Abstracts

The purpose of this study is to determine how functional MRI can modify the work-up, counseling, cortical mapping, and resection in cases of neurosurgery for intractable epilepsy.
60 consecutive patients (33 males, 27 females), between 6.8 and 44 years of age (mean 15.8 [plusmn]8.7) were recruited. 45 patients (75%) were right handed, 9 (15%) left handed, and 6 patients without known handedness. A clinician of the epilepsy surgery team filled two forms for each patient. The post-test form was filled after knowing the fMR result. The forms asked for the clinician to draw in a Brodmann[apos]s-area-template where he/she thought language, motor, sensory and visual areas were located. In addition, questions about further testing (Wada) requirement, counseling impact, modification on planning of cortical mapping, and planned resection were also included in the post-test form. Results are presented in descriptive statistics.
53 patients had language mapping, 7 visual mapping, and 33 motor mapping. Receptive and expressive language lateralization changed in 15 cases (28%) and 11 cases (20.8%), respectively, from one side to the other, or from either side to bilateral language representation. fMRI avoided Wada tests in 38 (63.3%) and, altered family and patient counseling in 35 (58.3%). In five (8.8%) surgical approach was changed from a II to I stage procedure. In 5 (8.3%), electro-cortical mapping approach was changed and in 4 (6.6%) patients surgical resection plans were altered. Overall, clinicians felt that fMRI provided useful information in 48 cases (80%)
fMRI may play an important role in the evaluation of patients for epilepsy surgery, altering the empirical judgment of lateralization, and influencing family or patient counseling, avoiding riskier tests, and modifying surgical planning.