Spinal MR imaging in Vitamin B12 deficiency: Case series; differential diagnosis of symmetrical posterior spinal cord lesions

We report three cases of Vitamin B12 deficiency with symmetrical posterior spinal cord lesions and discuss the differential diagnosis, some of which are not well known. Because the degree of resolution of the clinical symptoms in subacute combined degeneration depends on early detection, MRI findings should not be missed.     

骶尾部脊髓脂肪瘤的手术技巧

目的 介绍骶尾部脊髓脂肪瘤的病理解剖及相应的手术技巧.方法 2005年9月至2012年1月,上海儿童医学中心手术治疗骶尾部脊髓脂肪瘤119例,年龄1个月至18岁,神经系统症状有大小便失禁和(或)双下肢功能障碍.手术方法包括:切除皮下和椎管内脊髓外的脂肪瘤,脊髓内的脂肪瘤大部分切除,将脊髓从两侧硬脊膜上剪开,圆锥从硬脊膜囊末端剪开并分离下来,松解脊髓栓系.结果 骶尾部脊髓脂肪瘤主要病理解剖与腰骶部脊髓脂肪瘤相似,不同之处在于圆锥生长在末端硬膜囊上,圆锥发出的脊神经从圆锥腹侧斜向下方发出,脂肪瘤仅生长到脊髓内,并未生长到脊髓下方的脊神经内.108例得到随访,随访时间0.5～7.0年.术前有症状的患儿,术后多数有不同程度改善,1例症状加重,6例术后症状一过性加重;10例无症状者术后9例仍然无症状,1例症状一过性加重.结论 只有充分认识骶尾部脊髓脂肪瘤病理解剖,才能最大限度地切除脂肪瘤,彻底解除脊髓栓系,同时又能避免神经损伤,重建脊髓的正常解剖结构,最大限度恢复神经功能.     

Vertebral Artery Anomaly Causing C2 Suboccipital Neuralgia,Relieved by Neurovascular Decompression

We report imaging and surgical findings of a symptomatic 40‐year‐old male with an anomalous left vertebral artery. MR, CT myelography, angiography, and intraoperative photos demonstrate the vertebral artery entering the thecal sac at the C1‐C2 intervertebral foramen and compressing the dorsal C2 nerve rootlets against the cord. Open microvascular decompression alleviated the patient's long‐standing suboccipital and posterior cervical neck pain. An embryologic review of the vertebral and lateral spinal artery systems reveals possible developmental explanations for this variant. Intradural course of the vertebral artery at C2 is one of the few symptomatic developmental vertebral artery anomalies. Recognition of this condition is important because surgical intervention can alleviate associated neck pain.     

Neural activity in the hippocampus predicts individual visual short‐term memory capacity

Although the hippocampus had been traditionally thought to be exclusively involved in long‐term memory, recent studies raised controversial explanations why hippocampal activity emerged during short‐term memory tasks. For example, it has been argued that long‐term memory processes might contribute to performance within a short‐term memory paradigm when memory capacity has been exceeded. It is still unclear, though, whether neural activity in the hippocampus predicts visual short‐term memory (VSTM) performance. To investigate this question, we measured BOLD activity in 21 healthy adults (age range 19–27 yr, nine males) while they performed a match‐to‐sample task requiring processing of object‐location associations (delay period = 900 ms; set size conditions 1, 2, 4, and 6). Based on individual memory capacity (estimated by Cowan's K‐formula), two performance groups were formed (high and low performers). Within whole brain analyses, we found a robust main effect of “set size” in the posterior parietal cortex (PPC). In line with a “set size × group” interaction in the hippocampus, a subsequent Finite Impulse Response (FIR) analysis revealed divergent hippocampal activation patterns between performance groups: Low performers (mean capacity = 3.63) elicited increased neural activity at set size two, followed by a drop in activity at set sizes four and six, whereas high performers (mean capacity = 5.19) showed an incremental activity increase with larger set size (maximal activation at set size six). Our data demonstrated that performance‐related neural activity in the hippocampus emerged below capacity limit. In conclusion, we suggest that hippocampal activity reflected successful processing of object‐location associations in VSTM. Neural activity in the PPC might have been involved in attentional updating. © 2013 Wiley Periodicals, Inc.     

A comparative study of glial and non‐neural cell properties for transplant‐mediated repair of the injured spinal cord

Cell transplantation is one strategy for encouraging regeneration after spinal cord injury and a range of cell types have been investigated for their repair potential. However, variations in study design complicate determination of which cells are most effective. In this study we have carried out a direct comparison of the regenerative and integrative properties of several cell preparations following transplantation into the lesioned rat spinal cord. Transplants included: (i) purified olfactory ensheathing cells (OECs) and (ii) fibroblast‐like cells, from olfactory bulb (OBFB‐L), (iii) a 50:50 mixture of (i) and (ii) (OEC/OBFB‐L), (iv) dissociated nasal mucosa (OM), (v) purified peripheral nerve Schwann cells (SCs), (vi) peripheral nerve fibroblasts, and (vii) skin fibroblasts (SF). All transplants supported axonal regeneration: OECs and SCs promoted the greatest regeneration while OBFB‐like cells were least efficient and mixed cell populations were less effective than purified populations. Tract‐tracing experiments demonstrated that none of the cell types promoted regeneration beyond the lesion. Although all cell types prevented cavity formation, the extent of astrocytic hypertrophy [GFAP immunoreactivity (IR) at the transplant/lesion site] differed markedly. OECs and SCs were associated with the least GFAP‐IR, fibroblasts and fibroblast‐like cells resulted in greater GFAP‐IR while hypertrophy surrounding transplants of OM was most extensive. These differences in host‐transplant reactivity were confirmed by transplanting cells into normal spinal cord where the cellular interaction is not complicated by injury. Thus, purified glial cells have advantages for transplant‐mediated repair, combining maximal support for axonal regeneration with a minimal astrocytic reaction around the transplant site. © 2013 Wiley Periodicals, Inc.     

Syntenin‐a promotes spinal cord regeneration following injury in adult zebrafish

In contrast to mammals, adult zebrafish recover locomotor function after spinal cord injury, in part due to the capacity of the central nervous system to repair severed connections. To identify molecular cues that underlie regeneration, we conducted mRNA expression profiling and found that syntenin‐a expression is upregulated in the adult zebrafish spinal cord caudal to the lesion site after injury. Syntenin is a scaffolding protein involved in mammalian cell adhesion and movement, axonal outgrowth, establishment of cell polarity, and protein trafficking. It could thus be expected to be involved in supporting regeneration in fish. Syntenin‐a mRNA and protein are expressed in neurons, glia and newly generated neural cells, and upregulated caudal to the lesion site on days 6 and 11 following spinal cord injury. Treatment of spinal cord‐injured fish with two different antisense morpholinos to knock down syntenin‐a expression resulted in significant inhibition of locomotor recovery at 5 and 6 weeks after injury, when compared to control morpholino‐treated fish. Knock‐down of syntenin‐a reduced regrowth of descending axons from brainstem neurons into the spinal cord caudal to the lesion site. These observations indicate that syntenin‐a is involved in regeneration after traumatic insult to the central nervous system of adult zebrafish, potentially leading to novel insights into the cellular and molecular mechanisms that require activation in the regeneration‐deficient mammalian central nervous system.     

多模式神经电生理检测对脊髓手术患者神经功能状态的评估分析及其影响因素

 目的 使用肌电图(electromyography,EMG)、体感诱发电位(somatosensory evoked potential,SEP)与运动诱发电位(motor evoked potentials,MEP)多模式方法检测手术前后神经系统的多种电生理信号,探讨患者神经功能状态。方法 收集100例患者作为研究对象,术中监测患者双下肢的SEP与MEP情况;术后6个月复查患者EMG。结果 术中SEP波幅与潜伏期在较稳定情况下,MEP监测中42例患者术中的D波波幅发生降低未超过50%,22例患者出现D波波幅突然下降且超过50%。Pearson相关性分析结果表明,术中出血量与SEP及MEP波幅与潜伏期的改变具有相关性。术后复查,各组患者的腓总神经与胫神经的NCV与DL均有显著改善,异常组患者的改善情况明显低于其他四组。结论 使用EMG、SEP与MEP多模式神经电生理检测可以去除干扰因素,为脊髓手术提供客观、有价值的诊疗依据。     

过伸型胫骨平台骨折的临床治疗

目的探讨过伸型胫骨平台骨折的临床治疗。方法回顾性分析2013年11月—2017年12月南京医科大学第一附属医院治疗的12例过伸型胫骨平台骨折。其中男性4例,女性8例;年龄24～65岁,平均53.6岁;致伤原因均为道路交通伤。患者采用屈曲位复位,植骨后使用内外侧钢板固定。观察患者术后平台后倾角、美国特种外科医院膝关节功能评分(HSS评分)、关节屈曲度以及并发症情况。结果术后X线片显示均获得解剖复位。术后均无膝关节反曲,患者均得到随访6～18个月,平均9.7个月。骨折愈合时间8～12周,平均10.0周。所有患者术后测量后倾角5°～9°(平均7.9°),术后半年5°～10°(平均7.7°)。HSS评分90～98分(平均93.6分)。术后半年关节屈曲度120°～145°(平均131°),伸直均为0°。术后无一例发生钢板及螺钉断裂现象。结论通过恢复正常后倾角及关节面平整,充分植骨及锁定钢板固定治疗过伸型胫骨平台骨折,效果良好,值得临床推荐。     

Viper经皮内固定与经椎旁内固定治疗脊椎骨折的效果对比及对SF-36评分、Oswestry功能障碍指数的影响

目的比较Viper经皮内固定与经椎旁内固定治疗脊椎骨折的效果。方法 2015年1月—2017年3月上海交通大学医学院附属瑞金医院卢湾分院骨科收治116例脊椎骨折患者,按治疗方法分为Viper组和经椎旁内固定组各58例。其中Viper组患者给予Viper脊柱微创系统治疗,经椎旁内固定组患者给予经椎旁肌间隙入路椎弓根内固定治疗。比较两组手术情况相关指标(包括手术切口、手术时间、术中失血量、术后住院时间、骨折愈合时间),内固定术前、术后即刻和术后1年影像学指标(包括后凸Cobb角、椎体矢状面指数和椎体前缘高度)、Oswestry功能障碍指数(ODI),内固定术前、术后1周和术后1年SF-36评分。结果 (1)Viper组手术时间(91.04±16.81)min显著长于经椎旁内固定组(44.85±8.14)min,术中出血量(81.29±20.53)mL显著少于经椎旁内固定组(142.60±31.27)mL,P<0.05。(2)内固定术后即刻两组患者的Cobb角[(9.39±3.02)°,(9.41±3.07)°]较术前[(23.47±6.51)°,(23.23±6.72)°]明显减小;术后1年较术后即刻[(10.74±3.20)°,(10.83±3.27)°]显著增加(P<0.05);内固定术后即刻和术后1年两组患者的伤椎前缘高度[术后即刻(93.65±5.38)°,(93.92±6.27)°;术后1年:(86.26±6.04)°,(92.35±5.98)°]和椎体矢状面指数[术后即刻(178.93±27.49)°,(177.79±24.82)°;术后1年(169.37±22.15)°,(170.05±25.19)°]较术前显著升高[(64.75±12.13)°,(65.02±13.08)°,P<0.05]。内固定术后1年时,Viper组的伤椎前缘高度(86.26±6.04)%显著低于经椎旁内固定组(92.35±5.98)%,P<0.05。(3)内固定术后即刻(31.53±9.50,37.62±10.15)和术后1年(19.04±5.86,23.84±5.71)两组患者的ODI指数较术前显著降低(57.83±11.39,58.02±10.72,P<0.05),其中Viper组内固定术后即刻(31.53±9.50)和术后1年(19.04±5.86)的ODI指数均显著低于经椎旁内固定组(术后即刻:37.62±10.15;术后1年:23.84±5.71,P<0.05)。(4)内固定术后1周(58.20±5.92,44.52±5.09)和术后1年SF-36评分(69.32±7.76,51.07±6.69)较术前(39.42±3.91,40.05±4.20)均显著升高,且Viper组SF-36评分(术后1周:58.20±5.92;术后1年:69.32±7.76)均显著高于经椎旁内固定组(术后1周:44.52±5.09;术后1年:51.07±6.69,P<0.05)。结论 Viper经皮内固定的微创优势更显著,更有利于改善患者术后SF-36评分和ODI指数。