Abstracts

Rationale: Anterior temporal lobectomy (ATL) has been used to treat patients with temporal lobe epilepsy (TLE) that are intractable to medical therapy. ATL has been associated with aphasia in 5 to 40% of the TLE patients that undergo this surgery. It is still unclear how ATL affects the linguistic ability of the TLE patients. The present study aims to compare the cortical response of the TLE patients to a sentence completion task before and after ATL with functional magnetic resonance imaging (fMRI). Methods: Ten patients with the left TLE, ten patients with the right TLE, and ten healthy control subjects participated in this study. The fMRI paradigm consisted of covert sentence completion task. Blood-oxygen-level dependent (BOLD) signal was acquired from a 1.5 Tesla GE Signa Excite MRI scanner. A post-surgical fMRI was performed two to six months after the ATL. Results: Before the ATL, BOLD signal changes were observed in the inferior frontal gyrus (IFG), mid frontal gyrus (MFG) and supplementary motor area (SMA) on one side or bilaterally. Similar areas were activated after ATL. However, strongest activation occurred in the IFG before the surgery in the TLE patients. There was greater activation within the MFG after ATL. Conclusions: ATL affects the cortical network for language with the largest changes occurring within the IFG and MFG.