The goal of this study is to try to determine the effects of chronic complex partial seizures on brain structure as well as memory and other cognitive abilities. This is a follow-up test on a group of subjects first evaluated 4 years prior. The study will include 80 patients with complex partial seizures and 80 healthy control subjects. The study involves 1) an interview that will focus on the details of the patient's epilepsy, 2) a series of paper-and-pencil tests of cognitive function (including memory, attention, language, vision, and intelligence), with a telephone call follow-up one week later to ask questions about the test, 3) getting an MRI scan, and 4) possibly undergoing a memory test while in the MR scanner. The MRI scans will be performed to determine the volume of grey and white brain matter, and on a random subset of subjects, memory tests will be performed during fMRI scans to determine cognitive status. Processing software was provided by the Image Processing Lab at the University of Iowa and local processing technicians were trained in additional post-processing techniques such as diffusion tensor mapping and magnetization transfer ratios.
The aims of the study are as follows: 1) Determine whether temporal lobe epilepsy (TLE) subjects are more vulnerable to cognitive decline than normal controls, and if the nature and degree of decline is variably expressed across different cognitive domains. 2) Determine whether duration of epilepsy is the primary determinant of progressive cognitive decline in TLE. 3) Determine the extent of decline in total brain and segmented (gray and white matter) tissue volumes in TLE compared to controls. 4) Determine the relationship between MRI volumetrics and test-retest cognitive decline in TLE. 5) Determine whether there are progressive effects of epilepsy on functional activation (fMRI) of the mesial temporal region during a memory task.