Fetal Central Nervous System Anomalies Detected by Magnetic Resonance Imaging: A Two-Year Experience

Antenatally diagnosed intraspinal-posterior mediastinal neurenteric cyst - what is the optimal management?

Neurenteric cyst is a rare congenital anomaly that belongs to the spinal dysraphism spectrum. It is classically a disease of late childhood, with some rare reports of intrauterine and adult presentation. The increase in incidental antenatal diagnosis raises new management questions. We present a case of an asymptomatic combined intraspinal-posterior mediastinal neurenteric cyst. The cyst was diagnosed on antenatal ultrasound and was initially treated with image-guided aspiration in early infancy. However, the cyst recurred and the patient developed recurrent episodes of bacterial meningitis. Two-stage surgical resection was performed, although the infection prohibited complete excision. We caution against image guided aspiration of neurenteric cysts, and suggest a management algorithm based on the available literature.

Spontaneous regression of multiple intracranial capillary hemangiomas in a newborn-long-term follow-up and literature review

BACKGROUND

Intracranial capillary hemangiomas (ICHs) have a natural history and behavior that is very different from intracranial cavernous malformations. The literature is not consistent as to the best management strategy for ICHs.

CASE DESCRIPTION

Our patient is a 40-day-old male infant who presented with progressive increase in head circumference and multiple cutaneous capillary and ICHs. Obstructive hydrocephalus necessitated urgent cerebrospinal fluid (CSF) diversion, but no other surgical intervention was pursued due to the high risk-to-benefit ratio. All intracranial lesions spontaneously regressed by 11 years of age, albeit at a slower speed than the cutaneous lesions, with no functional or cognitive sequelae. We conducted a comprehensive literature review and provided a summary of all reported ICH cases.

CONCLUSION

Asymptomatic patients with ICHs are best approached with close follow-up and serial imaging studies as the potential for spontaneous regression is relatively high. Patients with isolated lesions or unclear diagnoses may benefit from a stereotactic biopsy, and surgical resection should be reserved for symptomatic lesions only.

Diagnosis of central nervous system abnormalities: comparison of prenatal neurosonography and foetal magnetic resonance imaging findings

Magnetic resonance imagining (MRI) is gradually becoming the more preferred imaging modality in the evaluation of central nervous system (CNS) abnormalities rather than foetal ultrasonography (USG). The aim of this study was to compare the findings of prenatal neurosonography and foetal MRI. The study was a retrospective study analysing the records of 160 pregnant women who underwent both foetal MRI and USG due to suspicion of CNS abnormalities between 2008 and 2019. Indications for applying foetal MRI were neurosonography and foetal MRI findings. When the compatibility between MRI and USG results was examined in CNS abnormalities, it was found fully compatible in 61.3% of cases, partially compatible in 24.53% of cases, and not compatible in 14.5% of cases. When comparing prenatal neurosonography and foetal MRI findings, additional findings were reported in 16.9% of cases, and no additional finding was reported in 66.8% of cases. While normal anatomical findings were reported in 8.8% of the cases in MRI, the diagnosis made by neurosonography changed in 7.5%. Foetal MRI has more advantages than USG both in imaging the CNS abnormalities in more detail and in determining the accompanying additional anomalies.IMPACT STATEMENTWhat is already known on this subject: USG is a safe, practical and cost-effective primary imaging method that is widely used for foetal anomaly screening. However, there may sometimes be difficulties in evaluating the foetal brain structures due to foetal position which is unsuitable for imaging, extremely obese with a high body mass index, oligohydramnios and ossified foetal skull. For this reason, magnetic resonance imaging (MRI) is used as the most commonly used imaging method after USG in the evaluation of foetal anatomy, especially CNS.What do the results of this study add?: In our study, we saw that foetal MRI has more advantages than neurosonography in both seeing CNS abnormalities in more detail and recognising additional anomalies that may accompany.What are the implications of these findings for clinical practice and/or further research?: We have seen that besides neurosonography, foetal MRI can provide important information that can affect the clinical approach in pregnancy management by increasing the correct diagnosis in pregnancies with congenital CNS abnormalities. MRI: it is the best secondary imaging modality that can aid diagnosis in addition to neurosonography in the diagnosis of CNS abnormalities and in suspected cases. Therefore, foetal MRI should be used more widely in prenatal diagnosis.

Detecting Fetal Central Nervous System Anomalies Using Magnetic Resonance Imaging and Ultrasound

Background:

Most fetal abnormalities can be detected on ultrasound, the evaluation of fetal CNS abnormalities can be limited by various factors, including obesity, polyhydramnios, multiple pregnancies, and increased cranial ossification during the third trimester.

Objective:

This study aimed to evaluate the ability to detect fetal central nervous system (CNS) anomalies using in utero magnetic resonance imaging (iuMRI) and ultrasound (US) techniques.

Methods:

This prospective study was approved by the institutional review board (Ref: 2968/QĐ-ĐHYHN dated 11 July 2019), and the requirement to obtain the informed consent of patients was waived. This study included 66 fetuses with diagnosed or suspected CNS abnormalities based on the results of a prenatal screening US performed at the antenatal diagnosis center of the Central Obstetrics and Gynecology Hospital. All pregnant women with a suspected diagnosis of abnormal fetal CNS on US underwent 1.5-Tesla iuMRI within 14 days of the US at Hanoi Medical University Hospital between June 2019 and June 2020. Cohen’s kappa coefficient (κ) was used to determine the agreement between US and iuMRI findings.

Results:

A total of 66 pregnant women were examined, including 66 fetuses, for which 79 abnormalities were detected by US and 98 abnormalities were detected by iuMRI. The average gestational age was 29 weeks and 6 days. The comparison of iuMRI and US findings revealed similar diagnoses for 71 abnormalities (67%) and different diagnoses for 35 abnormalities (33%). The level of agreement between US and iuMRI was almost perfect for ventriculomegaly and cystic lesions, with κ values 0.87 and 0.84, respectively. The level of agreement between US and iuMRI was the weakest for hemorrhage, with a κ value 0 (no agreement), and cortical abnormalities, with a κ value of 0.46 (weak agreement).

Conclusion:

The level of agreement between US and iuMRI diagnoses was almost perfect for the detection of ventriculomegaly and was weakest for the detection of hemorrhage and cortical abnormalities, which were abnormalities detected by iuMRI but not by ultrasound.

Corpus Callosum Agenesis: An Insight into the Etiology and Spectrum of Symptoms

Brain hemispheres are connected by commissural structures, which consist of white matter fiber tracts that spread excitatory stimuli to various regions of the cortex. This allows an interaction between the two cerebral halves. The largest commissure is the corpus callosum (CC) which is located inferior to the longitudinal fissure, serving as its lower border. Sometimes this structure is not completely developed, which results in the condition known as agenesis of the corpus callosum (ACC). The aim of this paper was to review the latest discoveries related to the genetic and metabolic background of ACC, including the genotype/phenotype correlations as well as the clinical and imaging symptomatology. Due to various factors, including genetic defects and metabolic diseases, the development of CC may be impaired in many ways, which results in complete or partial ACC. This creates several clinical implications, depending on the specificity of the malformation and other defects in patients. Epilepsy, motor impairment and intellectual disability are the most prevalent. However, an asymptomatic course of the disease is even more common. ACC presents with characteristic images on ultrasound and magnetic resonance imaging (MRI).

Prenatal diagnosis of central nervous system abnormalities: Neurosonography versus fetal magnetic resonance imaging

OBJECTIVE

To share our experience in diagnosis of congenital central nervous system (CNS) abnormalities by fetal magnetic resonance imaging (MRI).

STUDY DESIGN

This study consisted of 110 pregnancies. Neurosonography (NS) findings were compared with MRI results. Anomalies were categorized into 10 groups: 1) Corpus callosum (CC) and cavum septum pellucidum (CSP) anomalies, 2) Neural tube defects (NTD), 3) Posterior fossa anomalies (PFA), 4) Primary ventriculomegaly (PVM), 5) Microcephaly, 6) Macrocephaly, 7) Periventricular leukomalacia (PVL), 8) Craniosynostosis, 9) Intracranial hemorrhage (ICH) and 10) Lumbosacral teratoma. Demographic features, clinical characteristics and perinatal outcomes of the study subjects were evaluated.

RESULTS

Gestational weeks for NS and for MRI were 25.5 and 26.5 weeks, respectively. Fourteen (12.7%) pregnancies were terminated. PVM (n = 36, 32.7%), CC and CSP anomalies (n = 29, 26.3%), PFA (n = 11, 10%) and NTD (n = 11, 10%) were the most common fetal MRI indications. There were no statistically significant differences between the accuracy of fetal NS and fetal MRI for CC and CSP anomalies, NTDs, PFA and PVM (p = 0.09, 0.43, 0.45 and 0.23, respectively). However, fetal MRI was more accurate for the detection of normal anatomic findings in cases with suspected microcephaly, macrocephaly and craniosynostosis in NS when pooled together (p = 0.007). Furthermore, MRI also seemed to be advantageous in CC & CSP anomalies though it was not validated by statistical measures. No statistically significant difference was found for diagnostic performance of NS and MRI according to gestational week (p = 0.27).

CONCLUSION

Fetal MRI in addition to NS may improve diagnostic accuracy in pregnancies with congenital CNS abnormalities.

Selective Emotional Dysregulation in Splenium Agenesis. A Case Report of a Patient With Normal Cognitive Profile

Objective: Patients with lesions of the corpus callosum are rare and may present different symptoms of the disconnection syndrome. However, to-date studies on callosotomized patients have not been conclusive, likely because of the non-uniform nature of clinical features, the extent of resection, and methods used to investigate specific and related deficits. Agenesis of the corpus callosum (AgCC) may be asymptomatic and discovered incidentally or associated with very slight deficits diagnosed during neurological examinations. In this study, we reported a case of an apparently completely asymptomatic 23-year-old woman with appreciable agenesis of the splenium of the corpus callosum. Methods: She underwent a neurological evaluation, a comprehensive battery of neuropsychological tests to identify any subclinical dysfunction that may affect the functionality of the subject in the daily life. Specifically, the possible presence of emotion dysregulation was examined by using a self-report questionnaire. Results: She showed normal neuropsychological and emotional functioning, performing efficiently on tests measuring acquired brain impairment. Discussion: The present case is discussed in terms of neuroplasticity - with a focus on putative compensatory mechanisms - emphasizing the variegated clinical feature patterns of brain defects present from birth.

Congenital Aqueductal Stenosis: Findings at Fetal MRI That Accurately Predict a Postnatal Diagnosis

BACKGROUND AND PURPOSE

Congenital aqueductal stenosis is a common cause of prenatal ventriculomegaly. An accurate diagnosis provides prognostic information and may guide obstetric management. The purpose of this study was to identify specific anatomic findings on prenatal MR imaging that can be used as predictors of congenital aqueductal stenosis.

MATERIALS AND METHODS

Prenatal and postnatal MRIs of fetuses referred to our institution for ventriculomegaly between June 2008 and August 2015 were reviewed. Imaging findings in postnatally confirmed congenital aqueductal stenosis (disease group) were compared with those of ventriculomegaly cases from other causes (control group). Univariate analysis was performed using the Fisher exact test and the Wilcoxon rank test, and multivariate analysis, via the random forest method.

RESULTS

Forty-three cases of ventriculomegaly had a confirmed postnatal diagnosis of congenital aqueductal stenosis. Thirty-two ventriculomegaly cases negative for congenital aqueductal stenosis were included in the control group. Dominant findings associated with an accurate prenatal diagnosis of congenital aqueductal stenosis on multivariate analysis included the following: enlarged inferior third ventricular recesses, enlargement of the lateral ventricles and third ventricle, and an abnormal corpus callosum. Findings that significantly increase the probability of congenital aqueductal stenosis (high positive predictive value) included the following: enlarged third ventricular recesses, aqueduct funneling, hemorrhage in the cerebral aqueduct, ventricular diverticulum, rhombencephalosynapsis, and dystroglycanopathy-related cerebellar dysplasia.

CONCLUSIONS

Our study identified specific characteristics on fetal MR imaging that can be used as predictors of the diagnosis of congenital aqueductal stenosis. Most of these findings are secondary to the obstructive nature of the resulting hydrocephalus. Common associated malformations such as rhombencephalosynapsis and dystroglycanopathies should also increase the suspicion of congenital aqueductal stenosis when present with ventriculomegaly.