The authors reply
As Ghimire (1) points out, there are additional risk factors for poor neurodevelopmental outcome for which we did not control for in our study. Among patients with d-transposition of the great arteries, 82% underwent balloon atrial septostomy with no differences in neurodevelopmental outcome or cTOI variability between those who did and did not undergo that procedure. Three patients (7%) in our cohort had postoperative seizures. There were no differences in neurodevelopmental outcome or cTOI variability based on seizure activity. It should be noted that during the period of study, universal electroencephalogram monitoring in the postoperative period at the study institution was not routine, thus our findings are largely limited only to clinically apparent seizures. The relationship between cTOI variability and seizure activity, both clinical and subclinical, warrants further study.
Finally, among the 57% of our cohort that underwent neuroimaging studies, stratified analyses by diagnosis classification yielded no relationships between abnormalities found on clinical neuroimaging studies and neurodevelopmental outcome or cTOI variability. More specialized neuroimaging using advanced MRI technology may identify features associated with cTOI variability and neurodevelopmental outcomes, and it is our intent to include this in future studies.