neurapraxie

Neurapraxie is the mildest form of peripheral nerve injury in the Seddon classification. It is defined by a transient focal block of nerve conduction due to demyelination, with preservation of the axon and the surrounding connective tissue. Because the axon remains intact, there is no Wallerian degeneration, and the nerve’s structural framework is preserved, enabling recovery as myelin sheaths remyelinate.

Causes of neurapraxie include mechanical compression, traction or mild contusion, ischemia, or inflammatory processes that transiently disrupt myelin. It often occurs in settings such as prolonged pressure on a limb, compression neuropathies (for example, carpal tunnel syndrome), or temporary nerve stretch injuries from crutch use or improper positioning. The injury is typically localized to a short segment of the nerve.

Clinically, neurapraxie presents with sudden weakness and/or sensory disturbance in the distribution served by the affected nerve. Reflexes may be reduced, but there is usually little to no muscle atrophy initially. Function commonly improves as remyelination occurs, with most recoveries occurring within days to weeks, though the exact timeline depends on the length of the affected segment and the degree of demyelination.

Diagnosis is primarily clinical, supported by nerve conduction studies that show a conduction block across the involved segment with preserved distal axonal integrity. EMG may be normal early and may show gradual improvement as recovery proceeds. Imaging is not routinely required.

Management focuses on removing or mitigating the cause of compression or traction, along with supportive care and physical therapy. Prognosis is excellent, with full recovery in the majority of cases. If there is no improvement within weeks to a few months, reconsideration of the diagnosis or a more severe nerve injury may be necessary.