Magnetic resonance imaging findings in SCN1A-related epilepsies and Dravet syndrome: A systematic review.

We systematically reviewed the literature on neuroimaging findings in Dravet syndrome (DS) and SCN1A-related epilepsies to classify the reported structural abnormalities observed on magnetic resonance imaging (MRI). We searched PubMed and MEDLINE from January 2000 to June 2024 for studies describing brain MRI findings in DS and SCN1A-related epilepsies through specific keywords and MeSH (Medical Subject Headings) terms. Duplicates were removed, and titles and abstracts were screened. Studies with absent/marginal MRI focus and reviews were excluded. Images available were evaluated by two pediatric neuroradiologists in consensus. Manual reference checks were performed. For the selection process, we followed the latest PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Nineteen studies met the inclusion criteria, all of which had an observational design, including case reports (n = 3), case series (n = 7), and larger cohorts (n = 9). The most observed brain MRI findings were cortical/parenchymal atrophy, hippocampal sclerosis (HS), and malformations of cortical development. Less frequent abnormalities include callosal dysgenesis and postseizure changes on diffusion-weighted imaging. There was variability in the description across studies, as expected. This review represents a valuable reference database for current and future genetic therapy trials. DS, particularly when associated with SCN1A variants, involves a variety of neuroimaging abnormalities, including HS, diffuse brain atrophy, and malformations of cortical development. The spectrum of these findings probably reflects the interplay between genetic susceptibility, seizure duration/severity, medication effects, and timing of imaging. To date, high-quality studies on brain MRI findings are limited, and future research, with more standardized methodologies, a longitudinal design, and larger sample sizes, are needed to further uncover these relationships and improve our understanding of the disease.