Neuropsychological profile in dravet syndrome: A systematic review

Dravet syndrome (DS) is a severe developmental and epileptic encephalopathy characterized by pharmacoresistant seizures and progressive neurodevelopmental impairment. Despite increasing research, its neuropsychological phenotype remains poorly delineated due to marked heterogeneity in clinical severity, genetic variants, and the wide range of standardized assessment tools utilized across studies.

A systematic review was conducted in accordance with PRISMA guidelines across PubMed, Scopus, Web of Science, and PsycINFO. Studies examining neuropsychological functioning in individuals with DS were included. Methodological quality and internal validity of the included clinical designs were systematically appraised using the National Institutes of Health (NIH) Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies.

Twelve studies met inclusion criteria. Executive dysfunction was reported in the majority of studies (∼80%), while expressive language impairment was consistently identified across nearly all samples. Visuospatial deficits were described in more than two-thirds of studies, and psychiatric comorbidities were reported in over half of the samples. A dissociation between relatively preserved receptive language and impaired expressive abilities was a recurrent finding. Developmental trajectories were typically non-linear, with early normal development followed by stagnation or decline. Substantial heterogeneity in assessment tools and sample characteristics limited direct comparability.

DS is associated with a dynamic and evolving neuropsychological profile characterized by executive dysfunction, expressive language impairment, and high rates of neuropsychiatric comorbidity. These findings support the need for early, longitudinal, and multidimensional assessment frameworks. Future research should prioritize standardized protocols and longitudinal designs to clarify developmental trajectories and underlying mechanisms.