Meralgia paresthetica (Meros= thigh, Algos = pain) is a sensory mononeuropathy. This condition is characterized by pain, paresthesia, or sensory impairment along the distribuition of the lateral femoral cutaneous nerve. 
Meralgia paresthetica is caused by compression or entrapment of the nerve as it crosses the anterior superior iliac spine and runs beneath the inguinal ligament to enter the thigh.
Causes
The most common cause of damage to the lateral cutaneous nerve is entrapment at the level of the inguinal ligament, often seen in association with obesity or pregnancy, in which the nerve may be compressed by the bulging abdomen.
However wearing tight trousers (such as jeans), tight belt, trauma to the groin area where the nerve passes posterior to the inguinal ligament, avulsion of ASIS, surgical operations, pelvic mass or neuropathies (such as diabetis) also could cause this condition.
Diagnosis
The patient complains of sensory disturbance over the anterolateral aspect of the thigh (anesthesia, pain or hyperesthesia of anterior thigh). Palpation of the nerve near the ASIS may increase pain or paresthesia. Light touch may be decreased on the lateral thigh and pinprick response may be increased.
There is no motor loss (positive in L2-L3 radiculopathy).
Nerve conduction velocity studies are rarely needed and may help to exclude L2-L3 radiculopathy, femoral neuropathy, etc.
When a structural lesion is suspected a X-Ray, MRI, pelvic ultrasound or CT scanning may be needed.
Treatment
Most patients with meralgia paresthetica achieve satisfactory pain relief from conservative treatment by correcting the causes listed above, such as weight loss, correcting posture, avoiding external compressive and traumatic factors etc.
Physiotherapists/osteopaths/chiropractors may perform:
- pelvic, low back and hips manipulations or mobilization.
- massage therapy, myofascial release
- acupuncture
- taping
Administration of analgesic and anti-inflammatory drugs may help.
Pulsed radiofrequency has shown some success if conservative treatment fails.
Surgical decompression or transection of the nerve as a last resort.
Dott. Emanuele Luciani
Osteopath, physiotherapist, hatha yoga teacher
Osteopath registered with the General Osteopathic Council (GOsC)
(number 8232http://www.osteopathy.org.uk/home/)
"Centro Studi Tre Fontane"
Via Luigi Perna 51, Rome
