Abstracts

Rationale: Arterial spin labeling (ASL) magnetic resonance imaging (MRI) can demonstrate differences in regional brain perfusion. Similar to ictal SPECT, MRI ASL has identified seizure foci in case series of adults and children with epilepsy. It is unknown whether regional increases in blood flow on MRI ASL correlates with seizure location in newborns. Methods: The CNMC Neonatal neurocritical care service database was reviewed for all newborns with seizures from January 2013 to March 2017 when MRI ASL was routinely performed. Neonates with seizure were defined as newborns with either continuous EEG (cEEG) confirmed seizures or clinically-suspected seizures pre-treated prior to cEEG. Brain MR imaging was performed using a 3T magnet (Signa HDxt Optima; GE Healthcare, Milwaukee, WI). ASL images were acquired by pseudocontinuous ASL (pcASL) with segmented 3D fast spin-echo (FSE) readout. Gestational age, gender, seizure etiology, semiology, age at time of seizure onset, cEEG seizure location, and MRI ASL findings were examined. Concordance between cEEG seizure location and regional hyperperfusion on ASL MRI was defined if they occurred in the same lobe irrespective of additional regions of increased perfusion outside the seizure onset zone. Results: There were 172 newborns with seizures: 97 (56%) were male, mean gestational age was 37.7?4 weeks, and mean post menstrual age at seizure onset was 39.2?3.6 weeks. The most common seizure etiology was hypoxic ischemic encephalopathy (HIE) in 30%. MRI was performed in 161 newborns and 147 had MRI ASL images, of which 5 were uninterpretable. Seventy patients (49.3%) had increased perfusion in ASL images, of which 62 had cEEG-confirmed seizures and 8 with clinically-suspected seizures. In patients with cEEG-confirmed seizures and hyperperfusion ASL images, there were 54 patients (87.1%) who had concordance in location of cEEG seizure onset and hyperperfusion regions on ASL MRI. In patients with concordant findings, the seizure etiologies were HIE (n=18), stroke (n=15), intracranial infection (n=6), brain malformation (n=4), inborn error of metabolism (n=3), intracranial hemorrhage (n=3), epilepsy syndrome (n=1), and unknown causes (n=4). For the 8 patients without concordance, the etiologies were intracranial infection (n=2), intracranial hemorrhage (n=2), stroke (n=1), HIE (n=1), inborn error of metabolism (n=1), and brain malformation (n=1). Conclusions: In newborns with seizures, MRI ASL images often demonstrate hyperperfusion in the region(s) corresponding to the EEG location of seizure onset. Confounding factors such as time interval between last seizure and MRI ASL or seizure burden require further investigation. Funding: None