daily pain that greatly impairs their quality of life. Table 1 divides common chronic neuropathic pain syndromes into 2 groups based on a central or peripheral location of the nervous system lesion. It is probable, however, that both peripheral and central nervous system mechanisms contribute to the persistence of most types of neuropathic pain. Although precise estimates of the prevalence of neuropathic pain are not available, it is more common than has generally been appreciated. In the United States, there may be more than 3 million people with painful diabetic neuropathy (PDN)¹ and as many as 1 million with postherpetic neuralgia (PHN)

Interest in the mechanisms and treatment of chronic neuropathic pain has increased during the past several years, and this is likely to result in significant treatment advances in the future. These advances will make it possible to go beyond the determination of whether treatment is effective to the identification of what treatments are most effective for which patients.^13,67 Progress in basic science will lead to a greater understanding of the pathophysiologic mechanisms of neuropathic pain. Important goals for clinical research are to devise methods for reliably identifying specific mechanisms in individual patients and to target treatment to them.^13– 17 Greater attention should also be paid to developing preventive interventions for patients who are at risk for chronic neuropathic pain, including patients undergoing breast cancer surgery,⁶⁸ those with herpes zoster,⁶⁹ and those with diabetes.

Source: JAMA