Cochlear hypoplasia on MRI of fetuses with Walker-Warburg syndrome
1Diagnostic imaging, Schneider's Children Hospital of Israel, Israel
2Diagnostic imaging, division of neuroradiology, The hospital for Sick Children, Canada
Walker-Warburg syndrome (WWS) is a rare genetic disorder belonging to the heterogeneous group of congenital muscular dystrophies, also termed α-dystroglycanopathies.
Key imaging features of WWS as depicted on Magnetic Resonance Imaging (MRI) include cobblestone lissencephaly, dysplastic cerebellar cortex with polymicrogyria and cysts, hypoplasia of the vermis and cerebellar hemispheres, hypoplastic pons and a typical posterior kink of the brainstem at the pontomesencephalic junction.
Prenatal diagnosis of WWS by means of ultrasound and fetal MRI is challenging. Although the finding of ventriculomegaly and brainstem kinking on MRI is considered sensitive, other possible diagnoses might include tubulinopathies and X-linked hydrocephalus due to L1CAM mutation. The presence of distinctive imaging features as ocular abnormalities (pointing to WWS) or abnormal basal ganglia (pointing to tubulinopathies) might help in narrowing the differential.
In this study we present a series of 12 cases with confirmed WWS. In all cases, bilateral cochlear hypoplasia was detected on fetal MRI.
Potentially, the detection of this unique feature might assist in the prenatal diagnosis of WWS by fetal MRI.
Mika Shapira Rootman