Fetal and neonatal outcomes of posterior fossa anomalies: a retrospective cohort study

The primary aim of this study was to estimate the incidence of posterior fossa anomalies (PFA) and assess the associated outcomes in King Abdulaziz Medical City (KAMC), Riyadh. All fetuses diagnosed by prenatal ultrasound with PFA from 2017 to 2021 in KAMC were analyzed retrospectively. PFA included Dandy-Walker malformation (DWM), mega cisterna magna (MCM), Blake's pouch cyst (BPC), and isolated vermian hypoplasia (VH). The 65 cases of PFA were 41.5% DWM, 46.2% MCM, 10.8% VH, and 1.5% BPC. The annual incidence rates were 2.48, 2.64, 4.41, 8.75, and 1.71 per 1000 anatomy scans for 2017, 2018, 2019, 2020, and 2021, respectively. Infants with DWM appeared to have a higher proportion of associated central nervous system (CNS) abnormalities (70.4% vs. 39.5%; p-value = 0.014) and seizures than others (45% vs. 17.9%; p-value = 0.041). Ten patients with abnormal genetic testing showed a single gene mutation causing CNS abnormalities, including a pathogenic variant in MPL, C5orf42, ISPD, PDHA1, PNPLA8, JAM3, COL18A1, and a variant of uncertain significance in the PNPLA8 gene. Our result showed that the most common PFA is DWM and MCM. The autosomal recessive pathogenic mutation is the major cause of genetic disease in Saudi patients diagnosed with PFA.

[Megacisterna magna as incidental finding in a boy with ADHD]

In this case report we describe how a 13-year-old boy with a complex development profile was diagnosed with adhd and who was also found to have a megacisterna magna, a posterior fossa anomaly in the Dandy-Walker continuum. We searched the literature for reports of other patients who had this (mild) brain anomaly along with psychiatric problems in general and attention problems in particular. Our search of the literature suggested a possible link between the two diagnostic entities.

Outcome of fetal cerebral posterior fossa anomalies

INTRODUCTION

Limited data exist on the outcome of Dandy-Walker malformation (DWM), Dandy-Walker variant (DWV) and mega-cisterna magna (MCM). We report the first population-based study of posterior fossa anomalies from the northern region of England.

METHODS

Cases were identified from the Northern Congenital Abnormality Survey (NorCAS) and regional Fetal Medicine Unit databases for the period 1986-2004 for DWM/V and 1995-2005 for MCM (defined as a cisterna magna > or =10 mm). Outcome data was obtained from pediatric records and/or general practitioner/health visitor questionnaires for all survivors.

RESULTS

A prenatal diagnosis of a posterior fossa abnormality was made in 91 cases, with a further 12 cases of DWM/V diagnosed postnatally, giving incidences of DWM/V and MCM of 1/11574 and 1/8268 births respectively. In five cases where DWM/V was suspected prenatally, the diagnosis was not confirmed. Of the 47 with DWM/V, 41 (87%) had additional anomalies. There were three survivors, all with neurodevelopmental disability. Of the 39 cases of MCM, 24 (62%) had additional anomalies. There were 30 survivors; one child died at 3 months and the outcome was normal in 25 children including 12/13 (92%) with isolated MCM.

SUMMARY

Posterior fossa anomalies are relatively common. The outcome is very poor in DWM/V owing to the high rate of associated anomalies. The outcome appears better with MCM, especially if this is an isolated finding.

Parenchymal neurocutaneous melanosis in association with intraventricular dermoid and Dandy-Walker variant: a case report

Neurocutaneous melanosis (NCM) is a rare congenital disease that is characterized by the presence of large or multiple congenital melanocytic nevi and melanotic lesions of the central nervous system. We report here on the CT and MR imaging findings of an unusual case of NCM that was associated with intraventricular dermoid and Dandy-Walker malformation.

Dandy-Walker Malformation: A Review of 78 Cases Diagnosed by Prenatal Sonography

OBJECTIVE

The purpose of this study was to determine the associated abnormalities and clinical outcomes of fetuses with Dandy-Walker malformations.

METHODS

Sonograms and medical reports of 78 cases were reviewed and information regarding each outcome was collected from autopsy records, hospital charts and specialists caring for the surviving infants.

RESULTS

We identified 64 fetuses with classic Dandy-Walker malformation (DW) and 14 fetuses with Dandy-Walker variant (DWV). A high proportion (44.8%) of the parents were consanguineous. The spectrum and proportion of central nervous system (67.1 vs. 71.4%; p = 1.0) and other malformations (43.7 vs. 64.2%; p = 0.57) associated with DW and DWV were similar. Chromosome abnormalities were found in 9 of the 51 (17.6%) fetuses that underwent karyotype analysis. Only 4 of 64 (6.2%) DW and 3 of 14 (21.4%) DWV infants survived (p 0.14), and all surviving infants with DW or DWV had neurological disorders.

CONCLUSIONS

DW and DWV cases show so many similarities that a clear-cut distinction is difficult. There was no significant difference in the spectrum of associated anomalies and postnatal prognosis between DW and DWV cases.

Dandy-Walker Syndrome: Incidence in a Defined Population of Tabuk, Saudi Arabia

Dandy-Walker syndrome (DWS) is characterized by cystic dilatation of the 4th ventricle and absence of the cerebellar vermis. There may also be posterior fossa enlargement, hydrocephalus, hypoplastic cerebellar hemispheres and other malformations within and outside the central nervous system (CNS). The condition is uncommon, and the incidence is unknown. We studied the incidence of DWS in a defined Saudi Arabian population of military personnel and their dependants. We identified all patients diagnosed with DWS during an 11-year period (1989-1999) from a cohort of 45,274 live births. The incidence of DWS was 1.0 per 100,000 live births per year. The incidence by sex per 100,000 live births per year was 1.24 for males and 0.78 for females. DWS formed 3.5% of our cases of infantile hydrocephalus.

Sonographic detection of inferior vermian agenesis in Dandy-Walker malformations: prognostic implications

PURPOSE

To compare the prognoses for fetuses with sonographically detected inferior vermian agenesis (IVA) or complete vermian agenesis (CVA).

MATERIALS AND METHODS

The sonograms of 65 fetuses with Dandy-Walker malformations were retrospectively reviewed. Fetuses were divided into two groups--those with IVA and those with CVA.

RESULTS

Of the 65 fetuses, 37 had IVA; 28, CVA. Thirteen (20%) of the 65-nine (24%) of the 37 with IVA and four (14%) of the 28 with CVA--lived for longer than 1 year. Chromosomal abnormalities were found in 23 (45%) of the 51 fetuses tested for karyotypic abnormalities or clinically thought to have Down syndrome. Seventeen (53%) of the 32 with IVA and six (32%) of the 19 with CVA that were tested for karyotypic abnormalities or clinically thought to have Down syndrome had chromosomal abnormalities (P = .07). Associated morphologic abnormalities were prenatally detected in 49 (75%) of the 65-in 28 (76%) of the 37 with IVA and in 21 (75%) of the 28 with CVA.

CONCLUSION

The overall guarded prognosis is similar for fetuses with Dandy-Walker malformations for whom IVA or CVA has been sonographically diagnosed. Fetuses with IVA have a higher prevalence of karyotypic abnormalities.

Marked female predilection in some syndromes associated with facial hemangiomas

Analysis of the literature yielded 42 examples of the combination of sternal non-union and supraumbilical raphé without evidence of sex predilection. However, among an additional 31 cases in which the triad included facial hemangioma, there was almost exclusive female occurrence. Another condition involves extensive unilateral hemangioma of the face, absence of ipsilateral carotid and vertebral vessels, mental retardation, and Dandy-Walker malformation. Still another disorder has been proposed which includes facial hemangioma and dilatation of the carotid syphon. Both of these conditions exhibit marked female predilection. Examples of overlap of all three "disorders" cause the authors to question the independence of these disorders, hypothesizing instead that they represent a spectrum.

Cerebellar vermian defects: antenatal sonographic appearance and clinical significance

A partial or complete defect of the cerebellar vermis may occur sporadically or as a component of the Dandy-Walker syndrome, the Dandy-Walker variant, Down's syndrome, or Joubert-syndrome. We identified a defect of the cerebellar vermis in nine fetuses on routine antenatal sonographic studies. In five of the nine fetuses other abnormalities, including central nervous system and non-central nervous system lesions were identified. Three of these five fetuses died and two infants have remained well on follow-up. Four of nine fetuses (or infants) had no other abnormalities and have remained well on follow-up at 8 weeks to 4 years of age. Although cases of fatal and serious nonfatal outcomes have been reported by other investigators, in this small series the finding of an isolated inferior vermian defect was associated with a good prognosis.