Presurgical localization of language cortex:
We obtain maps of brain activation in patients who are enrolled in the MCW surgical program for intractable epilepsy. These studies are aimed at localizing language systems underlying speech perception, lexical access, semantic processing, and object naming. Our goals are to measure and optimize the reliability of these maps, assess there validity against invasive mapping techniques such as the Wada test, and use the maps to predict and prevent changes in neuropsychological function that can result from surgery on the temporal lobe dominant for language.
Presurgical evaluation of medial temporal lobe function:
The most common surgery for intractable epilepsy includes partial removal of the medial temporal lobe (hippocampus and surrounding structures), which may cause impairment of episodic memory encoding postoperatively. We obtain preoperative maps of medial temporal lobe activation during an episodic memory encoding task in patients who undergo such surgery. Our goals are to determine the utility of this information for prevention of memory deficits, for predicting the degree of lateralization of the seizure focus, and for predicting seizure control.
The figures below show two graphs comparing the correlation between an fMRI temporal lobe laterality index (LI) and the Boston Naming Test, versus the Wada laterality index and the BNT in patients with left anterior temporal lobectomy. The fMRI laterality index shows a slightly stronger correlation than the Wada LI (from Neurology, 2003).
Current FundingR01 NS35929
Presurgical Applications of Functional MRI in Epilepsy
Jeffrey R. Binder, M.D, Principal Investigator