A Face-name Association Task fMRI for Mapping Memory Networks in Epilepsy Patients
Yanmei Tie1, Rui Hui1,2, Laura Rigolo1, Prashin Unadkat1, Kim Willment1, Alexandra Golby1; 1Brigham and Women's Hospital, Harvard Medical School, Boston, US, 2Navy General Hospital, Beijing, China
Mapping of memory function in epilepsy patients who are candidates for surgery is important for surgical planning. The alterations and hemispheric lateralization of memory networks in epilepsy patients has been studied in neuropsychological and neuroimaging literature, however, it remains to be fully verified and elucidated. Twelve epilepsy patients were included in this study and underwent functional magnetic resonance image (fMRI) using a face-name association paradigm. Patients were scanned during encoding of 230 face-name pairs. During a post-scan recall test where 2 names (one correct and one incorrect) were shown for each face, patients were asked to point out the name that was paired with the face and how confident they were in their decision. A group analysis showed bilateral activation in the superior and medial frontal gyrus, caudate head and body, and cingulate gyrus. Compared with healthy subjects, these patients demonstrated significantly less activation in the bilateral hippocampus and left inferior frontal gyrus. In addition, alterations in the dominant hemisphere were greater than the non-dominant hemisphere. In eight patients who also underwent intracarotid sodium amobarbital procedure (Wada test) for lateralization of memory function, the fMRI results were consistent with Wada test in 5 patients. For the remaining 3 patients, fMRI indicated left domination whereas Wada test indicated bilateral domination. Results suggest that the face-name association task fMRI can be used to map memory function in epilepsy patients, including memory hemispheric lateralization.
Topic Area: METHODS: Neuroimaging