Naja Zoher, Naja Ahmad Salah, Rajab Omar, Mugharbil Anas, Shatila Abdul Rahman, Al Hassan Janah
Anesthesia Department, Makassed General Hospital, P. O. Box: 11-6301 Riad EI-Solh 11072210, Beirut, Lebanon, Tel.: +961 1 636 405, Fax: +9611646589.
Lebanese American University, Beirut, Lebanon.
Scand J Pain. 2018 Jan 26;18(1):125-127. doi: 10.1515/sjpain-2017-0155.
Schwannoma is a common neoplasm in the peripheral and central nervous systems. Sciatic nerve schwanommas are rare. We report the case of a 50-year-old woman who was referred for treatment of persistent neuropathic pain in the left lower limb after resection of a schwannoma on the left S1 nerve root. The patient's history goes back when she was 27 years old and started to have electric-like pain in her lower left limb upon intercourse. Examination revealed a left ovarian cyst which was surgically removed. Her pain persisted despite taking nonsteroidal anti inflammatory drugs (NSAIDs). Several years later a schwannoma on the left S1 nerve root was detected. The patient had surgical excision of the left S1 nerve root at the plexus along with the schwannoma. Following the surgery, she experienced pain upon sitting and touch, and had a limp in her left leg. She was prescribed NSAIDs, antidepressant and pregabalin. Despite the pharmacological treatment, the patient had persistent mild pain. Upon physical examination, the incision from her previous surgery was 4 cm away from the sacral midline and parallel to S1 and S2. The length of the incision was 3 cm. The patient had severe allodynia upon palpation at the area between S1 and L5 and the visual analog scale (VAS) score increased from 3 to 10. She had severe pain at rest and movement. Her neurologic exam revealed that the left lower extremity motor power showed mild weakness in the leg abduction, foot eversion, plantar and toes flexion, and in the hip extension. The sensory exam showed severe reduction in pinprick and temperature sensation in the lateral aspect of foot, lower leg and dorsolateral thigh and buttocks. Nerve stimulator guided injection was performed at the pain trigger point being 1 cm above the midline of the incision. Upon nerve stimulation the contraction of the gluteal muscle was observed. Then, 20 mL of the anesthetic mixture were injected. The patient had immediate pain relief after the block (VAS 1/10). She remained pain free for 15 days after which pain reappeared but with less severity (3/10). Repetitive sciatic nerve block was performed in a progressive manner and was shown to be effective in managing neuropathic pain.
施万细胞瘤是周围神经系统和中枢神经系统中常见的肿瘤。坐骨神经施万细胞瘤较为罕见。我们报告了一例50岁女性患者，她因左侧S1神经根施万细胞瘤切除术后左下肢持续性神经性疼痛前来接受治疗。患者的病史可追溯到27岁时，她在性交时开始出现左下肢电击样疼痛。检查发现左侧卵巢囊肿，遂行手术切除。尽管服用了非甾体抗炎药（NSAIDs），她的疼痛仍持续存在。几年后，检测出左侧S1神经根有一个施万细胞瘤。患者在神经丛处对左侧S1神经根连同施万细胞瘤进行了手术切除。手术后，她坐下和触摸时会疼痛，左腿跛行。她被开了NSAIDs、抗抑郁药和普瑞巴林。尽管进行了药物治疗，患者仍有持续性轻度疼痛。体格检查时，她上次手术的切口距离骶骨中线4厘米，与S1和S2平行。切口长度为3厘米。患者在S1和L5之间的区域触诊时有严重的痛觉过敏，视觉模拟评分（VAS）从3分增加到10分。她在休息和活动时都有严重疼痛。神经系统检查显示，左下肢运动力量在腿部外展、足背屈、跖屈和趾屈以及髋关节伸展方面有轻度减弱。感觉检查显示，足外侧、小腿、大腿背外侧和臀部的针刺觉和温度觉严重减退。在切口中线以上1厘米处的疼痛触发点进行了神经刺激器引导下的注射。神经刺激时观察到臀肌收缩。然后，注射了20毫升麻醉混合液。阻滞术后患者疼痛立即缓解（VAS 1/10）。她在15天内无疼痛，之后疼痛再次出现，但程度较轻（3/10）。以渐进方式进行了重复性坐骨神经阻滞，结果显示对管理神经性疼痛有效。
