Long-Term Neurocognitive Outcomes in Sagittal Synostosis: The Impact of Reoperation.

INTRODUCTION: Optimal age at surgery in nonsyndromic sagittal craniosynostosis continues to be debated. Previous reports suggest that earlier age at whole vault cranioplasty more frequently requires reoperation. It is unknown, however, whether reoperation affects neurocognitive outcome. This study examined the impact of reoperation on neurocognitive outcome in children with nonsyndromic sagittal craniosynostosis using comprehensive neurocognitive testing. METHODS: Forty-seven school-age children (age 5-16 years) with nonsyndromic sagittal craniosynostosis who underwent whole-vault cranioplasty were included in this analysis. Participants were administered a battery of standardized neuropsychological testing to measure neurocognitive outcomes. RESULTS: Thirteen of the 47 participants underwent reoperation (27.7%); 11 out of the 13 reoperations were minor revisions while 2 reoperations were cranioplasties. Reoperation rate was not statistically different between patients who had earlier surgery (at age ≤6 months) versus later surgery (at age >6 months) (P > 0.05). Nonreoperated patients who had only one later-in-life surgery did not perform statistically better than reoperated patients on any outcome measure of neurocognitive function, including IQ, academic achievement, visuomotor integration, executive function, and behavior. Comparing reoperated earlier surgery patients with nonreoperated later surgery patients, reoperated earlier surgery patients had higher full-scale and verbal IQ (P < 0.05), scored higher on word reading, reading comprehension, spelling, numerical operations, and visuomotor integration (P < 0.05), and had fewer indicators of suspected learning disabilities (P < 0.01) compared to nonreoperated later surgery patients. CONCLUSION: Reoperation rate after whole vault cranioplasty was 27.7%, with few cases of repeat cranioplasty (4.2% of all patients). Reoperation was not associated with worse neurocognitive outcome. Reoperated earlier surgery patients in fact performed better in IQ, academic achievement and visuomotor integration when compared to nonreoperated later surgery patients.

Exome sequencing implicates genetic disruption of prenatal neuro-gliogenesis in sporadic congenital hydrocephalus.

Congenital hydrocephalus (CH), characterized by enlarged brain ventricles, is considered a disease of excessive cerebrospinal fluid (CSF) accumulation and thereby treated with neurosurgical CSF diversion with high morbidity and failure rates. The poor neurodevelopmental outcomes and persistence of ventriculomegaly in some post-surgical patients highlight our limited knowledge of disease mechanisms. Through whole-exome sequencing of 381 patients (232 trios) with sporadic, neurosurgically treated CH, we found that damaging de novo mutations account for >17% of cases, with five different genes exhibiting a significant de novo mutation burden. In all, rare, damaging mutations with large effect contributed to ~22% of sporadic CH cases. Multiple CH genes are key regulators of neural stem cell biology and converge in human transcriptional networks and cell types pertinent for fetal neuro-gliogenesis. These data implicate genetic disruption of early brain development, not impaired CSF dynamics, as the primary pathomechanism of a significant number of patients with sporadic CH.

De Novo Mutation in Genes Regulating Neural Stem Cell Fate in Human Congenital Hydrocephalus.

Congenital hydrocephalus (CH), featuring markedly enlarged brain ventricles, is thought to arise from failed cerebrospinal fluid (CSF) homeostasis and is treated with lifelong surgical CSF shunting with substantial morbidity. CH pathogenesis is poorly understood. Exome sequencing of 125 CH trios and 52 additional probands identified three genes with significant burden of rare damaging de novo or transmitted mutations: TRIM71 (p = 2.15 × 10-7), SMARCC1 (p = 8.15 × 10-10), and PTCH1 (p = 1.06 × 10-6). Additionally, two de novo duplications were identified at the SHH locus, encoding the PTCH1 ligand (p = 1.2 × 10-4). Together, these probands account for ∼10% of studied cases. Strikingly, all four genes are required for neural tube development and regulate ventricular zone neural stem cell fate. These results implicate impaired neurogenesis (rather than active CSF accumulation) in the pathogenesis of a subset of CH patients, with potential diagnostic, prognostic, and therapeutic ramifications.

Two locus inheritance of non-syndromic midline craniosynostosis via rare SMAD6 and common BMP2 alleles.

Premature fusion of the cranial sutures (craniosynostosis), affecting 1 in 2000 newborns, is treated surgically in infancy to prevent adverse neurologic outcomes. To identify mutations contributing to common non-syndromic midline (sagittal and metopic) craniosynostosis, we performed exome sequencing of 132 parent-offspring trios and 59 additional probands. Thirteen probands (7%) had damaging de novo or rare transmitted mutations in SMAD6, an inhibitor of BMP - induced osteoblast differentiation (p<10-20). SMAD6 mutations nonetheless showed striking incomplete penetrance (<60%). Genotypes of a common variant near BMP2 that is strongly associated with midline craniosynostosis explained nearly all the phenotypic variation in these kindreds, with highly significant evidence of genetic interaction between these loci via both association and analysis of linkage. This epistatic interaction of rare and common variants defines the most frequent cause of midline craniosynostosis and has implications for the genetic basis of other diseases.

Normalization of brain morphology after surgery in sagittal craniosynostosis.

OBJECT Nonsyndromic craniosynostosis (NSC) is associated with significant learning disability later in life. Surgical reconstruction is typically performed before 1 year of age to correct the cranial vault morphology and to allow for normalized brain growth with the goal of improving cognitive function. Yet, no studies have assessed to what extent normalized brain growth is actually achieved. Recent advances in MRI have allowed for automated methods of objectively assessing subtle and pronounced brain morphological differences. The authors used one such technique, deformation-based morphometry (DBM) Jacobian mapping, to determine how previously treated adolescents with sagittal NSC (sNSC) significantly differ in brain anatomy compared with healthy matched controls up to 11.5 years after surgery. METHODS Eight adolescent patients with sNSC, previously treated via whole-vault cranioplasty at a mean age of 7 months, and 8 age- and IQ-matched control subjects without craniosynostosis (mean age for both groups = 12.3 years), underwent functional 3-T MRI. Statistically significant group tissue-volume differences were assessed using DBM, a whole-brain technique that estimates morphological differences between 2 groups at each voxel (p < 0.01). Group-wise Jacobian volume maps were generated using a spacing of 1.5 mm and a resolution of 1.05 × 1.05 × 1.05 mm(3). RESULTS There were no significant areas of volume reduction or expansion in any brain areas in adolescents with sNSC compared with controls at a significance level of p < 0.01. At the more liberal threshold of p < 0.05, two areas of brain expansion extending anteroposteriorly in the right temporooccipital and left frontoparietal regions appeared in patients with sNSC compared with controls. CONCLUSIONS Compared with previous reports on untreated infants with sNSC, adolescents with sNSC in this cohort had few areas of brain dysmorphology many years after surgery. This result suggests that comprehensive cranioplasty performed at an early age offers substantial brain normalization by adolescence, but also that some effects of vault constriction may still persist after treatment. Specifically, few areas of expansion in frontoparietal and temporooccipital regions may persist. Overall, data from this small cohort support the primary goal of surgery in allowing for more normalized brain growth. Larger samples, and correlating degree of normalization with cognitive performance in NSC, are warranted.

Intracranial infantile hemangiopericytoma.

Intracranial infantile hemangiopericytomas (HPCs) are exceedingly rare lesions. Only 11 cases have been previously reported in the literature. As such, little is known about the etiology, long-term prognosis, and optimal treatment paradigm. Clinically, they are consistently less aggressive than those in adults. The authors present the case of a 2-month-old boy with an intracranial HPC, review the available literature, discuss the evolving concepts of what defines an HPC, and offer a potential explanation to how HPC histology might relate to the clinical behavior of these lesions.

Thoracic epidural teratoma: case report and review of the literature.

PURPOSE: Spinal teratomas comprise a rare subset of spinal cord tumors, and here, we describe an even rarer childhood thoracic extradural-intracanalicular teratoma. The clinical presentation, management, and pathophysiology of these tumors are reviewed to promote recognition and guide treatment of these lesions. METHODS: We report the case of a 21-month-old boy who presented with marked spasticity, as well as failure to ambulate and meet motor milestones. Additionally, we provide a literature review of spinal teratomas, including their clinical presentation, work-up, pathophysiology, and underlying genetics. RESULTS: An MRI of the spine revealed a large dorsal epidural tumor extending from T3 to T10 with heterogeneous contrast enhancement and severe spinal cord compression. The tumor was resected revealing a cystic mass with tissue resembling hair, muscle, as well as cartilage; pathology confirmed the diagnosis of teratoma. Gross total resection was achieved, and the child eventually gained ambulatory function. CONCLUSIONS: Given that spinal teratomas are rare entities that can present with significant neurologic compromise, they must remain on clinicians' differentials. Unfortunately, the exact origin of these tumors remains inconclusive and requires further investigation.

Decompressive hemicraniectomy for ischemic stroke in the pediatric population.

Adult patients with space-occupying hemispheric infarctions have a poor prognosis, with an associated fatality rate of 80%. Decompressive hemicraniectomy (DH) has been studied as a treatment option for patients with malignant cerebral infarction refractory to maximal medical therapy, with reasonable outcomes demonstrated in the adult population if the patient is decompressed within 48 h. However, there are no randomized controlled trials in the pediatric literature to make the same claims. In this study, we evaluated the current literature in regards to DH following malignant stroke in the pediatric population. We found that excellent recovery, with an acceptable quality of life, is possible, particularly in the pediatric patient. Our cohort suggests that pediatric intervention beyond the 48-h time interval may still lead to positive outcomes, unlike adult patients. Regardless, randomized controlled trials are needed to determine optimal timing of intervention following symptom onset, as well as to identify predictors for positive outcome in the pediatric population.

Intracranial compartment volume changes in sagittal craniosynostosis patients: influence of comprehensive cranioplasty.

BACKGROUND: A retrospective analysis of intracranial compartment volume changes in children with sagittal craniosynostosis was performed to clarify the therapeutic objectives of corrective surgery. METHODS: Chart and computed tomographic review of 53 consecutive children with previously unoperated sagittal synostosis was performed, and preoperative and postoperative computed tomographic scans were examined and compared with 143 age- and gender-matched controls. RESULTS: Preoperative mean intracranial compartment volume and mean brain tissue volume of each subgroup were age dependent. Brain volume was less in unoperated male sagittal synostosis patients (<6 months old) compared with controls (672.63 ml versus 716.14 ml). Brain tissue volume was approximately the same as controls for the 7- to 12-month and 12- to 30-month age groups. Long-term brain volume, however, again became less than controls with longer periods without treatment (31 to 60 months, 1050.6 versus 1291.51 ml, respectively). Intracranial compartment volume was less in unoperated male sagittal synostosis patients (<6 months old) compared with controls (706.6 ml versus 757.76 ml). Preoperative mean intracranial compartment volume, however, was greater than in controls in the 7- to 12-month (979.78 versus 970.34 ml) and 13- to 30-month age groups (1108.23 versus 1177.52 ml). Long term (31 to 60 months), however, intracranial compartment volume was less in untreated sagittal synostosis patients (1206.3 ml versus 1311.37 ml). Comparing day-1 postoperative sagittal synostosis patient data to age- and gender-matched controls to 1 year postoperatively, the operated patients develop an equivalent increase in skull growth compared with normals. CONCLUSIONS: Intracranial compartment volume is increased preoperatively in untreated sagittal synostosis patients older than 6 months. Intracranial compartment volume enlargement is largely attributable to an increase in brain volume. Comprehensive cranioplasty before 12 months of age increases intracranial compartment volume over normal growth.

Primary myxopapillary ependymoma of the medulla: case report.

OBJECTIVE: Myxopapillary ependymoma is a subclassification of ependymoma that is thought to be nearly exclusive to the conus medullaris or filum terminale. Primary intracerebral or brainstem myxopapillary ependymomas are rare. CLINICAL PRESENTATION: An 8-year-old child presented with a 5-month history of nausea and vomiting and a 1-week history of headache. Magnetic resonance imaging revealed a nodular mass in the medulla with an associated cyst extending into the fourth ventricle. INTERVENTION: A suboccipital craniotomy was performed, and a gross total resection of the lesion and cyst was achieved. Histological examination confirmed the diagnosis of myxopapillary ependymoma. A discussion of other reported cases of extraspinal myxopapillary ependymomas is presented. CONCLUSION: This is the first report of a case of myxopapillary ependymoma, confirmed by histology, in the medulla. Although rare, myxopapillary ependymomas outside of the filum terminale do exist.

Primary, non-exophytic, optic nerve germ cell tumors.

Tumors of the optic chiasm are relatively uncommon and usually associated with phakomatoses such as neurofibromatosis. Even more rare is the presentation of a primary, non-exophytic, isolated optic chiasm germ cell tumor (GCT). These tumors have imaging characteristics nearly indistinguishable from optic chiasmatic gliomas (OCGs). Herein we describe two cases of young men who presented with similar findings of progressive, painless visual loss and hypothalamic-pituitary-adrenal axis dysfunction including diabetes insipidus. Brain imaging was non-diagnostic and suggestive of an OCG. Pathology demonstrated GCTs in each case highlighting the importance of biopsy confirmation of the diagnosis. Both patients underwent a pterional craniotomy and sub-frontal approach to the optic chiasm. The chiasm was diffusely enlarged and discolored in each case without evidence of sellar, suprasellar or perichiasmatic pathology. Pathology demonstrated a malignant mixed GCT in the first patient and a germinoma in the second. This case series highlights the importance of tissue biopsy for patients with progressive symptoms from optic chiasm tumors. Furthermore, this is the first report of a primary, non-exophytic malignant mixed GCT. As the treatment regimens differ widely between optic chiasm GCTs and chiasm gliomas, tissue diagnosis is important.

Longitudinal brain volume changes in preterm and term control subjects during late childhood and adolescence.

OBJECTIVE: Although preterm very low birth weight infants have a high prevalence of neuroanatomical abnormalities when evaluated at term-equivalent age, patterns of brain growth in prematurely born infants during school age and adolescence remain largely unknown. Our goal was to test the hypothesis that preterm birth results in long-term dynamic changes in the developing brain. METHODS: We performed serial volumetric MRI studies at ages 8 and 12 years in 55 preterm infants born weighing 600 to 1250 g and 20 term control children who participated in the follow-up component of a prospective, randomized, placebo-controlled intraventricular hemorrhage prevention study. RESULTS: Total brain volumes increased 2% to 3% between the ages of 8 and 12 years for both preterm and term children. These changes involved reductions in cerebral gray matter while white matter increased. Between 8 and 12 years of age, preterm subjects experienced a 2% decrease in left cerebral gray matter compared with a 10% reduction in left cerebral gray for term controls. For right cerebral gray matter, preterm children experienced a 3% decrease in volume between years 8 and 12, compared with 9% for term controls (group-by-time). In contrast, preterm subjects had a 10% increase in cerebral white matter volumes bilaterally between ages 8 and 12 years, compared with >26% increases for both hemispheres for term controls. Significant differences in regional volume changes between study groups were found in bilateral temporal gray and in parietal white matter. CONCLUSIONS: Preterm birth continues to perturb the trajectory of cerebral development during late childhood and early adolescence with preterm children, showing both lower gray matter reduction and less white matter gain over time compared with term control subjects.

Gastric bypass: a risk factor for neural tube defects? Case report.

Gastric bypass surgery has become a safe and acceptable surgical weight loss treatment for individuals who suffer from morbid obesity. Patients who undergo this procedure are subject to vitamin deficiencies due to an iatrogenic malabsorptive state. Folate, a vitamin known for its role in the prevention of neural tube defects (NTDs), can be part of the deficiency spectrum resulting from this procedure. The authors describe the case of a woman who was nonadherent to multivitamin treatment after undergoing gastric bypass surgery. Her lack of understanding and appreciation of the relationship between gastric bypass surgery, folate deficiency, and NTDs may have contributed to her noncompliance with daily multivitamin consumption. As a result, her potential problems with folate absorption could have contributed to her subsequently giving birth to a child with a myelomeningocele. Thus, patient awareness and counseling along with aggressive vitamin supplementation among this particular population may help prevent the occurrence of NTDs after gastric bypass surgery.

Cortical recruitment patterns in children born prematurely compared with control subjects during a passive listening functional magnetic resonance imaging task.

OBJECTIVES: To use functional magnetic resonance imaging (fMRI) to test the hypothesis that subjects who were born prematurely develop alternative systems for processing language. STUDY DESIGN: Subjects who were born prematurely (n = 14; 600-1250 g birthweight) without neonatal brain injury and 10 matched term control subjects were examined with a fMRI passive listening task of language, the Clinical Evaluation of Language Fundamentals (CELF) and portions of the Comprehensive Test of Phonological Processing (CTOPP). The fMRI task was evaluated for both phonologic and semantic processing. RESULTS: Although there were differences in CELF scores between the subjects born prematurely and control subjects, there were no significant differences in the CTOPP measures in the 2 groups. fMRI studies demonstrated that the groups differentially engaged neural systems known to process language. Children born at term were significantly more likely to activate systems for the semantic processing of language, whereas subjects born prematurely preferentially engaged regions that subserve phonology. CONCLUSIONS: At 12 years of age, children born prematurely and children born at term activate neural systems for the auditory processing of language differently. Subjects born prematurely engage different networks for phonologic processing; this strategy is associated with phonologic language scores that are similar to those of control subjects. These biologically based developmental strategies may provide the substrate for the improving language skills noted in children who are born prematurely.

A functional magnetic resonance imaging study of the long-term influences of early indomethacin exposure on language processing in the brains of prematurely born children.

BACKGROUND: Previous studies have demonstrated that indomethacin lowers the incidence and decreases the severity of intraventricular hemorrhage, as well as improves the cognitive outcome, in prematurely born male infants. OBJECTIVE: The purpose of this work was to use functional magnetic resonance imaging to test the hypothesis that neonatal indomethacin treatment would differentially affect brain activation across genders in school-aged, prematurely born children during performance of a language task. METHODS: Forty-seven prematurely born children (600-1250-g birth weight) and 24 matched term control subjects were evaluated using a functional magnetic resonance imaging passive language task and neurodevelopmental assessments that included the Wechsler Intelligence Scale for Children-III and the Peabody Picture Vocabulary Test-Revised. Neural activity was assessed during both phonologic and semantic processing in the functional magnetic resonance imaging protocol. RESULTS: Neurodevelopmental assessments demonstrated significant differences in full-scale, verbal, and performance intelligence quotient, as well as Peabody Picture Vocabulary Test scores, between the preterm and term control subjects. Rates of perinatal complications did not differ significantly across preterm treatment groups, but male preterm subjects randomly assigned to saline tended to have lower Peabody Picture Vocabulary Test-Revised scores than did all of the other preterm groups. During phonological processing, a significant treatment-by-gender effect was demonstrated in 3 brain regions: the left inferior parietal lobule, the left inferior frontal gyrus (Broca's area), and the right dorsolateral prefrontal cortex. CONCLUSIONS: These data demonstrate a differential effect of indomethacin administration early in postnatal life on the subsequent development of neural systems that subserve language functioning in these male and female preterm infants.

Sterile ascites from a ventriculoperitoneal shunt: a case report and review of the literature.

BACKGROUND: Symptomatic, sterile cerebrospinal fluid (CSF) ascites is a rare complication of ventriculoperitoneal (VP) shunt surgery. To date, reports in the literature have linked this unusual circumstance to various intra-abdominal, CNS, or nonspecific inflammatory causes. CASE REPORT: We present the case of a four-year-old boy with a recently fenestrated arachnoid cyst and VP shunt, who presented with sudden-onset, sterile CSF ascites. The ascites resolved with conversion of the preexisting VP shunt to a ventriculoatrial shunt.

Prevention of intraventricular hemorrhage by indomethacin in male preterm infants.

Our multicenter Indomethacin Intraventricular Hemorrhage (IVH) Prevention Trial demonstrated a reduction of IVH in preterm infants. Analysis of our cohort by sex showed indomethacin halved the incidence of IVH, eliminated parenchymal hemorrhage, and was associated with higher verbal scores at 3 to 8 years in boys.

Volumetric analysis of regional cerebral development in preterm children.

Preterm birth is frequently associated with both neuropathologic and cognitive sequelae. This study examined cortical lobe, subcortical, and lateral ventricle development in association with perinatal variables and cognitive outcome. High-resolution volumetric magnetic resonance imaging scans were acquired and quantified using advanced image processing techniques. Seventy-three preterm and 33 term control children ages 7.3-11.4 years were included in the study. Results indicated disproportionately enlarged parietal and frontal gray matter, occipital horn, and ventricular body, as well as reduced temporal and subcortical gray volumes in preterm children compared with control subjects. Birth weight was negatively correlated with parietal and frontal gray, as well as occipital horn volumes. Intraventricular hemorrhage was associated with reduced subcortical gray matter. Ventricular cerebrospinal fluid was negatively correlated with subcortical gray matter volumes but not with white matter volumes. Maternal education was the strongest predictor of cognitive function in the preterm group. Preterm birth appears to be associated with disorganized cortical development, possibly involving disrupted synaptic pruning and neural migration. Lower birth weight and the presence of intraventricular hemorrhage may increase the risk for neuroanatomic abnormality.