Postnatal Intracranial Findings Following Fetal Repair of Spinal Dysraphisms (original) (raw)
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Hindbrain Herniation in Chiari II Malformation on Fetal and Postnatal MRI
American Journal of Neuroradiology, 2017
As the practice of in utero repair of myelomeningoceles becomes more prevalent, knowledge of the expected MR imaging findings has become increasingly important. Our aim was to examine neuroimaging findings with a focus on hindbrain herniation and ventricular size in fetuses with open spinal dysraphism and to compare them with postnatal imaging features in groups undergoing prenatal-versus-postnatal repair. Single-center retrospective analysis was performed on MRIs of fetuses with open spinal dysraphism from January 2004 through July 2015 with available postnatal imaging. One hundred two fetuses were included. Reports from available fetal ultrasound were also examined. Images were reviewed by 2 board-certified fellowship-trained pediatric neuroradiologists. Descriptive analyses were performed to demonstrate the distribution of the imaging findings. Thirty-two of 102 (31.3%) fetuses underwent in utero repair of open spinal dysraphism; 68.6% (70/102) underwent postnatal repair. Ninety-four of 102 (92.2%) fetuses had cerebellar ectopia. Of those who underwent prenatal repair (26 grade 3, 6 grade 2), 81.3% (26/32) had resolved cerebellar ectopia postnatally. Of those who had severe cerebellar ectopia (grade 3) that underwent postnatal repair, 65.5% (36/55) remained grade 3, while the remaining 34.5% (19/55) improved to grade 2. The degree of postnatal lateral ventriculomegaly in those that underwent prenatal repair (20.3 Ϯ 5.6 mm) was not significantly different from that in those that underwent postnatal repair (21.5 Ϯ 10.2 mm, P ϭ .53). Increased Chiari grade was significantly correlated with decreased head size for gestational age on fetal sonography (P ϭ .0054). In fetuses with open spinal dysraphism and severe Chiari II malformation that do not undergo prenatal repair, most have no change in the severity of cerebellar ectopia/Chiari grade. However, in fetuses that undergo in utero repair, most have resolved cerebellar ectopia postnatally. S ince the Management of Myelomeningocele (MOMS) trial revealed that prenatal surgery for myelomeningocele reduces the need for ventricular shunting and improves motor outcomes in infants with Chiari II malformation, the practice has become more widely available and is being offered and performed with increasing frequency. 1 Fetal MR imaging continues to play an essential role in evaluating fetuses prenatally not only to determine which candidates may potentially benefit from the procedure but also to evaluate associated anomalies to shed some light on prognostic information that will aid in counseling. Ample literature describes postnatal MR imaging findings of Chiari II malformation after postnatal repair of myelomeningoceles. However, the literature describing imaging findings in Chiari II malformation on fetal MR imaging is somewhat limited, mostly comprised of review articles with a few small studies. There are even fewer articles in the literature comparing neuroimaging findings between pre-and postnatal brain MRIs in patients with Chiari II malformation. In order to improve our understanding of the disease and improving outcomes, studies evaluating the neuroimaging findings in these patients both preand postnatally are becoming increasingly important, particularly studies that describe imaging parameters that can be easily implemented in clinical practice.
Neurosurgery, 2012
Chiari II deformity is associated with open spinal dysraphism. A causal relationship has been proposed by McLone and Knepper. This article evaluates that hypothesis. To establish the frequency of Chiari II deformity in fetuses with open spinal dysraphism, assess whether meningocele sac neck area and volume influence the severity of posterior fossa changes, and assess whether the severity of associated findings (ventriculomegaly, amount of extracerebral CSF) are associated with Chiari II deformity. Sixty-five fetuses with open spinal dysraphism were compared with gestationally aged matched "normal" fetuses on ultrafast MR images. Cerebellar vermis and bony posterior fossa surface area were measured on midline sagittal images. Hindbrain herniation was noted if present. In the open spinal dysraphic group, sac neck area and volume were measured. Ventriculomegaly was assessed by linear measurement of the trigone of the lateral ventricle and extracerebral CSF depth was measured ...
MRI of fetal spinal malformations
Fetal magnetic resonance imaging is well accepted as secondary image tool for the evaluation of pathologies affecting the fetal brain as detected on prenatal ultrasonography. Significantly, fewer articles have focused on the fetal spinal canal and its contents. Many malformations and pathologies involving the spinal canal and cord may however have a significant impact on the quality of life. In addition, anomalies of the spinal cord may affect the development of the fetal brain or may be part of a more extensive malformation that may also affect the major thoracic and abdominal organs. A thorough knowledge of the normal and abnormal development of the spinal column and its contents is necessary to diagnose and understand the encountered findings. In the current review the value of fetal magnetic resonance imaging of the spinal column and cord is discussed. The most frequently encountered malformations will be presented and discussed in the context of the most relevant embryological processes.
Pediatric Radiology - PEDIAT RADIOL, 2007
We report a case of Chiari III malformation diagnosed by fetal MRI. Ultrasound (US) performed at a gestational age of 18 weeks demonstrated a posterior skull base cyst. Repeat US at 19 weeks demonstrated neural tissue in the cyst, consistent with an encephalocele. MR imaging at 23 weeks confirmed the presence of an occipital encephalocele, demonstrated additional bony defect in the upper cervical spine, and identified abnormal morphology and position of the brainstem consistent with the diagnosis of Chiari III. Postnatal MRI and CT confirmed the fetal MRI findings and demonstrate the utility of fetal MRI in the early evaluation of songraphically detected posterior fossa abnormalities.
Imaging of open spinal dysraphisms in the era of prenatal surgery
Pediatric Radiology, 2020
Over the last decade fetal surgery to repair open spinal dysraphisms has become an acceptable and in some cases desirable alternative to the traditional method of postnatal closure. Fetal MRI is an essential part of the workup in these patients, not only to select the appropriate candidates for fetal surgery but also to guide prenatal counseling and perinatal management. In this article we review current surgical techniques for prenatal repair, relevant imaging findings in the era of fetal surgery, and expected imaging findings of the brain and spine in the fetal and postnatal periods.
Reappraisal of intradural findings in Chiari malformation type I
Neurosurgical Focus
OBJECTIVE Management of Chiari malformation type I (CM-I) requires the functional restoration of an obstructed cisterna magna. In posterior fossa decompression with duraplasty (PFDD), various intradural pathologies are suggested to alter CSF flow at the craniocervical junction and require surgical correction. However, reports of the spectrum of intraoperative intradural findings and their nuances are scarce, especially those characterizing rarer findings pertaining to the vascular structures and vascular compression. METHODS The authors conducted a retrospective cohort analysis of adults and children who underwent first-time PFDD for CM-I (2011–2021), with and without syringomyelia. The surgical reports and intraoperative videos were reviewed, and the frequency and nature of the intradural observations in regard to the tonsils, arachnoid, and vasculature were analyzed along with the clinical findings and surgical outcomes. RESULTS All 180 patients (age range 1–72 years; median [inte...
Differentiating Closed Versus Open Spinal Dysraphisms on Fetal MRI
AJR. American journal of roentgenology, 2016
The purpose of this study is to identify differences in findings between open and closed spinal dysraphisms seen on fetal MR images. A single-institution retrospective analysis of fetal MR images for spinal dysraphism was performed. Postnatal images and clinical and operative reports were reviewed. Sixteen fetuses with postnatally confirmed closed spinal dysraphisms were included. Of these, 25% (4/16) had posterior fossa anomalies, 12.5% (2/16) had ventriculomegaly, and 37.5% (6/16) had OEIS (omphalocele, exstrophy, imperforate anus, and spinal defects) complex. Of 90 fetuses with postnatally confirmed open spinal dysraphism, 95.6% (86/90) had posterior fossa anomalies, 85.6% (77/90) had ventriculomegaly, and none had OEIS complex. Twenty fetuses with open spinal dysraphism were randomly selected to compare with fetuses with closed spinal dysraphisms. Continuity of the epidermal and subcutaneous tissues with the sac wall on fetal MR images was seen in 93.8% (15/16) of patients with ...
MR-Based Morphometry of the Posterior Fossa in Fetuses with Neural Tube Defects of the Spine
PLoS ONE, 2014
Objectives: In cases of ''spina bifida,'' a detailed prenatal imaging assessment of the exact morphology of neural tube defects (NTD) is often limited. Due to the diverse clinical prognosis and prenatal treatment options, imaging parameters that support the prenatal differentiation between open and closed neural tube defects (ONTDs and CNTDs) are required. This fetal MR study aims to evaluate the clivus-supraocciput angle (CSA) and the maximum transverse diameter of the posterior fossa (TDPF) as morphometric parameters to aid in the reliable diagnosis of either ONTDs or CNTDs.
European Journal of Paediatric Neurology, 1999
The pathogenesis of idiopathic Chiari I malformation (CM I) remains poorly understood, although it is thought to be due to disproportion between hindbrain structures and the posterior fossa (PF) dimensions. This study was undertaken to determine whether CM I and its possible complications are associated with disproportion between cranial and cerebral dimensions. Surface of the vermis, PF and supratentorial (ST) area were measured on magnetic resonance imaging midsagittal sections and were correlated with age in 19 children with CM I and 43 controls. The ratio of the PF/ST area and of the vermis/PF area were also plotted against age in the two groups and against length of the tonsils herniation in the CM I malformation group. Only the vermis midsagittal area and the vermis/PF ratio were found to be significantly higher in CM I malformation subjects. There was no correlation between the length of tonsils herniation and the vermis/PF area or the PF/ST area ratio in this group. The most severe complications (large syrinx and hydrocephalus) were not associated with particular measurements or calculated ratios in the children with CM I malformation except for the relatively small PF area in a neonate. We conclude that factors responsible for the appearance of clinical signs remain largely unknown. In particular, cranial and brain measurements alone do not seem to predict complications or unfavourable clinical evolution.
Chiari Malformations, Syringohydromyelia and Scoliosis
Neurosurgery Clinics of North America, 2007
This article addresses the key features, presentation, and current management of pediatric patients who have Chiari I and Chiari II malformations. It further discusses syringohydromyelia and scoliosis as they relate to pediatric Chiari malformations. Because of the focus on pediatric patients, acquired Chiari malformations are not discussed. Current management algorithms for the more recently described Chiari 0 (syringohydromyelia in the absence of cerebellar tonsillar herniation) and Chiari 1.5 (tonsillar herniation with associated brain stem herniation) malformations are based on the principles developed for the treatment of the more common Chiari I and Chiari II malformations. As such, Chiari 0 and 1.5 are not discussed.