Abstracts

Rationale: Anterior temporal lobe resection (ATLR) is an effective treatment in refractory Temporal Lobe Epilepsy (TLE), offering seizure freedom in up to 80% of patients. Surgery may be complicated by an impairment in language function, particularly naming, in the language dominant hemisphere. Language function is typically lateralized to the left hemisphere, thus patients with left TLE are usually at greater risk of language decline. Shortly after ATLR functional reorganization can occur in both ipsilateral and contralateral hemispheres. Little is known of long-term plasticity effects as protracted as 10 years after ATLR. Our aim was to examine reorganization of language pre- to 10 years post- temporal lobe surgery._x000D_ _x000D_ Methods: We studied 23 subjects (five controls, 18 TLE (9 LTLE)) across two time points (pre-surgery and 10 years after ATLR), and equivalent time points in controls. All participants performed verbal fluency and verb generation fMRI tasks. A flexible factorial design was used to examine changes in fMRI activations in patients from the pre-operative to long-term post-operative stage, relative to longitudinal changes in controls. _x000D_
Results: LTLE: Compared to prior to ATLR there was increased activation 10 years after surgery within the bilateral pre-frontal cortex, inferior frontal gyri, inferior temporal gyri and left fusiform gyrus. RTLE: After 10 years there was increased activation in bilateral fusiform gyri, right angular gyrus, right medial & superior temporal gyri and right inferior frontal gyrus._x000D_
Conclusions: Reorganization of language network is different for patients undergoing left or right ATLR. We showed that 10 years after surgery language networks remain in a dynamic state, which has important implications for development of strategies for cognitive remediation in the long-term following ATLR. _x000D_ _x000D_ Funding: NIHR UCLH/UCL Biomedical Research Center