Herwin Speckter, Presenter: Nothing to Disclose

Diones Rivera, Abstract Co-Author: Nothing to Disclose

Heidi Guerra, Abstract Co-Author: Nothing to Disclose

Peter Stoeter, Abstract Co-Author: Nothing to Disclose

Purpose: Functional magnetic resonance imaging (fMRI) might become a standard tool for the presurgical lateralization and mapping of brain areas involved in language processing. Our goal is to evaluate fMRI in order to substitute the WADA test in patients with drug-resistant temporal lobe epilepsy (TLE). Patients and Methods: Examinations are carried out in a group of patients with drug-resistant TLE and an age- and sex-matched normal control group. They consist out of 3T MR (ACHIEVA, PHILIPS) imaging with high-resolution T1- and T2-weighted sequences for determination of hippocampal volume and T2-time measurement, voxel-based 1H spectroscopy and high-resolution DTI imaging with determination of hippocampal FA values, fiber tracking from the hippocampus as a seeding area, and BOLD activation studies using a word- and face memory and a space-orientation paradigm. Because of PET reports about interictal reduction of blood flow in the affected hippocampus which might impair functional studies, Arterial Spin Labeling (ASL) perfusion scans are measured. For evaluation, a laterality index will be calculated for each parameter and compared to postoperative outcome data (Engel classification) in the patient group and to the findings in the controls. In addition we will compare the imaging results to the functional predictions of the Wada test. Results: Thus far, we are in the phase of data collection. The data of the first patient group and the controls will be presented. Discussion: By this multi-modal approach we expect to predict the outcome of surgery in TLE patients more reliably than it is possible by relying on structural imaging alone. We are aiming to statistically define a combination of imaging strategies with a sufficient high degree of predictive value for a good outcome, related to seizure control as well as to prevention of cognitive deterioration. Finally, we might be able to give up the Wada test which has turned out to be not completely reliable and carries the complication risk of an invasive angiographic procedure.

Speckter, H, Rivera, D, Guerra, H, Stoeter, P, Functional RM to Replace Wada Test in Epilepsy.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9016472.html