外側大腿皮神経障害に対して神経剝離術が有効であった1例

A Case of Meralgia Paresthetica Treated with Neurolysis

Ⅰ．はじめに

　外側大腿皮神経障害は，外側大腿皮神経（lateral femoral cutaneous nerve：LFCN）が鼠径靱帯近傍で圧迫されて生じる下肢絞扼性神経障害の1つである．今回われわれは，手術により良好な経過を辿ったLFCN障害の1例を経験したので報告する．

　A 60-year-old woman presented with a 1-year history of pain and numbness in the left anterolateral thigh. The symptoms aggravated on walking and standing. Her visual analogue scale（VAS）score was 7.1/10. Tinel's like sign was positive over the lateral femoral cutaneous nerve（LFCN）, in the inguinal ligament region. LFCN block at the trigger point, in the inguinal ligament, resulted in relief of the symptoms and we diagnosed meralgia paresthetica（MP), which is the entrapment neuropathy of the LFCN. Initially, we performed observation therapy with oral medication and LFCN blocks. However, these treatments failed to relieve the symptoms. Therefore, we performed neurolysis with a microscope under local anesthesia. The symptoms improved immediately after surgery and her VAS score of thigh symptom improved from 7.1 to 1.9 after 3 months. Conservative and surgical treatment for MP generally yield good outcome and we should pay attention to the MP as a differential diagnosis for thigh numbness and pain.