A-179: Co-Development of a Pilot Pediatric Neuropsychological Assessment Protocol in Myotonic Dystrophy Type 1

Abstract

Objective: Myotonic dystrophy type 1 (DM1) is a rare neuromuscular disorder affecting multiple organ systems, with high prevalence in the Saguenay–Lac-Saint-Jean region (Canada). Pediatric forms are more severe than adult-onset cases, leading to cognitive and social impairments that hinder academic achievement and integration. Despite these challenges, this population remains understudied, highlighting the need for standardized, age-appropriate assessment protocols to support inclusion in clinical trials. This pilot study aimed to co-develop and evaluate a neuropsychological assessment protocol for children and adolescents with DM1. Method/Data Selection: Parent and patient partners, along with clinicians specializing in pediatric neuropsychology and DM1, co-developed a cross-sectional pilot protocol. The battery assesses intellectual, attentional, executive, social, and motor domains, as well as daytime sleepiness, using validated standardized measures. Non-invasive neurophysiological measures, including portable EEG and eye tracking, were included to characterize attentional and socio-emotional processes. The protocol was designed for implementation in youth with DM1 and age- and sex-matched typically developing controls. Results/Data Synthesis: The co-development process produced a standardized pilot protocol targeting domains identified as clinically meaningful by stakeholders. The final protocol integrates neuropsychological (e.g., WISC-V, NEPSY-II) and neurophysiological measures. It documents acceptability and feasibility while providing an initial descriptive characterization of cognitive functioning in youth with DM1. Conclusions: This study establishes a methodological foundation for assessing children and adolescents with DM1. By combining neuropsychological and neurophysiological measures in a co-developed, clinically relevant protocol, it enables future large-scale studies to refine the cognitive and socio-emotional profile of this population, inform tailored assessment tools and interventions, and support families and educational settings.