Evaluation of cognition, structural, and functional MRI in juvenile myoclonic epilepsy

Abstract

Purpose: Previous studies using advanced imaging techniques have suggested subtle structural and functional changes in patients with juvenile myoclonic epilepsy (JME), mainly associated with the frontal lobes. In addition, it has been reported that these patients show neuropsychological deficits, often summarized as frontal lobe dysfunction. The aim of this study was a comprehensive analysis of neuropsychological parameters, and functional and structural magnetic resonance imaging (MRI) in an independent cohort of patients with JME. Methods: We studied 19 JME patients and 20 age-, sex-, and education-matched controls using a battery of standardized neuropsychological tests, optimized voxel-based morphometry (VBM), and two domain-specific working-memory paradigms combined with functional MRI (fMRI). Results: Our investigations did not reveal statistically significant differences between the groups of JME patients and normal controls in either the VBM or the fMRI study of working memory. The neuropsychological examination showed a slightly worse performance for the JME patients across most tests used, reaching statistical significance for semantic and verbal fluency. Conclusions: In our cohort of JME patients, we could not reproduce the findings of frontal gray matter changes from previous studies, and we could not detect an fMRI correlate of previously reported differences in working memory in JME. The neuropsychological deficits may be attributed partially to antiepileptic medication. We conclude that structural and functional frontal lobe deficits in JME patients have to be interpreted with care. One reason for a variation between different cohorts may be the genetic heterogeneity of the disease.