Neuropathic pain: mechanisms, therapeutic approach, and interpretation of clinical trials

Neuropathic pain (NP) is caused by a lesion of the somatosensory system and is characterized by a combination of positive symptoms (ongoing pain, paroxysmal pain, evoked pain) and negative phenomena (sensory deficit in the painful area). Examples of NP include painful diabetic and nondiabetic neuropathies, postherpetic neuralgia, traumatic nerve lesions, radiculopathies, and central pain (eg, spinal cord injury pain, poststroke pain). This review presents the mechanisms and therapeutic options for NP.

Consensus recommendations for the treatment of NP or of some neuropathic conditions propose using antidepressants, antiepileptics, and topical lidocaine as first-line treatment and using tramadol and other opioids as second- or third-line treatment. Clinical advances in the management of NP include the implementation of comparative studies and combination therapy trials, the study of rarer and often neglected NP conditions, and the identification of responder profiles based on a detailed characterization of symptoms and signs using sensory examination and specific pain questionnaires.

The management of patients with chronic NP is challenging because of the multiplicity of mechanisms involved in NP conditions. Evidence-based recommendations for the pharmacologic treatment of NP have recently been proposed.