Prenatal pseudocysts of the germinal matrix in preterm infants

The correlation between prenatal ultrasound and MRI in isolated periventricular pseudocysts: Analysis of 10 years' experience at the University Hospital of Angers

BACKGROUND

Periventricular cysts are one of the most extensively documented antenatal brain lesions found through fetal ultrasound at the University Hospital of Angers. The main purpose of our study was to determine the contribution of fetal magnetic resonance imaging (MRI) and postnatal transfontanellar ultrasound (TFU) in the assessment of isolated periventricular cysts found on antenatal ultrasound at the University Hospital of Angers.

METHODS

This retrospective, descriptive study was carried out over a 10-year period. Overall, 82 cases were included, divided into two groups according to the type of cysts found on the ultrasound: 13 cases of subependymal pseudocysts (SEPC) and 69 cases of frontal horn cysts (FHC). In all, 43 children underwent a postnatal TFU: seven in the SEPC group and 36 in the FHC group.

RESULTS

Our study found excellent agreement between antenatal ultrasound and fetal MRI in the FHC group concerning classification of the cysts (approval rate [TA]: 98.60%; kappa coefficient [κ]: 0.85), their location (TA: 98.80%; κ: 0.91), their number (TA: 78.20%; κ: 0.73), and the detection of FHC (TA: 81.10%; κ: 0.74), as well as a good agreement concerning the detection of SEPC and temporal horn cysts (THC; TA: 99.40% and 95.60%, respectively). Fetal MRI proved to be better in the SEPC group for cyst classification (TA: 66.70%; κ: 0.33), their location (TA: 60%; κ: 0.41), and their number (TA: 53, 30%; κ: 0.45) and the detection of SEPC (TA: 23.10%; κ: 0.14). In both groups, postnatal TFU did not provide additional information compared to MRI.

CONCLUSION

The finding of periventricular cysts in antenatal ultrasound should lead to a reference ultrasound, a key procedure for distinguishing between SEPC and FHC. In our study, no additional benefit from MRI and TFU was established for the evaluation of FHC. These findings should be considered as normal variants, thus limiting pre- and postnatal investigations. The visualization of SEPC, THC, or a parenchymal abnormality on the reference ultrasound should lead to an additional MRI being performed and a personalized follow-up of the child.

Neonatal Head Ultrasound: A Review and Update-Part 2: The Term Neonate and Analysis of Brain Anomalies

Neonatal head ultrasound has a key role in triaging neonates with antenatal imaging or postnatal clinical concerns. This article will discuss key features of various intracranial pathologies of concern in term infants. It will also illustrate various congenital malformations.

The developing brain by trimester

Transient anatomical entities play a role in the maturation of brain regions and early functional fetal networks. At the postmenstrual age of 7 weeks, major subdivisions of the brain are visible. At the end of the embryonic period, the cortical plate covers the neopallium. The choroid plexus develops in concert with it, and the dorsal thalamus covers about half the diencephalic third ventricle surface. In addition to the fourth ventricle neuroepithelium the rhombic lips are an active neuroepithelial production site. Early reciprocal connections between the thalamus and cortex are present. The corticospinal tract has reached the pyramidal decussation, and the arteries forming the mature circle of Willis are seen. Moreover, the superior sagittal sinus has formed, and at the rostral neuropore the massa commissuralis is growing. At the viable preterm age of around 24 weeks PMA, white matter tracts are in full development. Asymmetric progenitor division permits production of neurons, subventricular zone precursors, and glial cells. Myelin is present in the ventral spinal quadrant, cuneate fascicle, and spinal motor fibers. The neopallial mantle has been separated into transient layers (stratified transitional fields) between the neuroepithelium and the cortical plate. The subplate plays an important role in organizing the structuring of the cortical plate. Commissural tracts have shaped the corpus callosum, early primary gyri are present, and opercularization has started caudally, forming the lateral fissure. Thalamic and striatal nuclei have formed, although GABAergic neurons continue to migrate into the thalamus from the corpus gangliothalamicum. Near-term PMA cerebral sublobulation is active. Between 24 and 32 weeks, primary sulci develop. Myelin is present in the superior cerebellar peduncle, rubrospinal tract, and inferior olive. Germinal matrix disappears from the telencephalon, except for the GABAergic frontal cortical subventricular neuroepithelium.

Prenatal Evaluation, Imaging Features, and Neurodevelopmental Outcome of Prenatally Diagnosed Periventricular Pseudocysts

BACKGROUND AND PURPOSE

Periventricular pseudocysts are cystic cavities that lack the ependymal cell lining found in true cysts. The aim of this study was to characterize periventricular pseudocysts and related findings and their neurodevelopmental outcome.

MATERIALS AND METHODS

This was a retrospective study of periventricular pseudocysts detected prenatally on fetal MR imaging in 26 fetuses. The fetuses were divided into group A (n = 8), which included cases with isolated periventricular pseudocysts, and group B (n = 18), which included cases of periventricular pseudocysts with additional findings. Cases were further subdivided into connatal cysts and subependymal pseudocysts. Data collected included prenatal history, MR imaging features, sonographic follow-up, and neurodevelopmental outcome.

RESULTS

All cases in group A (n = 8) had a normal outcome. In group B (n = 18), 6 pregnancies were terminated and 2 had an abnormal outcome. Both cases with an abnormal outcome involved patients with subependymal pseudocysts. No significant association was found between the morphologic features on MR imaging and the neurodevelopmental outcome.

CONCLUSIONS

Neurodevelopmental outcome in cases of isolated periventricular pseudocysts detected prenatally appears to be normal. A detailed evaluation should be performed to rule out additional brain findings, chromosomal aberration, and fetal malformation. This evaluation should include the following: maternal TORCH status, detailed fetal sonographic anatomic evaluation, fetal echocardiogram, fetal brain MR imaging, amniocentesis and karyotyping/comparative genomic hybridization, and genetic counseling. Additional findings on MR imaging, including mild-to-moderate dilated ventricles, asymmetric ventricles, or T2 hyperintense signal in the white matter without other findings or major fetal abnormality, appear to be benign. Connatal cysts appear to be benign.

Prenatal features of isolated subependymal pseudocysts associated with adverse pregnancy outcome

OBJECTIVES

To identify at prenatal ultrasound (US) the features of apparently isolated subependymal pseudocysts (SEPC) that may indicate underlying pathology and should lead to further investigations.

METHODS

This was a retrospective study of cases with SEPC detected on prenatal US and/or magnetic resonance imaging (MRI). Those with apparently isolated SEPC at US were classified into two groups as follows: Group 1 (n = 29): normal prenatal US and MRI (except for SEPC) and normal outcome; Group 2 (n = 12): normal prenatal cerebral US (except for SEPC) and abnormal prenatal cerebral MRI with or without abnormal outcome. A third group (n = 9) included cases with abnormal prenatal US and MRI. The latter cases with obvious cerebral abnormalities at US were excluded from the statistical analysis as they do not represent a diagnostic dilemma for clinicians. Groups 1 and 2 were analyzed, comparing them with respect to their SEPC characteristics (size, number, location in relation to the caudothalamic notch and the ventricular horns and morphology) and extracerebral abnormalities.

RESULTS

The mean ± SD SEPC great axis was longer in Group 2 (11.67 ± 5.82 mm) than it was in Group 1 (8.00 ± 5.64 mm) (P = 0.021), suggesting an optimal cut-off for size of SEPC of ≥ 9 mm (sensitivity = 75%, specificity = 62%) to maximize sensitivity for predicting pathological outcome. SEPC adjacent to the temporal horns and SEPC located posterior to the caudothalamic notch were observed more frequently in Group 2, indicating their association with poor outcome (P = 0.003 and P = 0.003, respectively). Atypical morphology and extracerebral abnormalities were observed more frequently in Group 2 (P = 0.013 and P = 0.044, respectively). There was no statistically significant difference between groups for either number or location of cysts along the inferior wall or adjacent to the lateral wall of the frontal horns (P = 0.591 and P = 0.156, respectively).

CONCLUSION

When apparently isolated SEPC are observed at prenatal US, further investigations should be performed under the following circumstances: (1) SEPC great axis ≥ 9 mm; (2) SEPC adjacent to the occipital and temporal horns; (3) SEPC located posterior to the caudothalamic notch; (4) SEPC with atypical morphology.

How to use... neonatal TORCH testing

Toxoplasma gondii, rubella, cytomegalovirus and herpes simplex virus have in common that they can cause congenital (TORCH) infection, leading to fetal and neonatal morbidity and mortality. During the last decades, TORCH screening, which is generally considered to be single serum testing, has been increasingly used inappropriately and questions have been raised concerning the indications and cost-effectiveness of TORCH testing. The problems of TORCH screening lie in requesting the screening for the wrong indications, wrong interpretation of the single serum results and in case there is a good indication for diagnosis of congenital infection, sending in the wrong materials. This review provides an overview of the pathogenesis, epidemiology and clinical consequences of congenital TORCH infections and discusses the indications for, and interpretation of, TORCH screens.

Prenatal detection of periventricular pseudocysts by ultrasound: diagnosis and outcome

Congenital periventricular pseudocysts are found in about 1–5% of neonates. These pseudocysts originate from the persistence of the germinal matrix and have a good prognosis, disappearing in the first months. Periventricular pseudocysts are rarely detected in the fetus. We describe a case of prenatal detection of periventricular pseudocysts by prenatal transvaginal ultrasound and a three-dimensional technique. Prenatal ultrasound showed partial regression of the pseudocysts. At postnatal ultrasound, the complete disappearance of the pseudocysts was detected.

Timing of injury in utero causing respiratory inhibition after crying

BACKGROUND

The aim of this study was to clarify the timing of injuries in utero that cause respiratory inhibition after crying (RIAC). We evaluated infants with cranial ultrasound abnormalities diagnosed during hospitalization.

METHODS

We retrospectively examined the medical records of preterm infants who were treated in the neonatal intensive care unit at Nara Prefectural Hospital in Nara, Japan from January 2006 through December 2010. Inclusion criterion was gestational age less than 34 weeks. We evaluated the perinatal factors and cranial ultrasound abnormalities associated with RIAC, feeding hypoxemia, and prolonged apnea. We also evaluated the timing of appearance of cranial ultrasound abnormalities.

RESULTS

A total of 125 infants were examined. Mean gestational age was 30.6 ± 2.4 weeks and mean birthweight was 1465 ± 454 g. The numbers of infants who showed RIAC, feeding hypoxemia, and prolonged apnea were 44, 48, and 63, respectively. Among 91 infants who showed cranial ultrasound abnormalities, 67 had increased echogenicity in the ganglionic eminence (GE). There was a significant correlation between increased echogenicity and RIAC (P < 0.001). Of the infants who showed increased echogenicity in the GE, 19 had this finding during the course of hospitalization. In these 19 infants, however, gestational age of those with RIAC was less than 31 weeks.

CONCLUSION

We speculate that the timing of intrauterine injury resulting in RIAC in infants is less than 31 gestational weeks.

Newborn frontal horn cysts: cause for concern?

OBJECTIVE

To document the incidence, natural history and compare neurodevelopmental outcome of newborns with and without frontal horn cysts (FHC).

STUDY DESIGN

This was a case-control study. Newborns with and without FHC were identified and matched for demographics and worst cranial ultrasound scan (CUS) findings. Neurodevelopmental outcome was assessed at 18 to 24 months.

RESULT

A total of 30 FHC cases were identified from medical imaging database. Twenty-five cases occurred in preterm 32 weeks gestation with an incidence of 1% (25 of 2340). The diagnosis was made on the initial CUS in 28 cases. The cyst size and number varied from 1 to 18 mm and 1 to 6 respectively with no change noted on repeat CUS during hospital stay. Neurodevelopmental outcomes were not statistically significantly different between the groups.

CONCLUSION

FHC are not uncommon in the newborn period. They appear to be benign with no impact on neurodevelopmental outcome. This information is vital for counseling parents of infants with FHC.

Subependymal Pseudocysts in the Fetal Brain and Unrelated Hydrocolpos

Subependymal pseudocysts are found in approximately 5% of all neonates. When they are isolated, the outcome is usually favorable. However, when they are associated with other anomalies, the prognosis is often poor. The diagnosis of imperforate hymen is rarely diagnosed before puberty, but reports of diagnosis in utero have been documented. The authors present a case with two coexisting rare findings in one fetus. The postnatal outcome for the infant with these isolated unrelated findings proved to be reassuring.

Routine TORCH screening is not warranted in neonates with subependymal cysts

BACKGROUND

Congenital infections are associated with a wide variety of clinical symptoms, including subependymal cysts (SEC).

OBJECTIVE

To determine the co-occurrence of SEC and congenital infections, as diagnosed by TORCH serologic tests and/or cytomegalovirus (CMV) urine culture.

METHODS

We performed a retrospective study of all neonates admitted to our neonatal intensive care unit from 1998 to 2009 in whom SEC were detected on cranial ultrasound and TORCH serologic tests and/or CMV urine cultures were performed.

RESULTS

Fifty-nine neonates fulfilled the inclusion criteria. TORCH serologic tests were performed in 69% (41/59) of cases. Urine CMV culture was performed in 68% (40/59) of cases. None of the neonates tested positive for IgM Toxoplasma gondii, Rubella and Herpes simplex virus. Positive CMV IgM titers and/or a positive urine CMV culture were detected in 2% (1/59) of neonates.

CONCLUSION

The co-occurrence of TORCH congenital infections in infants with SEC is rare. Routine TORCH screening in neonates with SEC does not seem warranted.

Brain imaging findings in very preterm infants throughout the neonatal period: part I. Incidences and evolution of lesions, comparison between ultrasound and MRI

This study describes the incidence and evolution of brain imaging findings in very preterm infants (GA<32 weeks), assessed with sequential cranial ultrasound (cUS) throughout the neonatal period and MRI around term age. The accuracy of both tools is compared for findings obtained around term. Periventricular echodensities and intraventricular haemorrhage were the most frequent cUS findings during admission. Frequent findings on both cUS and MRI around term included ventricular dilatation, widened extracerebral spaces, and decreased cortical complexity. MRI additionally showed punctate white matter lesions and diffuse and excessive high signal intensity, but did not depict lenticulostriate vasculopathy and calcifications, and was less reliable for germinolytic and plexus cysts. cUS detected most abnormalities that have been associated with abnormal neurodevelopmental outcome.

Neurodevelopment in very low birth weight premature infants with postnatal subependymal cysts

The aim of this study was to investigate the neurodevelopmental outcome in very low birth weight infants with postnatal subependymal cysts. During a 3-year period, postnatal subependymal cysts were diagnosed by serial cranial ultrasound in 21 very low birth weight infants born prior to 33 weeks' gestation. These infants and 116 healthy very low birth weight controls were evaluated with the Bayley Scales of Infant Development at 2 years of age. Preterm infants with postnatal subependymal cysts had a significantly lower Psychomotor Development Index (P = .034) and were more likely than the normal group to have motor developmental delay (Psychomotor Development Index <70) (P = .013). The findings indicate that postnatal subependymal cyst is a significant risk factor for impaired motor development in very low birth weight infants (odds ratio 5.73, 95% confidence interval 1.57-20.97).

Differential Diagnosis of Intracranial Cystic Lesions at Head US: Correlation with CT and MR Imaging

The differential diagnosis of intracranial cystic lesions at head ultrasonography (US) includes a broad spectrum of conditions: (a) normal variants, (b) developmental cystic lesions, (c) cysts due to perinatal injury, (d) vascular cystlike structures, (e) hemorrhagic cysts, and (f) infectious cysts. These lesions vary in prevalence from common (cavum of the septum pellucidum, subependymal cyst, choroid plexus cyst) to rare (vein of Galen malformation). US can provide important information about the anatomic location, size, and shape of the lesions as well as their mass effect on adjacent structures. Differential diagnosis may be difficult because there is substantial overlap of US features between many of these conditions. However, if careful attention is paid to the location and characteristics of the cyst, a more specific diagnosis may be suggested. Understanding the spectrum of appearances of the various intracranial cystic lesions at head US improves the diagnostic yield, enables one to understand their pathogenesis, and facilitates patient care.

Adult unilateral periventricular pseudocysts with ipsilateral headache

OBJECTIVES

Unilateral periventricular pseudocysts (PVPC), manifesting as ipsilateral headache have been only rarely reported in adults.

CASE REPORT

In a 48-year-old woman, right-sided, pulsating headache occurred in 1999. Headache exclusively extended over the right head and periorbitally; it was frequently associated with a feeling of cold, lasted maximally for 1 day, and occasionally went along with nausea and right-sided lacrimation. Since January 2003, headache occurred daily with varying intensity. For headache, she was regularly taking doxepin (25 mg). Ordinary analgesics and tryptanes were only of minimal effect. Since 2001, left-sided hemi-hypesthesia occurred. CT and MRI scans of the brain disclosed right-sided cysts in the white matter with a maximal diameter of 1cm, partially grouped and partially disseminated and bilateral calcifications of the basal ganglia. Since hypoxemia/ischemia, subependymal hemorrhage, CNS infection, developmental defect of the mantle layer, chromosomal disorder, Zellweger syndrome, carbon monoxide intoxication, trauma, or mitochondriopathy were not causative, the etiology of PVPC remained questionable.

CONCLUSIONS

Rarely, unilateral PVPC become symptomatic in adulthood, manifesting as ipsilateral headache, contralateral hemi-hypesthesia, depression, collapses, and slight cognitive decline. Clinical progression of the disease is not necessarily related to the progression of the imaging findings. PVPC should be included in the differential diagnosis of unilateral headache.

Clinical features of infants with subependymal germinolysis and choroid plexus cysts

BACKGROUND

Periventricular cysts are not rare findings in neonates. However, they are sometimes associated with serious clinical complications, such as congenital viral infections and anomalies.

METHODS

We performed a retrospective follow-up study on newborns who had periventricular cysts on routine cranial ultrasound examination.

RESULTS

We followed 13 infants (three preterm) with periventricular cysts. Ten had single or multiple germinolysis cysts and the remaining three had choroid plexus cysts. All infants had various kinds of underlying complications, including congenital viral infection (two with cytomegalovirus and one with rubella),Sotos syndrome (n = 4), intrauterine growth retardation (n = 5), large-for-dates(n = 4), congenital heart disease (n = 1),myelomeningocele (n = 1) and other minor anomalies. All cases of germinolysis except for one developed a neurodevelopmental abnormality and/or delay. In contrast,all three cases with choroid plexus cysts appeared to develop well,despite the underlying complications.

CONCLUSIONS

Germinolysis cysts seem to be associated with systemic diseases and should be treated as a high-risk sign for impaired neurological development.

Fetal subependymal cysts with normal neonatal outcome. A case report

The authors report the prenatal sonographic diagnosis of subependymal cysts, confirmed by in utero MRI, in an apparently uneventful pregnancy. The sonographic appearance of the lesions, the obstetric management and the postnatal follow-up to one year are described. Special attention is paid to prenatal factors of neurological morbidity, rather than intrapartum and postnatal, thus emphasizing the importance of early and sequential evaluation of the developing fetal brain. Diagnosis, clinical significance and outcome of prenatal subependymal cysts are necessary for parental counselling and obstetric management. Furthermore, the detection of a prenatal brain injury may have remarkable medico-legal implications.

Congenital periventricular pseudocysts: prenatal sonographic appearance and clinical implications

OBJECTIVE

Periventricular pseudocysts (PVPC) are diagnosed in approximately 1% of premature newborns that undergo brain sonography during the first 24 h of life. These pseudocysts are thought to develop antenatally due to germinal matrix hemorrhage, but have not been described until now in prenatal ultrasound studies. The aim of this study was to report the identification, differential diagnosis, and prognosis of PVPC detected by prenatal ultrasound examination.

DESIGN

Between 1997 and 2001 we made an ultrasound diagnosis of PVPC in 11 fetuses. In nine fetuses the findings were characteristic of PVPC and these patients represent our study group. Fetal magnetic resonance imaging was performed in five patients. Termination of pregnancy was carried out in three patients, in one case intrauterine fetal death occurred at 31 weeks, and one infant died in the neonatal period. The surviving four newborns are being followed in the pediatric neurology clinic.

RESULTS

PVPC were diagnosed by ultrasound scan in fetuses between 16 and 37 weeks of gestation (mean, 29.7 weeks). Magnetic resonance imaging confirmed the presence of PVPC in two cases. In eight cases the pseudocysts were unilateral and in one case bilateral. They were an isolated finding in five patients. Four of these fetuses were delivered at term and have normal neurological development at ages ranging from 6 to 25 months. All fetuses with additional pathologies (coarctation of the aorta, hemimegalencephaly, cytomegalovirus infection, hypoplasia of the vermis with dysmorphism) did not survive.

CONCLUSIONS

The prenatal diagnosis of PVPC warrants an extensive search for possible associated pathological findings. As an isolated finding, antenatal PVPC seem to carry a good prognosis.

Subependymal pseudocysts in the fetal brain: prenatal diagnosis of two cases and review of the literature

Subependymal pseudocysts are cerebral cysts found in 5% of all neonates. When they are isolated and typical, they result from persistence of the germinal matrix, have a good prognosis and regress spontaneously within a few months. However, associated anomalies are frequent and in such cases the prognosis is poor. They can be of infectious, vascular, metabolic or chromosomal origin. Subependymal pseudocysts have rarely been described in the antenatal period. We report the prenatal diagnosis of two cases of isolated pseudocysts at 32 and 23 weeks. Both ultrasonography and magnetic resonance imaging assisted in the diagnosis and there was normal postnatal outcome in both cases.

Intracranial neonatal neurosonography: an update

This article reviews salient features of a normal neonatal cranial ultrasound examination with suggestions concerning techniques that take advantage of new developments in ultrasound technology. It also illustrates pathologic findings in such areas as congenital abnormalities, intracranial hemorrhage, and infection. Recent publications on the subject of neurodevelopmental outcome are explored, pointing out how varying descriptions of intraventricular hemorrhages affect their results.

Prenatal cocaine exposure and cranial sonographic findings in preterm infants

PURPOSE

Prenatal cocaine exposure has been linked with subependymal hemorrhage and the formation of cysts that are detectable on cranial sonography in neonates born at term. We sought to determine if prenatal cocaine exposure increases the incidence of subependymal cysts in preterm infants.

METHODS

We retrospectively reviewed the medical records and cranial sonograms obtained during a 1-year period on 122 premature (< 36 weeks of gestation) infants. Infants were categorized into 1 of 2 groups: those exposed to cocaine and those not exposed to cocaine. Infants were assigned to the cocaine-exposed group if there was a maternal history of cocaine abuse during pregnancy or if maternal or neonatal urine toxicology results were positive at the time of delivery.

RESULTS

Five of the 122 infants were excluded from the study because of insufficient medical and drug histories. The incidence of subependymal cysts in the 117 remaining infants was 14% (16 of 117). The incidence of subependymal cysts in infants exposed to cocaine prenatally was 44% (8 of 18) compared with 8% (8 of 99) in the unexposed group (p < 0.01).

CONCLUSIONS

We found an increased incidence of subependymal cyst formation in preterm infants who were exposed to cocaine prenatally. This result is consistent with results of similar studies in term infants.