Ascending vermian artery, branch of the V4 segment of the vertebral artery

A previously undescribed anatomical variant is reported here, that of vermian arteries (vAs) branched from the vertebral arteries (VAs) and replacing the medial branches of the posterior inferior cerebellar arteries (PICAs) that, in turn, were leaving the basilar artery. Both vAs left the VAs in the foramen magnum. The left vA initially looped in front of the spinal root of the accessory nerve (Sp11) and then looped inferiorly on the dorsal side of the spinal cord, in the vertebral canal and continued ascending on the dorsal surface of the medulla oblongata. The right vA looped dorsally to the Sp11 above the foramen magnum, and also ascended dorsally to the medulla. Both vAs were distributed to the vermis. On both sides, the PICAs looped above the glossopharyngeal nerves and the jugular foramina and continued as only lateral terminal branches of a normal PICA that descended in countercurrent on the outer side of the variant vAs. Such anatomical variation is relevant for surgery and microsurgery on both sides of the foramen magnum and in the posterior cerebral fossa.     

The radiological evaluation of the child with a myelomeningocele

Seven hundred fifty-five children with myelomeningoceles were evaluated radiologically at the Children's Memorial Hospital in Chicago. From our material, we propose a diagnostic radiologic model to accurately evaluate the neurological problems in the myelomeningocele child. This model is based on the clinical symptoms in these children and the radiologic modalities of magnetic resonance imaging (MRI), computed tomography (CT), ultrasound, myelography, and plain radiographs. We found MRI to be the best modality to evaluate the posterior fossa and total spine. Computed tomography and ultrasound are used to evaluate ventricular size. At times MRI may not adequately diagnose subtle cases of tethering of the spinal cord, cord infarction, arachnoid cysts, or diastematomyelia. In these cases, further evaluation may be necessary with real time ultrasound to look at cord pulsations and water soluble myelography with follow through CT to differentiate cord infarction, arachnoid cyst, localized hydromyelia, or diastematomyelia. If MRI is not adequate to completely visualize the cord because of the severe nature of the scoliosis, then water soluble myelography with CT is indicated.     

颈髓髓内室管膜瘤的影像解剖学分型及手术策略

目的　探讨颈髓髓内室管膜瘤的影像解剖学特点并制定相应的手术策略。 方法　用MRI成像技术分析26例颈髓髓内室管膜瘤影像学形态特点及脊髓受压变形情况,将肿瘤进行分型并在电生理实时监测下手术分离切除肿瘤。 结果　按肿瘤形态及其与脊髓之间的解剖学关系分为3种类型：I型：实质伴有空洞型;II型：实质型; III型：囊肿内瘤型。对I型肿瘤从肿瘤极端和空洞交界处或肿瘤中部开始从后正中沟切开脊髓分离切除肿瘤;对Ⅱ型肿瘤从肿瘤中部脊髓后正中沟切开分离切除肿瘤;对III型肿瘤从最近肿瘤结节处从脊髓后正中沟切开,囊内切除肿瘤。术中电生理监测显示体感诱发电位（SEP）波幅下降50% 或者潜伏期延长10%;目标肌群运动诱发电位（MEP）波幅持续下降至20%,应暂停手术。术后所有病例病理报告均为室管膜瘤。术后MRI复查23例肿瘤完全切除,3例肿瘤部分切除。术后症状明显减轻23例,好转2例,加重1例,无死亡病例。 结论　依据术前MRI进行分型并制定相应的手术策略可以达到完全切除肿瘤、减少脊髓损伤的目的。     

Spontaneous resolution of paraparesis because of acute spontaneous thoracolumbar epidural hematoma

Symptomatic spontaneous spinal epidural hematoma(SSEH) is an uncommon cause of cord compression that commonly is considered as an indication for emergent surgical decompression. We aimed to investigate a patient with a SSEH that completely resolved clinically and radiographically, without surgical treatment. The patient presented three days after the sudden onset of back pain, numbness, and weakness. Magnetic Resonance Imaging (MRI) revealed a posterior thoracolumbar epidural hematoma extending from the level of T10 to L2 with significant cord compression. Decompression was recommended but he refused surgery and was managed conservatively. One month later, weakness totally recovered and hematoma was absent on MRI.     

手术治疗枕骨大孔区畸形的初步探讨

目的:探讨治疗枕骨大孔区畸形的手术方法。方法:手术在枕骨鳞部至C_1～C_3椎板切除减压的基础上,分行单独减压、空洞穿刺、空洞分流、剪开硬膜等四种术式,观察手术效果。结果:全组病例近期效果良好。结论:对于枕骨大孔区畸形的手术治疗,应根据病情的不同采用不同的术式实施治疗。     

枕下减压和硬膜成形术治疗Chiari畸形I型

目的:探讨枕下减压和硬膜成形术治疗Chiari畸形I型的疗效以及手术技巧.方法:采用常规后正中入路、枕骨游离骨瓣、枕大孔区减压(包括C1后弓)、硬膜扩大成形术,治疗Chiari畸形I型患者44例;术后通过临床表现改善情况评价早期(术后1周)疗效,依据Karnofysky评分标准评价后期(术后6个月)疗效.结果:术后早期神经功能改善30例(68%).38例获得随访,平均随访17个月,随访期间神经功能改善率为89%(34/38),Karnofysky评分平均提高5分;稳定4例(11%);无神经功能恶化者.32例出现空洞的患者中,28例得到MRI随访,其中空洞消失8例(均为颈髓空洞)、较术前缩小的16例、无变化4例.结论:枕下减压+硬膜扩大成形术是治疗Chiari畸形I型的有效方法.     

小脑下后动脉在枕骨大孔区的解剖学研究

目的对颅后窝枕骨大孔区小脑下后动脉进行观察与测量,并探讨其临床意义。方法选取成人颅底标本15例,观察枕骨大孔区小脑下后动脉位置、走行、毗邻关系及其分布,测量相关数据并进行统计学处理。结果颅后窝枕骨大孔区小脑下后动脉左右两侧起始部外径:左侧为1.32~1.49 mm,平均(1.41±0.05)mm;右侧为1.27~1.49 mm,平均(1.39±0.07)mm,左右管径比较差异无统计学意义(P>0.05);小脑下后动脉走行呈“S”形,与第Ⅸ、Ⅹ、Ⅺ对脑神经的位置关系密切。结论小脑下后动脉在枕骨大孔区起点走行、分布具有特有的解剖特点,在临床中枕骨大孔区小脑下后动脉相关疾病的手术时应避免医源性损伤。     

Further characterization of NFIB-associated phenotypes: Report of two new individuals

Nuclear Factor I B (NFIB) haploinsufficiency has recently been identified as a cause of intellectual disability (ID) and macrocephaly. Here we report on two new individuals carrying a microdeletion in the chromosomal region 9p23-p22.3 containing NFIB. The first is a 7-year 9-month old boy with developmental delays, ID, definite facial anomalies, and brain and spinal cord magnetic resonance imaging findings including periventricular nodular heterotopia, hypoplasia of the corpus callosum, arachnoid cyst in the left middle cranial fossa, syringomyelia in the thoracic spinal cord and distal tract of the conus medullaris, and a stretched appearance of the filum terminale. The second is a 32-year-old lady (the proband' mother) with dysmorphic features, and a history of learning disability, hypothyroidism, poor growth, left inguinal hernia, and panic attacks. Her brain magnetic resonance imaging findings include a dysmorphic corpus callosum, and a small cyst in the left choroidal fissure that marks the hippocampal head. Array-based comparative genomic hybridization identified, in both, a 232 Kb interstitial deletion at 9p23p22.3 including several exons of NFIB and no other known genes. Our two individuals add to the knowledge of this rare disorder through the addition of new brain and spinal cord MRI findings and dysmorphic features. We propose that NFIB haploinsufficiency causes a clinically recognizable malformation-ID syndrome.     

Chiari畸形的解剖学特征及临床意义

目的:探讨Chiari畸形的病理解剖学特征及临床意义。方法：结合术前MRI检查和术中探查研究128例Chiari畸形的解剖特点，并据此选择手术方式。对96例合并脊髓空洞患者及13例无脊髓空洞但硬膜束带明显者行颅内窝、C1、C2减压加硬膜成形术，19例无脊髓空洞但有临床症状并进行性加重者行单纯颅后窝、C1、C2减压。结果：128例中全部有小脑扁桃体下疝，合并脊髓空洞96例（75％），颅底凹陷53例（41％），寰枕融合36例（28％），硬膜束带109例（85％），横窦下移50例（39％），枕窦粗大21例（16％），蛛风膜下腔粘连80例（63％），小脑下后动脉下移60例（47％）。手术总有效率92％）。结论：Chiari畸形病变并不仅限于小脑扁桃体下疝，常合并 寰枕区骨质、硬脑膜、蛛网膜、血管、脑室及脑池等结构的异常，手术时应详细了解病变情况，采取不同的方式。     

Acute respiratory failure as a manifestation of an arachnoid cyst

Arachnoid cysts are the most common congenital cystic lesions in the brain occurring in the middle fossa, suprasellar region and occasionally in the posterior fossa. Conventionally all cysts are considered as benign and symptoms are attributed to expansion of cysts causing compression of adjacent neurological structures, bleeds within the cyst or due to the development of acute hydrocephalus. We are reporting this case of a 15-year-old female patient with non-progressive weakness in the limbs since the age of seven years who presented with acute onset syncopal attacks and respiratory failure. She was intubated and ventilated. An magnetic resonance imaging scan showed large posterior fossa cyst extending up to mid second cervical vertebra causing compression of the medulla and pons, with mild hydrocephalus. After a failed attempt to wean her from the ventilator a cysto peritoneal shunt surgery was performed following which she was weaned from the ventilator successfully. Weakness in the upper and lower limbs, which had increased in the preceding month, also improved following the surgery.     

中枢神经系统血管母细胞瘤MRI特点分析

目的 进一步提高对中枢神经系统血管母细胞瘤MRI特点的认识。方法 搜集经手术病理证实的中枢神经系统血管母细胞瘤21例，对其MRI表现进行回顾性分析。结果 血管母细胞瘤常见于后颅窝，发生于椎管内者少见。本组21例23个病灶，大囊小结节型9例，实质型10例，单纯囊型2例。血管母细胞瘤典型表现为大囊、小结节且结节显著异常强化。实质型MRI特征性不强，术前误诊率高达70％，尤其脊髓内实质型，术前MRI正确诊断率仅为20％。结论 MRI是诊断血管母细胞瘤的有效检查方法，MRI增强对于血管母细胞瘤的正确诊断和分型尤为重要。     

A case of foramen magnum syndrome caused by atlanto-occipital assimilation with intracanal fibrosis

We describe a case of foramen magnum syndrome secondary to atlanto-occipital assimilation with spinal-cord compression caused by retro-odontoid fibrous pannus. Association of atlanto-occipital assimilation with the occurrence of severe neurological symptoms resulting from upper spinal cord compression remains rare in the literature. The embryonic process leading to this malformation is discussed. The anatomy and pathogenesis of this syndrome are described.     

Anatomical basis of the extraspinal cord compression

Knowledge of anatomical landmarks of the spinal cord within the vertebral foramen is essential to understand the pathogenesis of spinal cord compression by tumor growth. The spinal cord can spread in the intervertebral foramen, the epidural space, the vertebral body, and the posterior neural arch. The morphology of the spinal cord, the relations of the spinal roots with the vertebrae, the principal fiber tracts, the spinal membranes, and the arterial and venous distribution are described in order to explain and analyze signs and disorders caused by the most frequent tumors involved in spinal cord compression.     

Living with achondroplasia: quality of life evaluation following cervico-medullary decompression

Achondroplasia is the most common of the heritable skeletal dysplasias. Cervico-medullary compression is a frequently encountered and potentially lethal neurological complication. Cervico-medullary decompression (CMD) at the foramen magnum is often employed to relieve the pressure on the emerging cervical cord. Given the inherent risks associated with major surgery, there has been a substantial debate regarding the best criteria for CMD. Our objectives for this study are to explore the quality of life of patients who had undergone CMD, and to assess whether surgery is associated with mortality and increased long-term morbidity. A Medical Outcome Study 36-item Short Form General Health Survey designed to evaluate eight general health concepts as well as achondroplasia-related issues, was administered to patients assessed in the neurosurgery department in Johns Hopkins Hospital between 1977 and 1998. One hundred and sixty-seven patients were eligible for inclusion. Forty-three could not be contacted, and two refused consent. One hundred and twenty-two patients were assessed. Fifty-six (46%) individuals had CMD and 66 (54%) did not. There was 1 case of mortality in the CMD group and 12 cases in the non-CMD group. In the non-CMD group, all deaths, as far as we know, were unrelated to cervico-medullary compression. In this cohort of surviving patients (n = 109), the quality of life of the 55 (50.5%) who had undergone CMD is comparable to that of the 54 (49.5%) who did not have surgery, controlled for age and sex. CMD is indicated for patients with achondroplasia with significant symptomatic foramen magnum compression. It can be life saving. It can abolish profound central apnea that may cause sudden death and alleviate neurological complications associated with damage of the significantly compressed spinal cord. With regards to long-term outcome evaluation, the quality of life of individuals with achondroplasia who had CMD is similar to those age- and sex-matched patients who did not have this surgery. Moreover, CMD, with all its inherent surgical risks, does not appear to be associated with higher mortality or increased long-term morbidity.     

寰枕关节周围韧带的显微断层解剖

目的：揭示寰枕区的显微断层解剖结构,为临床手术提供准确的解剖学数据。方法：选取8具尸体头颅标本制作颅底组织块,并将这些组织块进行塑化,然后切成连续的切片。染色后在光学显微镜下观察。结果：齿突尖主要为骨密质,齿突中下部主要为骨松质。齿突尖韧带是连接齿突尖与枕骨大孔前缘的细小索状纤维束。覆膜是坚韧的薄膜,从枕骨斜坡下降,在十字韧带的上下纵束之后,与枢椎联系紧密。硬脊膜前方为覆膜,后方为蛛网膜。硬脊膜从斜坡开始与覆膜汇合,并向下移行至枕骨大孔前缘最下方的位置分开然后各自继续向下走行,在齿突的位置和覆膜再次汇合,向下走行至枢椎椎体后分离。在齿突尖水平的位置覆膜与前方的后纵韧带汇合。结论：Barkow韧带可能并不存在,临床手术中不能将其作为识别标志。     

Examination of spinal cord in diseases of the craniocervical junction and high cervical spine.

A simple necropsy technique for the removal of the craniocervical junction was devised: a relatively small specimen comprising part of the clivus, the foramen magnum, and cervical vertebral canal is removed in one piece with the medulla and spinal cord inside, and examined systematically after fixation. This method, used in a series of patients with chronic craniocervical instability, allows both good clinicopathological correlations to be made and histological changes in the lower medulla or upper cervical cord segments to be related to sites of extrinsic compression.     

Improvement in ventriculomegaly following cervicomedullary decompressive surgery in children with achondroplasia and foramen magnum stenosis

The role of cervicomedullary decompression (CMD) in the care of hydrocephalic achondroplastic children who present with simultaneous foramen magnum stenosis is not well understood. We sought to determine the percentage of symptomatic achondroplastic children with foramen magnum stenosis who had stabilization or improvement in ventriculomegaly following CMD. The authors retrospectively reviewed the records of pediatric patients at Cedars‐Sinai Medical Center with achondroplasia and signs of progressive ventriculomegaly who underwent CMD for symptomatic foramen magnum stenosis between the years 2000 and 2018. Clinical outcomes included changes in fontanelle characteristics, head circumference (HC) percentile, and incidence of ventriculoperitoneal (VP) shunting. Radiographic outcomes measured included changes in Evans ratio. We excluded individuals who were shunted before CMD from our study. Sixteen children presented with symptomatic foramen magnum stenosis and full anterior fontanelle or jump in the HC percentiles. Two children underwent placement of a VP shunt before decompressive surgery and were excluded from further analysis. Of the remaining 14 children who underwent CMD, 13 (93%) showed softening or flattening of their fontanelles post‐operatively. Ten of these 14 children had both pre‐ and post‐operative HC percentile records available, with 8 showing increasing HC percentiles before surgery. Seven of those eight children (88%) showed a deceleration or stabilization of HC growth velocity following decompression of the foramen magnum. Among 10 children with available pre‐ and post‐operative brain imaging, ventricular size improved in 5 (50%), stabilized in 2 (20%), and slightly increased in 3 (30%) children after decompression. Two children (14%) required a shunt despite decompression of the foramen magnum. A significant proportion of children with concomitant signs of raised intracranial pressure or findings of progressive ventriculomegaly and foramen magnum stenosis may have improvement or stabilization of these findings following CMD. CMD may decrease the need for VP shunting and its associated complications in the select group of hydrocephalic children with achondroplasia presenting with symptomatic foramen magnum stenosis.     

Chiari malformation with thick occipital bone

A case of a Chiari malformation with an extraordinarily thick occipital bone is described. The thick occipital bone might make the posterior fossa narrow with consequent herniation of the cerebellar tonsils to the foramen magnum and formation of a syrinx. At dural plasty, well-developed marginal and occipital sinuses should be deliberately handled with the preservation of normal venous drainage. This case gives us the essence of the occurrence mechanisms of Chiari malformation and foramen magnum decompression.     

Syringomyelia. A neuropathological study of 18 autopsy cases.

Eighteen autopsy cases of syringomyelia were studied neuropathologically. In six cases associated with Chiari II malformation, the central canal was patent from the fourth ventricle to the syrinx, and the syrinx was simply a dilated central canal. In four cases associated with Chiari I malformation, the syrinx was irregularly shaped and communicated with the subarachnoid space at the entry zone of the posterior nerve roots. In six cases associated with spinal cord or posterior fossa tumors, the syrinx was located adjacent to the tumor tissues, and occupied the medullary gray matter or the spinal intermediate zone and the ventral part of the posterior horn. With regard to the pathogenesis of syringomyelia, we concluded that in cases associated with Chiari II malformation, vermian protrusion and direct continuity between the fourth ventricle and the syrinx were essential. In cases associated with Chiari I malformation, in addition to tonsillar protrusion, communication between the syrinx and the subarachnoid space was thought to play an important role, and in cases associated with tumors, the circulatory disturbance due to the presence of the tumors caused the syrinx.