Ilioinguinal Neuralgia

Abstract

Ilioinguinal neuralgia is one of the most common causes of lower abdominal and pelvic pain encountered in clinical practice. Ilioinguinal neuralgia is caused by compression of the ilioinguinal nerve, and the most common causes of compression are traumatic injury to the nerve, including direct blunt trauma and damage during inguinal herniorrhaphy and pelvic surgery. Rarely, ilioinguinal neuralgia occurs spontaneously.

The ilioinguinal nerve is a branch of the L1 nerve root, with a contribution from T12 in some patients. The nerve follows a curvilinear course that takes it from its origin at the L1 (or occasionally T12) somatic nerves to inside the concavity of the ileum. The ilioinguinal nerve continues anteriorly to perforate the transverse abdominal muscle at the level of the anterior superior iliac spine. The nerve may interconnect with the iliohypogastric nerve as it continues to pass along its course medially and inferiorly, where it accompanies the spermatic cord through the inguinal ring and into the inguinal canal. The distribution of the sensory innervation of the ilioinguinal nerves varies from patient to patient, and overlap with the iliohypogastric nerve may be considerable. In general, the ilioinguinal nerve provides sensory innervation to the skin of the upper inner thigh and the root of the penis and upper scrotum in men or the mons pubis and lateral labia in women.

Keywords

ilioinguinal neuralgia, genitofemoral neuralgia, iliohypogastric neuralgia, entrapment neuropathy, ilioinquinal nerve block, ultrasound guided nerve block, diagnostic ultrasonography, groin pain, pelvic pain, inguinal hernia, Tinel’s sign, novice skier position

ICD-10 CODE G57.90

Keywords

ilioinguinal neuralgia, genitofemoral neuralgia, iliohypogastric neuralgia, entrapment neuropathy, ilioinquinal nerve block, ultrasound guided nerve block, diagnostic ultrasonography, groin pain, pelvic pain, inguinal hernia, Tinel’s sign, novice skier position

ICD-10 CODE G57.90

The Clinical Syndrome

Ilioinguinal neuralgia is one of the most common causes of lower abdominal and pelvic pain encountered in clinical practice. Ilioinguinal neuralgia is caused by compression of the ilioinguinal nerve, and the most common causes of compression are traumatic injury to the nerve, including direct blunt trauma and damage during inguinal herniorrhaphy and pelvic surgery. Rarely, ilioinguinal neuralgia occurs spontaneously.

The ilioinguinal nerve is a branch of the L1 nerve root, with a contribution from T12 in some patients. The nerve follows a curvilinear course that takes it from its origin at the L1 (or occasionally T12) somatic nerves to inside the concavity of the ileum. The ilioinguinal nerve continues anteriorly to perforate the transverse abdominal muscle at the level of the anterior superior iliac spine. The nerve may interconnect with the iliohypogastric nerve as it continues to pass along its course medially and inferiorly, where it accompanies the spermatic cord through the inguinal ring and into the inguinal canal. The distribution of the sensory innervation of the ilioinguinal nerves varies from patient to patient, and overlap with the iliohypogastric nerve may be considerable. In general, the ilioinguinal nerve provides sensory innervation to the skin of the upper inner thigh and the root of the penis and upper scrotum in men or the mons pubis and lateral labia in women.

Signs and Symptoms

Ilioinguinal neuralgia manifests as paresthesias, burning pain, and occasionally numbness over the lower abdomen that radiates into the scrotum or labia and occasionally into the upper inner thigh; pain does not radiate below the knee. The pain of ilioinguinal neuralgia worsens with extension of the lumbar spine, which puts traction on the nerve; thus patients often assume a bent-forward, novice skier’s position ( Fig. 80.1 ). If the condition remains untreated, progressive motor deficit, consisting of bulging of the anterior abdominal wall muscles, may occur. This bulging may be confused with inguinal hernia.