Friday, December 2, 2011

Meralgia Paresthetica


Meralgia paresthetica is an uncommon pathology of the lateral femoral cutaneous nerve.  It is most commonly caused by entrapment of the nerve as it courses through the inguinal ligament.  The nerve originates from the spinal cord at the L2-L3 level, and courses underneath the inguinal ligament as it travels into the thigh.  The nerve has no motor control, but it relays sensory information from the anterior-lateral thigh. 

Symptoms of meralgia paresthetica include a burning, tingling, numb, or painful sensation to the anterior-lateral thigh.  Most commonly it affects only one side of the body, but may affect both sides at the same time.  There is no loss of strength associated with meralgia paresthetica, as there is no motor function of the lateral femoral cutaneous nerve. 

The condition is most commonly caused by compression of the nerve, particularly underneath the inguinal ligament.  This compression may come from a heavy tool belt or utility belt applying pressure to the nerve, or it can come from increased pressure from the abdomen in obese individuals.  Rarely, the symptoms come from a space-occupying lesion along the nerve contents such as a tumor, or from a lesion along the psoas muscle. 

The diagnosis of meralgia paresthetica is made through clinical exam.  Tapping along the inguinal ligament may reproduce the symptoms, which is highly suggestive of meralgia paresthetica.  Occasionally EMG or nerve conduction studies may be ordered, however, this is usually only the case when ruling out pathology of the spinal cord, nerve roots, or compression of other nerves of the lower extremity.  In particular, pathology of the femoral nerve may present with similar symptoms, but will also show a loss of strength in the quadriceps muscle.

Treatment of meralgia paresthetica is supportive.  Weight loss in obese individuals has been shown to relieve symptoms.  Removal of a heavy tool belt or other form of compression along the nerve will also generally relieve symptoms.  Medications used for nerve pain such as gabapentin may also be used, with some patients reporting good results.  Injections with local anesthetics and steroids may eliminated pain temporarily, for a long period of time, or even permanently.  Surgical decompression of the nerve may be performed, but is reserved for unrelenting conditions.  Interestingly, meralgia paresthetica has been shown to be more common in diabetic individuals than in the general population, after controlling for weight differences.

If you have symptoms of meralgia paresthetica, or of any other nerve compression, it is important to discuss this with your doctor. Be sure to tell them of any other symptoms that may be associated with the pain, such as muscle weakness or fatigue, changes in vision or hearing, or numbness and tingling in any other parts of the body.



Central Florida Foot & Ankle Center, LLC 
101 6th Street N.W. 
Winter Haven, FL 33881 
Phone: 863-299-4551 
www.FLFootandAnkle.com