Neuropathic Pain

Neuropathic pain is defined as pain resulting from injury to the peripheral to the or central nervous system. This is much more common than is generally appreciated. Peripheral causes include failed back surgery syndrome, diabetic neuropathy, postherpetic neuralgia, peripheral nerve injuries, causalgia, and reflex sympathetic dystrophy. Central causes include spinal cord injuries, multiple sclerosis, and stroke. As with all pain syndromes, the first step is accurate diagnosis, and specific treatment if available. Symptomatic treatment for neuropathic pain is often unsatisfactory. Pharmacotherapy involves multiple agents, and patients often do best on combonations of low doses of multiple medications. First line medications include tricyclic antidepressants and gabapentin (Neurontin). Second-line medications include carbamazepine (Tegretol), phenytoin (Dilantin), mexilitene (Mexitil) and miscellaneous agents. Transcutaneous electrical nerve stimulation (TENS) may be useful in patients with focal peripheral neuropathies. Topical agents such as capsaicin or local anesthetic preparations may be useful. Patients with sympathetically-maintained pain may benefit from sympathetic blockade, IV regional blocks, and oral sympatholytic agents.

Interventional treatments, including spinal cord stimulation and spinal opioids may be remarkably helpful in patients with intractable neuropathic pain.

Many clinical trials are in progress for neuropathic pain as well.