Botulinum Toxin Type A Treatment of Painful Focal Neuropathies: New Evidence for Efference of Afferents

摘要

Without question there is a need for improved treatments for neuropathic pain, defined as pain caused by disease or dysfunction of the nervous system. An ideal treatment would be safe, effective, long-lasting, and relatively free from adverse effects, as well as inexpensive and easy to administer. Ranoux and colleagues' recent clinical trial, published in this issue of Annals, provides Class 1 evidence in support of an effective new approach to the treatment of focal neuropathic pain.Although this study is an important landmark in the treatment of neuropathic pain, limitations apply. Standard definitions of neuropathic pain encompass a variety of neuropathic processes resulting in pain, including thalamic stroke, myelopathy, radiculopathy, neuroma, focal neuropathy, and small-fiber neuropathy. These processes lead to different abnormalities in nociceptive signaling that share a common feature of pain; it is unlikely that a single therapy will address all causes of neuropathic pain. In this recent study, neuropathic pain was limited to that occurring in patients with postherpetic neuralgia or focal nerve injury experiencing both spontaneous pain and mechanical allo-dynia over a defined area.