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Updated: Jun 28, 2026
High Frequency Ultrasound for the Analysis of Fetal and Placental Development In Vivo
Published on: November 8, 2018
Prenatal ultrasonographic diagnosis of polymicrogyria
F Dhombres1, C Nahama-Allouche, A Gelot
1Service de Radiologie Pédiatrique, Hôpital Armand-Trousseau, AP-HP, Paris, France.
Abstract:
We report a rare case of polymicrogyria diagnosed at 27 weeks' gestation on ultrasound examination and associated with cytomegalovirus (CMV) infection. The ultrasound finding suggesting this diagnosis was the direct visibility of the overfolded cortical ribbon. The cerebral surface was clearly visible because of a markedly enlarged pericerebral space associated with micrencephaly secondary to CMV infection. Bilateral opercular dysplasia was also present. Very few sonographic markers of infectious fetopathy were observed other than periventricular cysts located behind both ventricular horns. Magnetic resonance imaging (MRI) of the fetal brain confirmed the ultrasound findings and also showed the presence of marked micrencephaly, whereas cephalic measurements acquired on ultrasound examination (biparietal diameter and head circumference) were within the normal range. This case emphasizes the complementary roles of sonography and MRI in the prenatal diagnosis of cerebral abnormalities. Moreover, it illustrates the fact that polymicrogyria is easier to diagnose on ultrasound examination during the second trimester, before the development of secondary sulci.
Insights
A rare case of polymicrogyria, a brain abnormality, was diagnosed prenatally via ultrasound in a fetus with cytomegalovirus (CMV) infection. This highlights the importance of advanced imaging for detecting fetal brain malformations.
Area of Science:
- Prenatal Diagnosis
- Neuroimaging
- Fetal Medicine
Background:
- Polymicrogyria is a congenital brain malformation characterized by an excessive number of small, unusually folded cerebral cortical gyri.
- Cytomegalovirus (CMV) infection during pregnancy can lead to various fetal brain abnormalities.
- Early and accurate diagnosis of fetal brain abnormalities is crucial for management and counseling.
Observation:
- A rare case of polymicrogyria was diagnosed at 27 weeks' gestation using ultrasound.
- Ultrasound revealed direct visibility of the overfolded cortical ribbon and enlarged pericerebral space, indicative of micrencephaly secondary to CMV infection.
- Associated findings included bilateral opercular dysplasia and periventricular cysts; fetal MRI confirmed marked micrencephaly despite normal ultrasound cephalic measurements.
Findings:
- The study demonstrated that polymicrogyria can be diagnosed prenatally through characteristic ultrasound findings, such as the visible overfolded cortical ribbon.
- Fetal magnetic resonance imaging (MRI) confirmed the ultrasound diagnosis and revealed significant micrencephaly, underscoring the complementary roles of both imaging modalities.
- The case suggests that polymicrogyria may be more readily diagnosed in the second trimester before secondary sulci develop.
Implications:
- This case highlights the utility of combining ultrasound and MRI for comprehensive prenatal diagnosis of complex fetal brain abnormalities.
- It emphasizes the potential for CMV infection to cause significant cerebral malformations like polymicrogyria and micrencephaly.
- Early second-trimester ultrasound may be valuable for detecting polymicrogyria before secondary sulci obscure the diagnosis.
