Spinal Cord After Compressive Injury

Refer to Figure 5 (below). Notice the area in the center of the spinal cord that is surrounded by a ring of connected astrocytes. This central area contains inflammatory cells and chemical mediators that kill the neurons and eventually form the glial scar that prevents migration of healing axons and neurons through this area. There is poor blood flow and swelling of the entire spinal cord. Neurons are dying, axons are severed, axons have lost their myelin sheath. The glial cells are dying (astrocytes and oligodendrocytes) and chemicals are being released that inhibit myelin from reforming and prevent healing of the axons. Note that some neurons and axons do however survive.

Compressive Injury

Figure 5. Spinal Cord Injury from IVDD in the Peracute and Acute Phase
 
GraphicNameDescription
astrocyteAstrocyteAstrocyte forming a ring or cyst around damaged area defining what will be the glial scar. Astrocytes are one of the three cell types in the spinal cord. Astrocytes are responsible for forming the Glial Scar and are responsible for generating new neurons as well. Modulation of Astrocyte function is therefore key to recovery of function.
White Blood CellWhite Blood CellWhite Blood Cells are recruited to damaged tissue to participate in the inflammatory process. Chemicals released from these cells are toxic to normal cells and to Stem Cells. Until the white blood cells dissipate, stem cell therapy is not effective.
Damaged NeuronDamaged NeuronDead or damaged neuron with no connections to other neurons.
DemyelinationDemyelinationDying or dead myelin producing cell. These cells are called oligodendrocytes. They make the insulating sheath that covers the neuron. Neurons do not work if there is no myelin. Loss of myelin is a major problem in spinal cord damage.
Neuron LossNeuron LossDying or dead neuron with loss of connections to other neurons.
Red Blood CellsRed Blood CellsRed blood cells representing hemorrhage.
Harmful ChemicalsHarmful ChemicalsToxic metabolites. Chemicals released from damaged tissues that in turn cause additional damage.
AxonAxonAxon of neuron. Loss of axons cause loss of the function of the neuron. Regeneration of axons is slow taking months to years greatly delaying healing and recovery
MyelinMyelinMyelin is the insulating covering of the nerve axons. Without this sheath, neurons “short out” and their impulse fails to communicate. Oligodendrocytes produce myelin. Myelin production is much faster than nerve axon regeneration.
Pinched off Blood VesselPinched off Blood VesselAttenuated blood vessel – one with no blood cells present. This is typical for damaged spinal cord due to compression.