Cell Therapy For Spinal Cord Injury

                                    

  Spinal   cord injury has no curative therapy at present . For a future efficient treatment one has to consider and combine the following approaches :
1. Tissue or cell transplantation ,
2. Providing growth stimulating factors. There is direct  disruption  of nerve tracts with secondary  damage done to oestemia and  hemorrhage. The glial scar forms at the site and is a barrier for future representations of the brain .
    
   Therefore in the acute setting, secondary damage is linked by decompression of the  spinal cord by laminectomy  to limit ischemia, orthopaedic fixation of the  involved  vertebrae  and high dose of steroids.
    
    Currently, the existence of endogenous mechanisms for neural  regeneration is being  accepted. In multiple  animal studies the presence of neural  stem cells in different areas of brain has been . Uchida et al have documented the existence  of adult neural stem cells in the subventricular zones of the brain .
     
                                                    

      During the last decade,

multiple attempts in animal  models of spinal cord injury have been investigated. The approaches have focused  on  I) replacement  of damaged  neural tissue, II) enhancement  of endogenous  neural  regeneration , III) modulation of inflammatory  response  after spinal cord injury .
       
     Mc Donald et al differentiated murine embryonic stem cells into neural progenitor cells and transplanted these  cells into a rat model of spinal cord injury with success. Transplantation of adult neural  stem cells isolated post-mortem out of human brains was associated with extensive remyelination comparable with myelination pattern  of Schwann's cells in the peripheral  nervous system, when transplanted in the demyelinated rat spinal cord.

         Others reported improvement after transplantation of murine neural stem cells embedded in a polymer scaffold  in a hemi section model in rat. Despite all the above success with cell therapy , immunological rejection has to be noted.
     
    To circumvent this problem of rejection MSCs residing in bone marrow have received much attention. These can be cultured easily out of bone marrow and in vitro have shown trans- differentiation into neural cells .
    
    After transplantation into brain and spinal cord their differentiation into cells with neuronal and astrocyte characteristics was reported.
      
     Olfactory ensheathing cells have been extracted in humans and their transplantation has improved motor and sensory recover after spinal cord injury.
      
     These results are encouraging and the autologous nature has the relative ease of obtaining these cells and is a good therapeutic  treatment  for spinal injury.