Ilioinguinal nerve entrapment syndrome

Ilioinguinal nerve

• ilioinguinal nerve originates from the T12 and L1 nerve roots
  • sensory area supplied
    • pubic symphysis and the superomedial aspect of the femoral triangle receive a sensory supply from this nerve
      
      
• ilioinguinal nerve entrapment syndrome is an abdominal muscular pain syndrome, characterized by the clinical triad of muscular type iliac fossa pain with a characteristic radiation pattern, an altered sensory perception in the ilioinguinal nerve cutaneous innervation area, and a well-circumscribed trigger point medial and below the anterosuperior iliac spine. Relief of pain by infiltration of a local anaesthetic confirms the diagnosis
  
  
  • ilioinguinal nerve can be injured during surgical approaches to the lower abdomen, during pregnancy and bone graft harvesting from the iliac region
    • nerve entrapment can occur at the point where it passes through the transversus abdominis and internal oblique muscles medial to the anterosuperior iliac spine (ASIS)
    • nerve injury can also occur with tearing of the lower external oblique aponeurosis
    • diagnosis of nerve injury is made clinically
      • neuropathy of the ilioinguinal nerve has three characteristics; pain, altered sensation and the presence of a trigger point
        • pain
          • occurs in the iliac fossa and radiates to the groin, scrotum or labia majora, the proximal medial aspect of the thigh and the back
        • altered sensation may be hyper-,hyo- or dysaesthesia
        • trigger point is present medial and distal to the ASIS
      • patient walks with a flexed trunk gait
        • provocative testing involves hip extension
        • also palpation of the inguinal canal or medial to the ASIS may reproduce these symptoms
    • local aesthetic injection can aid diagnosis as it is difficult to differentiate the pain caused by the iliohypogastric, ilioinguinal and genitofemoral nerves due to the overlap of sensory innervation

Reference:

• 1) Knockaert DC, D'Heygere FG, Bobbaers HJ. Ilioinguinal nerve entrapment: a little-known cause of iliac fossa pain. Postgrad Med J 1989; 65: 632-5