ENDOGENOUS NGF AND CNTF LEVELS IN HUMAN PERIPHERAL-NERVE INJURY

NERVE growth factor (NGF) is trophic to sensory and sympathetic fibres , and ciliary neurotrophic factor (CNTF) to motoneurones, in animal mo dels of peripheral nerve injury: NGF excess produces hyperalgesia. In this first study of injured human nerves and sensory ganglia, we quant ified and localized endogenous NGF and CNTF in 59 neonate and adult pa tients with brachial plexus and peripheral nerve injury. NGF levels we re generally depleted in injured nerves, but relatively preserved acut ely in nerve segments distal to injury. NGF immunostaining was observe d in Schwann cells in distal nerve segments with pockets of high level s in some neuromas. CNTF levels and immunostaining in Schwann cells we re markedly decreased distally within days of injury. We propose that early local administration of NGF and CNTF-like agents may help preven t degenerative changes in injured nerves, while at later stages local anti-NGF treatment (e.g. of some neuromas) may ameliorate chronic pain .