Children with “single–ventricle” defects are especially at risk for neurodevelopmental problems. “Single–ventricle physiology creates cerebrovascular hemodynamics that can reduce oxygen delivery to the brain,” explains Jane Newburger, MD, MPH, director of the Cardiac Neurodevelopmental Program at Boston Children’s Hospital.

How does this play out in adolescence? In three recent studies, Boston Children’s Heart Center collaborated with the departments of Neurology and Psychiatry to track neurodevelopmental outcomes after corrective Fontan operations. They evaluated preteens and teens as old as 19 — the longest follow–up to date.

In a study of cognitive and neurologic outcomes, led by Newburger and neurologist David Bellinger, PhD, post–Fontan patients had significantly lower scores for reading and math ability as compared with controls, and lower IQ scores. The heart patients also showed more autism–like behaviors. Twenty–two percent had an ADHD diagnosis and 37 percent had a diagnosed learning disability. MRI studies found brain abnormalities in 66 percent (vs. 6 percent of controls), and 13 percent had evidence of a prior stroke.

A study of mental health outcomes, led by Newburger and psychiatrist David DeMaso, MD, found that teens with single ventricle were much more likely than controls to have received a psychiatric diagnosis (65 vs. 22 percent). This was especially true for anxiety (35 vs. 7 percent) and ADHD (34 vs. 6 percent). The single–ventricle group also scored, on average, about 20 percent lower on measures of psychosocial functioning. These children also scored higher for anxiety, disruptive behavior and depressive symptoms.

Finally, neurologist Michael Rivkin, MD, led a detailed MRI study of structural brain changes. It found that the neuropsychiatric problems are accompanied by widespread, significant reductions in cortical and subcortical grey matter volumes (the colored portions in A and B below). The post–Fontan patients also had reduced cortical thicknesses (C and D) as compared with healthy controls.

Newburger stresses that these findings don’t necessarily apply to every child. “We see some brilliant individuals who have undergone the Fontan procedure, and others with profound neurocognitive and psychosocial challenges,” she says.

Early screenings, early intervention and Individualized Education Programs (IEPs) can make a difference for children with single ventricle and other forms of CHD, she adds.

Cognitive training may give these children a further leg up. Newburger is leading two clinical trials of CogMed, a game–based working memory and attention training program available for Apple and Android devices.