Narayan Sharwan
Gosford Hospital Gosford New South Wales Australia.
Australas J Ultrasound Med. 2016 Nov 21;19(4):164-168. doi: 10.1002/ajum.12029. eCollection 2016 Nov.
A middle-aged man with Carpal tunnel syndrome without any known predisposing risk factors is presented. Ultrasonography demonstrated two structures within the left carpal tunnel with similar echo pattern as median nerve, thus confirming an anatomical variation in the median nerve, described in the literature as bifid median nerve. The knowledge of the existence of bifid median nerve is an important factor in planning surgical decompression of median nerve to avoid nerve and persistent median artery injuries and/or potential relapse if decompression of both branches is not carried out. In addition, this knowledge is important in deciding whether to inject above the bifurcation or into the epineurial of individual nerve trunks in the setting of planned symptomatic corticosteroid injections. In conclusion, bifid median nerve is an anatomic variant that may contribute to carpal tunnel syndrome and can be demonstrated ultrasonographically. It is important to be aware of this anomaly when planning carpal tunnel release surgery and symptomatic corticosteroid injections.
本文介绍了一名患有腕管综合征的中年男性，他没有任何已知的诱发风险因素。超声检查显示左腕管内有两个结构，其回声模式与正中神经相似，从而证实了正中神经的一种解剖变异，文献中描述为双叉正中神经。了解双叉正中神经的存在是规划正中神经手术减压的一个重要因素，以避免神经和持续正中动脉损伤，以及如果不进行两个分支的减压可能出现的复发。此外，在计划进行有症状的皮质类固醇注射时，这一知识对于决定是在分叉上方注射还是注入各个神经干的神经外膜至关重要。总之，双叉正中神经是一种可能导致腕管综合征的解剖变异，可通过超声检查显示。在规划腕管松解手术和有症状的皮质类固醇注射时，了解这种异常情况很重要。
