Comparison of fMRI and Transcranial Magnetic Stimulation in the Localization of Motor Cortex
Richard Macdonell, Graeme Jackson, Samuel Berkovic
Tuesday April 15 3:00 pm / Exhibit Hall A
OBJECTIVE
Comparison of functional MRI (fMRI) with focal transcranial magnetic stimulation (TMS) mapping of the motor cortex.
BACKGROUND
Congenital brain lesions producing focal seizures may exhibit reorganization motor and sensory areas. There are no studies on the agreement between fMRI and TMS in cortical localization.
DESIGN/METHODS
In one patient with intractable seizures, the motor cortex for each hand was mapped with fMRI and TMS using a focal coil. The motor representation using both techniques was then compared. Intraoperative stimulation of the right hemisphere was performed during surgery to remove a dysplastic area.
RESULTS
fMRI and TMS agreed perfectly in the mapping of motor representation. Both localized motor function for both arms to the left hemisphere. That for the right arm correlated with the anatomical precentral gyrus. Left arm motor function was located in an area overlapping that for the right arm. No responses to TMS could be obtained from the right hemisphere or intraoperative stimulation.
CONCLUSIONS
Using complementary techniques such as fMRI and TMS to localize brain function increases the accuracy of localization.