Abstracts

Rationale: To assess the usefulness of passive functional magnetic resonance imaging for localizing the language cortex and motor cortex in children with epilepsy who are surgical candidate. To compare fMRI language acquisition data for the sedated and unsedated child with epilepsy. Methods: Data was gathered from 31 children with refractory epilepsy between the ages of 3 years to 22 years. The study looked at two groups of the sedated and unsedated patients. The unsedated group consisted of 17 patients between the ages of 7 to 22 years. The sedated group consisted of 14 patients between the ages of 3 to 18 years. fMRI was done in possible candidates for epilepsy surgery. The study used various paradigms to asses motor, language and sensory cortex. Not all patients were administered the same paradigms. Propofol, sevoflurane, precedex or a combination of previous were used in the sedated group. Propofol was the most commonly used sedating agent. Motor paradigms used were finger tapping, wrist movements, foot movement and tactile hand for both groups. Language paradigms included word listening, story listening and maternal story listening sedated group. Word listening, story listening and maternal story listening were conducted through prerecorded stories presented to the patient via headphones during the scan. Language paradigms for the unsedated group included the above task, as well as word generation, verb generation, sentence completion and object naming. A tactile stimulation task was used to assess the sensory cortex. Results: Sedate Group: Successful motor activation was seen in 13 of 14 patients (bilateral predominance). 11 of the 13 patients in whom motor activation was seen went onto have epilepsy surgery. Successful sensory activation was seen in 7 of 8 patients and 5 out 7 patients went on to surgery. Successful language activation via 1 or more language paradigm was seen in 11 of 12 patients. 8 out of the 11 patients went on to surgery. Story Listening via their mother's recorded voice was attempted for 4 patients and 3 out of the 4 patients had successful activation. All 3 patients went on to surgery. Nonsedated Group: Successful motor activation was seen in 16 of 16 patients with bilateral predominance. 15/16 went onto to have surgery. There was successful sensory activation in both patients with whom it was attempted. Activation for the language cortex was seen in 10 of the 12 patients and it was predominantly bilateral. 10/12 patients went on to have surgery. All 4 patients showed successful activation for maternal story reading. All activation was bilateral with left side predominance in 2 out of the 4 patients. When comparing the two groups there was no statistical difference the sedated and unsedated group for activation of motor( p value=0.47 ) sensory( p value=1) and language(p value=1) cortex. Conclusions: There was similar activation of the sedated and unsedated samples for motor, auditory and sensory cortex using various paradigms for fMRI studies with no statistical difference between the two groups.