Abstract
OBJECTIVE: Adults with juvenile myoclonic epilepsy (JME) have subtle brain structural abnormalities in the frontothalamocortical network, poorer cognitive function, and worse long-term social outcomes, even when their seizures are controlled and/or remitted. The natural history of JME and development of abnormalities in brain structure and cognition from epilepsy onset has not been studied. METHODS: The maturational trajectories of cognitive and brain development were prospectively compared between 19 children with new-onset JME in the first 2 years after diagnosis and 57 healthy controls. RESULTS: Cognitive abilities of children with JME were similar to or worse than healthy controls at baseline but failed to reach the competence level of healthy controls at follow-up across most of the tested cognitive abilities. Abnormal patterns of brain development, as assessed by magnetic resonance imaging studies, were evident in children with JME and included attenuation of age-related decline in cortical volume, thickness, and surface area compared to typically developing children. The altered brain developmental trajectory in the JME group was evident in higher-association frontoparietotemporal brain regions (p < 0.05, corrected for multiple comparisons). INTERPRETATION: Children with JME have abnormal structural brain development and impaired cognitive development early in the course of their epilepsy.