EP05.29: Abnormal Sylvian fissure operculisation in Chiari II: correlation with neuropathological data in children with intrauterine spina bifida repair

To identify whether the Sylvian fissure operculisation (SFO) features revealed on prenatal neurosonography in fetuses with Chiari II reflect on postnatal neurological outcomes. Prenatal ultrasound (US) 2/3D assessment of SFO was performed in 30 fetuses with Chiari II who underwent intrauterine spina bifida closure at our centre from 23.1 to 25.5 weeks of GA. Parieto-occipital, calcarine, olfactory, cingulate sulci were also studied. For comparison, nomograms data of sulci sonographic appearance in very preterm newborns without any congenital or acquired pathological conditions created by our centre was used. Prenatal US findings have been compared with postnatal US and pre/postnatal MRI in 17 cases. Neurological outcomes were assessed in 15 children (CAT/CLAMS scale). For genetic testing were performed amniocentesis with chromosomal microarray and whole exome sequencing. Abnormal Sylvian fissure has been revealed in all 30 fetuses. Starting from 30-31 weeks GA the typical triangular “fan” pattern of insula was absent in the parasagittal section at the level of the temporal lobe in 25/30 cases that was comparable with the results of postnatal US and MRI in 17 cases. The development of the remaining sulci was delayed, but their structure was typical, in accordance with the anatomical localisation in 21/30 cases. Neurological outcomes corresponded to age norms and was more than 80% (CAT/CLAMS scale) in 14/15 children. Prenatal US assessment of Sylvian fissure closure is preferable to perform in parasagittal plane at the level of the temporal lobe. Abnormal SFO with normal cortical architecture in Chiari II can be associated with pathognomonic reasons. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.