Affiliations: University College London, The PNI-Unit, The Royal
National Orthopaedic Hospital, Brockley Hill Stanmore, Middlesex, HA7 4LP, UK.
Tel.: +44 2089095803; Fax: +44 2084206582; E-mail:
[email protected]
Abstract: Spinal nerve root injuries have a profound effect on the different
parts (PNS and CNS) of the root itself as well as the pertinent spinal cord
segment. A root avulsion from the spinal cord is a longitudinal spinal cord
injury. There is degeneration of sensory and motor axons, loss of synapses,
deterioration of local segmental connections, nerve cell death and reactions
among non neuronal cells with scar formation, i.e. a cascade of events similar
to those known to occur in any injury to the spinal cord. For function to be
restored, nerve cells must survive and there must be regrowth of new nerve
fibres along a trajectory consisting of CNS growth-inhibitory tissue in the
spinal cord as well as PNS growth-promoting tissue in nerves. Problems in PNS
regeneration such as non directional growths and unspecific reinnervation of
target organs lead to unpredictable sensorimotor activity and conspires against
a useful recovery of function. From the results of basic science experiments, a
surgical strategy to treat root avulsion with spinal cord injury has been
developed. In humans this technique is currently the most promising treatment
of any spinal cord injury, with return of useful function together with pain
alleviation in cases where all nerves to the extremity have been avulsed from
the spinal cord. At present the shortcomings of this technique are
proportionate to the delay before surgery, which leads to death of nerve cells
and incomplete and unpredictable recovery. In order to improve this situation
and achieve further recovery of useful function including sensory perceptions
and to fully alleviate pain it is necessary to pursue research and development
of both basic and clinical science.
