Cognitive Function in Rett Syndrome During Trofinetide Treatment

Assessing cognitive functions among individuals with severe intellectual and developmental disabilities (IDD), including RTT, is often challenging due to floor effects of many standardized assessment batteries in this population. In addition, deficits in motor function and verbal ability may obscure certain abilities in this population when using standard IQ measures. Remote eye-tracking tasks have been proposed as an alternative approach for assessing cognitive functions among individuals with severe IDD, because eye-tracking tasks can be designed to minimize the influence of gross motor and receptive language deficits on performance. Although several types of eye-tracking tasks have been evaluated in RTT, most have been implemented only at a single time-point. As a result, it is unclear whether these measures are stable over time, or sensitive to developmental changes or alterations to health status that occur in RTT (e.g., developmental regression, development of seizures, change in medication, etc.). With the recent FDA approval of trofinetide for the treatment of RTT, we have a novel opportunity to test the sensitivity of eye-tracking and other psychophysiological measures to treatment changes. Anecdotally, parents and clinicians have reported improvements in attention and alertness during trofinetide treatment, but currently available outcome measures do not capture these types of effects. Therefore, we propose to conduct a pilot trial of changes in measures of attention, oculomotor function, learning, and autonomic function, all collected using non-invasive measures, during trofinetide treatment. This is an observational within-subject design with a 4-week post-treatment assessment compared to two pre-treatment assessments. Additional optional follow-up assessments will be performed with families who are interested and returning for standard-of-care visits to Gillette or who are willing to travel for a research-only visit.