Diastematomyelia in adults modern imaging and operative treatment

Diastematomyelia, an uncommon dysraphic state usually seen in children, is a rarity in adults; only 19 reports have been published in the literature so far. Two cases of diastematomyelia in adults are presented and the relevant literature is reviewed. Both of these were investigated by computed tomography and magnetic resonance imaging. These two procedures are proved to be complementary to each other in understanding this anomaly. Both patients exhibited associated congenital abnormalities of the neuroectoderm in the form of hyperpigmentation, hypertrichosis, lipomatosis, and dermal sinus that were demonstrated with clarity by the neuroimaging modalities used. Operative correction was performed in both patients, where findings correlated very well with the preoperative radiological evaluation.     

脊髓纵裂的CT诊断价值（附17例报告）

１９７８～１９９２年共收治脊髓纵裂３９例，其中１７例术前行ＣＴ检查确诊。ＣＴ特征：椎管中央有纵行骨嵴将脊髓或马尾分隔，多数骨嵴两侧蛛网膜下间隙及脊髓不均称；该部椎管扩大；椎体及附件结构紊乱。ＣＴ不仅能准确诊断损害的平面，而且能显示椎管的自然状态和骨嵴的种类及轮廓。     

Pathogenesis of diastematomyelia: can a surgical model in the chick embryo give some clues about the human malformation?

To reproduce diastematomyelia, a sagittal incision was carried out at the level of the rhomboidal sinus of 36- to 40-h-old chick embryos. A small piece of membrane shell, a small agar screen, or a piece of quail isochronous isotopic notochord was inserted into the gap. The embryos were killed and fixed after 9 days' incubation. Diastematomyelia was obtained in several embryos treated with interposition of a membrane screen or a piece of quail notochord. Microscopic examination revealed two hemicords, each containing its own central canal; in some cases one of the cords showed hydromyelia. Absence of the rump was seen in association with experimental diastematomyelia. The interposition of a resorbable agar screen did not succeed in reproducing diastematomyelia. The results of these surgical manipulations suggest that diastematomyelia cannot be explained by a primary disorder of neurulation. It supports the theory of noninvolution of a firm midline structure (probably the neurenteric canal, rapidly surrounded by mesodermal cells originating from the notochord), which prevents the fusion of the separated parts.     

Computed tomography and spinal dysraphism: Clinical and phantom studies

Summary Two cases illustrating the value of CT in the assessment of spinal dysraphic tissue are presented. In one case, the configuration and origins of two osseous diastematomyelic spurs were shown well; in the second case, the CT recognition of a sacral lipoma led to air myelographic confirmation of the tumor and tethered cord. CT phantom studies indicated that dysraphic tissues, such as fat, cartilage, and fibrous tissue, are better identified and quantitated in the spinal canal when surrounded by air. Varying degrees of image degradation occur with water (simulating CSF) or metrizamide.This work was presented at the XI. Symposium Neuroradiologicum in Wiesbaden, June 1978.     

Magnetic resonance imaging (MRI) of diastematomyelia

Summary The MRI-features of diastematomyelia in a patient with unusually late onset of symptoms are reported. Direct visualization of the split cord and low conus on frontal MR-images was facilitated by three-dimensional Fourier transform (3-DFT) image acquisition.     

Spinal neurenteric cyst. Association with vertebral anomalies, diastematomyelia, dorsal fistula, and lipoma

A 50-year-old man was admitted with complaints of difficulty in walking, urinary incontinence, and a lump over the lumbosacral region. X-ray examination of the lumbosacral spine revealed bizarre vertebral anomalies, including a hole in the L-5 vertebral body. At operation an enterogenous cyst in association with diastematomyelia, cutaneous fistula, and a lipoma was encountered. Post-operatively, some improvement ensued. The case is discussed and pertinent literature reviewed with particular reference to the etiopathology of the cyst.     

小儿脊髓神经管缺陷的MRI诊断价值(附55例报告)

目的:回顾55例小儿脊髓神经管缺陷的MRI表现并复习文献,探讨该病的MRI诊断价值。方法:男33例,女22例,使用1.5T超导MR机行病变区脊柱扫描。结果:脊髓脊膜膨出12例;脊膜膨出1例;脂肪脊髓脊膜膨出9例;终丝脂肪瘤4例;硬膜内脂肪瘤3例;背侧上皮窦12例;原发性脊髓栓系综合征4例;脊髓纵裂4例;神经肠源性囊肿2例;术后复查4例。结论:MRI是诊断该病最有效的无创检查方法,可以清晰显示脊髓栓系、脊髓神经组织粘连及压迫以及脊髓空洞积水,评估脂肪瘤的范围,进行脊髓纵裂分型。     

脊髓纵裂产前超声诊断并文献回顾

目的探讨脊髓纵裂的产前超声图像特征。方法对1例怀疑椎管内肿瘤的胎儿行系统产前超声检查,超声诊断为脊髓纵裂,总结胎儿脊髓纵裂产前超声诊断特点,与引产后胎儿的高频超声、X线、MRI及病理解剖进行对比研究,并对脊髓纵裂产前诊断相关文献回顾分析。结果本例脊髓纵裂发生于胸6～9水平,椎管内可见圆形高回声占位病变,脊髓受压分成两半,于远端汇合,相应的椎弓骨化中心明显增宽。脐血染色体核型正常。本例终止妊娠后,标本行产后超声、X线照片、MRI检查及病理解剖,证实产前超声诊断。结论脊髓纵裂有特征性超声表现,产前超声可作出诊断。     

Excision and short segment fusion of a double ipsilateral lumbar hemivertebrae associated with a diastematomyelia and fixed pelvic obliquity

We report the surgical treatment course of a 4-year-old girl with congenital scoliosis, diastematomyelia and double adjacent hemivertebrae. She had a lumbar curve with an apparent pelvic obliquity. Simultaneous excision of double segmented sequential hemivertebra at the L3–L4 level and fusion with short-segment instrumentation was performed via a posterior approach. Intraoperative radiographs revealed satisfactory curve correction and 0° pelvic obliquity. Following the excision of double adjacent hemivertebrae, three adjacent nerve roots were placed in one intervertebral foramen bilaterally. Nevertheless, no neurological deficit was developed, and the patient was able to ambulate with a brace at day one. Pelvic balance and deformity correction were maintained with no implant failure at the fifth year follow-up. Excision of two ipsilateral adjacent hemivertebra and short-segment posterior fusion performed via posterior-only approach simultaneously is an effective, safe, and less invasive technique for the treatment of the described case.     

儿童脊髓纵裂Ⅰ型与Ⅱ型的疗效对比分析

目的 评价Ⅰ型和Ⅱ型儿童脊髓纵裂的显微外科手术疗效.方法 清华大学玉泉医院自2004年1月至2011年1月收治并有效随访的191例脊髓纵裂患儿纳入本研究.根据Pang分型标准分为Ⅰ型(75例)和Ⅱ型(116例),术前均行神经系统检查、膀胱残余尿、神经电生理检查、MRI检查以及CT检查,术中在电生理监测下行显微外科手术治疗.手术后进行神经系统检查、尿动力学、神经电生理及MRI等检查.根据临床症状、膀胱残余尿、MRI检查和神经电生理等结果对比评定Ⅰ型和Ⅱ型的疗效.结果 Ⅰ型组75例患儿中,术后疗效优(痊愈)1例,良(显效)30例,可(有效)40例,差(无效)4例,总有效率94.6％.Ⅱ型组116例患儿中,术后疗效优(痊愈)28例,良(显效)49例,可(有效)36例,差(无效)3例,总有效率97.4％.Ⅰ型组和Ⅱ型组膀胱残余尿减少的患者比例差异有统计学意义(57.3％ vs.70.7％,P＜0.05);MRI检查在Ⅰ型组和Ⅱ型组间均未发现纵裂复发病例;Ⅰ型组和Ⅱ型组神经电生理改善的患者比例的差异有统计学意义(P＜0.05).结论 显微外科手术治疗儿童脊髓纵裂可获得较好的疗效,Ⅱ型的疗效优于Ⅰ型.