Validation of Sonographic Fronto-Occipital Ratio Based on Anatomical Landmarks compared to MR/CT-Derived Indexes in Children with Chiari II and Ventriculomegaly

Introduction: Ultrasound (US) based indexes such as fronto-occipital ratio (FOR) can be used to obtain an acceptable estimation of ventricular volume. Patients with colpocephaly present a unique challenge due to the shape of their ventricles. In the present study, we aim to evaluate the validity and reproducibility of modified US-FOR index in children with Chiari II-related ventriculomegaly. Methods: In this retrospective study, we evaluated Chiari II patients younger than one year who underwent head US and MR or CT scans for ventriculomegaly evaluation. MR/CT based FOR was measured in the axial plane by identifying the widest diameter of frontal horns, occipital horns, and the interparietal diameter (IPD). US based FOR (US-FOR) was measured using the largest diameter based on the following landmarks: frontal horn and IPD in the coronal plane at the level of the foramen of Monro, IPD just superior to the Sylvian fissures, and occipital horn posterior to the thalami and inferior to the superior margins of the thalami. Interclass correlation coefficients (ICC) were used to evaluate inter-rater reliability and Pearson correlation coefficients and Bland-Altman plots were applied to assess agreement between US and other two modalities. Results: Ninety paired US and MR/CT exams were assessed for agreement between US-FOR and MR/CT-FOR measurements. ICC showed an excellent inter-rater reliability for US-FOR (ICC=0.99, p<0.001) and MR/CT-FOR measurements (ICC=0.99, p<0.001). The mean (range) values based on US-FOR showed a slight overestimation in comparison to MR/CT-FOR [0.51 (0.36-0.68) vs 0.46 (0.34-0.64)]. Pearson correlation coefficient showed high cross-modality agreement for the FOR index (r=0.83, p<0.001). Bland-Altman plot showed excellent concordance between US-FOR and MR/CT-FOR with a bias of 0.05 (95% CI, -0.03-0.13) Conclusion: US-FOR in the coronal plane is a comparable tool for evaluating ventriculomegaly in Chiari II patients when compared with MR/CT-FOR, even in the context of colpocephaly.

Cerebral Abnormalities in Spina Bifida: A Neuropathological Study

Introduction Spina bifida (SB) is the most common neural tube defect in humans. Here, we analyzed systematically the neuropathological findings of the brain in SB cases. Methods 79 cases with SB aperta (SBA) and 6 cases with SB occulta (SBO) autopsied at the Charité Neuropathology from 1974 to 2000 were re-evaluated retrospectively. For this, case files and spinal cord as well as brain sections were studied. Results While no brain malformations were detected in SBO cases, 95% of SBA cases had brain malformations. Main brain anomalies identified were hydrocephalus (71%), Chiari II malformation (36%), heterotopia (34%), other cerebellar anomalies (36%), gyrification defects (33%), and ependymal denudation (29%). Hydrocephalus was observed as early as gestational week 17 and was highly associated to Chiari II and ependymal denudation. In 55% SBA was accompanied by further anomalies not primarily affecting the CNS. Conclusion We confirm using neuropathologic methods brain malformations in most SBA but none in SBO cases. In addition to our previous radiologic study, we now demonstrate the high prevalence of cerebellar malformations and cerebral heterotopias in SBA. The early detection of hydrocephalus and Chiari II malformation in fetuses raises the question whether these arise parallel rather than in strict temporal sequence.

Recurrent stridor in an infant

Paediatric upper airway obstruction is an emergency that requires immediate intervention. Among the myriad factors that leads to upper airway obstruction in paediatric age group, bilateral vocal cord palsy is not commonly encountered in clinical practice. The underlying cause of bilateral vocal cord palsy requires thorough investigation prior to deciding on the appropriate intervention. Herein, we report a 4-month-old baby boy who presented with recurrent inspiratory stridor with bilateral vocal cord palsy secondary to Arnold Chiari II malformation. Immediate intervention to drain the hydrocephalous resulted in complete resolution of stridor without having to perform a tracheostomy. We highlight the importance of meticulous and thorough investigations especially in children, as emergent airway intervention such as tracheostomy may result in detrimental effect to speech, swallowing as well as quality of life.

Impact of Brain Malformations on Neurodevelopmental Outcome in Children with a History of Prenatal Surgery for Open Spina Bifida

<b><i>Introduction:</i></b> This retrospective study investigates brain malformations and their impact on neurodevelopmental outcome in children after prenatal surgery for spina bifida (SB). <b><i>Methods:</i></b> Sixty-one patients were included. On neonatal MRI, SB-associated brain malformations were assessed. Ventricular size, ventriculo-peritoneal shunt (VPS), and endoscopic third ventriculostomy (ETV) were also documented. Neurodevelopment was assessed with the Bayley-III and correlated with brain malformations, ventricular size, and VPS/ETV placement. <b><i>Results:</i></b> Chiari II malformation was detected in all patients. Corpus callosum (CC) abnormality was noted in 40%, heterotopies in 35%, and cerebellar parenchymal defects in 11%. 96% had ventriculomegaly; in 46%, VPS/ETV was performed. Cognitive and language testing yielded results in the low-average range (Bayley-III: Cognitive Composite Score 93.6, Language Composite Score 89.7), motor testing was below average (Motor Composite Score 77.4). CC abnormalities, heterotopies, and cerebellar defects were not associated with poorer Bayley-III scores, whereas patients with severe ventriculomegaly performed poorer in all subtests, significantly so for the language composite score. Patients requiring intervention for hydrocephalus had significantly lower scores in motor testing. <b><i>Discussion/Conclusion:</i></b> Additional brain malformations in open SB do not seem to have an impact on cognitive function at 2 years of age. Severe ventriculomegaly is a risk factor for poorer cognitive outcome; hydrocephalus surgery adds an additional risk for delayed motor function.

Comparison of Follow-Up Length-Matched Single-Center Myelomeningocele Postnatal Closure Cohort to the Management of Myelomeningocele Study (MOMS) Trial Results

<b><i>Objective:</i></b> We sought to compare our large single-institution cohort of postnatal myelomeningocele closure to the 2 arms of the Management of Myelomeningocele Study (MOMS) trial at the designated trial time points, as well as assess outcomes at long-term follow-up among our postnatal cohort. <b><i>Methods:</i></b> A single-institutional retrospective review of myelomeningocele cases presenting from 1995 to 2015 at Children’s Hospital of Pittsburgh was performed. We compared outcomes at 12 and 30 months to both arms of the MOMS trial and compared our cohort’s outcomes at those designated time points to our long-term outcomes. Univariate statistical analysis was performed as appropriate. <b><i>Results:</i></b> One-hundred sixty-three patients were included in this study. All patients had at least 2-year follow-up, with a mean follow-up of 10 years (range 2–20 years). There was no difference in the overall distribution of anatomic level of defect. Compared to our cohort, the prenatal cohort had a higher rate of tethering at 12 months of age, 8 versus 1.8%. Conversely, the Chiari II decompression rate was higher in our cohort (10.4 vs. 1.0%). At 30 months, the prenatal cohort had a higher rate of independent ambulation, but our cohort demonstrated the highest rate of ambulation with or without assistive devices among the 3 groups. When comparing our cohort at these early time points to our long-term follow-up data, our cohort’s ambulatory function decreased from 84 to 66%, and the rate of detethering surgery increased almost 10-fold. <b><i>Conclusions:</i></b> This study demonstrated that overall ambulation and anatomic-functional level were significantly better among our large postnatal cohort, as well as having significantly fewer complications to both fetus and mother, when compared to the postnatal cohort of the MOMS trial. Our finding that ambulatory ability declined significantly with age in this patient population is worrisome for the long-term outcomes of the MOMS cohorts, especially given the high rates of cord tethering at early ages within the prenatal cohort. These findings suggest that the perceived benefits of prenatal closure over postnatal closure may not be as substantial as presented in the original trial, with the durability of results still remaining a concern.

Neurosurgery guidelines for the care of people with spina bifida

Myelomeningocele (MMC) arises from an early neural developmental anomaly and results in a variety of structural abnormalities and associated functional neurologic deficits. As such, neurologic issues are central to virtually all clinical problems. Neurosurgical intervention strives to correct or improve these defects and prevent secondary complications. These interventions include closure of the open myelomeningocele and management (across the life span) of hydrocephalus, the Chiari II malformation (C2M) and tethered spinal cord (TSC). The development of pre-natal closure techniques and reports of improved outcome with in-utero closure (IUMC) have revolutionized the neurosurgical approach to myelomeningocele. Controversies remain surrounding patient selection, maternal risks, technique of IUMC (endoscopic vs. open) and long-term outcomes. However, real gains include reduced rates of hydrocephalus, modestly improved motor capabilities and reduction in C2M morbidity. For many decades, the cornerstone of treatment of hydrocephalus for many decades has been the placement and support of ventricular shunts. Endoscopic third ventriculostomy (ETV) with or without choroid plexus coagulation (ETV/CPC) is an appealing alternate strategy that avoids the morbidity and complications associated with shunts. The exact criteria for ETV-CPC candidacy and best metrics for outcome analysis remain active areas of debate and controversy. Similarly, neurosurgical management C2M, has centered upon the indications and clinical thresholds for performing posterior fossa surgical decompression. Tethered spinal cord management incorporates the diagnosis and surgical management of adhesions formed at the initial closure site, the consequent longitudinal traction related stress on the cord and the resulting neurologic signs and symptoms.

Fetoscopic Multilayer, Dural Patch Closure Technique for Intrauterine Myelomeningocele Repair: 2-Dimensional Operative Video

Myelomeningocele (MMC) is the most common open neural tube defect associated with long-term survival. In 2011, The Management of Myelomeningocele Study (MOMS) trial demonstrated that fetal repair for MMC reduced the rate of shunted hydrocephalus and improved developmental, motor, and ambulation outcomes at 30 mo compared to postnatal intervention.1 Recent studies have demonstrated the safety and feasibility of fetoscopic MMC repair as well as reduction in preterm birth, lower risk of uterine dehiscence, and the option of vaginal delivery with this approach compared to open fetal repair.2-4 The patient is a 25-yr-old female, G4 P2, who presented at 20 wk's gestation with ultrasound findings concerning for MMC and Chiari II malformation. These findings were further corroborated with fetal magnetic resonance imaging. After extensive prenatal counseling in a multidisciplinary fashion and discussion regarding risks and benefits of prenatal closure of the MMC, the patient chose to undergo prenatal repair and surgical consent was obtained. At 25 wk's gestation, the patient underwent a fetoscopic multilayer closure with dural patch repair using a standardized, 3-port, carbon dioxide insufflation technique for the intrauterine treatment of MMC without any postoperative complications. The duration of the entire procedure was 275 min. At 36 wk's and 1 d's gestational age, the patient had a spontaneous vaginal delivery, resulting in a healthy male newborn. The surgical site was well healed without complications, and follow-up radiographic imaging was reassuring. This edited, 2-dimensional operative video highlights the key steps of the fetoscopic closure with follow-up postnatal clinical and radiographic outcomes.