Nerve conduction studies of the lateral femoral cutaneous nerve. Implications in the diagnosis of meralgia paresthetica.

The diagnosis of meralgia paresthetica, while based on clinical suspicion, can be confirmed via electrophysiological testing. Previous testing of the sensory conduction of the lateral femoral cutaneous nerve placed the stimulating electrode one centimeter medial to the anterior superior iliac spine (ASIS). This position is both uncomfortable for the patient and difficult for the operator to perform. The following article suggests an alternate position for the stimulating electrode, four centimeters distal to the ASIS. Twenty subjects served as their own controls and both the old technique and the new technique were performed. Using the old technique, the response rate was 35% (7 out of 20 subjects). Using the new technique, the response rate was 90% (18 out of 20 subjects). These results indicate a significantly higher response rate when the only variable altered is the electrode placement. This simple change in technique requires no more effort, cost, or training on the part of the operator yet produces a much higher percentage of responses.