OBJECTIVE Identify sonographic features of the lateral femoral cutaneous nerve (LFCN) in meralgia paresthetica (MP) and report therapeutic outcomes in sonographically confirmed cases. MATERIALS AND METHODS Retrospective review of 50 patients with clinically suspected MP and 20 controls. Ultrasounds were reviewed for characteristics of the LFCN and compared between groups. When available, MRIs were reviewed. In cases of sonographically pathologic LFCN, subsequent therapeutic interventions were recorded. RESULTS Thirty-five of the suspected MP cases (70%) had ultrasound findings suggestive of MP, 10 (20%) were negative, and in 5 (10%) the LFCN was not seen. Sonographic findings in positive cases included nerve enlargement in all cases (mean cross-sectional area 9 mm2 (standard deviation (SD) ± 5.59) versus 4 mm2 (SD ± 2.31) and 3 mm2 (SD ± 2.31) in negative cases and normal controls, respectively; p < 0.01), nerve hypoechogenicity (30 of 35 cases, 86%), and focal lesion (7 of 35 cases, 20%). Sixteen ultrasounds positive for MP had MRIs with only 4 (25%) reporting a concordant LFCN abnormality (enlargement or T2 hyperintensity). Twenty-five of the 35 (71%) patients with positive sonographic findings for MP had a US-guided LFCN block (local anesthetic ± corticosteroid), with 24 of 25 (96%) patients reporting immediate symptomatic improvement. Eighteen of 35 (51%) underwent LFCN neurectomy or neurolysis, all of whom experienced symptomatic improvement. CONCLUSION Ultrasound is a useful modality for LFCN assessment in clinically suspected MP and is more sensitive for abnormalities than MRI. Nearly all patients who received perineural analgesia and/or neurectomy or neurolysis had symptomatic improvement.

中文翻译：

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超声检查股骨外侧痛的感觉异常。

目的鉴别痛觉麻痹（MP）中股外侧皮神经（LFCN）的超声特征，并报告经超声检查证实的病例的治疗结果。材料与方法回顾性分析50例临床怀疑为MP的患者和20例对照。超声检查了LFCN的特征，并在各组之间进行了比较。如果可用，则对MRI进行检查。对于超声病理学LFCN，应记录随后的治疗干预措施。结果35例疑似MP病例（70％）的超声检查结果提示MP，10例（20％）阴性，而5例（10％）未发现LFCN。阳性病例的超声检查结果包括所有病例的神经增大（平均截面积为9 mm2（标准差（SD）±5.59），而4 mm2（SD±2.31）和3 mm2（SD±2）。31）分别为阴性病例和正常对照者；p <0.01），神经退行性（35例中的30例，86％）和局灶性病变（35例中的7例，20％）。16例MP阳性的MRI MRI仅有4例（25％）报告了一致的LFCN异常（肿大或T2高强度）。在MP超声检查阳性的35例患者中，有25例（71％）有美国指导的LFCN阻滞（局麻药±皮质类固醇），而25例患者中有24例（96％）报告立即症状改善。35名患者中有18名（51％）进行了LFCN神经切除术或神经溶解，所有这些患者的症状都有改善。结论超声是用于临床可疑MP的LFCN评估的有用方式，并且对异常的敏感性比MRI敏感。