OC03.05: Cerebellar hypoplasia: prenatal diagnosis and outcome

The purpose of this study is to define the imaging features in a group of fetuses with suspected cerebellar hypoplasia and to evaluate the clinical outcome of these pregnancies. This is a retrospective study on a cohort of fetuses diagnosed with suspected cerebellar hypoplasia, between 2011 and 2018. The records of each patient, including US and MR examinations were reviewed. The results were compared with postnatal clinical evaluation, imaging and genetic and pathology examinations. 48 patients with suspected cerebellar hypoplasia were included in the study. Nine patients were diagnosed with isolated cerebellar hypoplasia; eight delivered with average follow up of 40.5 months (range of 2.5-57 months); two children had normal neurological development, five children had neurodevelopmental delay, and one child was lost to follow up. One patient was lost to follow up. Two other patients had cerebellar hypoplasia with parvovirus infection during pregnancy. One delivered (normal neurodevelopment at age 24 months) and one had a termination of pregnancy (TOP). Three patient had unilateral cerebellar hypoplasia; two delivered (one normal neurological development, one mild developmental delay) and one was lost to follow up. 34 patients had cerebellar hypoplasia with associated malformations; 32 of them had other CNS malformation with and without non-CNS malformations and two patients had only non-CNS malformation. Four patients delivered (one with global developmental delay and genetic syndrome, three were lost to follow up). Twenty-two had TOP and eight patients were lost to follow up. MRI was performed in 28 patients. Cerebellar hypoplasia is a subgroup of congenital cerebellar malformations. The information on long term outcome is limited especially on isolated cases. In our study children with cerebellar hypoplasia had a high prevalence of neurological deficit even in isolated cases.