Neurapraxia

Excerpt

In 1942, Seddon classified the severity of peripheral nerve injury (PNI) in three types; neurapraxia, axonotmesis, or neurotmesis. A few years later, in 1951, Sunderland classified them in five different degrees. Neurapraxia is the mildest type of PNI commonly induced by focal demyelination or ischemia. It corresponds to grade 1 in Sunderland classification. In neurapraxia, the conduction of nerve impulses is blocked in the injured area. Motor and sensory conduction are partially or entirely lost. All the structures of the nerve stump, including the endoneurium, perineurium, and epineurium, remain intact.

Neurapraxia occurs when the myelin sheath of the nerve is damaged. If the nerve is stimulated distal to the injured area, conduction is preserved. Neurapraxic injuries generally have a good prognosis. Spontaneous clinical and electrodiagnostic recovery of this type of injury is expected in three months when the nerve completes remyelination.

Frequently, the word neuropraxia is incorrectly used in the literature. In the original 1942 classification by Seddon, neurapraxia was used; therefore, its correct use should continue in the scientific world.