Prenatal diagnosis of diastematomyelia: presentation of eight cases and review of the literature

Management of split cord malformation and tethered cord syndrome: Experience of a main referral center in Uzbekistan

BACKGROUND

Split cord malformation and tethered cord syndrome are challenging pathologies in the pediatric population. During 2016-2022, 56 cases of split cord malformation (SCM) and tethered cord syndrome were treated at the Republican Specialized Scientific Medical Practical Center of Neurosurgery (RSSMPCN) of Uzbekistan. This article aims to provide a retrospective analysis of the clinical presentation, radiological findings, and surgical outcomes of patients with split cord malformation and tethered cord syndrome.

METHODS

The retrospective study was conducted for 56 pediatric patients with split cord malformation and tethered cord syndrome during the abovementioned six-year period. All patients underwent MR imaging with computed tomography, followed by surgery with intraoperative neurophysiological monitoring. Each patient underwent follow-up examinations at 3 and 6 months postoperatively and yearly thereafter.

RESULTS

The mean patient age was 5.7 years (10 months to 15 years), and the male-to-female ratio was 1:2.2. Encouragingly, 44 (78.6 %) of the 56 patients showed improved neurological status postoperatively. Even in the cases where spur resection procedures were performed, there was partial neurological improvement, demonstrating the overall positive outcomes of the surgeries. Importantly, none of the 56 patients had neurological deteriorations in the postoperative period CONCLUSIONS: Split cord malformation is a rare but challenging pathology of childhood. The presentation is primarily characterized by movement, sensory or bowel disorders, and back and leg pain. This underscores the importance of early recognition and intervention when neurological symptoms are evident. Surgical intervention, as demonstrated in our study, is both appropriate and efficient in improving the neurological status of the patients.

Proposal for standardized prenatal assessment of fetal open dysraphisms by the European reference network for Intellectual disability, TeleHealth, Autism and Congenital Anomalies (ITHACA) and eUROGEN

Open dysraphisms, that is, myelomeningocele and myeloschisis, are rare diseases associated with a risk of severe disability, including lower limb motor and sensory deficiency, sphincter deficiency, and potential intellectual deficiency. Open dysraphism is diagnosed in Europe in 93.5% of cases. In case of suspicion of fetal open dysraphism, a detailed fetal morphologic assessment is required to confirm the diagnosis and exclude associated structural anomalies, as well as genetic assessment. In case of isolated fetal open dysraphism, assessment of prognosis is based on fetal imaging including the level of the lesion, the presence or not of a sac, the presence and nature of intra cranial anomalies, and the anatomical and functional evaluation of the lower extremities. Based on these biomarkers, a personalized prognosis as well as comprehensive information about prenatal management alternatives will allow parents to decide on further management options. Standardization of prenatal assessment is essential to compare outcomes with benchmark data and make assessment of surgical innovation possible. Herein, we propose a protocol for the standardized ultrasound assessment of fetuses with isolated open dysraphism.

Prenatal Diagnosis of Diastematomyelia: a Case Report and Literature Review

Diastematomyelia is a type of closed spinal dysraphism in which there is splitting of the spinal cord. It is a rare entity that accounts for less than 3% of closed spinal dysraphisms and affects females 1.3 to 6 times more frequently than males. Lesions are usually found in the lower thoracic and upper lumbar regions. It is characterised by two hemicords separated by a bony or cartilaginous spur. In most cases, it is an isolated malformation with a favourable prognosis. However, it may be associated with other abnormalities and sonography is the imaging test par excellence for early prenatal diagnosis. We report a case of diastematomyelia diagnosed by prenatal sonography at 24 weeks' gestation. Amniotic fluid alpha-fetoprotein (AF-AFP) was normal, while amniotic fluid acetylcholinesterase (AF-AChE) was positive. After birth, the diagnosis was confirmed with magnetic resonance imaging (MRI). The anomaly was associated with a spinal lipoma, tethered cord and dermal sinus. A review of all the cases described in the literature to date is carried out.

[Prenatal ultrasound prognostic of myelomeningocele at the era of fetal surgery]

Myelomeningocele (MMC) is a severe congenital condition responsible for motor and sensory impairments of the lower limbs, incontinence and cognitive impairment. Its screening, sometimes as early as the first trimester, is one of the major goals of modern prenatal care, supported by the emergence of prenatal surgery that results in a significant improvement in motor function, ambulation and ventriculoperitoneal shunt rate in patients undergoing in-utero surgery. From screening to pre- and post-operative prognostic evaluation, prenatal ultrasound is now an essential tool in the antenatal management of this condition. Using the multi planar and three-dimensional modes, it can be used to assess the vertebral level of MMC, which remains the key antenatal prognostic marker for motor function and ambulation, incontinence and the need for a ventriculo-peritoneal shunt. A careful and systematic ultrasound examination also makes it possible to assess the severity and progression of ventriculomegaly, to search for associated cerebral, spinal cord or vertebral anomalies, or to rule out exclusion criteria for in-utero surgery such as severe kyphosis or serious cortical anomalies. New tools from post-natal evaluation, such as the "metameric" ultrasound assessment of lower limb mobility, appear to be promising either for the initial examination or after in-utero surgery. Ultrasonography, associated with fetal MRI, cytogenetic and next generation sequencing, now allows a highly customized prognostic evaluation of these fetuses affected by MMC and provides the parents with the best possible information on the expected benefits and limitations of fetal surgery.

Prenatal diagnosis of fetal hemivertebra in the first trimester

Hemivertebra is a congenital spinal abnormality. The condition may affect one or multiple vertebrae. Hemivertebra occurs because of malformations or absence of the ossification centers. Most cases reported in the literature are diagnosed in the second trimester, usually after 22 weeks. It is very unusual and difficult for the hemivertebra to be detected at the first trimester.

How to Explore Fetal Sacral Agenesis Without Open Dysraphism: Key Prenatal Imaging and Clinical Implications

The estimated prevalence of fetal caudal dysgenesis is 1 per 100,000 births. The functional prognosis of sacral agenesis is dominated by the large spectrum of associated caudal malformations. Except for cases associated with hydrocephalus secondary to open spinal dysraphism or chromosomal anomalies, association with mental deficiency is rare. We propose a systematic prenatal approach to cases of fetal sacral agenesis based on 9 etiologic items: clinical context, type of sacral dysgenesis, associated spinal cord malformations, mobility of lower limbs, investigation of the presacral region, analysis of the gastrointestinal tract, analysis of the genitourinary tract, associated vertebral defects, and cytogenetic analysis.

The Clinical Value of Prenatal 3D Ultrasonic Diagnosis on Fetus Hemivertebra Deformity- A Preliminary Study

Objective:

The present study is planned to discuss the clinical value of prenatal 3D ultra-sonic diagnosis on fetus hemivertebra deformity through the retrospective analysis of clinical data of fetus hemivertebra deformity.

Methods:

Selected 9 fetus hemivertebra deformity cases, which have been admitted to our hospital during the period from January, 2010 to January, 2016 as study samples, and analyzed their 2D and 3D ultrasonic examination data.

Results:

4 cases of the fetus hemivertebra deformity occurred at lumbar vertebra, 3 cases at thoracic vertebra, and 2 cases at thoracolumbar vertebra. There were scoliosis and opened spine bifida (OSB). In 7 cases, there was absence of ribs in fetus. The 2D ultrasonic image showed that: The echo at the center of fetus vertebral arch lesion was blurred or lost. The coronal section showed the deformity of the spine. There was obvious loss of the ossification center. From the cross section, we could see that the vertebral body of the fetus was shrinking and the edges were relatively blurred. The 3D ultrasonic image showed that: the echo at the ossification center of the fetus vertebra was relatively blurred, or even lost. The image also indicated scoliosis deformity of the spine. The vertebral body lesion could be accurately located.

Conclusion:

9 cases of fetus hemivertebra deformity have been detected through examination. Labor inductions have been carried out after getting the permission from the family members. The X-ray examination of the fetus after labor induction showed that the diagnosis was correct. Prenatal ultra-sonic examination holds strong potential for the diagnosis of fetus hemivertebra deformity quite early and deserves further clinical evaluation with large sample size.

The Value of Prenatal Ultrasonographic Diagnosis of Diastematomyelia

OBJECTIVES

To evaluate the value of prenatal ultrasonographic diagnosis of diastematomyelia, and to provide a basis for the diagnosis and differential diagnosis of fetal diastematomyelia.

METHODS

Four fetuses with suspected diastematomyelia based on prenatal ultrasonography are presented. Detailed prenatal ultrasonography was performed to examine spinal cord abnormalities. The region of interest-based spine sagittal plane was defined and 3D volumetric scans were performed, as needed. Images were stored and compared with MRI or ultrasonographic images after abortion.

RESULTS

In the four cases of diastematomyelia diagnosed by prenatal ultrasonography, two were confirmed by MRI after birth, and the other two were confirmed by autopsy and pathologic examination after abortion. Varying degrees of spine or spinal cord deformities were noted. Two pregnancies were terminated, and two newborns underwent surgery.

CONCLUSIONS

Prenatal ultrasonography contributes to the diagnosis of diastematomyelia and provides a basis for prenatal counseling and prognosis.

Sonographic Evaluation of Fetal Conus Medullaris and Filum Terminale

Background: Sonographic evaluation of the fetal conus medullaris (CM) level is not reproducible. The objectives of this study were to determine the normal position of the fetal CM during pregnancy as well as the normal intradural filum terminale (FT) length and to evaluate their use in detecting tethered cord. Methods: This is a prospective evaluation of normal singleton pregnancies examined by sonography from 17 weeks of gestation to term. Each sonographer had to identify the top of the first sacral vertebra (S1) to measure the distance between it and the conus extremity (CM-S1 distance). The intradural FT distance was measured with 5- to 8-MHz probes. Results: 194 consecutive pregnant women were included. The CM and intradural FT were demonstrated clearly in 164 (84%) cases. The mean CM-S1 distance was 20.6 mm (range 0.5-42). The mean intradural FT distance was 27.9 mm (range 6.6-49.3). Linear regression analysis showed a significant association between both those distances and gestational age (p < 0.05). In cases of tethered cord, the mean CM-S1 distance and the mean intradural FT distance were both below the 5th percentile. Conclusion: Prenatal evaluation of the CM and the intradural FT is feasible and reproducible and seems useful in detecting tethered cord.

Fetal diastematomyelia associated with vertebral malformation: ultrasound, MRI, and pathomorphological findings

Using a specific clinical example, we demonstrate the ability of prenatal magnetic resonance imaging (MRI) to diagnose associated spine and spinal cord malformations in the group of spinal dysraphisms. Thus, the original ultrasound (US) and MRI results for the affected fetus at week 21 are illustrated and described in detail. The paucity of reports of prenatal MR-semiotic findings of split cord malformation comparing US and pathomorphological findings at a relatively early gestational age makes the present case unique and instructive. The outstanding capability of MRI to diagnose spinal pathologies indicates the necessity of including prenatal MRI in the diagnostic algorithm to determine the severity of the lesions and the appropriate management during pregnancy, childbirth, and the early postnatal period.

The Diagnostic Features of Spina Bifida: The Role of Ultrasound

Myelomeningocele (MMC) is one of the most devastating, nonlethal congenital anomalies worldwide. The live birth prevalence of MMC changed dramatically in the 1980s with the introduction of maternal serum screening and the widespread use of prenatal ultrasound imaging. The high-resolution ultrasound affordable today with state-of-the-art equipment allows us to make a very accurate diagnosis of MMC, including details related to the entire fetal central nervous system. Ultrasound can accurately localize the site of the osseous and soft tissue defects. Congenital spinal defects can be characterized definitively as open or closed, which are treated very differently with in utero repair, which is done in some cases, compared to only conservative follow-up with postnatal therapy for occult defects. Additional findings of kyphosis, scoliosis and anomalous vertebrate and associated conditions such as cervical syrinx can be identified. The state of the intracranial structures, including the presence or absence of ventriculomegaly and hindbrain herniation, as well as unexpected complications such as intracranial hemorrhage can be diagnosed. The severity of neurological compromise in some fetuses can be estimated by detailed examination of the lower extremities. As well as searching for talipes, we also now routinely characterize flexion and extension motions at the hip, knee and ankle joints. The information provided by ultrasound plays a crucial role, now more than ever, in patient counseling and pregnancy management. This article emphasizes how we utilize ultrasound in the evaluation of patients with suspected MMC at the Center for Fetal Diagnosis and Treatment at the Children's Hospital of Philadelphia.

A sonographic approach to prenatal classification of congenital spine anomalies

Objective: To develop a classification system for congenital spine anomalies detected by prenatal ultrasound. Methods: Data were collected from fetuses with spine abnormalities diagnosed in our institution over a five-year period between June 2005 and June 2010. The ultrasound images were analysed to determine which features were associated with different congenital spine anomalies. Findings of the prenatal ultrasound images were correlated with other prenatal imaging, post mortem findings, post mortem imaging, neonatal imaging, karyotype, and other genetic workup. Data from published case reports of prenatal diagnosis of rare congenital spine anomalies were analysed to provide a comprehensive work. Results: During the study period, eighteen cases of spine abnormalities were diagnosed in 7819 women. The mean gestational age at diagnosis was 18.8w ± 2.2 SD. While most cases represented open NTD, a spectrum of vertebral abnormalities were diagnosed prenatally. These included hemivertebrae, block vertebrae, cleft or butterfly vertebrae, sacral agenesis, and a lipomeningocele. The most sensitive features for diagnosis of a spine abnormality included flaring of the vertebral arch ossification centres, abnormal spine curvature, and short spine length. While reported findings at the time of diagnosis were often conservative, retrospective analysis revealed good correlation with radiographic imaging. 3D imaging was found to be a valuable tool in many settings. Conclusions: Analysis of the study findings showed prenatal ultrasound allowed detection of disruption to the normal appearances of the fetal spine. Using the three features of flaring of the vertebral arch ossification centres, abnormal spine curvature, and short spine length, an algorithm was devised to aid with the diagnosis of spine anomalies for those who perform and report prenatal ultrasound.

Prenatal diagnosis of spinal dysraphism

INTRODUCTION

Since intrauterine repair of open spinal dysraphism have demonstrated promising results, it has become crucial to accurately define the various prenatal pathologies. The embryogenesis of spinal dysraphism according to a clinical neuroradiological classification is reviewed, with special emphasis on the recent advances in prenatal ultrasound (US), such as high-frequency linear transducers and three-dimensional imaging.

FUNDINGS

The role of magnetic resonance imaging (MRI) of the fetus as a complementary tool for delineating complex fetal spinal anomalies and further defining associated central nervous system (CNS) anomalies is explored. Differentiation between normal appearance of the fetal spine and the wide range of congenital neural tube defects are demonstrated in both modalities with special emphasis on their complementary role in the accurate diagnosis of neural tube defects.

Split cord malformation types I and II: a personal series of 131 patients

PURPOSE

A personal series of 131 patients with split cord malformation (SCM) operated on is presented.

METHODS

Age, gender, symptoms and signs, radiological and operative findings, complications, associated anomalies, outcome, and pathological specimens were analyzed.

RESULTS

There were 88 girls (73 %) and 43 boys (27 %). The female predominance was slightly more remarkable in type I SCMs than in type II SCMs. The presenting symptoms can be summarized as skin lesions, spina bifida aperta, scoliosis or kyphoscoliosis, sphincter disturbance, foot deformities and weakness, and/or atrophy in the lower extremities. The ages of patients with neurological deficits and orthopedic deformities were significantly older than those without deficits (P = 0.030). The duration of symptoms was longer in the patients with neurological deficits and orthopedic deformities than that in those without deficits (P = 0.00095). In six patients, composite SCMs were present. Only one patient with a type II SCM did not have an associated spinal cord lesion. A type I SCM was more frequently encountered in patients with spina bifida (P < 0.0005). Transient postoperative complications were seen in 29 patients (22 %). There was no permanent complication. Retethered cord syndrome developed in five patients with a type I SCM.

CONCLUSIONS

The risk of neurological and orthopedic deficits increases with the age of the patient. The risk of permanent deficit after surgery is very low. The whole spine must be examined for additional lesions. All patients should be surgically treated when diagnosed, especially before the development of orthopedic and neurological manifestations, and all associated lesions should also be treated at the same session.

A Sacral Mass in a Newborn: A Variant of Type II Diastematomyelia with Triple Splitting of the Cord

Ultrasonographic (US) evaluation of spinal anomalies is limited. MRI is increasingly being used in the diagnosis of spinal anomalies. MRI has been able to show clearly the detailed anatomy of this rare case of type II diastematomyelia with triple splitting of the cord.

Prenatal diagnosis of split cord malformation by ultrasound and fetal magnetic resonance imaging: case report and review of the literature

INTRODUCTION

Split cord malformation (SCM) is rare congenital disorder of spine in which bony, fibrous, or cartilaginous septum subdivides partially or completely the vertebral canal. SCM can be associated with other spinal abnormalities such as spina bifida, Arnold-Chiari malformation, hemivertebra, butterfly vertebra, or kyphoscoliosis and also can be seen as part of Jarcho-Levin syndrome. Prenatal diagnosis of SCM is possible by ultrasonography (US). Fetal magnetic resonance imaging (MRI) and amniotic fluid acetylcholine esterase (AF-AChE) levels can be helpful to rule out additional anomalies. We present a case of fetal SCM diagnosed by US and fetal MRI.

CASE

An 18-year-old woman with no obstetrics risk factor was referred for routine US screening. At sagittal section, fetal spine was seen to be disordered. A coronal view of the spinal canal showed evidence of widening at the lower thoracic and lumbar level. An echogenic mass was identified within the enlarged spinal canal at level of T6-L5. Fetal MRI and AF-AChE analysis confirmed diagnosis and ruled out other anomalies and spina bifida. Neurological examination of the baby at 16 months of age was normal.

Prenatal diagnosis of diastematomyelia: a case report and review of the literature

Diastematomyelia is a rare congenital disorder in which the spinal cord is divided longitudinally for part of its length. It can be accurately identified in the prenatal period by detailed sonographic examination of the spine. We report a case of diastematomyelia localized to spinal levels T6-T9 diagnosed prenatally at 31 weeks' gestation and review the existing literature on the diagnosis and management of this condition during pregnancy.

Diastematomyelia: a retrospective review of 138 patients

Diastematomyelia is a rare congenital abnormality of the spinal cord. This paper summarises more than 30 years' experience of treating this condition. Data were collected retrospectively on 138 patients with diastematomyelia (34 males, 104 females) who were treated at our hospital from May 1978 to April 2010. A total of 106 patients had double dural tubes (type 1 diastematomyelia), and 32 patients had single dural tubes (type 2 diastematomyelia). Radiographs, CT myelography, and MRI showed characteristic kyphoscoliosis, widening of the interpedicle distance, and bony, cartilaginous, and fibrous septum. The incidences of symptoms including characteristic changes of the dorsal skin, neurological disorders, and congenital spinal or foot deformity were significantly higher in type 1 than in type 2. Surgery is more effective for patients with type 1 diastematomyelia; patients without surgery showed no improvement.

Prenatal evaluation of the position of the fetal conus medullaris

OBJECTIVES

To determine the position of the fetal conus medullaris during pregnancy in relation to the last vertebral body and to examine its use in detecting skin-covered spinal dysraphism.

METHODS

This was a retrospective study involving 300 consecutive ultrasound examinations between 15 weeks of gestation and term. Two operators independently assessed images of the spine to determine whether the conus medullaris and the last vertebral body could be visualized in a single image in a midsagittal plane. The distance between these two landmarks (the conus distance) was measured twice by both operators who were not aware of any previous measurements. Intra- and interobserver variability was assessed by 95% limits of agreement. Linear regression analysis was used to determine the relevant contributors to the conus distance and a normal range was computed based on the best-fit model. The normal results were compared with five cases of prenatally detected skin-covered spinal dysraphism.

RESULTS

In 84.7% of the 300 cases, both operators were able to visualize the conus medullaris and the last vertebral body. Ninety-five percent limits of agreement for the intraobserver variability in measurement of conus distance were ± 1.9 mm. For the interobserver variability, they were - 3.7 and 2.5 mm. We found a linear relationship between conus distance and gestational age, biparietal diameter and abdominal circumference. The strongest relationship was observed for femur length (conus distance = - 8.2 + femur length (mm)). In the five abnormal cases, conus distance was well below the 5(th) percentile.

CONCLUSIONS

Determination of conus distance allows for an objective and feasible assessment of the conus medullaris position. This parameter promises to be useful in the prenatal detection of skin-covered spinal dysraphism.

Fetal diastematomyelia: MR imaging: A case report

MRI is increasingly being used in the diagnosis of fetal anomalies suspected on USG. The USG evaluation of fetal spinal anomalies is limited by acoustic shadowing, fetal position and the amount of liquor. Fetal MRI is able to show spinal anomalies well, as in our case of fetal diastematomyelia with a dorsal dermal sinus, suspected on USG at 28 weeks gestation.

Prenatal US evaluation of the spinal cord using high-frequency linear transducers

We illustrate the contribution of high-frequency linear abdominal transducers in the prenatal US examination of the spinal cord. After birth, such transducers are commonly used in US examination of the spinal cord. During the third trimester of gestation, the fetal spine is commonly facing anteriorly and US images of the spinal cord can be acquired using a high-frequency linear abdominal transducer. Images of the normal spinal cord, normal variants (ventriculus terminalis, cyst of filum terminale) and spinal cord abnormalities (myelomeningocele, meningocele, diastematomyelia, tethered spinal cord and caudal regression syndrome) are presented. In this pictorial essay, comparison between images acquired with low- and high-frequency transducers are provided as well as correlation with postnatal data. In the normal spine, anatomical details such as the conus medullaris, the filum terminale and the nerve root bundles are exquisitely depicted, making it possible to differentiate normal variants from abnormalities. In abnormal cases, the position of the conus medullaris, its shape and the nerve roots can be analyzed in detail. We describe the benefits of using high-frequency linear transducers in US examination of the spinal cord, which is common after birth but has not been hitherto reported in fetuses.

Prenatal diagnosis of fetal hemivertebra at 20 weeks' gestation with literature review

Hemivertebra is a rare congenital spinal malformation, where only one side of the vertebral body develops, resulting in deformation of the spine, such as scoliosis, lordosis, or kyphosis. We present the ultrasonographic features of a fetus with hemivertebra at 20 weeks’ gestation confirmed by post mortem radiography and pathological examination. The prenatal literature on this disorder is also reviewed. Useful background information is provided for both clinicians and other health professionals who are not familiar with this condition.