Can Scar Tissue Form Inside a Nerve?

Scar tissue can develop inside a spinal nerve.  Intraneural scar cannot be repaired through surgical intervention.  A nerve fascicle refers to a collection of nerve fibers that travel together within a nerve to reach their destination.  Most of the spinal nerves are made up of numerous fascicles separated from each other by fatty tissue that also lies within the nerve.  In summary, there are various compartmentalized microenvironments within a spinal nerve that are susceptible to the development of scar tissue.  The presence of scar tissue within a nerve can disrupt blood supply to the nerve and compromise the venous supply that carries blood out of the nerve.  The build up of chemical (metabolic) waste products promotes inflammation and more scar formation.  Internal nerve swelling and edema increases pressure within the nerve, which can complicate compression from outside the nerve.

The duration of nerve compression influences recovery as well as the degree of physical compromise of the nerve. The reduction of symptoms may take many months and in some cases over a year.

Myelinated Nerves:

Many nerves are lined with a special fatty substance referred to as myelin.  Myelin is formed within specialized cells referred to as Schwann cells which lie on the outside surface of nerve fibers.  Schwann cells develop the Myelin that wraps around the outside of the nerve providing a form of fatty insulation.  Myelin influences electrical nerve signal transmission.  Large diameter myelinated nerves can conduct nerve signals at a greater speed than nerves that have lesser degree of myelin.

Compression of a spinal nerve can cause a loss of myelin (demyelination) and to the development of abnormal myelination during the healing process sometimes referred to as dysmyelination.  This pressure usually occurs as the result of a bone spur or disc herniation.  Once pressure is taken off a nerve, Schwann cells have the potential to reproduce myelin around the nerve.  In cases of incomplete recovery, the quality of the myelin is not of the same as the quality of the original myelin.

Loss of Structural Nerve Integrity:

Compression of a nerve can lead to demyelination and/or physical compromise of the nerve fiber (axon).  The axon refers to the elongated portion the nerve cell body that travels to the target tissue.  When the nerve axon is compromised it may undergo degenerative changes and structurally breakdown.  When this happens there is no capacity to deliver chemicals across the nerve or for an electrical impulse to cross the site of injury.  The entire portion of the axon below the site of injury becomes disrupted.  This can cause tissue changes such as muscle atrophy.  Tissues connected to a nerve require ongoing chemical and electrical influences from the nerve in order to function and to remain healthy.