What are the symptoms of peroneal neuropathy?

Symptoms of Peroneal Neuropathy

The primary symptoms of peroneal neuropathy include foot drop, weakness in ankle dorsiflexion, numbness over the dorsum of the foot, and pain along the lateral aspect of the leg, which can significantly impact mobility and quality of life. 1

Clinical Presentation

Motor Symptoms

• Foot drop (inability to dorsiflex the ankle) - most common presenting symptom
• Weakness in ankle eversion
• Difficulty walking, especially with heel strike
• Gait abnormalities including steppage gait (lifting the knee higher than normal to clear the foot from the ground)
• Instability while walking on uneven surfaces

Sensory Symptoms

• Numbness or tingling over the dorsum of the foot and lateral aspect of the leg
• Decreased sensation in the first web space (deep peroneal nerve)
• Altered sensation on the lateral calf and dorsum of the foot (superficial peroneal nerve)
• Pain that may increase with activity such as walking, running, or squatting 2

Location-Specific Symptoms

Symptoms vary based on which part of the peroneal nerve is affected:

1. Common Peroneal Nerve (CPN) Compression:

   • Complete or partial foot drop
   • Weakness in both ankle dorsiflexion and eversion
   • Sensory loss over dorsum of foot and lateral lower leg

2. Superficial Peroneal Nerve (SPN) Entrapment:

   • Preserved ankle dorsiflexion
   • Weakness in foot eversion
   • Numbness/tingling over dorsum of foot with sparing of first web space
   • Soft tissue bulge approximately 10 cm above lateral malleolus 2

3. Deep Peroneal Nerve (DPN) Compression:

   • Weakness in ankle dorsiflexion with preserved eversion
   • Sensory loss limited to first web space between great and second toe

Associated Findings

• Tinel's sign (tingling sensation when tapping over the compressed nerve, typically at the fibular head)
• Tenderness over the fibular head or along the nerve course
• Visible muscle atrophy in chronic cases
• Decreased or absent deep tendon reflexes in proportion to sensory loss 3
• Possible orthostatic hypotension in cases with autonomic involvement (less common)

Diagnostic Considerations

Peroneal neuropathy must be differentiated from other conditions causing similar symptoms:

• L5 radiculopathy
• Sciatic neuropathy
• Lumbosacral plexopathy
• Motor neuron disease
• Polyneuropathy 4

Clinical Course

• Symptoms typically begin acutely with complete or partial foot drop 5
• Pain and sensory symptoms may precede motor weakness
• Symptoms often worsen with activities that compress the nerve (crossing legs, prolonged squatting)
• Without treatment, permanent nerve damage and disability may occur

Common Pitfalls in Diagnosis

• Failing to perform a comprehensive neurological examination
• Overlooking non-compressive causes of peroneal neuropathy
• Missing associated injuries (especially in trauma cases)
• Confusing with L5 radiculopathy (which typically also affects hip abductors and knee flexors)
• Delaying diagnosis, which can lead to poorer outcomes

Early recognition and appropriate management of peroneal neuropathy are crucial to prevent permanent nerve damage and functional limitations. Electrodiagnostic studies including nerve conduction studies and electromyography are essential for confirming the diagnosis, localizing the lesion, and determining prognosis.