Axonotmesis neurotmesis neuropraxia pdf

damage being more extensive in axonotmesis than in neura- praxia, spontaneous regeneration is still possible, although longer, taking up weeks to months after the injury. In axo- notmesis, as well as in neurotmesis, a sequence of patho- logical events known as wallerian degeneration occurs in the nerve segment distal to the injury. c a neuropraxia, where there is focal or segmental demyelination with preservation of the axon and recovery in 2-12 weeks c an axonotmesis, where the axon is divided but the epineurium remains intact and regrows at 1 mm per day from the site of injury c a neurotmesis,where the nerve is divided and no longer in continuity with no recovery. In the Seddon classification, the peripheral nerve injuries are divided into three types: neuropraxia, axonotmesis, and neurotmesis. Neurapraxia refers to a mild injury to a nerve with impairment of both motor and sensory functions. There is no loss of axon, whereas there is a temporary loss of myelin sheath. The lowest degree of nerve injury in which the nerve remains intact but signaling ability is damaged is called neurapraxia. The second degree in which the axon is damaged but the surrounding connecting tissue remains intact is called axonotmesis. The last degree in which both the axon and connective tissue are damaged is called neurotmesis. Axonotmesis is the second degree of nerve injury where the axon is damaged but the surrounding connecting tissue remains intact. The most severe form of nerve injury is neurotmesis where both the axon and connective tissue (s) are damaged. In 1953, Sunderland expanded Seddon's classification from three to five degrees of peripheral nerve injury. Treatment can involve observation, repair, tendon transfers or nerve grafting depending on the acuity, degree of injury, and mechanism of injury. Epidemiology. Incidence. major peripheral nerve injury sustained in 2% of patients with extremity trauma. nerve injuries account for approximately 3% of injuries affecting the upper extremity and hand. Axonotmesis the axon and myelin is disrupted here, but the neuronal connective tissue remains intact (endo-, peri-, epineurium) more severe crush injury than that which causes neuropraxia Wallerian degeneration occurs because of loss of axoplasmic flow Electrodiagnostic findings: (click the image to the right) There are two commonly used classification for PNI- the Seddon Classification and the Sunderland Classification. Seddon classified nerve injuries into three major groups: neurapraxia, axonotmesis, and neurotmesis whereas Sunderland expanded Seddon's Classification to five degrees of peripheral nerve injury as described in the table below: [2] [3] "neurapraxia," "axonotmesis," and "neurotmesis" to describe peripheral nerve injuries.35 Neurapraxia is a comparatively mild injury with motor and sensory loss but no evidence of Wallerian degeneration. The nerve distally conducts normally. Focal demyelin-ation and/or ischemia are thought to be the etiolo-gies of the conduction block. Neurotmesis Neurotmesis (in Greek tmesis signifies "to cut") is part of Seddon's classification scheme used to classify nerve damage. It is the most serious nerve injury in the scheme. In this type of injury, both the nerve and the nerve sheath are disrupted. While partial recovery may occur, complete recovery is impossible. Contents 1 Symptoms Axonotmesis • Axonal injury with subsequent degeneraon and r