Deep Phenotyping of Executive Function Deficits Using the NIH Toolbox in Duchenne Muscular Dystrophy
Mathula Thangarajh1, Shreya Arun1, Hakinya Karra2, Matthew Ridder1, Dominik Feliciano1, Sanjana Javalkar1, Varsha Penumalee1, Genila Bibat3, Aaron Kaat4
1Virginia Commonwealth University, 2University of Virginia, 3Kennedy Krieger Institute Johns Hopkins Medical Center, 4Northwestern University
Objective:
To quantitate deficits within the  various domains of executive function using the National Institutes of Health Toolbox Cognition Battery (NIHTB-CB) in Duchenne Muscular Dystrophy. 
Background:

Boys with Duchenne Muscular Dystrophy (DMD) have disproportionate vulnerability in executive function, a term that denotes constructs of attention, inhibitory control, working memory, processing speed and cognitive flexibility. Executive function deficits are impactful, affecting academic performance as well as hindering equitable vocational opportunities. The neurobiology of the domains within executive function that are affected in individuals affected by DMD has not been well-quantified. We address this gap in our study by quantitating deficits in the various domains of executive function using the NIHTB-CB, which we previously showed to be a sensitive and discriminative psychometric tool in DMD. 

Design/Methods:
We prospectively evaluated 60 individuals with DMD between ages 4 to 27 years of age. All participants completed age-appropriate assessment of the NIHTB-CB. The BRIEF questionnaire was completed either by the parent- or self. 
Results:
Our demographic representation of participants in this cohort included nearly 65 boys and 1 girl with DMD. There was nearly equal distribution of proximal versus distal DMD mutations. Similar to our earlier results, individuals with DMD scored 1.5 standard deviation below age-corrected score for fluid cognition score. Data is being analyzed to characterize the phenotypic features of executive function deficits in DMD. 
Conclusions:

Final conclusions are pending verification and will be presented during the Annual Meeting. Our choice of the NIHTB-CB underscores our commitment to healthy equity by using technology-enabled tools to remove access barriers. 

10.1212/WNL.0000000000206354