Altered Cortical Anatomy Seen in Infants With Congenital Heart Disease

By MD Will Boggs

Infants with congenital heart disease (CHD) have decreased cortical surface area and regional alterations in cortical folding before corrective cardiac surgery, according to new research.

"Previously, there has been debate regarding the etiology of neurodevelopmental problems in children with CHD," said Dr. Courtney Jane Wusthoff, a neurologist at Stanford University in Palo Alto, California, who was not involved in the study.

"In particular, there was some speculation that perioperative complications were a primary contributor," she told Reuters Health by email. "For example, physicians and families might attribute later difficulties to hypoxia experienced around the time of surgery or to intraoperative complications. More recently, emerging data shows that brain development is different in children with CHD well before they go to the operating room."

For the new study, Dr. Cynthia Ortinau from St. Louis Children's Hospital in Missouri and colleagues quantified global brain cortical folding and regional sulcal depth differences in 15 term infants with CHD requiring surgery in early infancy and in12 healthy term-born infants (controls).

Five of the cases had transposition of the great arteries, four had right-sided lesions requiring a Blalock-Taussig shunt, five had hypoplastic left heart syndrome requiring a Norwood procedure, and one had transposition of the great arteries with tricuspid atresia and interrupted aortic arch and underwent a Norwood procedure, the researchers report online August 28 in The Journal of Pediatrics.

Infants with CHD had significantly reduced cortical surface area and gyrification index (a measure of cortical folding), compared with controls, in both the left and right hemispheres, even after controlling for head circumference.

Alterations in sulcation were greater in the orbitofrontal region, cingulate, and central sulcus of the left hemisphere and in the posterior ascending limb of the lateral sulcus of the right hemisphere.

Seven of the 15 infants (46%) with CHD had focal signal abnormalities in the white matter, compared with none of the control infants.

"A potential explanation for this finding is that these folding abnormalities are caused by neuronal or axonal injury that could be associated with altered cerebral perfusion related to the underlying cardiac defect that alters cortical folding but is not visible as signal abnormality on MRI," the researchers speculate. "Another potential explanation is that the folding abnormalities are unrelated to hypoxic/ischemic injury but share a common etiology, such as genetic, with CHD."

"Prenatal cortical growth in preterm infants has been associated with subsequent cognitive outcome," they write, "but the relationship of these alterations in cortical surface-based measures to subsequent outcomes in infants with CHD remains unknown."

"The clinical implications of these findings are that babies with CHD have fundamentally different brain development," Dr. Wusthoff said. "While some may also suffer additional brain injury during the neonatal period and beyond, they are starting out with brain structures different than their peers without CHD. It isn't clear why these differences exist."

"The main message I would hope physicians take away from this research is that we increasingly recognize children with CHD have a number of unique risk factors for abnormal neurodevelopment; this paper specifically describes how their cortical structures form differently from other children," she added. "As survival for children with CHD improves, the battle is no longer just to keep these children alive -- we also need to consider how to best provide care and follow-up that optimizes their long-term neurodevelopment."

Dr. Ortinau was not available to comment on her findings.

SOURCE: http://bit.ly/1autv0J

J Pediatr 2013.