Absence Of Cavum Septum Pellucidum Research Articles

Evaluation and Significance of Nonvisualization of the Cavum Septum Pellucidum on Prenatal Ultrasonography

ABSTRACT Importance The identification of the cavum septum pellucidum (CSP) is an integral part of the routine second trimester fetal anatomy scan. The absence or nonvisualization of the CSP has significant clinical implications and requires further evaluation and counseling for the pregnant patient. Objective The aim of this review is to review the importance of accurate sonographic identification of the CSP and the underlying pathologies that can be associated with nonvisualization of this structure. Evidence Acquisition A literature review was performed with PubMed using key words including CSP, fetal anatomy ultrasound, and fetal anomalies. Results The absence of the CSP is associated with several central nervous system pathologies, all with a wide range of phenotypic outcomes, ranging from normal to very severe or lethal. Relevance Most obstetrician-gynecologists will have a patient in whom a CSP is not identified on fetal ultrasound. Thus, it is imperative to have a general understanding of this relatively common entity. Target Audience Obstetricians and gynecologists, family physicians Learning Objectives After completing this activity, the learner will be able to describe the CSP, the importance of accurate identification on ultrasonography, and the pitfalls to avoid/be aware of; explain the additional workup required in the setting of absent CSP including utility of antenatal ultrasound, fetal magnetic resonance imaging, and genetic counseling; and discuss the various pathologies that have an association with the absence of the CSP and patient counseling regarding the absence of the CSP.

We are Reporting an Infant with Genito Patellar Syndrome and KAT6B Gene Mutation Presenting with Facial Dysmorphism, Bilateral Genu Recurvatum, Hip Dislocations, Absence of Cavum Septum Pellucidum, Anal Abnormality and Hydronephrosis

A preterm female infant was admitted to neonatal intensive care unit with respiratory distress, facial dysmorphism, bilateral genu recurvatum, hip dislocations, absence of cavum septum pellucidum, anal abnormality, and hydronephrosis. Exome study confirmed the diagnosis of Genito patellar syndrome.

A Case Report of a Complex Constitutional Karyotype Resulting in Three Derivative Chromosomes Characterized by Chromosomal Analysis, Florescent in situ Hybridization (FISH), and Chromosome Microarray

Abstract Introduction/Objective Structurally complex karyotypes are rarely identified in the postnatal constitutional setting. Abnormalities involving multiple chromosomes are likely to have a deleterious effect or be incompatible with life. Herein, we describe a case of a structurally complex karyotype in a newborn male. Methods/Case Report A newborn male presented at birth with microcephaly, severe ventriculomegaly, cerebellar hypoplasia and absent cavum septum pellucidum. Seizures, optic nerve dysplasia, and feeding difficulties were later noted. Microarray testing revealed eight small deletions of unclear significance on chromosome 7, with three located on the p arm and five clustered on the q arm. The deletions were gene poor, and none contained known haploinsufficient genes. Based on this finding a structural abnormality involving chromosome 7 was suspected. Karyotype revealed a structurally abnormal chromosome 7 and a complex rearrangement between chromosomes 11 and 18. Chromosome paint and metaphase FISH studies were performed to further characterize the abnormalities. Based on results from these cytogenetic tests, the observed abnormalities were characterized as an insertion on chromosome 7, and a translocation between chromosome 11 and 18 with an inversion on the derivative 18 [46,XY,ins(7)(p21q22q11.2),der(11)t(11;18)(q14.2;p11.2),der(18)(11qter→11q21::18q11.2→18p11.2::11q14.2→11q21:: 18q11.2→18qter)]. Rapid whole genome sequencing was done at an outside institution which was negative. Results (if a Case Study enter NA) NA Conclusion The exact cause of this individual’s phenotypic findings is unknown. Although the genomic imbalance detected by CMA is small, the complex structural abnormalities likely contribute to the clinical findings. Further supporting a deleterious effect of the karyotype findings is the negative whole genome sequencing results in this individual. Some apparently balance rearrangements have been shown to disrupt genes or important regulator elements. It is possible that a gene was disrupted at the breakpoint of one or more of the detected abnormalities or the rearrangement resulted in abnormal gene regulation. Additional submicroscopic abnormalities may also be present that were not detectable by the methodologies used.

Classification of Ventriculomegaly and its Associated Findings using Antenatal Ultrasound Scan at a Tertiary Care Hospital: Andhra Pradesh, India: A Retrospective Descriptive Study

Introduction: Foetal Ventriculomegaly (VM) is defined as the enlargement of the lateral ventricles in the developing foetal brain. The measurement of foetal cerebral lateral ventricles’ size is routinely recommended as part of the second-trimester foetal scan to screen for anomalies. VM can occur due to obstruction of the Cerebrospinal Fluid (CSF) tract, absorption disorders, inadequate brain development, or excessive CSF production. Aim: To classify VM based on severity to differentiate between isolated and non isolated VM. Materials and Methods: A retrospective descriptive study was conducted in the Department of Radiology at PESIMSR, Andhra Pradesh, India., a tertiary medical hospital, from April 2018 to April 2021. Cases were selected from computer records showing a diagnosis of hydrocephalus or foetal VM in patients who underwent the Ultrasound (US) anomaly scan. VM was defined as a lateral ventricle width of ≥10 mm. Foetal VM was classified, and associated CNS and extracranial abnormalities and their details were collected. Descriptive statistics were used, and results were expressed in terms of frequency and percentage. Results: The VM was observed in 91 foetuses, with mild VM in 59 foetuses (64%), moderate VM in 14 foetuses (15.2%), and severe VM in 18 foetuses (19.5%). The median age at diagnosis was 26.5 weeks. Isolated mild VM was seen in 26 cases (44%), and it was associated with other abnormalities in 33 cases (56%). Isolated moderate VM was observed in four cases (28.5%), while 10 cases (71.4%) were associated with other abnormalities. Isolated severe VM was seen in (33.3%) 6, and it was associated with abnormalities in 12 cases (66.6%). The most common associated abnormalities were foetal growth restriction (15 cases), absent cavum septum pellucidum (eight cases), and open spina bifida, Arnold-Chiari malformation (eight cases). Conclusion: Ultrasound is a sensitive tool for detecting VM. Once VM is diagnosed, a detailed examination of the fetus should be conducted to evaluate other CNS and non CNS anomalies, thereby differentiating isolated from non-isolated VM, as the prognosis may vary. This information will be valuable for counseling patients.

Apert Syndrome: Radiologist’s Perspective

Background: Apert syndrome (acrocephalosyndactyly type 1) is a rare syndrome, well known by severe syndactyly, dysmorphic face and craniosynostosis and is caused by FGF (fibroblast growth factor) receptor-2 gene mutations. Case Report: This is a case report of one year old girl child who presented with syndactyly of bilateral hands and feet, delayed milestones and dysmorphic facial features. Radiograph of the hands and feet of the patient revealed bilateral soft tissue and bony syndactyly, single broadened dysplastic phalanx in both great toes and presence of only two phalanges in 2nd to 5th toes. Non-contrast computed tomography of the head revealed bi-coronal synostosis and a widely open midline calvarial defect extending from posterior fontanelle to the root of the nose with hypoplastic bilateral maxillae. Intra-parenchymal findings including ventriculomegaly, corpus callosum thinning, absent cavum septum pellucidum and enlarged cystic space in posterior fossa were also present. Conclusion: Recognition of characteristic clinical and imaging abnormalities are crucial to radiologists and clinicians in the diagnosis and management of these patients. Since there is multi-system involvement, a multidisciplinary approach is needed in the management of patients.

A practical approach to prenatal diagnosis of malformations of cortical development

<h2>Abstract</h2> Malformations of cortical development (MCD) can frequently be diagnosed at multi-disciplinary Fetal Neurology clinics with the aid of multiplanar neurosonography and MRI. The patients are usually referred following prenatal sonographic screening that raises the suspicion of a possible underlying MCD. These indirect findings include, but are not limited to, ventriculomegaly (lateral ventricles larger than 10 mm), asymmetric ventricles, commissural anomalies, absent cavum septum pellucidum, cerebellar vermian and/or hemispheric anomalies, abnormal head circumference (microcephaly or macrocephaly), multiple CNS malformations, and associated systemic defects. The aim of this paper is to suggest a practical approach to prenatal diagnosis of malformations of cortical development utilizing dedicated neurosonography and MRI, based on the current literature and our own experience. We suggest that an MCD should be suspected in utero when the following intracranial imaging signs are present: abnormal development of the Sylvian fissure; delayed achievement of cortical milestones, premature appearance of sulcation; irregular ventricular borders, abnormal cortical thickness (thick, thin); abnormal shape and orientation of the sulci and gyri; irregular, abnormal, asymmetric, and enlarged hemisphere; simplified cortex; non continuous cortex or cleft; and intraparenchymal echogenic nodules. Following the putative diagnosis of fetal MCD by neurosonography and MRI, when appropriate and possible (depending on gestational age), the imaging diagnosis is supplemented by genetic studies (CMA and trio whole exome sequencing). In some instances, no further studies are required during pregnancy due to the clear dire prognosis and then the genetic evaluation can be deferred after delivery or termination of pregnancy (in countries where allowed).

‘Pseudo-septum’ Appearance in Septal Agenesis on Fetal MRI

Abstract Background Absence of the cavum septum pellucidum (CSP) can be associated with a wide spectrum of congenital brain malformations. It is necessary to describe the anatomic structures that can be mistaken for the CSP in cases of septal agenesis. Results We retrospectively studied MRI of 12 fetuses referred with suspicion of absent CSP on sonography. The structures simulating CSP in axial sections (Pseudo septum) are: volume averaging from the medial edge of the frontal lobes (lateral ventricles) in the anterior aspect, fornices in the mid and posterior aspect and internal cerebral veins in the postero-inferior aspect. Eleven out of the twelve suspected cases of absent CSP showed a false positive ‘pseudo-septum’ appearance in axial sections of fetal brain MRI. The absence of the ‘pseudo-septum’ was confirmed on coronal MRI sections of the fetal brain. Conclusion It is important to study the axial and coronal sections of the fetal brain for accurate diagnosis of septal agenesis.

Prenatal abnormal width of the cavum septum pellucidum – MRI features and neurodevelopmental outcome

Purpose: The purpose of this study is to describe the morphological characteristics of fetal MRIs and outcome of prenatally-detected abnormal width of the CSP (cavum septum pellucidum).Material and methods: A retrospective study of cases with abnormal width of the CSP demonstrated prenatally on MRI. Data collected included: prenatal history, MRI features, sonographic follow up, and neurodevelopmental outcome.Results: Most of the cases referred (34/39) had an abnormal CSP on MRI. Thirty cases had an abnormal width: 23 had narrow CSP and seven had wide CSP. Only three out of 12 cases that were referred with US diagnosis of absent CSP were confirmed by MRI, the rest had narrow CSP. Follow up was performed in 24 out of 30 cases with an abnormal CSP width; all had normal neurodevelopment.Conclusion: To the best of our knowledge, this is the first study to examine the outcome in narrow and wide CSPs detected prenatally. An abnormal width of the CSP prenatally, without an associated fetal abnormality such as aneuploidy, appears to have normal outcome. MRI should be offered when an absence of the CSP is suspected on US to rule out narrow CSP, which seems to be a benign finding.

Absent cavum septum pellucidum: a review with emphasis on associated commissural abnormalities.

The cavum septum pellucidum (CSP) is an important fetal midline forebrain landmark, and its absence often signifies additional underlying malformations. Frequently detected by prenatal sonography, absence of the CSP requires further imaging with pre- or postnatal MRI to characterize the accompanying abnormalities. This article reviews the developmental anatomy of the CSP and the pivotal role of commissurization in normal development. An understanding of the patterns of commissural abnormalities associated with absence of the CSP can lead to improved characterization of the underlying spectrum of pathology.

Prenatal Diagnosis of WAGR Syndrome.

Wilm's tumour, aniridia, genitourinary abnormalities, and mental retardation (WAGR) syndrome is a rare genetic disorder with an estimated prevalence of 1 in 500,000 to 1 million. It is a contiguous gene syndrome due to deletion at chromosome 11p13 in a region containing WT1 and PAX6 genes. Children with WAGR syndrome mostly present in the newborn/infancy period with sporadic aniridia. The genotypic defects in WAGR syndrome have been well established. However, antenatal ultrasonographic presentation of this syndrome has never been reported. Prenatal diagnosis of this condition is possible in some cases with careful ultrasound examination of classical and nonclassical manifestations of this syndrome. The key point for this rare diagnosis was the decision to perform chromosomal microarray analysis after antenatal diagnosis of absent corpus callosum and absent cavum septum pellucidum, as this finding mandates search for potentially associated genetic disorders. We report a case of WAGR syndrome diagnosed prenatally at 29-week gestation. The diagnosis of the anomaly was based on two- and three-dimensional ultrasound as well as fetal MRI scan and microarray analysis. The ultrasonographic findings included borderline ventriculomegaly, absent corpus callosum, and absent cavum septum pellucidum. Cytogenetic results from the amniotic fluid confirmed WAGR syndrome. Parental karyotype was normal, with no evidence of copy number change, deletion, or rearrangement of this region of chromosome 11.

P04.13: Agenesis of the cavum septum pellucidum in the third trimester of pregnancy

The visualization of the cavum septum pellucidum is an important marker of neuroencephalic proper development. The suspicion of absence requires to perform a throrough study of brain structures. In case of absence, the prognosis of affected children is variable. A 34 year old woman primigravida of 29 weeks of pregnancy, arrives to perform a ultrasound report. Prior control of gestation in a private center without significant abnormalities. First trimester ultrasound: Nuchal Translucency: 1.1 mm (CRL: 62 mm < P95 ) First trimester combined screening: low risk (combined risk trisomy 21: 1/542; trisomy 18 < 1/10.000). In the third trimester ultrasound it was seen a defect in the middle line of the brain. No cavum septum pellucidum is displayed, with extensive communication between the lateral ventricles anteriorly. The corpus callosum is present. Ventricular atriae appear in a limit size (9.7 mm). In MRI there was seen the absence of cavum septum pellucidum, as well as a deformity of the lateral ventricles and mild ventriculomegaly (10.7 and 11.7 mm). There is no evidence of agenesis or dysgenesis of the corpus callosum. It also appeared to be a nonfusion of frontal lobes suggesting lobar holoprosencephaly. The patient decides to finish her pregnancy in France. The necropsy showed isolated septal agenesis without ventricular abnormalities. The corpus callosum was present. No other abnormalities including ocular or optic chiasm alterations were present. The karyotype of amniotic fluid was normal (46 XY).

Ultrasound and MRI findings of syntelencephaly and correlation with perinatal pathology

Background: Holoprosencephaly (HPE) is a complex brain malformation characterized by impaired midline cleavage of the embryonic forebrain. Syntelencephaly (SE) is an uncommon and distinct subset of holoprosencephaly. In cases with syntelencephaly, hemispheric fusion does not occur at rostral forebrain but rather across posterior frontal region. Here we report ultrasound and magnetic resonance findings of a fetal case with syntelencephaly, which is an extremely rare prenatal diagnosis, and its correlation with fetal autopsy. Case Presentation: A 20-year-old woman gravida 2, para 1 at 26 th week of gestation was referred to our perinatology unit for second opinion ultrasound (US). The couple was third degree consanguine and their first child suffered from hearing loss with no detectable etiology. On axial and sagittal planes of grayscale US, bilateral ventriculomegaly, absence of cavum septum pellucidum and interventricular septum with the presence of interhemispheric fissure and suspected agenesis of corpus callosum were detected. Additionally, coronal examination revealed suspected cerebral hemispheric fusion and absence of interhemispheric fissure near the fetal vertex. Fetal cranial magnetic resonance imaging (MRI) revealed dilatation at all anatomic regions of lateral ventricles and no interventricular septum. Interhemispheric fissure was present at anterior frontal and occipital regions. However, the middle part of the interhemispheric fissure was absent and the fusion of both hemispheres was evident between posterior frontal and parietal regions. Additionally, the midbody of corpus callosum was absent. These findings were considered as the characteristics of SE. Amniocentesis revealed normal karyotype and the couple chose pregnancy termination after our disclosure about the possible poor postnatal prognosis of the entity. Conclusion: The diagnosis of fetal HPE and its subtypes is important to determine prognosis and proper parental counselling. As in our case, multidisciplinary approach should be performed for the accuracy of the diagnose and fetal brain MRI may play an important role in more subtle cases.

P43.07: Prenatal MR imaging of fetal teratomas: Intracranial, oropharyngeal and sacrococcygeal locations. A series of 7 cases

24years-old nullipara was referred at 23 weeks of gestation because absent cavum septum pellucidum was noticed at a routine ultrasound scan. Ultrasonography showed complete absence of septum pellucidum resulting in box like frontal horns and a mild form of holoprocencephaly. No other abnormalties were detected. An MRI image at 25 weeks has confirmed absent septum pellucidum without fusion of frontal lobes ruling out the diagnosis of lobar holoprocencephaly. Bilateral atrophy of optic nerve with hypoplasia of optic chiasm was seen on coronal 3D image. A normal male karyotyping was found. The fetus was followed up on 4-weekly basis. At 41 weeks gestation, following the onset of spontaneous contractions, an emergency caesarean section was performed for fetal distress. A 3650-g male baby was delivered with Apgar scores of 9, 10 and 10 at 1, 5 and 10 min, respectively. No resuscitation or respiratory support was required. Neonatal dilation fundoscopy examination at 3 months of age has revealed slightly small right optic nerve head and normal left one. Neonatal MRI at 4 months of age has confirmed complete absence of the septum pellucidum, low lying fornices, hypoplasia of cerebral white matter and mild ventriculomegaly. The posterior fossa, anterior visual pathway and optic nerves were normal. A hydrocortisone day curve at 4 months of age revealed low endogenous cortison level, which was replaced. the neonate has normal milestone. He was followed up until age of 14 months when he required a growth hormone replacement and his vision was normal. In conclusion, prenatal diagnosis of septo-optic dysplasia should involve MRI examination in order to outline the diagnosis followed by neonatal MRI and ophthalmological examination to help define the extent of optic-nerve lesion and therefore the prognosis. Neonatal multidisciplinary care is crucial for satisfactory outcome

Absence of Cavum Septum Pellucidum Related With Optic Nerve Hypoplasia

Absence of the cavum septum pellucidum is an unusual abnormality found in newborns that is associated with malformations of the brain. It is estimated that 2 to 3 individuals per 100,000 people in the general population have an absence of the cavum septum pellucidum. This anomaly can be associated with neurological anomalies such as optic nerve hypoplasia, holoprosencephaly, septo-optic dysplasia, abnormalities of the corpus callosum, and Chiari II malformation. It is rare to have an absent cavum septum pellucidum without any other brain anomalies.

Three-Dimensional Ultrasonographic Reslicing of the Fetal Brain to Assist Prenatal Diagnosis of Central Nervous System Anomalies

The purpose of this study was to evaluate the potential of 3-dimensional ultrasonographic planar and nonplanar reslicing techniques. Fetuses with severe brain anomalies diagnosed by means of 2-dimensional ultrasonography were prospectively included in the study. Good-quality 3-dimensional volumes of the fetal head were obtained in each case. Subsequently, these volumes were reviewed with use of 3-dimensional extended imaging with Oblique View and DynamicMR (Medison Co, Ltd, Seoul, Korea). Eight fetuses (mean gestational age, 23 weeks; range, 20-30 weeks) with the following central nervous system anomalies were examined: semilobar holoprosencephaly, absent cavum septum pellucidum, porencephaly in twin-to-twin transfusion syndrome, partial agenesis of the corpus callosum, Dandy-Walker variant, open-lip schizencephaly, aneurysm of the vein of Galen, and dilated cavum vergae. Planar and nonplanar reslicing of the volumes delivered informative images in any reconstructed plane. One important prerequisite, however, was the absence of acoustic shadowing during data acquisition.

OC2.05: 3D ultrasound evaluation of the fetal optic chiasm: a potential parameter for the differential diagnosis of developmental midline brain anomalies

Objective: Visualization of the fetal optic chiasm by ultrasound has not previously been reported. MRI is often used to image the fetal optic chiasm for the differential diagnosis of septo-optic dysplasia and absent cavum septum pellucidum. We describe herein a new sonographic technique to visualize the optic chiasm using multiplanar three-dimensional ultrasound and to evaluate its dimensions during gestation. Methods: This cross-sectional study included 76 singleton fetuses with no congenital or anatomical abnormalities. The optic chiasm was identified as a hypoechoic structure in the shape of an ‘‘X’’, located anterior to the cerebral peduncles and below the circle of Willis. The optic chiasm diameter was measured in the axial plane at its midline. Intraand inter-observer agreement was analyzed by the Bland–Altman plot. Regression analysis was used to determine the relationship between the optic chiasm and gestational age. Results: Seventy-two of 76 (94.7%) normal fetuses had a visible optic chiasm. The mean optic chiasm diameter at 12 and 40 weeks of gestation measured 1 mm and 4.27 mm, respectively. Intraand inter-observer mean differences between paired measurements were 0.007 mm (95% limits of agreement −0.30 to 0.32 mm) and 0.19 mm (95% limits of agreement −0.85 to 1.24 mm), respectively. The optic chiasm diameter and gestational age fit a linear regression model with a multiple R = 0.84, and a R2 = 0.70 (chiasm diameter = 0.129 + 0.119 * gestational age). Conclusions: 1) The fetal optic chiasm can be reproducibly imaged and measured from 12.5 weeks of gestation to term; 2) the diameter of the optic chiasm increases with gestational age; 3) this novel parameter may be useful in the differential diagnosis of septo-optic dysplasia and absent cavum septum pellucidum, which currently requires MRI. OC2.06 ‘‘Intraventricular fused fornices’’, a marker for complex midline anomalies