Neurodevelopmental outcome of fetal isolated ventricular asymmetry without dilation: a cohort study

OBJECTIVE

Fetal isolated ventricular asymmetry (IVA) is a relatively common finding in pregnancy, but data regarding its effect on neurodevelopmental outcome are scarce and founded principally on ultrasound-based studies. The purpose of this study was to assess the neurodevelopmental outcome of IVA cases in a magnetic resonance imaging (MRI)-based study.

METHODS

Cases referred for fetal brain MRI as part of the assessment of IVA without ventriculomegaly (lateral ventricular atrial diameter ≤ 10 mm), identified during routine ultrasound examination, were assessed for possible inclusion. Asymmetry was defined as a difference in width of ≥ 2 mm between the two lateral ventricles. Forty-three cases were included in the study group and compared with a control group of 94 normal cases without IVA. Children were assessed at ages 13-74 months using the Vineland-II Adaptive Behavior Scales (VABS-II).

RESULTS

VABS-II scores were within normal range. There was no significant difference in composite VABS-II score between the study and control groups (106.5 vs 108.0; P = 0.454). VABS-II scores did not differ between the groups when matched for gender and age at VABS-II interview (109.6 in study group vs 107.8 in control group; P = 0.690).

CONCLUSION

In cases of IVA without ventriculomegaly on MRI, neurodevelopmental test scores were normal and did not differ from cases without IVA. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Outcome of fetuses with prenatal diagnosis of isolated severe bilateral ventriculomegaly: systematic review and meta-analysis

OBJECTIVE

To quantify from the published literature survival and neurodevelopmental outcome of fetuses with prenatally detected isolated severe bilateral ventriculomegaly.

METHODS

MEDLINE, EMBASE and the Cochrane Library were searched electronically. Only cases with a prenatal diagnosis of apparently isolated severe ventriculomegaly and postnatal neurodevelopmental assessment were selected and included. Severe ventriculomegaly was defined as enlargement of the ventricular atria, with a diameter of greater than 15 mm in the transventricular plane. All cases in which the investigators were unable to detect associated structural abnormality, chromosomal abnormality or fetal infection, and in which the ventriculomegaly was therefore regarded as apparently isolated, were included. Those for which the etiology was identified prenatally were excluded, whereas those with postnatal identification of the underlying cause were not excluded, since this information was not available prenatally. The quality of the included studies was assessed using the Newcastle-Ottawa Scale (NOS) for cohort studies. Pregnancy outcomes such as termination, stillbirth, neonatal survival and developmental outcome of the baby, were recorded. The degree of disability was classified as no, mild or severe disability. Statistical assessment was performed by meta-analysis of proportions to combine data, weighting the studies using the inverse variance method and a random-effects model. Proportions and CIs were reported.

RESULTS

Eleven studies including 137 fetuses were found. Twenty-seven pregnancies underwent termination and were excluded. The remaining 110 fetuses with apparently isolated severe ventriculomegaly for which continuation of pregnancy was intended, form the study population. Overall quality assessed using NOS for cohort studies was good. Survival was reported in 95/110 (pooled proportion 87.9% (95% CI, 75.6-96.2%)) cases. In 15/110 (pooled proportion 12.1% (95% CI, 3.8-24.4%)), either stillbirth or neonatal demise was reported. No disability was reported in 41/95 survivors (pooled proportion 42.2% (95% CI, 27.5-57.6%)). However, 17/95 showed mild/moderate disability (pooled proportion 18.6% (95% CI, 7.2-33.8%)) and 37/95 were reported to have severe disability (pooled proportion 39.6% (95% CI, 30.0-50.0%)).

CONCLUSIONS

Four-fifths of fetuses with severe ventriculomegaly survive and, of these, just over two-fifths show normal neurodevelopment. The overall survivors without disability account for more than one third of the total. Given that many cases undergo termination of pregnancy and require longer follow-up in order to detect subtle abnormalities, mortality and prevalence of developmental delay may be even higher than that reported in this paper. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Anatomical subgroup analysis of the MERIDIAN cohort: ventriculomegaly

OBJECTIVE

To assess the contribution of fetal magnetic resonance imaging (MRI) in fetuses of the MERIDIAN cohort diagnosed with ventriculomegaly (VM) as the only abnormal intracranial finding on antenatal ultrasound.

METHODS

This was a subgroup analysis of the MERIDIAN study of fetuses with only VM diagnosed on ultrasound in women who had a subsequent MRI examination within 2 weeks and for whom outcome reference data were available. The diagnostic accuracy of ultrasound and MRI was reported in relation to the severity of VM. The difference in measurements of trigone size on the two imaging methods and the clinical impact of adding MRI to the diagnostic pathway were also studied.

RESULTS

In 306 fetuses with VM, ultrasound failed to detect 31 additional brain abnormalities, having an overall diagnostic accuracy of 89.9% for ultrasound, whilst MRI correctly detected 27 of the additional brain abnormalities, having a diagnostic accuracy of 98.7% (P < 0.0001). There were other brain abnormalities in 14/244 fetuses with mild VM on ultrasound (diagnostic accuracy, 94.3%) and MRI correctly diagnosed 12 of these (diagnostic accuracy, 99.2%; P = 0.0005). There was a close agreement between the size of trigones measured on ultrasound and on MRI, with categorical differences in only 16% of cases, showing that MRI did not systematically overestimate or underestimate trigone size. Complete prognostic data were available in 295/306 fetuses and the prognosis category changed after MRI in 69/295 (23.4%) cases. The overall effect of MRI on clinical management was considered to be 'significant', 'major' or 'decisive' in 76/295 (25.8%) cases.

CONCLUSION

Our data suggest that a woman carrying a fetus with VM as the only intracranial finding on ultrasound should be offered an adjuvant investigation by MRI for further evaluation. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Cerebrospinal fluid flow in children with normal and dilated ventricles studied by MR imaging

Purpose: To quantify the cerebrospinal fluid (CSF) dynamics in the aqueduct of children with normal and dilated ventricles using MR phase-contrast technique.

Material and Methods: Eighteen patients (6 months to 17 years of age) with various neurological symptoms underwent routine brain MR imaging and CSF flow measurement in the aqueduct. Nine patients had normal ventricles, 5 had dilated ventricles and 4 had a ventriculoperitoneal shunt.

Results: The CSF velocity and flow rates in the aqueduct in patients with normal and dilated ventricles showed marked inter-individual variation and clear overlap. In a patient with tight aqueductal stenosis and increased ventricular pressure, pronounced CSF flow in the aqueduct was measured. Absence of flow in another patient with aqueductal stenosis was detected. Measurable although low flow in the aqueduct in 4 patients with a ventriculoperitoneal shunt was found.

Conclusion: Quantitative phase MR flow measurement in the aqueduct demonstrated aqueductal stenosis; these patients had either pronounced flow or no flow in the aqueduct.

Fetal ventriculomegalies during pregnancy course, outcome, and psychomotor development of born children

PURPOSE

The objectives of this study were as follows: to present the course and outcome of pregnancies complicated with fetal ventriculomegaly, determine the association between prenatal ultrasound diagnoses and definitive postnatal diagnosis or diagnoses after autopsy and additional analysis, and to monitor the psychomotor development of children born with ventriculomegaly.

MATERIALS AND METHODS

The survey was designed as retrospective study and included 62 pregnant women who were attending a regular ultrasound examinations at the Department of Gynecology and Obstetrics, Clinical Center of Serbia, or patients who were referred from other institutions in Serbia.

RESULTS

Ventriculomegalies were divided into three groups: mild, moderate, and severe or hydrocephalus. The most common were severe ventriculomegalies, with 34 cases (55%). Of all pregnancies complicated with ventriculomegalies, 61% were terminated. Among those continued, 88% had normal psychomotor development. In 97% ultrasonographic diagnosis was confirmed.

CONCLUSION

Majority of pregnancies complicated with ventriculomegaly were continued and most of the children born with anomalies had normal psychomotor development.

Surgery is associated with ventricular enlargement as well as cognitive and functional decline

INTRODUCTION

In preclinical studies, surgery/anesthesia contribute to cognitive decline and enhance neuropathologic changes underlying Alzheimer's disease (AD). Nevertheless, the link between surgery, anesthesia, apolipoprotein E ε4 (APOE ε4), and AD remains unclear.

METHODS

We performed a retrospective cohort analysis of two prospective longitudinal aging studies. Mixed-effects statistical models were used to assess the relationship between surgical/anesthetic exposure, the APOE genotype, and rate of change in measures of cognition, function, and brain volumes.

RESULTS

The surgical group (n = 182) experienced a more rapid rate of deterioration compared with the nonsurgical group (n = 345) in several cognitive, functional, and brain magnetic resonance imaging measures. Furthermore, there was a significant synergistic effect of anesthesia/surgery exposure and presence of the APOE ε4 allele in the decline of multiple cognitive and functional measures.

DISCUSSION

These data provide insight into the role of surgical exposure as a risk factor for cognitive and functional decline in older adults.

Left cerebral hemisphere and ventricular system abnormalities in a Mexican Meier Gorlin syndrome patient: widening the clinical spectrum

The Meier-Gorlin syndrome (MGS) or ear, patella, short stature syndrome (MIM #224690) is a rare disorder with bilateral microtia, aplasia or hypoplasia of the patellae and severe intra-uterine and post-natal growth retardation. We report the case of a 10-year-old male with MGS diagnosis, his parents were related, he also showed conductive hearing loss and maloclussion and long upper central incisors, more importantly he had asymmetry of the left cerebral hemisphere and ventricular system, his intelligence was normal. As far as we know, these abnormalities have not been previously described in patients with MGS and the present report corresponds to the first Mexican case described so far.

Severe second-trimester obstructive ventriculomegaly related to disorders of diencephalic, mesencephalic and rhombencephalic differentiation

By review of a series of cases, we set out to identify sonographic features suggestive of an obstructive mechanism in second-trimester fetuses with ventriculomegaly and describe developmental disorders related to pathological differentiation of the diencephalon, mesencephalon and rhombencephalon that lead to obstruction of cerebrospinal fluid flow. We studied retrospectively 11 fetuses referred for severe second-trimester ventriculomegaly of undetermined origin. Neurosonography was performed with detailed analysis of the third ventricle, thalami, cerebral aqueduct and cerebellum. The cerebral imaging data were compared with neuropathological data in eight patients, with a focus on the level and etiology of the obstruction. Parenchymal thinning and reduction of the pericerebral spaces were highly suggestive of ventriculomegaly due to an obstructive mechanism. The ventriculomegaly was related to diencephalosynapsis (thalamic fusion and third ventricle atresia) in five cases and partial/complete aqueduct stenosis in six; it was associated with cerebellar hypoplasia in six cases, including rhombencephalosynapsis in two cases. In nine patients, disorders of the diencephalon, mesencephalon and rhombencephalon were present. In cases of severe isolated ventriculomegaly in which sonographic features are suggestive of an obstructive mechanism, close examination of the third ventricle, thalami, aqueduct of Sylvius and cerebellum may reveal pathological differentiation of the diencephalon, mesencephalon or rhombencephalon, often in combination.

[Congenital mydriasis as an initial sign of septo-optic dysplasia]

Septo-optic dysplasia (SOD)[MIM182230] consisting of a heterogeneous and uncommon condition characterised by the classictriad: optic nerve hypoplasia, abnormalities of pituitary hormone, and defects of thebrain midline (including agenesis of the septum pellucidum and/or the corpus callosum; ithas also been described associated cortical malformations, it was referred to as SOD plus syndrome).We report the first known case in which the initial diagnostic sign of SOD was a bilateralmydriasis as a manifestation ofhypoplasia of both optic nerves, pituitary hypoplasia andcerebral dysgenesis with neuronal migration disorder.We discuss thedifferential diagnosis of congenital mydriasis.

Serial fetal MRI for the diagnosis of Aicardi syndrome

Aicardi syndrome (AS) is defined by the triad of corpus callosum agenesis, chorioretinal "lacunae" and infantile spasms. Additional neuroimaging findings including migrational abnormalities are common. We report on serial neuroimaging findings of a female fetus with ventriculomegaly, corpus callosum agenesis and focal migrational abnormalities, suggestive of AS. Postnatal neuroimaging follow-up as well as ophthalmological evaluation and occurrence of infantile spasms confirmed the prenatally suspected diagnosis of AS. This case points out the key role of serial fetal magnetic resonance imaging (MRI) in detecting the full spectrum of pathologies associated with fetal ventriculomegaly. The associated neuroimaging findings may go undetected on prenatal ultrasound, but are important in terms of diagnosis and counseling of the parents. Additionally, this case emphasizes the importance of serial fetal MRI studies to more accurately delineate the progression of findings during brain development.

Enlargement of cerebral ventricles as an early indicator of encephalomyelitis

Inflammatory disorders of the central nervous system such as multiple sclerosis and acute disseminated encephalomyelitis involve an invasion of immune cells that ultimately leads to white matter demyelination, neurodegeneration and development of neurological symptoms. A clinical diagnosis is often made when neurodegenerative processes are already ongoing. In an attempt to seek early indicators of disease, we studied the temporal and spatial distribution of brain modifications in experimental autoimmune encephalomyelitis (EAE). In a thorough magnetic resonance imaging study performed with EAE mice, we observed significant enlargement of the ventricles prior to disease clinical manifestation and an increase in free water content within the cerebrospinal fluid as demonstrated by changes in T2 relaxation times. The increase in ventricle size was seen in the lateral, third and fourth ventricles. In some EAE mice the ventricle size started returning to normal values during disease remission. In parallel to this macroscopic phenomenon, we studied the temporal evolution of microscopic lesions commonly observed in the cerebellum also starting prior to disease onset. Our data suggest that changes in ventricle size during the early stages of brain inflammation could be an early indicator of the events preceding neurological disease and warrant further exploration in preclinical and clinical studies.

Periventricular nodular heterotopia on prenatal ultrasound and magnetic resonance imaging

OBJECTIVES

To describe the prenatal ultrasound and magnetic resonance imaging (MRI) findings suggestive of periventricular nodular heterotopia (PNH).

METHODS

This retrospective case series included fetuses referred to our institution for brain MRI between 2007 and 2012, which were diagnosed with PNH and confirmed by postnatal MRI or autopsy. The type of PNH, associated ventriculomegaly and associated malformations are reported.

RESULTS

We included 11 fetuses (nine female, two male) with a mean gestational age at diagnosis of 31 (range, 23-34) weeks. PNH lesions were small and diffuse (n = 7), large and multiple (n = 1) or single (n = 3). A targeted ultrasound examination performed before fetal MRI missed the diagnosis in four cases (one diffuse and three single); a further ultrasound examination performed after MRI diagnosed PNH in two of these four cases. Ventriculomegaly was present in six cases (four unilateral and two bilateral). PNH appeared in all cases as nodules of intermediate echogenicity protruding into the ventricular lumen. In all cases of diffuse PNH, the frontal horns and bodies of the lateral ventricles appeared square in shape on coronal view, with irregular borders on axial view. Associated cerebral malformations were observed in seven cases and included corpus callosal agenesis (n = 4, with additional malformations in two) and retrocerebellar cyst (n = 3). Extracerebral malformations were also present in two cases. Maternal MRI was performed in five of the six cases of isolated small and diffuse PNH in female fetuses, and demonstrated PNH in two of these.

CONCLUSION

PNH is underdiagnosed at prenatal ultrasound, even on targeted scans. Irregular ventricular borders on axial view and irregular square-shaped lateral ventricles on coronal view are suggestive of PNH at prenatal ultrasound.

Arl13b-regulated cilia activities are essential for polarized radial glial scaffold formation

The construction of cerebral cortex begins with the formation of radial glia. Once formed, polarized radial glial cells divide either symmetrically or asymmetrically to balance appropriate production of progenitor cells and neurons. Following birth, neurons use the processes of radial glia as scaffolding for oriented migration. Radial glia therefore provide an instructive structural matrix to coordinate the generation and placement of distinct groups of cortical neurons in the developing cerebral cortex. We found that Arl13b, a cilia-enriched small GTPase that is mutated in Joubert syndrome, was critical for the initial formation of the polarized radial progenitor scaffold. Using developmental stage-specific deletion of Arl13b in mouse cortical progenitors, we found that early neuroepithelial deletion of ciliary Arl13b led to a reversal of the apical-basal polarity of radial progenitors and aberrant neuronal placement. Arl13b modulated ciliary signaling necessary for radial glial polarity. Our findings indicate that Arl13b signaling in primary cilia is crucial for the initial formation of a polarized radial glial scaffold and suggest that disruption of this process may contribute to aberrant neurodevelopment and brain abnormalities in Joubert syndrome-related ciliopathies.

Colpocephaly in adults

Colpocephaly is a congenital abnormality in the ventricular system of the brain. The radiological diagnosis is usually made in the perinatal period and later presages intellectual disability. Adult cases of newly diagnosed colpocephaly have only rarely been reported. We have studied an adult with massive colpocephaly who is an otherwise functional woman. The diagnosis should be considered in patients with ventriculomegaly disproportionately affecting the occipital horns and must be differentiated from the more common form of adult ventriculomegaly-idiopathic normal pressure hydrocephalus (NPH).

Chronic daily headache in a patient with cavum septum pellucidum and cavum verge

Cavum septum pellucidum (CSP) and cavum Vergae (CV) are unusual variants and usually asymptomatic, but their expansion or inside lesions can produce symptoms by mass effect. A 46-year-old female Taiwanese worker presented with chronic daily headaches for eight years. Magnetic resonance imaging revealed coexistent CSP and CV. She declined surgical drainage recommended by a neurosurgeon and thus visited our clinic for a second opinion. Physical examination did not show any abnormality. With the help of the patient's one-month headache diary, she was diagnosed with chronic migraine according to the International Classification of Headache Disorders, 2(nd) edition, with further modification in 2006. In addition, hypertension was also identified. Over the following week, taking a daily selective β1-antagonist relieved the headache and hypertension. The medication was continued and the following year was uneventful. Therefore, the chronic daily headache was ascribed to chronic migraine, rather than symptomatic CSP and CV.

[Anormalies of the fetal posterior fossa during second trimester--diagnosis and management]

Six cases of Dandy-Walker malformation are presented. Five of them, diagnosed in 18-20 gestation weeks, respectively ended up in intermission of the pregnancy in second trimester and one case, diagnosed in 29-30 gestation weeks ended up in giving birth to a hypotrophical foetus in a good general state. The opportunities for diagnosis by 2D/3D echography have been considered in accordance with the new classification of abnormality of the fetal posterior fossa fluid collections. This is a clinical approach and a possible way out for the pregnancy and the new-born baby.

[Ocular coloboma and results of brain MRI: preliminary results]

INTRODUCTION

Congenital ocular colobomas are the result of a failure in closure of the embryonal fissure. We present a prospective study (2007-2011) in which we report brain MRI findings in children with ocular coloboma.

PATIENTS AND METHODS

Thirty-five children (54 eyes) were included; 15 boys, 20 girls with a median age of 24.0 months (1.0-96.0) at first presentation. Within 2 to 3 months following complete ophthalmologic examination, brain MRI was performed.

RESULTS

Colobomas were bilateral in 19 cases and unilateral in 16 cases. Eleven different types of coloboma were identified. Of 54 eyes, 74% demonstrated optic nerve coloboma, of which 28 were severe. Of 35 MRI's performed, abnormalities were present in 86%: gyration abnormalities (n=21), lateral ventricular dilatation (n=17), dilatation of the Virchow-Robin and subarachnoid spaces (n=14), signal abnormalities and brain stem malformations (n=14), white matter signal abnormalities (n=11), corpus callosum abnormalities (n=10). Most of these abnormalities were related. Gyration abnormalities were the most frequent. There was no significant association between the severity of the coloboma and the abnormalities found (P=1.0). Likewise, there was no significant association of gyration abnormalities with the severity of coloboma in children (P=1.0).

DISCUSSION AND CONCLUSION

This study shows, for the first time, the existence of frequent cerebral abnormalities on MRI in children with ocular coloboma. The most common abnormality being gyration abnormalities, in 60% of cases.

Callosal dysgenesis in fetuses with ventriculomegaly: levels of agreement between imaging modalities and postnatal outcome

OBJECTIVE

To assess neurodevelopmental outcome of fetuses diagnosed with callosal abnormalities after referral for ventriculomegaly.

METHODS

This sub-analysis of a prospective study of 430 fetuses, which were referred for ventriculomegaly and underwent sonography and magnetic resonance imaging (MRI), included those fetuses with a diagnosis of corpus callosal abnormalities after recruitment into the main study. Between three and six radiologists independently reviewed ultrasound and MR images and recorded central nervous system (CNS) abnormalities, with final diagnoses being decided by consensus. Postnatal outcomes of fetuses with callosal abnormalities were compared between those with and those without other abnormalities.

RESULTS

Callosal abnormalities were detected in 13% (58/430) of the fetuses referred with ventriculomegaly. Callosal dysgenesis was isolated in 24% (14/58) of these cases, with the remainder complicated by CNS, karyotypic or other major abnormalities. Five fetuses diagnosed prenatally as having isolated callosal abnormalities had additional CNS findings on postnatal assessment. Preconference kappa for callosal abnormalities was 0.76 for ultrasound and 0.78 for MRI, indicating that these investigations had a similar level of operator dependence. Neurodevelopmental outcome was normal or showed only mild delay that resolved in 67% (8/12) children with isolated callosal abnormalities compared to 7% (2/27) in those with non-isolated callosal abnormalities (P = 0.003).

CONCLUSION

Callosal abnormalities are present in a significant proportion of fetuses with a diagnosis of ventriculomegaly. Isolated callosal abnormalities are associated with normal neurodevelopmental outcome in approximately two-thirds of fetuses.

Cerebral ventricular system in fetuses with open spina bifida at 11-13 weeks' gestation

OBJECTIVE

To determine if in fetuses with open spina bifida at 11-13 weeks' gestation there are alterations in the cerebral ventricular system.

METHODS

In this study we selected 10 cases of open spina bifida and 410 normal singleton pregnancies which subsequently resulted in the delivery of phenotypically normal neonates. In all cases transvaginal sonography was carried out at 11-13 weeks' gestation and three-dimensional (3D) brain volumes were acquired. The fetal head was systematically assessed in a series of transverse views and measurements were obtained of the area of the lateral ventricles, the diameter of the roof of the third ventricle, the diameter of the aqueduct of Sylvius and the diameter of the fourth ventricle. The measurements obtained on the normal and affected fetuses were compared.

RESULTS

In normal fetuses the area of the lateral ventricles and the diameter of the roof of the third ventricle increased, the diameter of the aqueduct of Sylvius decreased and the diameter of the fourth ventricle did not change significantly with biparietal diameter (BPD). In fetuses with open spina bifida, compared with normal fetuses, the measurements of the lateral ventricle area, the diameter of the roof of the third ventricle, the diameter of the aqueduct of Sylvius and the diameter of the fourth ventricle were significantly decreased (P < 0.01).

CONCLUSION

In fetuses with open spina bifida at 11-13 weeks' gestation the intracranial collection of cerebrospinal fluid is substantially reduced.

Volumetric and surface-based 3D MRI analyses of fetal isolated mild ventriculomegaly: brain morphometry in ventriculomegaly

Diagnosis of fetal isolated mild ventriculomegaly (IMVM) is the most common brain abnormality on prenatal ultrasound. We have set to identify potential alterations in brain development specific to IMVM in tissue volume and cortical and ventricular local surface curvature derived from in utero magnetic resonance imaging (MRI). Multislice 2D T2-weighted MRI were acquired from 32 fetuses (16 IMVM, 16 controls) between 22 and 25.5 gestational weeks. The images were motion-corrected and reconstructed into 3D volumes for volumetric and curvature analyses. The brain images were automatically segmented into cortical plate, cerebral mantle, deep gray nuclei, and ventricles. Volumes were compared between IMVM and control subjects. Surfaces were extracted from the segmentations for local mean surface curvature measurement on the inner cortical plate and the ventricles. Linear models were estimated for age-related and ventricular volume-associated changes in local curvature in both the inner cortical plate and ventricles. While ventricular volume was enlarged in IMVM, all other tissue volumes were not different from the control group. Ventricles increased in curvature with age along the atrium and anterior body. Increasing ventricular volume was associated with reduced curvature over most of the ventricular surface. The cortical plate changed in curvature with age at multiple sites of primary sulcal formation. Reduced cortical folding was detected near the parieto-occipital sulcus in IMVM subjects. While tissue volume appears to be preserved in brains with IMVM, cortical folding may be affected in regions where ventricles are dilated.

Abnormal or delayed development of the posterior membranous area of the brain: anatomy, ultrasound diagnosis, natural history and outcome of Blake's pouch cyst in the fetus

OBJECTIVES

To review the normal and pathological development of the posterior membranous area (PMA) in the fetal brain, to define sonographic criteria with which to diagnose a Blake's pouch cyst (BPC) in the fetus and to review the ultrasound features, associations and outcome of 19 cases of BPC seen at our center over the last 5 years.

METHODS

We conducted a MEDLINE search using the terms 'Blake's pouch', with or without 'fourth ventricle' or '4(th) ventricle', with or without 'roof' and identified articles describing normal and/or abnormal development of the PMA, whether or not they were cited in the limited clinical literature on BPC. A description of the normal and abnormal development of BPC was derived by collating these articles. The clinical retrospective study included 19 cases of posterior fossa anomalies with a final diagnosis of BPC seen at our institution. The following variables were assessed: referral indication, gestational age at diagnosis, ultrasound and magnetic resonance imaging (MRI) findings, associated anomalies, natural history and pregnancy and neonatal outcome. A transvaginal three-dimensional (3D) ultrasound examination was performed in all cases and 15 cases underwent MRI. To confirm the diagnosis, postnatal MRI, transfontanellar ultrasound or autopsy were available in all cases.

RESULTS

Among the 19 cases reviewed, referral indications were: suspicion of vermian abnormality in 11 (58%) cases and other non-central nervous system anomaly in eight (42%) cases. Sonographically, all cases showed the following three signs: 1) normal anatomy and size of the vermis; 2) mild/moderate anti-clockwise rotation of the vermis; 3) normal size of the cisterna magna. On 3D ultrasound, the upper wall of the cyst was clearly visible in 11/19 cases, with choroid plexuses on the superolateral margin of the cyst roof. On follow-up, the BPC had disappeared by 24-26 gestational weeks in six of the 11 cases which did not undergo termination of pregnancy (TOP), and remained unaltered until birth in the other five cases. There were associated anomalies in eight (42%) cases, in five of which this consisted of or included congenital heart disease. Karyotype was available in 14 cases, two of which were abnormal (both trisomy 21). Regarding pregnancy outcome, there were eight (42%) TOPs, two (10%) neonatal deaths and nine (48%) survivors. One neonate, in whom the BPC had disappeared by the time of birth, had obstructive hydrocephaly confirmed. Another neonate was diagnosed with Down syndrome after birth. Excluding the Down syndrome baby, neurodevelopmental outcome was normal at the time of writing in all eight cases.

CONCLUSIONS

Based on our analysis of ultrasound features, we propose that for BPC to be diagnosed in a fetus the following three criteria should be fulfilled: 1) normal anatomy and size of the vermis; 2) mild/moderate anti-clockwise rotation of the vermis; 3) normal size of the cisterna magna. Furthermore, we found that BPC can undergo delayed fenestration at 24-26 weeks in more than 50% of cases. Finally, it seems that BPC shows a risk of association with extracardiac anomalies (heart defects in particular) and, to a lesser extent, trisomy 21.

Deficiency of mDia, an actin nucleator, disrupts integrity of neuroepithelium and causes periventricular dysplasia

During development of the central nervous system, the apical-basal polarity of neuroepithelial cells is critical for homeostasis of proliferation and differentiation of neural stem cells. While adherens junctions at the apical surface of neuroepithelial cells are important for maintaining the polarity, the molecular mechanism regulating integrity of these adherens junctions remains largely unknown. Given the importance of actin cytoskeleton in adherens junctions, we have analyzed the role of mDia, an actin nucleator and a Rho effector, in the integrity of the apical adherens junction. Here we show that mDia1 and mDia3 are expressed in the developing brain, and that mDia3 is concentrated in the apical surface of neuroepithelium. Mice deficient in both mDia1 and mDia3 develop periventricular dysplastic mass widespread throughout the developing brain, where neuroepithelial cell polarity is impaired with attenuated apical actin belts and loss of apical adherens junctions. In addition, electron microscopic analysis revealed abnormal shrinkage and apical membrane bulging of neuroepithelial cells in the remaining areas. Furthermore, perturbation of Rho, but not that of ROCK, causes loss of the apical actin belt and adherens junctions similarly to mDia-deficient mice. These results suggest that actin cytoskeleton regulated by Rho-mDia pathway is critical for the integrity of the adherens junctions and the polarity of neuroepithelial cells, and that loss of this signaling induces aberrant, ectopic proliferation and differentiation of neural stem cells.

[Outcome and prognosis of isolated mild fetal ventriculomegaly in uterus]

OBJECTIVE

To investigate outcome and prognosis of isolated mild fetal ventriculomegaly (IMV) of fetus in uterus.

METHODS

From Jan. 2006 to Dec. 2009, 18 200 singleton pregnancy women from 20 weeks gestation underwent prenatal ultrasonography examination in Department of Obstetrics and Gynecology, Second Affiliated Hospital of Wenzhou Medical College. One hundred and forty-eight women with IMV (transverse diameter of the atrium of the lateral ventricle measuring between 10 and 15 mm with no other abnormalities) were studied prospectively, which were divided into two groups: 99 women with transverse diameter of the lateral ventricle of 10 - 11 mm in group A and 49 women with transverse diameter lateral ventricle of 12 - 15 mm in group B. The changes of ventriculomegaly and the associated intracranial and extracranial anomalies were observed regularly every 2 or 4 weeks until delivery. The development of neurological system was also followed up.

RESULTS

(1) The overall incidence of IMV was 0.08% (148/18 200). The rate of bilateral ventriculomegaly were 20% (20/99) in group A and 51% (25/49) in group B, which reached statistical difference (P < 0.05). (2) Prognosis of fetus: 139 cases with 2 or more ultrasonographic examinations, IMV resolved throughout pregnancy in 41.7% (58/139), regressed in 7.9% (11/139), remained stable in 36.7% (51/139) and progressed in 13.7% (19/139). Five cases in group A and 11 cases in group B present progress, which reached significantly difference (P < 0.05). (3) One hundred and eleven cases infant were followed up for 5-12 months, the rate of psycho-motor developmental delay was 5.4% (6/111). The rate of neuro-developmental delay in progressed group (3/15) was higher than 2.5% (1/40) in resolved group, 0 (0/8) in regressed group and 4.2% (2/48) in remained stable group, which reached significantly difference (P < 0.05).

CONCLUSIONS

About 85% of cases of IMV resolved, regressed or remained stable in utero would exhibited good prognosis. IMV with a transverse atrial size ≥ 12 mm or progression in utero was usually associated with a poor prognosis, which should be observed carefully.

Prognosis of isolated mild to moderate fetal cerebral ventriculomegaly: a systematic review

AIMS

To ascertain risk of aneuploidy, infection and neurological abnormality for the fetus diagnosed with isolated mild (10.1-12.0 mm) to moderate (12.1-15.0 mm) cerebral ventriculomegaly and to compare the neurological outcome between symmetrical vs. asymmetrical and stable vs. progressive ventriculomegaly.

METHODS

A systematic review was conducted. Literature was identified by searching two bibliographical databases between 1980 and 2009 without language restrictions. The data extracted were inspected for heterogeneity. Overall rates and confidence intervals (CIs) for each prognostic factor were calculated. When comparative data existed, the odds ratio (OR) was calculated.

RESULTS

The search strategy yielded 2150 relevant citations of which 28 studies were included in the review. The overall rate of infection and chromosomal abnormality was 1.5 and 5% (95% CI 3, 7), respectively. The risk of neurological abnormality regardless of karyotype or infection screen was 14% (95% CI 10, 18) and this reduced to 12% (95% CI 9, 15) when both chromosomes and infection screen were normal. The risk of neurological abnormality was significantly lower in stable compared to progressive ventriculomegaly [OR 0.29 (95% CI 0.15, 0.58)]. No significant differences were detected when symmetrical vs. asymmetrical ventriculomegaly were compared [OR 0.91 (95% CI 0.34, 2.41)].

CONCLUSION

This systematic review provides the physician with some estimates of prognosis in cases of isolated mild to moderate ventriculomegaly.

Absence of the septum pellucidum associated with a midline fornical nodule and ventriculomegaly: a report of two cases

We report two autopsy cases that revealed the partial absence of the septum pellucidum with ventriculomegaly. In each case, the brain showed mild dilatation of both frontal horns of the lateral ventricles, normal third and fourth ventricles and no aqueductal stenosis. The posterior portion of the septum pellucidum was absent and the fornices were fused in a single midline nodule, abnormally displaced to a caudal position and lodged in the foramina of Monro. The brain base showed no apparent abnormalities; the optic nerves were well developed. We conclude that the caudally displaced fornix in the absence of the septum pellucidum may have intermittently obstructed the foramina of Monro and induced mild ventriculomegaly.

Supratentorial abnormalities in the Chiari II malformation, IV: the too-far-back ventricle

OBJECTIVE

The sonographic diagnosis of fetal myelomeningocele (MMC) has improved mainly because the diagnostic focus has shifted from observation of the spinal abnormality to observation of cranial abnormalities. We describe an abnormality in the position of the occipital horn in fetuses with MMC. The occipital horn appears to be too posterior in location when compared to healthy fetuses.

METHODS

We searched for all cases in which fetal MMC was sonographically detected from 1999 to 2009. Random controls from normal pregnancies were identified. We then measured the shortest distance of the edge of the occipital horn to the occipital bone in fetuses with MMC compared to healthy fetuses. Only fetuses with MMC who had normal-size ventricles were included.

RESULTS

A total of 91 fetuses with MMC were identified. Twenty-six fetuses had a normal ventricle size. The gestational age range in this cohort was 18 weeks 5 days to 30 weeks 0 days. The comparison group of 39 healthy fetuses all had normal ventricles and had a gestational age range of 18 weeks 3 days to 35 weeks 2 days. After adjusting for gestational age, the statistical analysis showed that fetuses with MMC had significantly shorter measured distances from the posterior edge of the occipital horn to the occipital bone than healthy fetuses (P = .003).

CONCLUSIONS

The occipital horn both appears to be and measures closer to the occipital bone in fetuses with MMC compared to healthy fetuses.

[Fetal ventriculomegaly: diagnosis using magnetic resonance imaging and its prognosis]

OBJECTIVE

To evaluate the diagnostic value of magnetic resonance imaging (MRI) on fetal ventriculomegaly identified through prenatal ultrasonography and the outcomes of these newborns were followed up.

METHODS

From March 2006 to July 2008, MRI was performed on 135 pregnant women whose fetuses diagnosed as fetal ventriculomegaly at an average of 32 gestational weeks in Shengjing Hospital Affiliated to China Medical University. Mild ventriculomegaly was defined when the width of unilateral or bilateral fetal cerebral ventricle triangle was 10-15 mm, moderate ventriculomegaly 16-20 mm and severe ventriculomegaly >20 mm. We introduced the Denver developmental screening test (DDST) to follow-up the mild ventriculomegaly and normal babies, confirmed by MRI, at 6-12 months after birth and a case-control study was conducted. The intelligence and growth of these infants were analyzed.

RESULTS

(1) Diagnostic rate of fetal ventriculomegaly through MRI: Among the 135 gravidas, 60 (44.4%) showed isolated ventriculomegaly, 5(3.7%) complicated with ventricular hemorrhage; 12 (8.9%) complicated with agenesis of corpus callosum (ACC) and 2 (1.5%) complicated with cerebellar hypoplasia, while 56 (41.5%) were normal. Seventy-nine cases had fetal ventriculomegaly on MRI and 15.2% (n = 12) of them complicated with ACC. (2) Degree of fetal ventriculomegaly on MRI: Among the 60 isolated ventriculomegaly cases, 55 (91.7%) were mild and 5 (8.3%) moderate ones. Among the 5 cases complicated with ventricular hemorrhage, one was mild ventriculomegaly, and 4 moderate or severe cases. Among the 12 cases with ACC, 8 (66.7%) were moderate ventriculomegaly and 4 (33.3%) severe cases. The 2 cases with cerebellar hypoplasia were both moderate ventriculomegaly fetuses. (3) Follow-up at 6-12 months after birth: thirty out (case group) of the 55 isolated ventriculomegaly cases, 38 out of the 56 normal babies and 42 babies with normal MRI results were followed up, and the later 80 cases were taken as control. Four infants (13.3%) in the case group and 10 (12.5%) in the control group showed abnormal or suspected results in DDST (P > 0.05), the rest babies were all normal. (4) Clinical outcomes of the 79 ventriculomegaly fetuses diagnosed by MRI: thirty mild ventriculomegaly babies and 5 moderate ones were born at term and showed normal at follow ups. However, 7 gravidas were not compliant, 6 pregnancies were terminated, and 12 were lost. Three of the 12 cases with ACC continued the pregnancy, and postnatal MRI of the babies showed the same with the prenatal MRI, 8 pregnancies were induced and one was lost. All of the 5 fetuses with ventricular hemorrhage were induced and the prenatal diagnosis was confirmed by autopsy. One of the 2 fetuses with cerebellar hypoplasia was term delivered and diagnosed as cerebral palsy at the age of 6 months, and the other one was induced.

CONCLUSIONS

MRI is an indispensable complementary diagnostic method for fetal ventriculomegaly diagnosed through ultrasound. The development of intelligence and growth of babies born with mild isolated ventriculomegaly is the same as normal ones.

What is the clinical importance of echogenic material in the fetal frontal horns?

OBJECTIVE

The purpose of this study was to evaluate the importance of echogenic material in the fetal frontal horns.

METHODS

This was a Health Insurance Portability and Accountability Act-compliant, Institutional Review Board-approved retrospective study. In part 1 of the study, prenatal sonography, prenatal magnetic resonance imaging (MRI), and birth outcomes of 17 fetuses (mean gestational age, 19 weeks; range, 15-34 weeks) with prospective echogenic material in the frontal horns were assessed. In part 2, 400 consecutive sonographic fetal surveys (mean gestational age, 19 weeks; range, 15-38 weeks) were reviewed to determine the incidence. In part 3, 2 independent reviewers assessed the appearance of the frontal horns in 40 fetuses (20 with suspected intraventricular hemorrhage from parts 1 and 2 and 20 who were interpreted to have normal findings in part 2).

RESULTS

Part 1 of the study showed that suspected hemorrhage was unilateral in 13 fetuses and bilateral in 4. Additional findings by sonography were grade 4 intraventricular hemorrhage (n = 2), ventriculomegaly (n = 2), and porencephaly (n = 1). An additional finding by MRI was porencephaly in 1 fetus. In part 2, echogenic material in the frontal horns was identified in 3 of 400 fetuses (0.8%). In part 3, hemorrhage was probably or definitely present in 11 of the 20 fetuses with abnormalities; material looked like a cyst in 6; and normal choroid was in an abnormal position in 2 and a normal position 1. Of 19 fetuses with abnormalities, 14 had a posteriorly symmetric choroid; 9 had material of different echogenicity compared with the choroid; and 17 had an expanded frontal horn. Birth outcomes were abnormal in 7, including platelet abnormalities (n = 2), hemorrhage on imaging or pathologic examination (n = 2), extraventricular hemorrhage (n = 3), and ventriculomegaly (n = 3).

CONCLUSIONS

The incidence of echogenic material in the frontal horns is less than 1%. This does not represent the normal location of the choroid plexus and may represent hemorrhage, which may resolve without sequelae or result in ventriculomegaly and porencephaly.

Clozapine administration in adolescence prevents postpubertal emergence of brain structural pathology in an animal model of schizophrenia

BACKGROUND

Schizophrenia is a neuropsychiatric disorder of a neurodevelopmental origin manifested symptomatically after puberty. Structural neuroimaging studies show that neuroanatomical aberrations occur before onset of symptoms, raising a question of whether schizophrenia can be prevented. Treatment with atypical antipsychotic drugs before the development of the full clinical phenotype might reduce the risk of transition to psychosis, but it remains unknown whether neuroanatomical abnormalities can be prevented. We used a neurodevelopmental animal model of schizophrenia to assess the efficacy of the atypical antipsychotic clozapine to prevent neuroanatomical deterioration.

METHODS

Pregnant rats received injection on gestational day 15 with the viral mimic polyriboinosinic-polyribocytidylic acid (PolyI:C) or saline. Structural brain changes in the male offspring were assessed at adolescence and adulthood (35 days and 120 days) with structural neuroimaging. In the second part, male offspring of PolyI:C- and saline-treated dams received daily clozapine (7.5 mg/kg) or saline injection in adolescence (days 34-47) and underwent behavioral testing and imaging at adulthood (from 90 days onward).

RESULTS

In utero exposure to maternal infection led in the offspring to postpubertal emergence of hallmark structural abnormalities associated with schizophrenia, enlarged ventricles, and smaller hippocampus. These abnormalities were not observed in the offspring of mothers who received PolyI:C that were treated with clozapine in adolescence. This was paralleled by prevention of behavioral abnormalities phenotypic of schizophrenia, attentional deficit, and hypersensitivity to amphetamine.

CONCLUSIONS

This is the first demonstration that pharmacological intervention during adolescence can prevent the emergence of brain structural changes resulting from in-utero insult.

[Fetal ventriculomegaly secondary to germinal matrix hemorrhage--case report]

A germinal matrix is an area of the fetal brain where neuroblasts proliferate till the 20th week of gestation after which their migration takes place. Germinal matrix hemorrhage (GMH) is a frequent cause of fetal ventriculomegaly or hydrocephalus, yet the pathophysiological conditions of GMH remain unclear. A case of fetal ventriculomegaly resulting from GMH has been reported in the article. A prenatal ultrasonographic examination (US) carried out in the 30th week of gestation revealed enlarged ventricles. Utero magnetic resonance imaging (MRI) performed in the 34th week of gestation demonstrated asymetric ventriculomegaly and the changes suggesting the occurance of GMH and ependymal intraventricular hemorrhage. Fetal ventriculomegaly and hydrocephalus are commonly detected by ultrasonographic examination, but it is often difficult to determine the causes of the diseases by US. In these cases MRI allows to establish the final diagnosis.

Maternal antenatal complications and the risk of neonatal cerebral white matter damage and later cerebral palsy in children born at an extremely low gestational age

In a 2002-2004 prospective cohort study of deliveries of infants at <28 weeks at 14 US centers, the authors sought the antecedents of white matter damage evident in newborn cranial ultrasound scans (ventriculomegaly and an echolucent lesion) and of cerebral palsy diagnoses at age 2 years. Of the 1,455 infants enrolled, those whose mothers received an antenatal steroid tended to have lower risks of ventriculomegaly and an echolucent lesion than their peers (10% vs. 23%, P < 0.001 and 7% vs. 11%, P = 0.06, respectively). Risk of ventriculomegaly was increased for infants delivered because of preterm labor (adjusted odds ratio (OR) = 2.3, 95% confidence interval (CI): 1.1, 4.9), preterm premature rupture of fetal membranes (OR = 3.6, 95% CI: 1.5, 8.7), and cervical insufficiency (OR = 2.8, 95% CI: 1.4, 5.5) when compared with infants delivered because of preeclampsia. Risk of an echolucent lesion was increased for infants delivered because of preterm labor (OR = 2.7, 95% CI: 1.2, 5.7) and intrauterine growth retardation (OR = 3.3, 95% CI: 1.2, 9.4). The doubling of diparesis risk associated with preterm labor and with preterm premature rupture of fetal membranes did not achieve statistical significance, nor did the doubling of quadriparesis risk and the tripling of diparesis risk associated with cervical insufficiency.

Aicardi syndrome mimicking intrauterine hydrocephalus

Congenital enlargement of the cerebral ventricles is now commonly recognized in utero due to the availability of high resolution prenatal ultrasonography. It is important to distinguish between congenital hydrocephalus and ventricular enlargement due to malformations, infections or other destructive processes because these disorders can have markedly different prognoses. We report an infant diagnosed with Aicardi syndrome in the newborn period based on brain MRI and ophthalmological findings after she was referred for evaluation of hydrocephalus seen on fetal ultrasound. Aicardi syndrome most commonly comes to medical attention because of seizures later in infancy.

Counseling in isolated mild fetal ventriculomegaly

In this Review we aim to provide up-to-date and evidence-based answers to the common questions regarding the diagnosis of isolated mild fetal ventriculomegaly (VM). A literature search was performed to identify all reports of antenatal VM in the English language literature. In addition, reference lists of articles identified using the search were scrutinized to further identify relevant articles. Fetal mild VM is commonly defined as a ventricular atrial width of 10.0-15.0 mm, and it is considered isolated if there are no associated ultrasound abnormalities. There is no good evidence to suggest that the width of the ventricular atria contributes to the risk of neurodevelopmental outcome in fetuses with mild VM. The most important prognostic factors are the association with other abnormalities that escape early detection and the progression of ventricular dilatation, which are reported to occur in about 13% and 16% of cases, respectively. Most infants with a prenatal diagnosis of isolated mild VM have normal neurological development at least in infancy. The rate of abnormal or delayed neurodevelopment in infancy is about 11%, and it is unclear whether this is higher than in the general population. Furthermore, the number of infants that develop a real handicap is unknown. There are limitations of existing studies of mild VM. Although they address many of the relevant questions regarding the prognosis and management of fetal isolated mild VM, there is a lack of good-quality postnatal follow-up studies. The resulting uncertainties make antenatal counseling for this abnormality difficult.

The neurocognitive outcome of mild isolated fetal ventriculomegaly verified by prenatal magnetic resonance imaging

OBJECTIVE

Neurocognitive outcome of preschool children, prenatal diagnosis of isolated mild ventriculomegaly compared with 2 control groups.

STUDY DESIGN

Case-controlled study at the University Hospital of Tel Aviv between October 1999 and December 2002. Study groups consisted of 12 children with bilateral isolated mild ventriculomegaly, and 16 children with unilateral isolated mild ventriculomegaly, mean age 4.4 years, prenatally diagnosed by both ultrasound and fetal magnetic resonanace imaging. Control groups consisted of 16 children with normal prenatal magnetic resonance imaging and 16 regular kindergarten children. A neurodevelopmental examination and the Kaufman Assessment Battery for Children were performed.

RESULTS

The neurodevelopmental and Kaufman scores were within normal range in the study groups. No significant differences between the study and control groups for most measures; however, Kaufman achievement score was significantly lower for the bilateral isolated mild ventriculomegaly group (P < .05) compared with the kindergarten children.

CONCLUSION

Preschool children with isolated mild ventriculomegaly performed within normal range compared with the controls. Nevertheless, a significant percentage of the children demonstrated developmental difficulties, lower achievement scores, justifying early school years follow-up.

Perinatal and neurodevelopmental outcome with isolated fetal ventriculomegaly: A systematic review

OBJECTIVE

To establish the perinatal and neurodevelopmental outcomes of fetuses diagnosed with isolated ventriculomegaly (IVM).

METHODS

A systematic review of cohort, case/control studies, case series and case reports of IVM (unilateral or bilateral enlargement of the lateral ventricle, >or=10 mm, with no additional diagnosis at the time of the initial ultrasound), identified by searching, without language restrictions, The Cochrane Library, MEDLINE and Embase databases in June 2004.

RESULTS

No cohort study was retrieved but 577 cases were identified in one case/control study and 29 case series/case reports. Of 207 cases with follow-up and known gestational age at diagnosis, normal developmental outcomes were found in 82%, mild impairments in 9% and moderate/severe impairments in 10%. Prenatal diagnosis could possibly have reduced the risk of moderate/severe impairments to 7%. In 137 cases followed to at least 20 months of age, 79% had normal neurodevelopment, 10% were mildly delayed and 11% had moderate/severe developmental delays.

CONCLUSIONS

Outcome was favorable in 85% of IVM cases, decreasing to 79% when cases were followed to at least 20 months of age. We recommend prospective cohort studies with new diagnostic modalities to better identify the underlying conditions relating to moderate/severe impairments in the remaining cases.

Incidence, mechanisms, and patterns of fetal cerebral lesions in twin-to-twin transfusion syndrome

OBJECTIVE

To determine the incidence of fetal cerebral lesions and their characteristics in twin-to-twin transfusion syndrome (TTTS).

DESIGN AND SETTING

This was a retrospective analysis at a single center for the period 1999 to 2004 in which 299 cases of severe TTTS at 15-28 weeks of gestation were reviewed.

METHODS

Only cerebral injuries diagnosed during pregnancy or ischemic lesions diagnosed within the first week of life were considered in order to exclude those related to prematurity. We only included cases resulting in at least one survivor at one week after delivery, as well as fetuses that were terminated because of severe cerebral abnormalities. We excluded all fetuses delivered at <24 weeks of gestation that died prior to undergoing postnatal cranial ultrasonography. The main outcome measures were fetal cerebral lesions, intrauterine death, survival, and neonatal death.

RESULTS

Two hundred and ninety-nine pregnancies were evaluated. Three hundred and fifteen fetuses were reviewed. Cerebral abnormalities developed antenatally in 26/315 fetuses (8.25%). All lesions but one were diagnosed prenatally. Prenatal diagnosis of these lesions was achieved primarily by ultrasound (US) and magnetic resonance imaging (MRI), in 20/25 (80%) and in 5/25 (20%) fetuses, respectively. Cerebral abnormalities developed following primary laser coagulation in 12/222 (5.40%), following serial amnioreduction in 9/66 (13.63%), and following expectant management in 3/14 (21.4%) fetuses. Abnormalities developed after single intrauterine fetal death (IUFD) in 14 cases.

CONCLUSIONS

Cerebral morbidity in TTTS mainly occurs following vascular disruptive lesions. Both donors and recipients are at risk of developing either ischemic or hemorrhagic lesions. The risk of developing cerebral lesions in single survivors is significantly lower following laser treatment. Combined use of a targeted US and fetal MRI could detect most cerebral abnormalities antenatally. Timing of the triggering event is critical for planning serial US and MRI follow-up examinations.

3D reconstructions of the cerebral ventricles and volume quantification in children with brain malformations

RATIONALE AND OBJECTIVES

The aim of this study was to assess the ability of a semiautomated process to produce three-dimensional reconstructions of the ventricles and calculate ventricular volumes from magnetic resonance (MR) imaging data in children with structural brain abnormalities.

MATERIALS AND METHODS

Fourteen children referred for MR imaging of the brain for neurologic symptoms were selected. Seven participants had structural brain abnormalities on MR imaging; seven further participants were age-matched controls with normal brain morphology. MR imaging included T1-weighted volumetric images in all cases. Semiautomated postprocessing techniques were performed on the MR imaging data to generate three-dimensional reconstructions of the ventricles. These were analyzed for morphologic changes, and volumes were calculated. Inter- and intrarater agreement of ventricular volumes were calculated.

RESULTS

This technique produced detailed three-dimensional reconstructions of the ventricles, even in children with grossly abnormal ventricular morphology. All MR imaging data were successfully postprocessed in <5 minutes. Inter- and intrarater reliability was excellent, with correlation coefficients of 0.99 and 0.92, respectively.

CONCLUSION

This methodology can create detailed three-dimensional visualizations and volumetric measurements of morphologically abnormal ventricles. This technique could help physicians and parents comprehend abnormal ventricular anatomy better and may have future clinical uses in monitoring disease progression or neurosurgical planning.

Fetal borderline cerebral ventriculomegaly: clinical significance and management

AIM

The aim of this study was to evaluate the clinical significance and the management of fetal borderline lateral cerebral ventriculomegaly.

METHODS

Fetuses with a sonographic diagnosis of lateral cerebral ventriculomegaly isolated or associated to other fetal malformations were followed monthly and a review of the English-language literature was made.

RESULTS

Of 86 fetuses analyzed, 30 suffered from hydrocephaly (monolateral, bilateral), 56 showed also several other malformations . Chromosomal aberrations is possible also in case of isolated hydrocephaly. Neurological sequelae, mostly a mild to moderate delay in cognitive and/or motor development, is present in 10% of the cases.

CONCLUSIONS

In most cases, isolated borderline lateral cerebral ventriculomegaly has no consequence. However, the risk of cerebral maldevelopment, delayed neurological development and, possibly, chromosomal aberrations is increased. The optimum management of these cases remains uncertain.

Supratentorial abnormalities in the Chiari II malformation, II: tectal morphologic changes

OBJECTIVE

The sonographic diagnosis of fetal myelomeningocele has improved mainly because the diagnostic focus has shifted from observation of spinal manifestations to observation of cranial abnormalities. Intracranial diagnostic criteria rely on abnormalities in the posterior fossa. We describe abnormalities in tectal morphologic characteristics that, although well described on magnetic resonance imaging, have received little attention in the sonographic literature. This study analyzed the frequency of this observation and technical aspects that improve its visualization.

METHODS

From a database of obstetric sonograms, we identified all cases of sonographically detected myelomeningocele. The search covered the years 1999 to 2007. We retrospectively reviewed the fetal intracranial findings with special attention to elongation or "beaking" of the tectum.

RESULTS

A total of 89 fetuses were identified. The mean and median gestational ages were 22 weeks 4 days and 22 weeks 2 days, respectively. Of the 89 cases, 59 (66%) had an abnormal tectal shape. The abnormality was seen in 77% of cases judged to be suboptimally visualized and 62% of cases with good visualization. Tectal abnormalities were seen equally well in fetuses before and after 24 weeks. Finally, tectal abnormalities were seen more frequently as the severity of posterior fossa findings increased.

CONCLUSIONS

Tectal morphologic alteration is a common supratentorial feature of the Chiari II malformation on prenatal sonography both before and after 24 weeks' gestation. Its frequency increases with the severity of posterior fossa abnormalities. Therefore, it may be useful as a supratentorial indicator of both the presence and, potentially, the severity of the Chiari II malformation.