In neuropraxia, what is the pathological finding?

Appeared in: INI-CET EXAM -2026

Explanation

Neuropraxia is the mildest form of nerve injury, classified by Sir Herbert Seddon.
It involves a temporary, focal block of nerve conduction, typically due to compression or ischemia, without any anatomical disruption of the axon.
The key pathological finding is a physiological conduction block with the axon and nerve sheaths remaining structurally intact.
This leads to temporary motor paralysis and sensory disturbances, but recovery is usually complete and rapid once the pressure is removed.

Option A: Nerve trunk damage implies a complete severance of the nerve, which is the definition of neurotmesis, the most severe type of nerve injury.
Option B: Damage to the perineurium (the connective tissue sheath surrounding a fascicle of nerve fibers) is seen in neurotmesis, not neuropraxia.
Option C: Axon disruption, where the axon itself is severed but the surrounding connective tissue is intact, defines axonotmesis, a more severe injury than neuropraxia.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pathophysiology of Peripheral Nerve Injury as background academic context rather than a clinical decision trigger.
A classic clinical example of neuropraxia is 'Saturday night palsy,' where the radial nerve is compressed against the humerus from sleeping with an arm draped over a chair, leading to wrist drop.
Nursing assessment for suspected neuropraxia involves checking motor function, sensory perception (light touch, pinprick), and reflexes in the affected limb and comparing them to the unaffected side.
Patient education is key, reassuring them that in most cases of neuropraxia, function will return completely, and teaching them to avoid the positions or activities that led to the compression.

How to Approach the Question

First, identify the key term in the question stem: 'neuropraxia'.
Recall the definition and classification of peripheral nerve injuries. Remember that neuropraxia is the mildest form.
Analyze the options based on the severity of injury they describe.
Option A ('Nerve trunk damage') and B ('Perineurium damage') represent the most severe injury (neurotmesis).
Option C ('Axon disruption') represents a moderate injury (axonotmesis).
Option D ('Physiological conduction block with intact axon') describes a temporary, functional problem without structural damage, which perfectly matches the definition of neuropraxia.

Concept Tested & Keywords

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E6 Pathology- ROBBINS & COTRAN PATHOLOGIC BASIS OF DISEASE 10TH Ed pp. 1217-1219, 1216-1218

E6 Physiology Ganong 27e Vol 1 Part 1 p. 115-117

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