We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Motor system hyperconnectivity in juvenile myoclonic epilepsy: a cognitive functional magnetic resonance imaging study.
- Authors
Vollmar, Christian; O’Muircheartaigh, Jonathan; Barker, Gareth J.; Symms, Mark R.; Thompson, Pamela; Kumari, Veena; Duncan, John S.; Janz, Dieter; Richardson, Mark P.; Koepp, Matthias J.
- Abstract
Juvenile myoclonic epilepsy is the most frequent idiopathic generalized epilepsy syndrome. It is characterized by predominant myoclonic jerks of upper limbs, often provoked by cognitive activities, and typically responsive to treatment with sodium valproate. Neurophysiological, neuropsychological and imaging studies in juvenile myoclonic epilepsy have consistently pointed towards subtle abnormalities in the medial frontal lobes. Using functional magnetic resonance imaging with an executive frontal lobe paradigm, we investigated cortical activation patterns and interaction between cortical regions in 30 patients with juvenile myoclonic epilepsy and 26 healthy controls. With increasing cognitive demand, patients showed increasing coactivation of the primary motor cortex and supplementary motor area. This effect was stronger in patients still suffering from seizures, and was not seen in healthy controls. Patients with juvenile myoclonic epilepsy showed increased functional connectivity between the motor system and frontoparietal cognitive networks. Furthermore, we found impaired deactivation of the default mode network during cognitive tasks with persistent activation in medial frontal and central regions in patients. Coactivation in the motor cortex and supplementary motor area with increasing cognitive load and increased functional coupling between the motor system and cognitive networks provide an explanation how cognitive effort can cause myoclonic jerks in juvenile myoclonic epilepsy. The supplementary motor area represents the anatomical link between these two functional systems, and our findings may be the functional correlate of previously described structural abnormalities in the medial frontal lobe in juvenile myoclonic epilepsy.
- Subjects
MAGNETIC resonance imaging of the brain; COGNITIVE ability; MYOCLONUS; MOTOR cortex; NEUROPSYCHOLOGY; FRONTAL lobe epilepsy; BRAIN function localization
- Publication
Brain: A Journal of Neurology, 2011, Vol 134, Issue 6, p1710
- ISSN
0006-8950
- Publication type
Article
- DOI
10.1093/brain/awr098