Executive Function Impairments in Neurofibromatosis Type 1: A Meta-Analytic Review

Objective: To determine whether executive function impairment is a defining feature of individuals with Neurofibromatosis Type 1 (NF1) through analyses using the BRIEF questionnaire. Design: Systematic review and meta-analysis examining executive func-tions assessed with the BRIEF or BRIEF-P in individuals with NF1.Data Sources and Study Selection: Relevant studies using BRIEF or BRIEF-P to evaluate executive functions in clinically diagnosed NF1 populations were identified. Studies reporting parent or teacher assessments and providing effect sizes suitable for meta-analysis were included. Data Extraction: Effect sizes (Cohen’s d) were computed across BRIEF scales, including clinical and global indices. Results: Individuals with NF1 showed significant executive function deficits compared with community controls. Small but significant deficits were observed in Emotional Control (d = 0.31) and Inhibitory Self-Control (d = 0.26). Moderate deficits emerged in Inhibition (d = 0.50), Global Executive Functioning (d = 0.58), and Or-ganization of Materials (d = 0.52). Large deficits appeared in Self-Monitoring (d = 1.03), Working Memory (d = 0.97), Metacognition (d = 0.95), and Planning/Organization (d = 0.72). No significant differences were found in Flexibility scales. Parent reports indicated moderate deficits (d = 0.63), while teacher reports showed smaller effects (d = 0.49). Defi-cits were larger with the BRIEF (d = 0.82) than with the BRIEF-P (d = 0.38). Conclusions: Executive function impairment is a prominent characteristic of NF1, particularly in meta-cognitive and behavioral regulation domains, as demonstrated by BRIEF-based assess-ments.