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
Graphic Name Description
astrocyte Astrocyte Astrocyte 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 Cell White Blood Cell White 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 Neuron Damaged Neuron Dead or damaged neuron with no connections to other neurons.
Demyelination Demyelination Dying 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 Loss Neuron Loss Dying or dead neuron with loss of connections to other neurons.
Red Blood Cells Red Blood Cells Red blood cells representing hemorrhage.
Harmful Chemicals Harmful Chemicals Toxic metabolites. Chemicals released from damaged tissues that in turn cause additional damage.
Axon Axon Axon 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
Myelin Myelin Myelin 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 Vessel Pinched off Blood Vessel Attenuated blood vessel – one with no blood cells present. This is typical for damaged spinal cord due to compression.