The sodium-channel blocker lidocaine in subanesthetic concentrations reduces spontaneous and evoked pain in human painful neuroma

Abstract

Neuropathic pain is pain caused by a lesion or disease of the omatosensory nervous system. It commonly persists for years, ay remain a lifelong problem, and is often associated with sigificant reduction in quality of life, decreased mood and sleep isturbance. Current available drug treatments often provide only artial pain relief and are only effective in a subgroup of patients 1]. It is therefore striking that Miclescu et al. in this issue of the candinavian Journal of Pain, demonstratedanalmost completepain elief from subanesthetic concentrations of lidocaine injected close o a neuroma in patients with peripheral nerve injury and neuomapain [2]. The studywas adouble-blind randomized cross-over rial, in which lidocaine was given as 0.5% and 0.1% in randomized rder. The lowest (0.1%) concentration of lidocaine was used as a ontrol rather than saline in order to reduce the acute pain from he injection and it probable also helped preserve blinding. There as also a marked effect of the 0.1% low concentration lidocaine. his study is important for at least three reasons: (1) It can help s understand the mechanisms by which local anesthetics provide ain relief, (2) improve our understanding ofmechanisms bywhich europathic pain is maintained, and (3) help to identify targets for ain treatment.