Retinoic acid downregulates microRNAs to induce abnormal development of spinal cord in spina bifida rat model

Objects MicroRNAs have been found in the developing central nervous system, but little is known about their functions in development, especially in the abnormal development of spinal cord in spina bifida. To this end, we have studied the mechanism of microRNAs involved in the morphogenesis of the spinal cord in all-trans-retinoic acid (RA)-treated spina bifida rat fetus. Materials and methods Timed-pregnant rats were gavage-fed RA, and embryos were obtained on 13.5, 15.5, 17.5, and 19.5 days. MicroRNAs’ expression profile was analyzed by Northern blot. In situ apoptosis detection and microRNA in situ hybridization methods on sections of paraffin-embedded tissues were employed to explore the mechanism. Conclusion Administration of RA reduced the size of the spinal cord, probably as a consequence of increased cell death. There is a dramatic decrease in the expression of miR-9/9*, miR-124a and miR-125b, and Bcl2 and P53 as well in the sacral cord from E13.5 to E19.5 days post coitum. Our data showed that expression of these microRNAs was dysregulated in RA-treated spinal cord during embryonic development, suggesting that they may be involved in the development of the spinal cord.     

Magnetic resonance imaging in patients with multiple sclerosis and spinal cord involvement: 28 cases

In patients with clinically isolated spinal disease, magnetic resonance imaging (MRI) provides a non-invasive method of detecting surgically treatable causes and is also useful in detecting asymptomatic brain lesions where the cord syndrome is due to multiple sclerosis (MS). We report the findings of spinal and brain MRI in 28 patients with spinal cord disorder due to MS. It was possible to detect intrinsic plaques reliably in the majority of patients (60.7%) with clinical findings of spinal cord MS. The results of MRI are compared with the clinical status and with cerebrospinal fluid findings and evoked potentials.     

Intramedullary spinal teratoma with spina bifida

Spinal intramedullary teratoma is a rare tumor. We report a case of intramedullary teratoma of the conus medullaris with spina bifida. A 5-year-old boy was admitted to our hospital for removal of a lumbosacral tumor sited in an intramedullary location at the conus medullaris, which was totally resected with neuroendoscopic assistance. The pathological diagnosis was mature teratoma consisting of three germ cell layers. The pathogenesis of spinal intramedullary teratoma is discussed with special reference to spina bifida. Received: 21 July 1999 Revised: 21 December 1999     

Simultaneous functional magnetic resonance imaging in the rat spinal cord and brain

Functional magnetic resonance imaging (fMRI) method was developed to investigate the pattern and temporal relationship in neuronal pathways of brain and spinal cord. Signal intensity changes correlating with stimulation patterns were observed simultaneously in the rat spinal cord and brain using fMRI at 9.4 T. Electrical stimulation of the forepaw was used to elicit activity. A quadrature volume RF coil covering both brain and the cervical spinal cord was used. Sets of fast spin echo (FSE) images were acquire simultaneously for both brain and spinal cord fMRI. Experiments were repeated in single animal and across animals. Activities within the dorsal horn of the spinal cord and within the somatosensory cortex were observed consistently within each animal as well as across animals.     

Lordotic alignment and posterior migration of the spinal cord following en bloc open-door laminoplasty for cervical myelopathy: A magnetic resonance imaging study

We investigated lordotic alignment and posterior migration of the spinal cord following en bloc open-door laminoplasty for cervical myelopathy. Fifty-five patients (32 men and 23 women) were studied, with an average follow-up of 2.4 years. Radiological examination included evaluation of lordosis of the cervical spine and spinal cord, degree of enlargement of bony spinal canal, and the magnitude of posterior cord migration. We also correlated these changes with neurological improvement. Postoperatively, there was an average of 5% loss of cervical spine lordosis (P > 0.01) on radiographs and 12% reduction in the lordotic alignment of the spinal cord (P > 0.05) on magnetic resonance imaging. Postoperatively, the size of the bony spinal canal increased by 48%. Posterior cord migration showed a significant correlation with the preoperative cervical spine and spinal cord lordosis (P < 0.05). Thirty-seven (67%) patients with neurological improvement exceeding 50% showed significant posterior cord migration following laminoplasty compared with those demonstrating less than 50% improvement (P = 0.01). Our results suggest that a significant neurological improvement is associated with posterior cord migration after cervical laminoplasty.     

脊髓转移瘤的MRI诊断

目的 探讨脊髓转移瘤(ISCM)的MRI特征及其病理机制,以提高对该病的认识.方法 搜集15例经手术病理证实及临床确诊的ISCM,回顾性分析其MRI表现.全部病例均行MRI平扫及钆喷替酸葡甲胺(Gd-DTPA)增强扫描.结果 15例转移瘤均为单发,位于颈髓3例,胸髓5例,胸腰段脊髓圆锥部7例.MRI表现:T1WI呈等信号12例,低信号3例;T2WI呈高信号14例.等信号1例;增强扫描肿瘤均呈明显强化,7例呈环形强化,4例结节状强化,4例不均匀强化.结论 ISCM的特征性MRI表现为脊髓内明显强化的环形或结节状病灶,结合临床病史可以明确诊断.     

The prediction of postoperative hydrocephalus in patients with spina bifida

Object The object was to derive a prediction rule for the development of postoperative hydrocephalus in patients with spina bifida by the measurement of cranial ventricular diameters using ultrasound.Methods Eighty-nine patients with spina bifida were studied prospectively. Each child had preoperative cranial ultrasound with measurement of the bifrontal diameter, bicaudate diameter and maximum transverse diameter of the body of the lateral ventricle by a single blinded observer. Repair of meningomyelocele was then undertaken and the patients followed up for development or progression of hydrocephalus. Logistic regression analysis determined the lowest values of the three cranial ventricular diameters associated with the maximum sensitivity and specificity for predicting postoperative hydrocephalus. These values were—bifrontal diameter >26 mm, bicaudate diameter >20 mm and body of lateral ventricle diameter >26 mm.Conclusions It is possible to predict the development of postoperative hydrocephalus in patients with spina bifida by measuring cranial ventricular dimensions using preoperative ultrasound.     

High resolution nuclear magnetic resonance imaging of the spinal cord in experimental demyelinating disease

Summary Chronic recurrent experimental allergic encephalomyelitis was induced in a strain 13 guinea pig by inoculation of isologous spinal cord homogenate. The spinal cord was obtained after perfusion with 4% paraformaldehyde and examined with nuclear magnetic resonance (NMR) imaging. Proton NMR spin echo images (repetition time: 3 s; echo times: 20 and 60 ms) were obtained from intact, isolated spinal cord in a 4.7 Tesla, 50 mm bore magnet. The slice thickness of the images was 380 m and the inplane resolution was 40×40 m. The images showed superficial areas of low signal intensity in the lateroventral regions of the white matter, in some instances with a seam of higher signal intensity. Neuropathologically, these abnormalities corresponded exactly to areas of demyelination. Control images did not show these abnormalities. The present high resolution imaging allowed a correlation between demyelination and abnormal NMR signals in a small laboratory animal with an inflammatory demyelinating disease.Supported by the Belgian Foundation of Medical Scientific Research (FGWO, grant 3.0096.86 and grant 3.0019.86), by the Institute for the promotion of Scientific Research in Industry and Agriculture (IWONL) and by the Scientic Research Planning Office of the Belgian Government (DPWB), contract no. 87/92-120     

Magnetic resonance evaluation of spinal dysraphism in children

Magnetic resonance (MR) imaging of the spine was performed as the initial imaging technique in 20 children when spinal dysraphism was suspected clinically and plain radiographs showed spina bifida. The correlation with surgical findings indicated that MR provided accurate information preoperatively in all the cases. Some unusual observations in cases with spina bifida cystica and occulta are discussed. It is concluded that plain radiograph and MR complete the preoperative radiologic evaluation of cases with spinal dysraphism.     

Functional outcome in young adults with spina bifida and hydrocephalus

Introduction Quality of life was studied in 31 adult survivors of spina bifida, each with Verbal or Performance IQ score over 70.Methods Instruments measured physical and occupational function, cognitive/psychological function, somatic sensation, and social interaction in the context of the ability to live independently.Results Domain group means except motor independence were in the average range (±1 standard deviation). Variability within the group with respect to physical phenotype (high spinal lesions were associated with poorer motor independence) and medical history [a greater number of shunt revisions (>4) were associated with poorer functional numeracy] was predictive of quality of life. Both spinal lesion level and number of shunt revisions influenced occupational status.Discussion There was a relation between everyday mathematics, reading skills, and quality of life. The consequences of the physical, medical, and cognitive effects of spina bifida extend into young adulthood and have an impact on quality of life.     

Imaging of the spine and spinal cord: An overview of magnetic resonance imaging (MRI) techniques

This review will discuss conventional and advanced magnetic resonance (MRI) imaging techniques used to study the spine and spinal cord according to the anatomical structures and clinical indications. Clinical challenges that neuroradiologists may face are also discussed, such as the “when” and “where” concerning the use of each technique, and in which pathology or clinical scenario each technique is useful. Finally, some “tips and tricks” to overcome the challenges are provided with clinical examples.     

Idiopathic spinal cord herniation through the inner layer of duplicated anterior dura: Evaluation with high-resolution 3D MRI

We report a case of idiopathic spinal cord herniation through the inner layer of duplicated anterior dura. High-resolution three-dimensional (3D) MRIs clearly depicted the duplicated dura mater ventral to the spinal cord and herniation of the cord through the inner layer of dura mater, which was confirmed at surgery. Presurgical high-resolution 3D MRI thus enables precise determination of the site of cord herniation in patients with this condition.     

Medical complication in adults with spina bifida

Setting

Cohort study.

Introduction

Spina bifida (SB) is a congenital malformation affecting the central nervous system (CNS) and is one of the most prevalent CNS disorders in children. Hydrocephalus (HC) is present in 80% of newborns with SB. The aim of the present study was to analyze the medical complications and to relate the complications to age at examination, the level of injury, AIS grade and presence of HC in adults with SB.

Materials and methods

SB patients were recruited from the Spinalis out-patient clinic at the Karolinska University Hospital at their annual follow-up. The patients underwent a thorough general and neurological examination and background data including medical complications were retrieved from the medical files.

Results

127 of 157 (82%) SB patients (114 with MMC and 13 SB occulta) with a mean age of 34 years were included. Half of the patients had a complete SCI and a lumbar level was most common. Nearly 60% of the patients had HC. 88 patients (69%) suffered from at least one medical complication. Urinary tract infection (UTI), scoliosis and pain were the most common complications found in 46%, 30% and 28% of the patients, respectively. Less common complications were epilepsy, pressure ulcers (PU) and spasticity.

Discussion

SB gives a disability including motor, sensory dysfunctions and the patients suffer from a high frequency of medical complications like UTI, scoliosis, pain, and epilepsy. Data gives basis for adequate routines for medical examination at the follow-up.     

脊髓型多发性硬化临床诊断分析

目的 总结分析脊髓型多发性硬化(MS)的临床特点和MRI表现.方法 回顾性分析21例脊髓型MS的临床特点和MRI表现,所有患者行脊髓和颅脑MRI检查.结果 脊髓型MS除有脊髓病变的临床表现外,临床症状和体征的多样性是其特点,如感觉障碍、肢体无力、视力障碍等;脊髓内病灶的MRI特点是不规则斑片状和条带状异常信号,位于脊髓两侧和后部,在T:WI像上为高或稍高信号,在T1WI上为等信号或稍低信号;80.9%(17/21)脊髓型MS合并脑内病灶.结论 脊髓型MS临床表现呈多样性,MRI可以准确显示脊髓内病灶,颅脑MRI检查有助于脊髓型MS的诊断.     

Endogenous recovery of injured spinal cord: longitudinal in vivo magnetic resonance imaging

Pathological changes were followed longitudinally with in vivo magnetic resonance imaging (MRI) and behavioral studies in experimental spinal cord injury (SCI). MRI-observed pathology was correlated with histology. On MRI, the cavitated regions of the injured cord were gradually filled with viable tissue between two and 8 weeks postinjury, and a concomitant improvement was observed in the neurobehavioral scores. By weeks 3-6, on MRI, the gray matter (GM) returned in the segments caudal, but not rostral, to the injury site. The corresponding histological sections revealed motor neurons as well as other nuclei in the gray matter immediately caudal to the epicenter, but not at the site of injury, suggesting neuronal recovery in perilesioned areas. The neuronal and neurological recovery appeared to occur about the same time as neovasculature that was reported on the contrast-enhanced MRI, suggesting a role for angiogenesis in recovery from SCI. The role of angiogenesis in neuronal recovery is further supported by the immunohistochemical observation of greater bromodeoxyuridine uptake by blood vessels near the lesion site compared with uninjured cords.     

Enterogenous cyst in the thoracic spinal canal in association with a syringomeningomyelocele

A thoracic intradural extramedullary enterogenous cyst in association with a syringomeningomyelocele in a 5-year-old boy is presented. The pathogenesis of this rate association is discussed and the pertinen literature reviewed.     

Heterogeneity of muscle fat infiltration in children with spina bifida

Children with spina bifida have well recognized functional deficits of muscle, but little is known about the associated changes in muscle anatomy and composition. This study used water-fat magnetic resonance imaging (MRI) to measure fat infiltration in the lower extremity muscles of 11 children with myelomeningocele, the most severe form of spina bifida. MRI measurements of muscle fat fraction (FF) were compared against manual muscle test (MMT) scores for muscle strength. The FF measurements were objective and reliable with mean inter-rater differences of <2% and intraclass correlation coefficients > 0.98. There was a significant inverse relationship between muscle FF and MMT scores (P ≤ 0.001). Surprisingly, however, muscles with negligible strength (MMT 0–1) exhibited a bimodal distribution of FF with one group having FF > 70% and another group having FF < 20%. The MRI also revealed striking heterogeneity amongst individual muscles in the same muscle group (e.g., 4% fat in one participant's lateral gastrocnemius vs. 88% in her medial gastrocnemius), as well as significant asymmetry in FF in one participant with asymmetric strength and sensation. These results suggest that quantitative water-fat MRI may serve as a biomarker for muscle degeneration which may reveal subclinical changes useful for predicting functional potential and prognosis.     

多发性硬化患者颈髓扩散张量成像研究

目的 通过扩散张量成像研究多发性硬化患者常规MRI表现正常脊髓(NASC)的改变,并探讨其临床应用价值.方法 采用平面回波成像技术对13 例多发性硬化患者和13 例健康志愿者施行颈髓扩散张量成像检查,分别测量第2 ~ 5 颈椎(C2 ~ 5)水平前索、后索、侧索及灰质兴趣区的部分各向异性(FA)值及平均扩散率(MD)值,比较两组之间所存在的差异性;相关分析检验多发性硬化组患者FA值和MD 值与扩展残疾状态量表(EDSS)评分之间的关系.结果 与正常对照组相比,多发性硬化组患者C2 ~ 5 前索、侧索、后索和灰质NASC 的FA 值降低、MD 值升高(均P < 0.05);相关分析显示,FA 值与EDSS 评分呈负相关(r = - 0.328 ~ - 0.207,P = 0.001 ~ 0.035),各兴趣区MD 值与EDSS 评分呈正相关(r =0.234 ~ 0.409,P = 0.000 ~ 0.018).结论 多发性硬化患者常规MRI 表现比正常脊髓的FA 值降低,提示存在隐匿性病变.脊髓扩散张量成像对多发性硬化患者临床评价和疗效判断有一定应用价值.     

Embryogenesis Why do we need a new explanation for the emergence of spina bifida with lipoma?

Spina bifida with lipoma is a human malformation that most often affects the lumbosacral area. It is a complex morphological type. Its origin is controversial, and none of the previous hypotheses can be retained in view of the most recent advances in experimental embryogenesis. Contrary to earlier opinons, adipocytes cannot arise from meninges, vessels or glial cells and spina bifida cannot be explained by incarceration of mesodermal tissues during primary neurulation or developmental defect at the level of the tail bud. Spina bifida with lipoma, which actually involves all the derivatives of the so-called dorsal mesoderm, must therefore result from abnormal development of this mesoderm, which is induced by the dorsal neural tube. The location of the primary defect (dorsal mesoderm or neural tube) remains to be established. Received: 25 November 1996     

抑郁症患者脑的磁共振研究

目的;采用磁共振技术（MRI）分析抑郁症患者的脑结构改变。方法：以抑郁症患者32例为病例组,正常23例为对照组,作头颅磁共振扫描。结果：病例组第3脑室横径,双侧外侧裂宽度显著增宽,透明中隔至额极距离减少。结论：抑郁症患者额、颞叶均明显萎缩。