Tarsal tunnel syndrome refers to entrapment or irritation of the tibial nerve in the tarsal tunnel, which represents an anatomical site of narrowing.
Symptoms
The cardinal symptom is burning, electric shock-like pain in the sole of the foot, often radiating to the heel, lateral foot border, or toes. Typical features include:
Plantar paresthesias and hypoesthesia
Activity-related worsening of symptoms
Positive Tinel sign over the tarsal tunnel
Intrinsic foot muscle weakness in advanced cases
The symptoms are often nonspecific and are not infrequently confused with plantar fasciitis or radicular syndromes.
Diagnosis
Diagnosis is based on a combination of clinical findings, neurophysiology, and imaging:
ENG\/EMG: Prolonged distal motor latencies, reduced sensory nerve conduction velocities
High-resolution ultrasound: Detection of masses or nerve swelling
MRI: Visualization of structural causes and exclusion of differential diagnostic pathologies
From a neurosurgical perspective, demonstration of a clear cause of compression is particularly relevant to the indication for surgery.