VP21.06: Functional neurodevelopment evidence in a case of Chiari II with prenatal surgery of open spina bifida

Assessment of neurodevelopment is controversial for fetuses undergoing prenatal surgery for open spina bifida (OSB). Resting state networks (RSNs) mirror spontaneous brain activity spatially coherent across the brain.The Default Mode Network (DMN) is a RSN active during passive moments and deactivated when engaging mental tasks. Precursors of the DMN can be detected in fetuses and newborns. Major evidence highlighted that DMN includes cerebellar structures, involved in higher-order cognitive functions.Our aim was to investigate patterns of fetal and neonatal functional neurodevelopment through the investigation of DMN functional connectivity patterns in a case of Chiari II undergoing successful prenatal surgical treatment of OSB. Intrauterine correction of lumbar open spina bifida with Chiari II anomaly was carried out at 22 weeks with mini-hysterotomy described by CFA Peralta. In utero surgical treatment of OSB was successful with complete early postoperative hindbrain herniation reversal. DMN functional connectivity (rs-fMRI) was investigated at 28 weeks (fetal) and at 38 weeks (neonatal). Reoriented and realigned rs-fMRI images for both fetus and neonate were analysed independently within a single-subject SPM model testing for positive functional connectivity patterns between pCC and mPFC seeds and the whole brain. Patterns of observed DMN-related subcortical, allocortical and isocortical connectivity revealed an adequate DMN configuration for gestational age, both prenatally and postnatally. Interestingly, DMN functional synchronisation with both fetal and neonatal cerebellar structures arised. Our case with succesful intrauterine surgery for OSB showed normal postoperative neurodevelopment.