A novel extradural nerve transfer technique by coaptation of C4 to C5 and C7 to C6 for treating isolated upper trunk avulsion of the brachial plexus

The study aimed to demonstrate the feasibility of an extradural nerve anastomosis technique for the restoration of a C5 and C6 avulsion of the brachial plexus. Nine fresh frozen human cadavers were used. The diameters, sizes, and locations of the extradural spinal nerve roots were observed. The lengths of the extradural spinal nerve roots and the distance between the neighboring nerve root outlets were measured and compared in the cervical segments. In the spinal canal, the ventral and dorsal roots were separated by the dura and arachnoid. The ventral and dorsal roots of C7 had sufficient lengths to anastomose those of C6. The ventral and dorsal of C4 had enough length to be transferred to those of C5, respectively. The feasibility of this extradural nerve anastomosis technique for restoring C5 and C6 avulsion of the brachial plexus in human cadavers was demonstrated in our anatomical study     

Plexiform neurofibroma of the cauda equina: a case report and review of the literature

Plexiform neurofibroma of the cauda equina is extremely rare. Herein, a case is reported in a 56-year-old man who also had muscle atrophy, severe motor disturbance, and mild sensory disturbance of the left leg due to childhood poliomyelitis. The clinical symptoms manifested insidiously until the patient developed cauda equina syndrome. At operation, the tumor mass was observed to engulf the nerve roots of the cauda equina. After pathological examination, the diagnosis of plexiform neurofibroma was made. Neither the patient described herein nor any previously reported patients had neurofibromatosis.     

Spinal arachnoid calcifications

Arachnoid calcifications have been imaged on axial-CT and MRI. These often clinically asymptomatic deposits have been attributed to trauma, myelography (particularly with the use of oil-based contrast), subarachnoid hemorrhage, and spinal anesthesia. This report describes calcified arachnoid plaques in an 86-year-old male cadaver located in the dorsal thoracic level. A laminectomy from C4 to the lumbo-sacral junction was performed and the dura mater was transected and pinned aside. Three plaques between T2-T3, 3 at T7, 2 at T9 were noted. Plaques were 1.0 mm in thickness and ranged from 0.5 cm to 1.0 cm in diameter. The spinal cord or nerve roots were not displaced. The plaques stained positively with Von Kossa and Alizarin Red S staining, confirming that the deposits included calcium phosphate and calcium. Arachnoid calcifications are an incidental finding in cadavers and typically do not compress the spinal cord or nerve roots. However such plaques may be precursors to spinal arachnoid ossificans, a more serious condition that may cause spinal cord or nerve root compression.     

齿状韧带的形态观测及临床意义

目的　为临床SPR和SAR提供可靠的脊神经前、后根鉴别和定位的形态学依据。方法　对 30例 (6 0例 )成人尸体的齿状韧带进行了解剖学观测和测量。结果　齿状韧带位于椎管内脊神经前、后两神经根之间。颈部脊神经前、后根之间有恒定的齿状韧带。两侧形成平均 2 0个锯齿状齿尖 ,以齿尖在上、下脊神经根之间附着于硬脊膜。结论　在选择性脊神经根切断术中 ,齿状韧带可作为一标志 ,脊神经前、后根可通过齿状韧带加以鉴别和定位 ,特别在颈部。     

犬马尾与骶神经根的解剖学观察

目的：为从马尾和骶神经根途径开展犬的神经泌尿学研究提供解剖依据。方法：对3只犬灌后进行解剖,并对22只犬进行术中观察,总结马尾、骶神经根的解剖特征。结果：犬的盆底器官由S1～S2脊髓节段和神经根支配;脊髓圆锥延续较长,达L6椎体下缘,而马尾神经较短;髓神经前后根出硬膜后,有各自独立的硬膜囊包绕直至后根神经节处,长1～1.5cm。结论：犬马尾和骶神经根的解剖特征与人类不同。     

The posterior longitudinal ligament and peridural (epidural) membrane

The posterior longitudinal ligament (PLL) is described as having deep and superficial layers, though recent studies have suggested that there may be three layers. Additional membranous structures have been reported, although there is no consensus as to their presence or morphology. The vertebral canal and dural sac were opened and the spinal nerve roots and spinal cord removed. The anterior dural ligaments were sectioned at their attachment to the PLL and the dura mater freed from the posterior surface of the vertebral bodies. The borders of the PLL were identified and the superficial and deep layers separated. The PLL is a wide band in the cervical region becoming more denticulate inferiorly, the widest parts being attached to the intervertebral discs (IVD) and adjacent vertebral body where the superficial and deep layers could not be separated. A continuous well developed peridural membrane attaching to the pedicles was present anterior to the deep PLL as well as a separate, thin, incomplete layer in 6 of 18 cadavers, covering the posterior surface of the superficial PLL.     

Cauda equina syndrome

Single or double-level compression of the lumbosacral nerve roots located in the dural sac results in a polyradicular symptomatology clinically diagnosed as cauda equina syndrome. The cauda equina nerve roots provide the sensory and motor innervation of most of the lower extremities, the pelvic floor and the sphincters. Therefore, in a fully developed cauda equina syndrome, multiple signs of sensory disorders may appear. These disorders include low-back pain, saddle anesthesia, bilateral sciatica, then motor weakness of the lower extremities or chronic paraplegia and, bladder dysfunction. Multiple etiologies can cause the cauda equina syndrome. Among them, non-neoplastic compressive etiologies such as herniated lumbosacral discs and spinal stenosis and spinal neoplasms play a significant role in the development of the cauda equina syndrome. Non-compressive etiologies of the cauda equina syndrome include ischemic insults, inflammatory conditions, spinal arachnoiditis and other infectious etiologies. The use of canine, porcine and rat models mimicking the cauda equina syndrome enabled discovery of the effects of the compression on nerve root neural and vascular anatomy, the impairment of impulse propagation and the changes of the neurotransmitters in the spinal cord after compression of cauda equina. The involvement of intrinsic spinal cord neurons in the compression-induced cauda equina syndrome includes anterograde, retrograde and transneuronal degeneration in the lumbosacral segments. Prominent changes of NADPH diaphorase exhibiting, Fos-like immunoreactive and heat shock protein HSP72 were detected in the lumbosacral segments in a short-and long-lasting compression of the cauda equina in the dog. Developments in the diagnosis and treatment of patients with back pain, sciatica and with a herniated lumbar disc are mentioned, including many treatment options available.     

Two cases of nondura-based clear cell meningioma of the cauda equina

Clear cell meningioma is a rare disorder. We report two cases of nondura-based clear cell meningioma of the cauda equina, one in a 24-year-old male and the other in a 19-year-old female. Both patients had complained of numbness and spontaneous pain in the lower back and limbs for several months. Magnetic resonance imaging and computed tomography scanning revealed an intradural tumor in the cauda equina in each case. At surgery, a neurilemoma was suspected, because each of the tumors had displaced nerve roots and had attached to one of the nerve roots without any adherence to the dura. Light microscopy revealed that both tumors were well-demarcated with a thin capsule and consisted mainly of clear, glycogen-rich, polygonal cells with vague whorl formations, and of copious deposits of hyalinized blocky collagen in the stroma and perivascular areas. The neoplastic cells were immunopositive for vimentin and epithelial membrane antigen, but immunonegative for S-100 protein and chromogranin A. Positive nuclei for MIB-1 were very few in both cases, and PCNA-labeling indices were 12.1% and 24.7%, respectively. No local recurrence has been seen for 61 months and for 52 months, respectively.     

腰骶部脊神经根的临床解剖学

通过临床选择性脊神经后根切断术中观察与测量,为临床提供了重要的参考数据。腰骶神经前、后根解剖会合点至椎间孔距离平均为1.5～2.0cm。前后两根相比,后根明显较前根粗,其中以L_5后根最粗、L_2～S_1各后根内小束的数目为4～18束,平均为7束,临床分离后根时可分为7束,以便进行电刺激选择。这些资料为腰骶部选择性脊神经后根切断术和马尾神经的手术提供了重要依据。     

脊神经前后根的应用显微解剖学研究

目的　探讨脊神经前后根神经小束的分束标准和数目 ,为临床手术提供可靠的依据和新的手术标准。方法　在 15例 (30侧 )成人脊柱标本上 ,对L1～S2节段的脊神经前后根进行形态学观察和显微测量。结果　脊髓圆锥部脊神经根是由根丝逐步汇合而成。应用显微外科技术 ,后根一般可分为 10～ 18小束 ,前根一般分为 6～ 11小束 ,其小束的直径是基本一致 ,数值较为恒定。结论　在高选择性手术 ,脊神经前后根的分束标准应尽量细 ,这样有利于准确切断引起痉挛的Ia类神经纤维 ,一般前根达到 6～ 11小束 ,后根达到 10～18小束     

Scanning electron microscopic observations of normal and regenerating nerve roots in the cat

The surface morphology of normal and regenerated nerve roots was studied using correlated scanning and transmission electron microscopic methods. Nerve roots of the cauda equina were either cut and rejoined or crossed from a segment above to a segment below. Good regeneration was observed in both experimental procedures. The regenerated nerve root sheath had alterations in surface structure created by extensive growth of collagen. Despite this collagen formation, regenerated axons crossed the anastomotic site with relative ease. Surface features of the regenerated axons were similar in appearance to those of the normal axon. Schwann cells were easily recognized, as were the collagen fibers of the endoneurium, although the endoneurium was more prominent and occupied more of the interaxonal space. Macrophages were identified as round structures with a laminated surface or as a honeycomb structure. Internal features of the regenerating axons were more difficult to identify, but mitochondria and a fibrous network were observed. These studies have demonstrated the application of scanning electron microscopic methods to visualize surface structures and cells in regenerated nerve roots.     

Reimplantation of avulsed lumbosacral ventral roots in the rat ameliorates injury-induced degeneration of primary afferent axon collaterals in the spinal dorsal columns

Injuries to the cauda equina/conus medullaris portion of the spinal cord can result in motor, sensory, and autonomic dysfunction, and neuropathic pain. In rats, unilateral avulsion of the motor efferents from the lumbosacral spinal cord results in at-level allodynia, along with a corresponding glial and inflammatory response in the dorsal horn of the spinal cord segments immediately rostral to the lesion. Here, we investigated the fate of intramedullary primary sensory projections following a motor efferent lesion. The lumbosacral (L6 and S1) ventral roots were unilaterally avulsed from the rat spinal cord (VRA; n=9). A second experimental group had the avulsed roots acutely reimplanted into the lateral funiculus (Imp; n=5), as this neural repair strategy is neuroprotective, and promotes the functional reinnervation of peripheral targets. A laminectomy-only group served as controls (Lam; n=7). At 8 weeks post-lesion, immunohistochemical examination showed a 42% reduction (P<0.001) in the number of RT97-positive axons in the ascending tracts of the dorsal funiculus of the L4-5 spinal segment in VRA rats. Evidence for degenerating myelin was also present. Reimplantation of the avulsed roots ameliorated axon and myelin degeneration. Axons in the descending dorsal corticospinal tract were unaffected in all groups, suggesting a specificity of this lesion for spinal primary sensory afferents. These results show for the first time that a lesion restricted to motor roots can induce the degeneration of intramedullary sensory afferents. Importantly, reimplantation of the lesioned motor roots ameliorated sensory axon degeneration. These data further support the therapeutic potential for reimplantation of avulsed ventral roots following trauma to the cauda equina/conus medullaris.     

Anatomy of the lumbar spinal nerves in the intervertebral foramen

The anatomic relationships between the dorsal and ventral roots, spinal nerve, and dorsal and ventral rami of the lumbar spinal nerves have been described previously primarily on the basis of gross dissection and not on sectional anatomic techniques. Therefore, we examined the proximal spinal nerves in 16 cadavers by gross dissection, cryomicrotomy, and histology. On opening the root sheath that had been exposed by gross dissection, multiple fascicles could be identified intervening between the spinal nerve and the spinal nerve roots. Anatomic sections in a sagittal plane immediately distal (lateral) to the dorsal root ganglion demonstrated a plexus of fascicles 6–15 in number and 2–6 mm in length. On histologic sections the 6–15 fascicles were identified interspersed with fat and numerous small blood vessels. The proximal spinal nerve is formed from the convergence of these fascicles.     

颈椎硬脊膜后方膜椎韧带的解剖学研究

目的　研究颈椎硬脊膜后方膜椎韧带的解剖学特征,探讨其临床意义。 方法　内窥镜下观测13具成人防腐标本颈椎硬脊膜后方膜椎韧带的形态学特点,随后打开椎管,肉眼及手术显微镜下对膜椎韧带进行观测,记录其起止点、走行方向。用游标卡尺测量膜椎韧带的长度、宽度、厚度或直径。对膜椎韧带进行HE染色、Masson三色法染色,观察其组织形态结构特点。 结果　13例颈椎标本中硬脊膜后方均有膜椎韧带出现,膜椎韧带将硬脊膜向后连于椎板或黄韧带。膜椎韧带与黄韧带连接较紧密且数量居多,占72.4%。膜椎韧带在C1/2、C4/5黄韧带出现率为100%,C1/2黄韧带处膜椎韧带厚度最大,为（1.04±0.61）cm(0.3~2.01 cm)。膜椎韧带多呈前上后下走行。根据形态特点可将膜椎韧带分4型：条带型、条索型、网格型、薄片型。光镜下观察膜椎韧带由大量密集排列的胶原纤维构成。 结论　颈椎硬脊膜背部膜椎韧带是将硬脊膜连于椎管后壁的正常结构,其两端分别与硬脊膜背侧及椎管后壁尤其是黄韧带连接紧密,膜椎韧带可牵拉固定硬脊膜,从而维持脊髓在椎管中的相对位置。另外膜椎韧带可能是颈椎后路手术中硬脊膜撕裂及硬脊膜外出血的解剖学因素,建议相关手术中先予辨认并切断。     

Microsurgical anatomy of the denticulate ligaments and their relationship with the axilla of the spinal nerve roots

The denticulate ligaments (DL), 20 or 21 pairs of meningeal extensions, spread from the lateral aspect of the spinal cord to the internal aspect of the spinal dura mater. The aim of this study is to define the specific relationship of the DL with adjacent axilla of the spinal nerve roots and to investigate the anatomical features of the DLs and their variations. The topographical anatomy of the DLs and their relationships with the adjacent axilla of the spinal nerve roots was examined on 16 formalin‐fixed adult cadaveric spinal cords. The distances from the dural attachment of the DL to the axilla of the superior and inferior spinal nerve roots were measured bilaterally at every spinal level. Also the distances from the dural attachment of the DL to the lateral aspect of the spinal cord were measured bilaterally. Cervical DLs showed a triangular shape, while in the thoracic segment the ligament changes the shape to “Y.” Also the most caudal DL was identified to be at the L1–2 level. Our study revealed that the distances from the dural attachment of the DL to the superior and inferior spinal nerve root axilla were different at the cervical, upper thoracic and the lower thoracic segments. Both distances to the superior and inferior spinal nerve root axilla were shown to increase from cervical to lower thoracic segments. This study provides a detailed anatomy of the DLs and their relationship with the adjacent spinal nerve root axilla. Clin. Anat. 27:733–737, 2014. © 2013 Wiley Periodicals, Inc.     

颈椎椎间孔外口区韧带的解剖学观测

目的　对颈椎C_2~7椎间孔外口区域的韧带进行解剖学描述并探讨其临床意义。 方法　对10具成人尸体标本的 100个椎间孔进行解剖观测。鉴别所有出现的韧带,观察并记录C2~7椎间孔外口区域椎间孔外韧带的数量、形态、分布和起止位置。并用游标卡尺分别测量每条韧带的长度、宽度和厚度。 结果　在100个椎间孔外口区域共发现252个椎间孔外韧带。椎间孔外韧带可以分为放射型韧带236 个(93.7 %)和横跨型韧带16个(6.3 %)两种。放射型韧带将神经根连接到周围结构,可分为上方韧带（25.0%）,下方韧带（60.2%）,前方韧带（6.3%）和后方韧带（8.5%）;横跨型韧带与神经根相垂直并横跨于神经根上,其中,横跨型韧带在C4~5节段最为常见,在C4~5节段的平均长度为横跨型韧带长度为(8.12±1.38) mm(6.28~9.93 mm),厚度最厚可达1.04 mm,每个颈椎椎间孔最多只有一条横跨型韧带。 结论　椎间孔外韧带是椎间孔正常的生理结构,可能与颈椎减压术后C5神经麻痹的发生有关。在颈椎减压术后,横跨型韧带可能是造成神经根卡压而引起神经损伤的潜在原因之一。而放射型韧带可以限制脊神经移位,可能因此牵拉神经引起损伤。     

拇指腕掌关节周围韧带的解剖学分析

目的　解剖拇指腕掌关节周围各条韧带及观察其组织形态学特征,探讨其在拇指腕掌关节稳定性中的作用。 方法　采用大体解剖学方法对10例新鲜冰冻手标本进行解剖,识别拇指腕掌关节周围韧带的连接部位与方向性,对韧带的宽度、长度、厚度进行形态学对比分析。并组织学观察拇指腕掌关节背侧和掌侧韧带细胞数。 结果　确定拇指腕掌关节周围存在7条主要韧带：即由3条背侧韧带（桡背侧韧带、背侧中央韧带、后斜韧带）组成的复合体,厚度分别为(1.24±0.12)、(1.91±0.15)、(1.61±0.12) mm。2条掌侧韧带（前斜韧带、尺侧副韧带）,厚度分别为(0.78±0.11) mm、 (1.03±0.11) mm。2条尺侧韧带（大多角骨-第1掌骨背侧韧带,第1、2掌骨间韧带）,厚度分别为(0.78±0.19) mm、(0.89±0.19) mm。背侧韧带明显厚于掌侧韧带（P<0.01）,桡背侧韧带、背侧中央韧带、后斜韧带的细胞数多于前斜韧带,后斜韧带的细胞数也多于尺侧副韧带,均有统计学差异（P<0.05）。 结论　3条背侧韧带组成粗厚坚韧的复合体,在拇指腕掌关节的稳定中,前斜韧带起着更大的作用。     

Cauda equina syndrome with multiple lumbar diverticula complicating long-standing ankylosing spondylitis

A patient with cauda equina syndrome complicating long-standing inactive ankylosing spondylitis is described. The first neurological symptoms started 15 years after the onset of ankylosing spondylitis. Over a follow-up period of 12 years the cauda equina syndrome showed a slowly progressive but disabling course leading to sensory disturbances in the lumbar and sacral dermatomes, weakness and wasting of the muscles innervated by these nerve roots, sphincter disturbances, and impotence. Magnetic resonance imaging, computed tomography, and lumbar myelography showed enlargement of the dural sac with multiple lubar diverticula eroding the lumbosacral vertebrae. The pathophysiology of the cauda equina syndrome in ankylosing spondylits is unclear. Surgical treatment seems justified only in patients with a short history of neurological symptoms. Correspondence to: R. Schröder     

颈椎间孔内口锚链韧带的形态和分布特征

目的 通过解剖学观察,揭示颈椎间孔内口区锚链韧带的形态及其分布特征,探讨其与神经根型颈椎病神经卡压之间的关系。 方法 12具成人脊柱颈段防腐标本,正中矢状切开,从脊神经根袖根部切断根袖,在外科显微镜下解剖观察C3/4～C7/T1椎间孔内口处神经根袖周围的锚链韧带,记录韧带的形态、分布、起止点及走行。 结果 120个椎间孔内口脊神经根袖周围共发现560条锚链韧带,所有韧带均呈放射状连于神经根袖与椎间孔内口周围骨膜壁,两端附着紧密,不易分离。各椎间孔内口韧带的数目均≥4个。锚链韧带形态主要包括带形和索形两种。带形韧带258条,宽度（4.5±2.6）mm（4.1~5.2 mm）,索形韧带302条,直径（2.5±1.8）mm（1.2~3.8 mm）。C3/4、C7/T1椎间孔内口区韧带较为松散纤细,数量较少;C4/5~C6/7椎间孔内韧带较为坚韧而粗壮,数量较多。 结论 颈椎椎间孔内口区神经根周围存在锚链韧带,将神经根锚定于周围椎间孔骨膜壁,极大限制了神经根自由移动范围,可能与突出椎间盘一起导致神经根卡压,是神经根型颈椎病的潜在解剖学因素。