Meralgia Paresthetica: Finally There is A Test I Can Do On My Patient

Meralgia Paresthetica (MP) is a mononeuropathy (pathology of one nerve) occurring to the lateral femoral cutaneous nerve.  The condition causes paresthesia and numbness over the anterolateral aspect of the thigh.  MP is a neurological condition which is caused commonly by a nerve being “entrapped”  near its surroundings or origin. The nerve itself may get compressed by the inguinal ligament, tensor fascia latae and psoas.

The most interesting aspect of meralgia paresthetica is the multiple different causes. MP has been reported to be caused by obesity, pregnancy and compression from tight pants, belts, uterine fibroids and tumours. Furthermore, MP can be due to direct trauma, surgery complications and even associated with disorders such as diabetes and leprosy. [2]   Recent reports have also surfaced regarding MP being causes by exercise [1].

However like most neuropathies, MP may produce arbitrary findings and examination results. It is often hard for a manual therapist to perform a test which confirms his or her suspicion of Meralgia Paresthetica. Most neuropathies don’t follow a perfectly mapped out distribution of symptoms. MP can often be mis-diagnosed as a radiculopathy or a referral pattern from pathology of the gluteus medius muscle. Nerve conduction studies can often help confirm one’s diagnosis but are not easily accessible to manual therapist.  The following is a fairly new test which can be used by manual therapist to help diagnose Meralgia Paresthetica.

Pelvic Compression Test [3]

This test is based on the premise the LFCN is compressed by the inguinal ligament and by relieving this compression symptoms will temporarily be alleviated. With the patient focusing on their symptoms the examiner attempts to apply a downward and lateral compressive force on the pelvic. The pressure is held for 45 seconds and a positive result is when patients report an alleviation of their symptoms. By compressing the pelvic in this manner the two attachments of the inguinal ligament are brought closer together causing the ligament to become slacker.

This test was only performed on a small number of subjects (20) who were confirmed to have MP by electrophysiological studies. However, 19/20 patients confirmed patients received a positive test result. The validity of the test stood to have a sensitivity of 95% and specificity of 93.3% making it the only valid test to date which can be used by manual therapist. The only downfall of the test is the patient has to be presenting with symptoms in order for it to be performed and MP confirmed.   In summary, the study only has a small subject size and wasn’t only designed to look at this one entity. However, due to the lack of other testing procedures at our exposure in the literature for this condition I feel it is a test worth trying. So the next time a patient comes in with symptoms down their leg see if you can relieve it. Dr. Wayne Button, BSc, D.C

Kho KH, Blijham PJ, & Zwarts MJ (2005). Meralgia paresthetica after strenuous exercise. Muscle & nerve, 31 (6), 761-3 PMID: 15654691                                                                                                                                                                                                            Harney, D., & Patijn, J. (2007). Meralgia Paresthetica: Diagnosis and Management Strategies Pain Medicine, 8 (8), 669-677 DOI: 10.1111/j.1526-4637.2006.00227.x                                                                                                                                                                     Shimizu, S. (2008). A Novel Approach to the Diagnosis and Management of Meralgia Paresthetica Neurosurgery, 63 Kho, K., Blijham, P., & Zwarts, M. (2005). Meralgia paresthetica after strenuous exercise Muscle & Nerve, 31 (6), 761-763 DOI: 10.1002/mus.20271