1/25. An unusual case of dorsally situated bony spur in a lumbar split cord malformation.A case of lumbar split cord malformation (SCM) with a bony spur situated dorsally is presented. This was associated with a hypertrophied posterior arch. The ventral dura was totally intact, and there was no fibrous septum connecting the bony arch to the dura. To our knowledge, such a case has not been reported earlier. In view of this unique finding, we propose a slight modification in Pang's unified theory of embryogenesis in the development of SCM.- - - - - - - - - - ranking = 1keywords = embryo (Clic here for more details about this article) |
2/25. The detection of spina bifida before 10 gestational weeks using two- and three-dimensional ultrasound.We present three cases of spina bifida during the embryonic period detected by ultrasound before 10 weeks' gestational age. The last-menstrual-period-based ages ranged from 9 weeks 1 day to 9 weeks 4 days and the crown rump lengths ranged from 22 mm to 28 mm. The cases were identified prospectively in a program of targeted ultrasound examination of high-risk pregnancies, using a 7.5 MHz annular array transvaginal transducer. The use of 3D ultrasound made additional diagnostic ultrasound tomograms possible, but was not necessary for the definite diagnosis. The scalloping of the frontal bones and the Arnold Chiari malformation did not occur before 12 weeks.- - - - - - - - - - ranking = 1keywords = embryo (Clic here for more details about this article) |
3/25. spinal dysraphism associated with congenital heart disorder in a girl with MELAS syndrome and point mutation at mitochondrial dna nucleotide 3271.We describe a case of mitochondrial encephalopathy, lactacidosis, and stroke-like episode (melas syndrome) associated with ventricular septal defect and meningocele at the L3 level in a 5-year-old girl. Mitochondrial dna analysis showed point mutation at nucleotide 3271--> TC. The occurrence of heart and neural tube defects in association with usual features of the melas syndrome might be explained by either defective high-energy metabolism during early embryogenesis or a common genetic cause.- - - - - - - - - - ranking = 1keywords = embryo (Clic here for more details about this article) |
4/25. Embryonic hydromyelia: cystic dilatation of the lumbosacral neural tube in human embryos.In a large collection of human embryos (the Kyoto Collection of Human Embryos, Kyoto University), we encountered five cases with abnormal dilatation of the neural tube at the lumbosacral level. In these examples, the central canal was enlarged, and the roof plate of the neural tube was extremely thin and expanded. The mesenchymal tissue was scarce or lacking between the roof plate and the surface ectoderm. This type of anomaly was assumed to be formed after neural tube closure and may be an early form of spina bifida. In two of the cases, some abnormal cells were found ectopically between the thin roof plate and the surface ectoderm. Morphologically, these cells resembled those forming spinal ganglia and could be of the neural crest origin. Since neural crest cells are pluripotent and can differentiate into a variety of tissues, such ectopic cells might undergo abnormal differentiation into teratomatous tumors and/or lipomas, which are frequently associated with spina bifida. We also discuss the definition of spina bifida and the classification of neural tube defects from the embryological and pathogenic viewpoints and propose a new classification of neural tube defects.- - - - - - - - - - ranking = 6keywords = embryo (Clic here for more details about this article) |
5/25. Dorsal bony septum: a split cord malformation variant.Split cord malformations (SCMs) are rare spinal anomalies and their classification is still a matter of debate. There is no widespread consensus on the embryological basis of this entity. The unified theory, proposed by Pang et al. [neurosurgery 1992;31:451-480], was an attempt to explain the embryogenetic mechanism as a basic error occurring around the time when the primitive neuroenteric canal closes. We report two unusual cases of SCMs with a dorsally situated bony spur. We analyzed the radiological, clinical and surgical features of the lesions and were not able to classify these cases according to the unified theory. Further embryological studies should be conducted to elucidate the mechanisms of occurrence of these lesions, and the dorsal bony septum variant should be considered in SCM surgery.- - - - - - - - - - ranking = 3keywords = embryo (Clic here for more details about this article) |
6/25. Multiple subpial lipomas with dumb-bell extradural extension through the intervertebral foramen without spinal dysraphism.BACKGROUND: Intradural subpial lipomas not associated with spinal dysraphism, account for less than 1% of spinal cord tumors. The simultaneous existence of multiple intradural subpial lipomas with dumb-bell extradural extension through the intervertebral foramen in the same patient without any evidence of spinal dysraphism has not been previously reported. CASE DESCRIPTION: A 38-year-old man presented with progressive spastic paraparesis, and weakness of right elbow extension and opposition of the medial three fingers. He also had ascending paraesthesia from the C6 dermatome to the saddle region and loss of joint and position sense of both lower limbs with hesitancy and precipitancy of micturition. There was no spinal tenderness, deformity, neurocutaneous markers, or spinal dysraphism. The total duration of illness was 11 years.The oblique views of the plain radiographs of the cervical spine revealed an enlarged right C7-D1 intervertebral foramen. The T1- and T2-weighted magnetic resonance (MR) images showed two intradural, hyperintense lesions (with extensive loss of signal on fat suppression sequences), one extending from C5 to D2 and the other opposite the C3-4 disc space. The parasagittal and axial images showed the extradural component of the lesion emerging from the right C7-D1 intervertebral foramen.At surgery, a C2 to D2 laminectomy was performed. The lipoma, enclosed in a fine pial membrane, was situated on the right posterolateral aspect of the cord. The right-sided nerve roots from the C6 to D1 levels were completely enmeshed by the lipoma. There was a separate superficial subpial lipoma adherent to the posterior aspect of the cord at the C3-4 level. A distinct area of normal cord was present between the two lesions. A subtotal decompression of the lesions including the component emerging through the right C7-D1 intervertebral foramen and a duraplasty were performed.At follow-up after 18 months, the posterior column impairment, lower limb hypoaesthesia, and right upper limb paraesthesia had improved. However, residual elbow extension and lower limb weakness, mild lower limb spasticity and sphincteric dysfunction persisted. CONCLUSIONS: The multiplicity of intradural subpial lipomas without spinal dysraphism points to a dysembryogenetic basis similar to that seen in patients with spinal dysraphism that results in lipomas, but in which the defect is not severe enough to give rise to coexisting vertebral and soft tissue anomalies. The dumb-bell extradural extension through the intervertebral foramen is extremely rare. The magnetic resonance imaging and surgical principles are discussed.- - - - - - - - - - ranking = 1keywords = embryo (Clic here for more details about this article) |
7/25. Multiple coexistent dysraphic pathologies.INTRODUCTION: Four distinct dysraphic anomalies were observed in a single child. While combinations of such anomalies are well recognised, quadruple dysraphic pathology, nevertheless, is extremely uncommon. To our knowledge, no previous cases have been reported in the literature. CASE REPORT: We present the management of a child with a concurrent segmental meningocele, a type-1 split cord malformation (SCM) associated with hemivertebrae, lipomyelomeningoceles in each hemicord of the SCM and a terminal myelocystocele, and we review the literature on potential mechanisms of dysmorphogenesis. DISCUSSION: Existing embryologic hypotheses for the dysraphic spectrum lack experimental evidence and studies in animal models. This case challenges the existing hypotheses and illustrates our incomplete understanding of human terminal spinal cord embryogenesis. Further studies on the morphogenetic basis for these anomalies are required.- - - - - - - - - - ranking = 2keywords = embryo (Clic here for more details about this article) |
8/25. Caudal duplication syndrome: more evidence for theory of caudal twinning.Caudal duplication syndrome is a rare entity in which structures derived from the embryonic cloaca and notochord are duplicated to various extents. The term encompasses a spectrum and often is quoted as one type of incomplete separation of monovular twins. The authors present more evidence giving credence to caudal twining as the mechanism behind the syndrome. The authors report successful surgical management of a full-term infant with a constellation of anomalies of caudal duplication syndrome.- - - - - - - - - - ranking = 1keywords = embryo (Clic here for more details about this article) |
9/25. adult complex spinal dysraphism with situs inversus totalis: a rare association and review.STUDY DESIGN: First published report of an adult complex spinal dysraphism with situs inversus. OBJECTIVES: To describe a previously asymptomatic adult patient of multiple vertebral anomalies with cervical split cord malformation type II, tethering of the spinal cord (cervical and lumbar), and intraspinal arachnoid cyst along with dextrocardia and situs inversus. SUMMARY OF BACKGROUND DATA: Only 5 cases (fetus, 1; neonates, 3; child, 1) of spinal dysraphism with dextrocardia or situs inversus have been reported. All these cases have had associated multiorgan developmental anomalies usually incompatible with survival and requiring multidisciplinary care. methods: The case has been described and relevant literature reviewed. RESULTS: The patient was operated for cervical and lumbar levels in the same sitting. A C4-C5 laminectomy was performed, 2 hemicords enclosed in the same dural sac were visualized, dorsal paramedian nerve roots and the tethering arachnoid bands were cut, and the arachnoid cyst wall was partially excised. This was followed by L4-L5 laminectomy and detethering by sectioning of the thickened filum terminale. The patient showed significant neurologic improvement after surgery. CONCLUSIONS: The present case is a rare instance in which there has been an association of adult onset occult spinal dysraphism along with situs inversus totalis. Successful management requires appropriate understanding of embryology, anatomy, and imaging and has implications in neurosurgical and perioperative anesthetic care.- - - - - - - - - - ranking = 1keywords = embryo (Clic here for more details about this article) |
10/25. The NAT1 C1095A polymorphism, maternal multivitamin use and smoking, and the risk of spina bifida.BACKGROUND: The risk of having a child with a neural tube defect (NTD) can be reduced by maternal, periconceptional supplementation with folic acid, but the underlying folate-dependent protective mechanism remains unclear. N-acetyltransferase 1 is involved in acetylation of aromatic and heterocyclic amines and the catabolism of folates. Hence, functional polymorphisms in NAT1, the gene encoding N-acetyltransferase 1, are plausible risk factors for NTDs. Such variants could exert an influence on the risk of NTDs via their role in acetylation or folate catabolism and could act through the maternal or the embryonic genotype. methods: NAT1 C1095A genotypes and information on maternal, periconceptional multivitamin use and smoking were obtained as part of a family-based study of spina bifida. Associations between spina bifida and the embryonic and maternal NAT1 C1095A genotypes, and potential NAT1 C1095A genotype-exposure interactions were evaluated using log-linear modeling. RESULTS: The analyses provided no evidence that the embryonic or maternal NAT1 C1095 genotypes influence the risk of spina bifida independently, or through interactions with maternal use of multivitamins. There was evidence that the embryonic, and possibly the maternal, NAT1 C1095A genotype influence the risk of spina bifida via interactions with maternal smoking status. CONCLUSIONS: The genotype for the NAT1 C1095A polymorphism does not appear to be an independent risk factor for spina bifida. However, the results of these analyses provide preliminary evidence that this polymorphism may be associated with the risk of spina bifida in the offspring of women who smoke during early pregnancy.- - - - - - - - - - ranking = 4keywords = embryo (Clic here for more details about this article) |
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