Meralgia paresthetica

Specialty: Neurology.

• lateral femoral cutaneous nerve entrapment syndrome
• compression of the Roth nerve

Why it occurs

• Compression of the lateral femoral cutaneous nerve as it passes under the inguinal ligament (associated with obesity, pregnancy, wearing very tight clothing or heavy belts)
• Focal diabetic neuropathy (lateral femoral cutaneous nerve ischemia)
• Post-surgical iatrogenesis (inguinal hernia surgery, hip arthroplasty or taking bone graft from the iliac crest)
• Prolonged mechanical compression from held positions (e.g., prolonged prone position in intensive care units)
• Retroperitoneal or pelvic mass that compresses the nerve in its proximal course

Initial workup

Physical examination identifying hypoesthesia strictly limited to the anterolateral aspect of the thigh, without motor or reflex involvement; positive Tinel sign over the inguinal ligament medial to the anterior superior iliac spine; electroneuromyogram (ENMG) with comparative study of sensory conduction of the lateral femoral cutaneous nerve; ultrasound of the nerve in the iliac spine to detect focal thickening due to compression.

Standard management

• Local infiltration of the nerve at its exit point (1-2 cm medial and inferior to the anterior superior iliac spine) with local anesthetic and corticosteroid (e.g., methylprednisolone 40 mg) for symptomatic relief and diagnostic confirmation
• Gabapentin — 300-1200 mg/day) or Pregabalin (75-300 mg/day
• Weight loss and use of loose clothing as fundamental initial measures.