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
