Why is the nerve compressed?
The external cutaneous nerve of the thigh emerges from the pelvic cavity near the anterior superior iliac spine and passes in a narrow canal under the inguinal ligament, sometimes directly through it. This area is very vulnerable: any increase in pressure in the groin area - a tight belt, a belt with a heavy tool, a corset, body armor, a growing belly during pregnancy or excess weight - presses the nerve against the ligament. Additionally, the nerve is stretched when the hip is extended, so the complaints intensify with prolonged standing and walking. Sometimes damage occurs during hip surgery or bone graft removal.
- Tight belts, girdles, corsets and tight clothing
- Excess weight and increased abdominal volume
- Pregnancy
- Prolonged standing and walking
- Surgeries in the pelvis and hip area
- Diabetes mellitus as a nerve vulnerability factor
Symptoms
Complaints are limited to an area of skin on the front and outer surface of the thigh, approximately from the groin to the knee, almost always on one side. Patients describe a burning sensation, a sensation of goosebumps, numbness, and sometimes severe sensitivity in which the touch of clothing is unpleasant. There is no muscle weakness, reflexes are preserved, which is important for distinguishing from lesions of the lumbar roots. Symptoms are aggravated by prolonged standing, walking, and hip extension, and are relieved by sitting.
- Burning and tingling on the outer thigh
- Numbness of a clearly defined area of skin
- Unpleasant sensations from touching clothes
- Increased when walking and standing
- Relief while sitting
- No weakness in the leg
Survey
In typical cases, the diagnosis is made based on complaints and examination; no additional research is required. They are prescribed for an atypical picture: if there is weakness, if numbness extends beyond the boundaries of the nerve zone, if the complaints are bilateral or are accompanied by back pain. Then electroneuromyography, ultrasound examination of the nerve and MRI of the lumbar region or pelvis are performed. It's also worth checking your glucose levels because diabetes contributes to nerve damage and changes tactics.
- Examination by a neurologist with mapping of the numbness zone
- Testing muscle strength and reflexes
- ENMG for atypical symptoms
- Ultrasound of the external cutaneous nerve of the thigh
- MRI of the lumbar region or pelvis if indicated
- Glucose and glycated hemoglobin
Treatment
In most cases, it is enough to remove the cause of the compression: give up tight belts and tight trousers, reduce weight, change the nature of the work if it involves prolonged standing. Already these measures lead to improvement for many within a few weeks or months. If the sensations are pronounced, the doctor may prescribe medications that act on neuropathic pain and local remedies. For persistent complaints, a nerve block with local anesthetic is performed, which simultaneously confirms the diagnosis. Surgical release of the nerve is rarely used, only when everything else is ineffective.
- Refusal of tight belts, corsets and tight clothing
- Weight loss
- Limiting prolonged standing, breaks while sitting
- Drugs for the treatment of neuropathic pain as prescribed by a doctor
- Local remedies and physiotherapy
- Nerve block for persistent pain
- Surgical decompression in rare cases