Risk factors for Dandy-Walker malformation: a population-based assessment.

Dandy-Walker malformation (DWM) is the most common congenital malformation of the cerebellum, but its causes are largely unknown. An increasing number of genes associated with congenital cerebellar malformations have been identified; however, few studies have examined the potential role of non-genetic, potentially modifiable risk factors. From the National Birth Defects Prevention Study, we examined maternal, paternal, and infant characteristics and maternal conditions and periconceptional exposures (from 1 month before to 3 months after conception) among infants with DWM (n = 160) and unaffected controls (n = 10,200), delivered between 1997 and 2009. Odds ratios, crude (cOR) and adjusted (aOR) were computed using logistic regression. Maternal factors associated with DWM included non-Hispanic black race/ethnicity (aOR = 2.0, 95%CI: 1.3-3.2). Among maternal conditions, a history of infertility increased the risk for DWM (all: aOR = 2.4, 95%CI: 1.3-4.6; multiple: aOR = 3.9, 95%CI: 1.7-8.9). The lack of association with many maternal exposures supports the hypothesis of a major contribution of genetic factors to the risk for DWM; however, the observed associations with maternal non-Hispanic black race/ethnicity and maternal history of infertility indicate that further research into factors underlying these characteristics may uncover potentially modifiable risk factors, acting alone or as a component of gene-environment interactions.

Complejo de Dandy Walker: evaluación prenatal / Dandy Walker complex: prenatal assessment

Síndrome al que se define como la asociación de hidrocefalia de grado variable con aumento de tamaño de la fosa craneal posterior y defecto del vermis del cerebelo. Se describen su etilogía, etiopatogenia, diagnóstico, y nuevas formas de abordaje de la fosa posterior.

MRI and multiplanar 3D ultrasound compared in the prenatal assessment of enlarged posterior fossa.

Our aim was to compare the diagnostic capabilities of the multiplanar mode of 3D ultrasound (3D US) and MRI in the assessment of a fetal enlarged cisterna magna. Two fetuses showing an enlarged posterior fossa by conventional two-dimensional ultrasound at 24 and 29 weeks of pregnancy were assessed using both diagnostic methods. One fetus was found to have Dandy-Walker syndrome malformation. In the other, the syndrome was ruled out using both methods. Our results suggest that multiplanar 3D US is able to achieve similar results as does MRI when observing the fetal brain.

Magnetic resonance imaging and ultrasound in the assessment of the fetal central nervous system.

Ultrasound is the screening modality of choice for evaluation of the fetal central nervous system (CNS). However, in cases of difficult diagnosis further fetal investigation is desirable. Due to ultrafast magnetic resonance imaging (MRI) techniques artifacts from fetal motions are minimized. MRI involves no exposure to radiation and hence appears to be safe. Due to the better soft tissue contrast, additional investigation by MRI may extend the sonographic diagnosis of fetal CNS-anomalies. Ultrasound and MRI are complementary imaging methods in the evaluation of the fetal CNS. The most important indications for ultrasound are screening for CNS anomalies and serial assessment of the dynamic of the disorder. The most important indications for fetal MRI are the "second opinion" and investigation by fetal MRI instead of postpartum MRI (especially in cases of planned postpartum intervention). In this article the indications and limitations of ultrasound and magnetic resonance imaging in the evaluation of the fetal CNS are discussed.

Quantitative assessment of brainstem development in Joubert syndrome and Dandy-Walker syndrome.

Key features of Joubert syndrome include developmental delay, hypotonia, hyperpnea and apnea, oculomotor apraxia, and the presence of the molar tooth sign on axial imaging through the brainstem isthmus--the junction of the pons and mesencephalon. Interestingly, 1 in 10 patients with Joubert syndrome has abnormal cerebrospinal fluid collections misdiagnosed as Dandy-Walker variants. Because of important differences in patient management, genetic counseling, and prognosis between these conditions, we undertook a study to determine if the brainstem isthmus is normal in Dandy-Walker syndrome. Using standard landmarks, we evaluated development of the isthmus in normal subjects and in subjects with Joubert syndrome and Dandy-Walker syndrome. Four of five brainstem measures increased with age in normal subjects. In subjects with Joubert syndrome, the depth and length of the interpeduncular fossa were increased, and the width of the isthmus was decreased. In subjects with Dandy-Walker syndrome, the width of the brainstem isthmus was normal, and the molar tooth sign was absent. Although the pons can be hypoplastic in Dandy-Walker syndrome, we conclude that the pontomesencephalic junction is normal. Thus, the molar tooth sign can effectively distinguish between Joubert and Dandy-Walker syndromes. Genetic heterogeneity or epigenetic factors may account for abnormal cerebrospinal fluid collections in some cases of Joubert syndrome.