Abstracts

Juvenile myoclonic epilepsy (JME) is the most common form of idiopathic generalized epilepsy. Only a few studies to date have investigated cognitive status in JME, but most have implicated executive system dysfunction (e.g., cognitive speed and planning, response inhibition, mental flexibility). Similarly, a few neuroimaging studies of JME have been conducted to date (e.g., MR-spectroscopy, PET), but there has been no systematic investigation of quantitative MR volumes and the relationship of MR volumes to cognition in JME. The current study examined three issues: 1) the adequacy of cognitive performance of JME patients compared to healthy controls, with a particular focus on executive functioning, 2) comparison of segmented whole brain volumes in JME and healthy controls, and 3) the relationship between whole brain volumes and cognition in JME., 21 subjects diagnosed with JME (mean age = 14.92, mean age of onset =13.94) and 51 healthy controls underwent neuropsychological testing and MRI imaging ( 1.5T GE Signa MR scanner). All JME patients had been formally diagnosed within the past one year. First, age and ICV adjusted volumes of total cerebrospinal fluid (CSF), white matter (WM), and gray matter (GM) were compared between the JME and control groups to look at the relative magnitude of abnormalities in whole brain volumetrics. Second, age adjusted scores for cognitive tests were compared between the groups. Last, Pearson partial correlation coefficients (age and ICV) were computed between brain volumes and the cognitive scores for JME patients., Children with JME performed significantly poorer than controls on measures of intelligence, processing speed, response inhibition, sustained attention and mental flexibility (all p[apos]s [lt] .01), but not memory, reading, namind, and motor speed. The JME group had larger CSF volume (p [lt] .01) and less gray matter volume (p=.053), but not white matter volume ( p= .49). Decreased white matter volume was associated with poorer performance on measures of intelligence (r=.51), response inhibition (r =.46 ), sustained attention (r =-.51), and mental flexibility ( r =.50 ). Increased CSF was associated with lower IQ scores ( r =-.49)., Children with recent onset JME performed selectively more poorly than controls on measures of IQ and executive functioning. They also exhibit increased CSF and decreased gray matter volumes than controls. White matter volume was significantly associated to cognitive status. These findings have potentially important implications in furthering the understanding of the pathophysiology of JME, as well as diagnostic and management implications., (Supported by NIH NINDS RO1 44351, F32 MH64988-01A2, [amp] MO1 RR 03186.)