A lumbosacral ventral root avulsion injury and repair model for studies of neuropathic pain in rats.

Neuropathic pain may develop after a variety of injuries to peripheral nerves and roots. Most injury models have included a direct injury to primary afferent fibers or neurons. Recently, it has been demonstrated that injury to motor fibers in ventral roots may also result in neuropathic pain. A lumbosacral ventral root avulsion injury results in acute and persistent mechanical allodynia, but not thermal hyperesthesia. Interestingly, an acute replantation of the avulsed ventral roots into the spinal cord results in amelioration of the neuropathic pain. A detailed description of this injury and repair model is provided.