The clinical picture of neuropathic pain

Neuropathic pains refer to a heterogenous group of pain conditions characte rised by lesion or dysfunction of the normal sensory pathways. Clinical cha racteristics include: delayed onset of pain after nervous system lesion, pa in in area of sensory loss, spontaneous and different evoked types of pains . It has so far only been possible to classify these pains on basis of unde rlying cause or on anatomical location. The mechanisms underlying neuropath ic pain are not yet clear, but neuronal hyperexcitability in those neurons that have lost their normal patterned input seems to be a common denominato r for many, if not all types, of neuropathic pains. Along these lines, a me chanism-based classification has recently been proposed, which is an attrac tive approach because it provides a frame for a rationally based therapy of neuropathic pains, The clinical manifestations of neuronal hyperexcitabili ty due to nervous system lesions is described. (C) 2001 Published by Elsevi er Science B.V.