Year: 2005
Type: conference-abstract
Abstract: Visualization of the posterior fossa is routine on fetal sonograms. However, the brainstem is rarely assessed sonographically since it is difficult to visualize. Fetal magnetic resonance (MR) imaging allows visualization of the brainstem in a manner not previously possible. We reviewed sonograms and MR images from 5 cases where the brainstem had a “kinked” appearance on fetal MR imaging. Gestational ages were 19–34 weeks. In each case there was either severe cerebellar hypoplasia or cerebellar aplasia. In 3 of these cases, the abnormal midbrain was mistaken for the cerebellum on sonography. In addition, microcephaly was present in 4 cases with thin brain parenchyma, the fifth case having severe hydrocephalus and an enlarged head. Other associated abnormalities included ventriculomegaly (in 4 cases) and one case each of lissencephaly, schizencephaly, holopresencephaly variant, encephalocele, agenesis of the corpus callosum, and hypoplastic optic nerve. Three pregnancies were terminated and 2 delivered liveborn infants, one with lissencephaly died at 3 days of age and one with holoprosencephaly variant died at 1 year of age. The kinked brainstems visualized on fetal MR imaging bear striking resemblance to structures normally present early in gestation. Specifically, the mesencephalic, cervical, and pontine flexures characteristic of the developing CNS at approximately seven weeks gestational age form a “kink” very similar to that seen in our cases. At this point in development, the cerebellum has not yet developed into a grossly detectable structure. The anatomic anomalies of the central nervous system seen in these cases are therefore consistent with arrest of brainstem and cerebellar developmental at approximately seven weeks.
DOI: 10.1002/uog.2221
Language: English
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2088021576