Neurapraxia

Neurapraxia
Classification and external resources
Specialty	neurology
ICD-10	G58.9
[]

Neurapraxia is a disorder of the peripheral nervous system in which there is a temporary loss of motor and sensory function due to blockage of nerve conduction, usually lasting an average of six to eight weeks before full recovery. Neurapraxia is derived from the word apraxia, meaning “loss or impairment of the ability to execute complex coordinated movements without muscular or sensory impairment”.

This condition is typically caused by a blunt neural injury due to external blows or shock-like injuries to muscle fibers and skeletal nerve fibers, which leads to repeated or prolonged pressure buildup on the nerve. As a result of this pressure, ischemia occurs, a neural lesion results, and the human body naturally responds with edema extending in all directions from the source of the pressure. This lesion causes a complete or partial action potential conduction block over a segment of a nerve fiber and thus a reduction or loss of function in parts of the neural connection downstream from the lesion, leading to muscle weakness.

Neurapraxia results in temporary damage to the myelin sheath but leaves the nerve intact and is an impermanent condition; thus, Wallerian degeneration does not occur in neurapraxia. In order for the condition to be considered neurapraxia, according to the Seddon classification system of peripheral nerve injury, there must be a complete and relatively rapid recovery of motor and sensory function once nerve conduction has been restored; otherwise, the injury would be classified as axonotmesis or neurotmesis. Thus, neurapraxia is the mildest classification of peripheral nerve injury.

Neurapraxia is very common in professional athletes, especially American football players, and is a condition that can and should be treated by a physician.

A variety of nerve types can be subjected to neurapraxia and therefore symptoms of the injury range in degree and intensity. Common symptoms of neurapraxia are disturbances in sensation, weakness of muscle, vasomotor and sudomotor paralysis in the region of the affected nerve or nerves, and abnormal sensitivity of the nerve at the point of injury. It has been observed that subjective sensory symptoms include numbness, tingling, and burning sensations at the site of the injury. Objective sensory symptoms are generally minimal in regards to touch, pain, heat, and cold. In cases of motor neuron neurapraxia, symptoms consist of flaccid paralysis of the muscles innervated by the injured nerve or nerves. Symptoms are often transient and only last for a short period of time immediately following the injury. However, in severe cases of neurapraxia, symptoms can persist for weeks or months at a time.

...
Wikipedia