| 摘要: |
| 目的 报道一例Neidre-Macnab-IIB型腰骶神经根畸形(LSNA)并L3-5椎间盘突出及L4-5右侧隐窝狭窄术前漏诊、术中起初误诊为IIA型LSNA的病例。分析漏误诊原因。材料和方法：62岁女性,腰痛并右下肢间歇性放射痛及跛行20余年,左下肢放射痛2周入院。体检示左侧L5及右侧L4-5神经根受损,CT及MR示L3-4椎间盘右旁侧突出,L4-5椎间盘中央偏左突出并右侧隐窝狭窄,未发现LSNA。术中发现L4-5椎间盘左侧突出部分压迫L5神经根,予以切除。L4-5右侧椎间孔有两个神经根发出,L3-4椎间盘右侧突出压迫上方神经根,予以切除并扩大椎间孔；L4-5右侧狭窄侧隐窝打开后未在L4-5椎间盘表面见到典型神经根结构,怀疑IIA型LSNA。阅读CT及MR发现L4-5右侧隐窝偏下方及L5S1椎间孔存在神经结构。继续探查证实L5神经根受到突出间盘和狭窄侧隐窝共同压迫呈扁平膜状覆盖在L4-5间盘表面,起源于L4-5椎间盘上方的硬膜囊偏腹侧。将其分离后,摘除突出椎间盘。植入椎间cage,椎弓根系统内固定。结果：术后左下肢疼痛消失,右下肢放射痛加重2周后减轻。结论：II型LSNA术前CT及MR漏诊率较高。从L4-5右侧椎间孔发出的结合神经相互接近及观察不细是术前影像漏诊的原因,右侧L5神经根受压变扁失去正常色泽覆盖在L4-5间盘表面使得初始误以为IIA型LSNA。术中要注意仔细分辨,避免误诊。 |
| 关键词: 结合神经 腰骶神经根畸形 误诊 漏诊 Neidre-Macnab分型 |
| DOI：10.16781/j.0258-879x.2017.04.0527 |
| 投稿时间：2016-10-18修订日期：2016-12-19 |
| 基金项目:海军总医院创新培育基金（CXPY2014-13）. |
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| Neidre and Macnab's classification Type-ⅡB lumbosacral nerve root anomaly missed preoperatively and initially misdiagnosed as type-ⅡA anomaly intraoperatively: a case report |
| HOU Li-sheng*,BAI Xue-dong,HE Qing,WANG Jing,CHENG Shi |
(Department of Orthopaedics, Navy General Hospital of PLA, Beijing 100048, China
*Corresponding author) |
| Abstract: |
| Objective:A patient with L3-5 lumbar disc herniations and right spinal recess stenosis at L4-5 level associated with type IIB lumbosacral nerve anomaly(LSNA) at right side according to Neidre and Macnab classification system missed preoperatively and initially misdiagnosed as type IIA intraoperatively was reported. The reasons leading to missed diagnosis preoperatively and misdiagnoses intraoperatively were analyzed. Methods: A 62-year-old female was admitted to our hospital for intermittent radiating pain and claudication to the right lower extremity for about 20 years, radiating pain to the left lower extremity for 2 weeks. Physical examination found the left L5 nerve and right L4 and L5 nerves were impinged. CT and MR scannings revealed L3-4 disc herniation at right side, L4-5 disc herniation at central and left side with severe lateral recess stenosis at right L4-5 level. Image examinations failed to find a nerve root anomaly preoperatively. Following failed conservative treatment, the patient accepted decompression operation initially at left side. Left L5 nerve compressed by the herniated L4-5 disc was found firstly, which was liberated by discectomy. When doing decompression exploration at right side, it was found that two lumbar nerve roots exited L4-5 intervertebral foramen while the upper one was compressed by the herniated L3-4 disc which was liberated by discectomy and the lower one was free of compression. With exposing the right side and partly unroofing of stenosed right L4-5 lateral recess , no typical L5 nerve root was found passing over the posterior surface of the herniated L4-5 disc except that there was a slim membrane-like structure covering it. The patient was initially considered as type IIA LSNA skeptical according to Neidre and Macnad Classification. But detailed observation of the axial CT and MR sequences at L4-5 lateral recess space and sagittal CT and MR sequences at L5S1 intervertebral foramen found there was nerve-like structure, which was further confirmed to be the L5 nerve root by total unroofing of stenosed lateral recess. The membrane-like structure covering the L4-5 disc was confirmed to be the flattened right L5 nerve root compressed by herniated L4-5 disc and stenosed lateral recess, which emerged from the dura’s ventral-lateral side just above the L4-5 disc, the L5 nerve was stripped and pushed medially from its lateral boundary meticulously, L4-5 discectomy was done at right side. Intervertebral cages were inserted after L3-4 and L4-5 disc spaces preparation, following pedicle screw system fusion. Results: No nerve damage occurred intraoperatively. The patient was free of radiating pain to the left lower extremity the day after operation, two weeks later the radiating pain to the right lower extremity alleviated after temporary aggravating. Conclusion: type II lumbar nerve anomalies were not easily to be detected by CT or MR images preoperatively, that closer distance between the conjoined nerves existing the L4-5 foramen and careless observation was responsible for missed diagnosis preoperatively. That the flattened right L5 nerve covering the L4-5 disc was difficult to be recognized intraoperatively for losing its typical contour and color was responsible for misdiagnosing type-IIB anomaly as IIA LSNA.. The operators should be alert and observed carefully in case of misdiagnosing. |
| Key words: conjoined nerve roots lumbosacral nerve anomaly misdiagnosis missed diagnosis Neidre-Macnab classification |
