Abstract 12972: Neural Activation on a Working Memory Functional MRI Task in Emerging Adults with Congenital Heart Disease
Patients with congenital heart disease (CHD) have a high incidence of white matter injury in infancy with later impairments in executive function. Functional MRI (fMRI) measures brain activity during different tasks. This modality may help to understand the biological underpinnings of executive dysfunction in CHD patients. This study examined brain activation during a 3-back working memory fMRI paradigm.
Hypothesis: Patients with CHD demonstrate a specfic pattern of suppression or "deactivation" when engaged in tasks of executive function.
Methods: Young adults (n=17) with CHD (10 two ventricle critical CHD lesions; 7 single ventricle) and 17 demographically matched healthy controls participated. Groups had similar age (18±1.7 yrs), sex (71% male), handedness, race/ethnicity, and WASI IQ (107±12). Analyses were completed using voxel-based morphometry to examine 3>0 back; threshold set at Z>1.96, corrected p≤.05.
Results: Groups evidenced comparable performance across working memory load (mean accuracy & reaction times: 0back=96%, 558ms; 3back=87%, 798ms). Conjunction analyses revealed both groups had similar activations across the working memory network. Activations correlated with accuracy on 3-back across each of these regions: bilateral frontal, cingulate, thalamus, parietal, and left cerebellum. The CHD group showed greater deactivation in a large cluster containing left & right orbital frontal and right temporal regions (Fig). Discussion: Overall similar behavioral performance and neural activation was observed in regions consistent with prior studies. However, significant task-related deactivation of the orbital frontal and temporal regions during working memory relative to vigilance task was observed in the CHD group only. It is possible that these deactivations are related to compensatory activity, brain reorganization, or transient resource support to achieve similar performance.
- © 2013 by American Heart Association, Inc.