腰四方肌筋膜疼痛症候群併僵直性脊柱炎所致似腰椎間盤凸出症的下背痛：病例報告

Myofascial Pain Syndrome of Quadratus Lumborum with Ankylosing Spondylitis Mimicking Herniation of Lumbar Intervertebral Disc: A Case Report

下背痛常見的原因包括腰扭傷、腰椎間盤凸出症、姿勢性下背痛、僵直性脊柱炎、腰四方肌之肌筋膜疼痛症候群等，其中腰椎間盤凸出症與腰四方肌之肌筋膜疼痛症候群兩者在病人症狀及理學檢查的表徵極為相似，必須仔細加以區分。臨床上醫師常根據腰椎側面X光片的椎間盤空間變窄來診斷病人有椎間盤凸出症，此種間接判讀的方法其實準確率不高，尤其在有過渡型脊椎症的患者更會造成誤判，因變窄的椎間空閒是椎間盤萎縮退化所致。本研究報告一位20歲年輕男性因車禍摔傷後即背痛難耐，咳嗽、打噴涕會引起嚴重的左下背痛，經診斷為腰椎間盤凸出症復健治療兩週後，病情毫無改善。理學檢查發現病人左下背部僵直，無法作太大腰部前彎的動作，直腿前抬測試約只能到達70?；左下背部及薦髂關節有明顯之壓痛點，按壓左下背部之引痛點可導致疼痛傳導至髂脊下方及左下臀部。視察其所照之X光片，可見到兩側薦髂關節有發炎白化現象，左側第五腰椎薦椎化（過渡型脊椎症），及第五腰椎與薦椎間之椎間盤空間變小。磁振造影檢查除腰薦之間的椎間盤萎縮外，並無發現腰椎間盤凸出或其他異常。抽血檢查發現病人有上升的紅血球沈降速率及陽性HLA-B27反應。回憶病人過去病史，間歇性的輕微左下背痛曾持續過數個月。綜合以上所有檢查資料及臨床病史，診斷為腰四方肌之肌筋膜疼痛症候群合併僵直性脊柱炎及過渡型脊椎症。經給予消炎止痛藥、肌肉鬆弛劑及局部伸展運動後，病人的嚴重下背痛即獲得相當大的改善。本文詳述病患之臨床症狀及診斷技巧，並回顧相關文獻資料，以作為臨床醫師處理此類病症的參考。

Herniation of lumbar intervertebral disc (HIVD) and quadrants lumborum myofascial pain syndrome ate two common causes of low bark pain and sciatica. Their symptoms and signs are similar in many respects. The incidence of quadratus lumborum myofascial pain syndrome-induced lumbago is underestimated. Physician always makes the diagnosis of HIVD by the finding of intervertebral joint space narrowing in lateral view spine X-ray, in addition to patient's symptoms and signs. In fact, plain X-ray only offers little information in HIVD cases. Intervertebral joint space narrowing may be due to hypoplastic or vestigial disc, especially in patients with transitional vertebrae. This article reports the case of a 20-year-old man who experienced severe left low back pain after minor traffic accident. According to the patient's symptoms and clinical physical findings, lumbar HIVD was diagnosed Rehabilitation programs were given for 2 weeks but in vain. X-ray showed L5-S1 joint space narrowing. L5 transitional vertebrae, and bilateral sacroiliac joints sclerosis. However, MRI revealed no HIVD. As there were characteristic trigger points and referred pain patterns in left quadratus lumborum muscle, with the typical findings in pelvic X-ray, physical examination, and positive past history of intermittent low back pain for several months, the impression of quadratus lumborum myofascial pain syndrome and ankylosing spondylitis was made. The symptoms responded well after our treatment. Based on our experience, quadratus lumborum myofascial pain syndrome should be suspected in intractable lumbar HIVD cases.