Cognition.
Cognitive function was measured using the nonverbal scales of the Bayley Scales of Infant and Toddler Development, 3rd Edition (BSID-III) (The BSID-III is a validated and standardized developmental tool comprising 5 domains (cognitive, language, motor, social-emotional, and adaptive functioning) intended to assess developmental function in children ages 1 to 42 months (The KABC-II is a validated and standardized clinical psychological diagnostic test for assessing cognitive development (BSID-III or the KABC-II assessments were performed every 12 weeks in Study 250-201. Baseline, week 24, and week 48 visits involved 2 days of testing, with the cognitive, adaptive, and behavioral testing occurring on the first day (morning preferred), and MRI, lumbar puncture, and laboratory testing occurring on the second day to avoid confounding effects of sedation or general anesthetic administration.