Segmental Spinal Dysgenesis-"Redefined"

Segmental spinal dysgenesis: insights from three consecutive cases and a review of the literature

OBJECTIVE

Segmental spinal dysgenesis (SSD) is a rare congenital spinal abnormality affecting the thoracic and lumbar region of the spine, as well as the spinal cord of neonates and infants. The purpose of the study was to analyze our institution's surgical case series to provide insights into our best practices to contribute to SSD management principles, while conducting a comprehensive literature review.

METHODS

Following institutional review board approval, a retrospective review of SSD surgical cases was examined to observe clinical findings, radiographic findings, management, surgical intervention, and outcomes. Keywords in the comprehensive literature review included SSD, congenital spinal dysgenesis, congenital spinal stenosis, spinal aplasia, and surgery.

RESULTS

Three cases underwent successful surgical management with either improvement or maintenance of neurological baseline. Patients were diagnosed at an average age of 2.7 months, while surgical intervention averaged at 40.3 months with fecal incontinence, neurogenic bladders, spinal cord compression, clubfoot, and concerns for worsening spinal deformity as surgical indicators. The average time for follow-up was 33.7 months and no complications were reported.

CONCLUSIONS

Operative management for SSD is a clinically complex decision that requires multidisciplinary input and care. Patients should be observed at neurological baseline and receive intervention at the appropriate time to allow sufficient growth for functioning without permitting drastic disease progression. Consideration of patient size and spinal instrumentation are significant towards surgical success.

Cervicothoracic dislocation due to congenital and bone-dysplasia-related vertebral malformations

PURPOSE

To evaluate the approaches to treatment of congenital and bone-dysplasia-related pediatric cervicothoracic dislocations and define the optimal treatment method.

METHODS

The publications available in PubMed and Google Scholar data bases were selected following such criteria as the disease in question, pediatric age, the treatment description, and follow-up results. The paper also includes the descriptions of our own six cases of the cervicothoracic dislocations detected in children with different vertebral malformations.

RESULTS

Only eight patients meeting the abovementioned selection criteria were found in the publications: three of them had the Klippel-Feil syndrome (KFS), two had one-level vertebral anomaly, one had neurofibromatosis (NF type 1), one had the Larsen syndrome, and one had a variation of VACTERL association. Their treatment was long term, multi stage, and complicated. Among six our own cases, four patients also had KFS, one had a variation of VACTERL association, and one had NF type 1. All the patients suffered from preoperative neurological disorders. Posterior instrumental fixation with posterior vertebral body resection was performed in four cases and one patient underwent a combined surgery. The parents of one of the patients refused the operation, so he was observed while receiving bracing treatment. Since the treatment was long term and complicated by reoperations, the average follow-up period comprised 5 years.

CONCLUSION

Congenital cervicothoracic dislocations are an extremely rare pathology that manifests itself in early age and requires an early surgical treatment. Failure to provide the treatment leads to the patient's disability. The surgical tactics for such patients is determined individually, but the published data and our own experience demonstrate that early multi-stage combined treatment has been the best option available so far. The cervicothoracic dislocations due to NF 1 manifest later and have a more favorable forecast.

Severe type of segmental spinal dysgenesis with complete disconnection of the spinal cord and vertebra associated with open neural tube defect

Background

Severe type of segmental spinal dysgenesis (SSD) is a rare and complex anomaly in which the spinal cord completely disconnects at the portion of the spinal dysgenesis. Although closed spinal dysraphisms have been associated with SSD, to the best of our knowledge, the association between open neural tube defect (ONTD) and SSD is significantly rare, with only one case being reported to date.

Case Description

We report a case of an infant with severe SSD and a disconnected spinal cord and spinal column at the thoracolumbar junction associated with myelomeningocele (MMC) in the lumbosacral region. The patient presented severe neurological deficits in the legs and impaired bowel function. The spinal column of L1-L3 was absent. The lower spinal segment consisted of neural placode at the L5-S1 level and no connecting structure between the upper and lower spinal cords. A repair surgery for MMC, including cord untethering and dura plasty, was performed. Histopathological findings revealed a neural placode consisting of a neuroglial tissue and leptomeninges.

Conclusion

The management of severe SSD during the perinatal period is more challenging when it is associated with ONTD. We report detailed neuroradiological, intraoperative, and histological findings of such a case and discuss the embryopathogenesis of the associated ONTD and the treatment strategies.

Spinal Dysraphisms: A New Anatomical–Clinicoradiological Classification

Background Spinal dysraphisms refer to the congenital abnormalities of the spine and spinal cord due to aberrations in the processes of gastrulation, primary neurulation, and secondary neurulation. Embryology of many complex spinal dysraphisms are yet poorly understood and there is no agreeable anatomical–clinicoradiological classification with inclusion of recently documented and complex spinal dysraphisms.

Aims and Objectives The main objective of this study was to review the imaging features of spinal dysraphisms with a better understanding of embryological abnormalities and propose a new classification inclusive of all complex and unusual dysraphisms based on anatomical and clinicoradiological correlation.

Materials and Methods This was a retrospective single institutional observational study of 391 cases of spinal dysraphism for 10 years in our institution. Of 391 cases included in the study, 204 were males and 187 were females. Also, 123 cases belonged to the 0–6 months age group, 38 cases belonged to the 7–12 months age group, 156 belonged to the 1–5 years age group, 39 cases belonged to the 6–10 years age group, and 35 cases belonged to 10–20 years age group.

Results An anatomical–clinicoradiological analysis of cases yielded a high proportion of cases of spinal lipomas, including lipomyeloceles and lipomyelomeningoceles (31.3%) and posterior myelomeningocele (14.2%). Anterior myelocoele (0.2%), sacral chordoma(0.2%), and intrasacral meningocele (0.2%) formed the least proportion of cases. A new classification was proposed based on the analysis of acquired data.

Conclusion A structured approach in imaging spinal dysraphism is necessary for imaging evaluation in recent years. The proposed new classification based on clinicoradiological correlation and anatomic location is inclusive of unusual and complex dysraphisms.

An Unusual Case of a Conus Hanging by a Thread

We report a rare cause of paraparesis in a 2-year-old girl. Along with lower limb weakness, she presented with a neurogenic bladder and lower limb deformities. Her magnetic resonance imaging showed multiple dorsolumbar segmentation defects and a dysgenetic spinal cord segment between T10 and S1. A thin septum connected the lower end of the normal cord to a bulky conus at S1-2. These features were suggestive of type 1 segmental spinal dysgenesis. The findings were confirmed at surgery, and the child was referred for supportive care.

Surgical treatment of segmental spinal dysgenesis: a report of 19 cases

STUDY DESIGN

Retrospective review.

OBJECTIVE

To describe clinical presentation, surgical management, long-term results, and complications in patients with segmental spinal dysgenesis (SSD). In addition, we sought to emphasize early surgery for this complex congenital abnormality. SSD is a rare congenital malformation characterized by focal stenosis, spinal subluxation, kyphosis, and absence of the nerve roots. Neurologic function ranges from normal to complete paraplegia. Progression of the deformity and neurologic deterioration is the rule.

METHODS

An independent spinal surgeon reviewed the complete records of 19 patients with SSD, between 1998 and 2015 at a single institution. Mean follow-up was 10 years and 6 months (2-14 years).

RESULTS

We evaluated 11 males and 8 females, with a mean age of 2 years and 9 months (5 months-15 years). The dysgenetic segment involved an average of 2.9 vertebrae (1-5); the upper thoracic region was most commonly involved in ten cases. Fifteen patients had severe spinal stenosis. 14 patients presented neurological deficits and 15 patients had associated organ and musculoskeletal anomalies.Twenty-seven surgeries were performed, a mean of 1.76 procedures (1-5) to obtain solid fusion. Neurologic function improved in four, deteriorated in three, and remained unchanged in 12 patients Seven complications were recorded.

CONCLUSION

We strongly recommend decompression and fusion as soon as possible to preserve or prevent neurologic deterioration. Although challenging, it was possible to achieve a solid instrumented fusion in all cases; however, a high rate of patients may deteriorate or not recover neurological status after surgery.

LEVEL OF EVIDENCE

Level IV evidence.

A Practical Approach to Diagnosis of Spinal Dysraphism

Spinal dysraphisms (SDs) are congenital malformations of the spinal cord, determined by derangement in the complex cascade of embryologic events involved in spinal development. They represent a heterogeneous group ranging from mild clinical manifestations-going unnoticed or being discovered at clinical examination-to a causal factor of life quality impairment, especially when associated with musculoskeletal, gastrointestinal, genitourinary, or respiratory system malformations. Knowledge of the normal embryologic development of the spinal cord-which encompasses three main steps (gastrulation, primary neurulation, and secondary neurulation)-is crucial for understanding the pathogenesis, neuroradiologic scenarios, and clinical-radiologic classification of congenital malformations of the spinal cord. SDs can be divided with clinical examination or neuroradiologic study into two major groups: open SDs and closed SDs. Congenital malformations of the spinal cord include a wide range of abnormalities that vary considerably in imaging and clinical characteristics and complexity and therefore may represent a diagnostic challenge, even for the experienced radiologist. Online supplemental material is available for this article. ^©RSNA, 2021.

Segmental spinal dysgenesis with open spinal dysraphism and Chiari II features, case report

Segmental spinal dysgenesis (SSD) is a complex spinal anomaly characterized by localized dysgenesis of the lumbar or thoracolumbar spine, and severe congenital kyphosis or kyphoscoliosis. We describe a newborn who presented with severe congenital paraplegia and a lumbar mass. Magnetic resonance imaging confirmed SSD type II associated with open spinal dysraphism and intracranial Chiari II features; this association has not been reported. The association modifies the disease management and outcome. The previous classification of SSD could be revisited based on our case.