Background: Adolescents with Fontan completion often present with cognitive deficits, in particular working memory and attention. However, it is unknown whether working memory and attention / concentration, as well as brain tissue integrity can be improved with a computer-based cognition intervention.

Objective: Examine the impact of the Cogmed® Working Memory Training in adolescents with Fontan completion on working memory and attention / concentration and brain tissue integrity.    
Methods: Pre- and post-intervention pilot study, 5 adolescents [age, 15-18 years] with Fontan completion participated in Cogmed® (home, computer-based working memory training program with Zoom coaches), 45-minute sessions, 5 days a week, for a total of 5 weeks [total 25 sessions]. The primary outcome was working memory [examined with the Wide Range Assessment of Memory and Learning 2; Working Memory Index (WMI), Attention / Concentration Index (ACI), and General Memory Index (GMI)]. Secondary outcome was brain tissue integrity assessed by 3.0-Tesla brain MRI using DTI-based mean diffusivity (MD) measures. All measures were assessed at baseline and post intervention using one-sample, 2 tailed t-test for cognitive scores, and MD values via paired t-test (SPM12 software; covariate, age; p<0.005).  
 
Results: Five adolescents [3 male, age 16.6 ± 1.1 years, BMI 20.4 ±4.9 kg/m2] with extracardiac Fontan completion, 3 with single right ventricle, mean oxygen saturation level 92%, completed all 25 sessions in 5 weeks.  Post-intervention assessments were performed between 3-8 weeks.  WMI (88 vs. 110, p<.001), ACI (80 vs. 97, p=.001), and GMI (79 vs. 106; p<.001) scores showed significant improvement at post- over pre-intervention. Decreased MD values appeared in the right cerebellum (10-3 mm2/s; 0.67±0.03 vs 0.68±0.03), caudate (10-3 mm2/s; 1.02±0.13 vs 1.04±0.11), putamen (10-3 mm2/s; 0.60±0.34 vs 0.61±0.34), thalamus (10-3 mm2/s; 0.73±0.08 vs 0.74±0.07), frontal white matter (10-3 mm2/s; 0.70±0.04 vs 0.72±0.03) and left frontal cortex (10-3 mm2/s; 1.36±0.28 vs 1.40±0.27), post- vs pre-intervention, respectively, indicating post-intervention brain tissue improvement.  

Conclusion:  Cogmed® intervention showed significant improvement in general memory, working memory and attention / concentration in adolescents who have undergone Fontan completion.  Improved brain tissue integrity in regions that support working memory / attention indicate potential post-intervention improvement. Further studies are needed in a larger cohort to validate these findings and assess potential for long-term intervention benefit.