Neurotrophic factors and neuropathic pain.

Neuropathic pain is a debilitating consequence of nerve damage. Existing treatment is largely ineffective. Current models of neuropathic pain recognise the importance of ectopic activity in primary sensory neurones impinging on a sensitised central nervous system. Neurotrophic factors have been shown to be neuroprotective for damaged sensory neurones, providing a rationale for testing their effects in neuropathic pain states. Recent data have demonstrated potent analgesic effects of one factor (glial cell line-derived neurotrophic factor) in animal models of neuropathy, and implicated changes in sodium channel alpha-subunits in the generation of afferent ectopic activity. The new findings provide a rational basis for the use of neurotrophic factors as a novel therapeutic treatment for neuropathic pain states.