Abstracts

Rationale: To investigate the effects of Carbamazepine (CBZ), lamotrigine (LTG), and levetiracetam (LEV) on cognitive functional MRI (fMRI) network activations in patients with focal epilepsy. Methods: In a retrospective, cross-sectional study, we identified patients from our clinical database of verbal fluency fMRI studies that were treated at the time of scanning with either CBZ (n=42) or LTG (45), but not LEV, TPM or ZNS[MK1] . We matched a further 46 patients for clinical parameters who took LEV, but not TPM, ZNS, LTG, CBZ, or other sodium channel blockers (lacosamide (LCM), oxcarbazepine (OXC)). We use age at time of scan, age of onset, and gender, as nuisance variables between groups. Results: We found common fMRI effects in patients taking LTG and CBZ, with increased activations in task-negative cognitive parietal lobe networks compared to those taking LEV. Impaired deactivation in task-positive cognitive frontal lobe network was only seen with CBZ. Conclusions: Our findings suggest that LTG and CBZ are associated with similar dysfunctions of parietal cognitive / resting state networks. Our findings of CBZ associated with both impaired attenuation of language-associated deactivation and task-negative default mode network suggests a more widespread effect of CBZ on cognition in patients with focal epilepsy. These studies imply medication specific effects on the functional neuroanatomy of language and working memory networks. Funding: We are grateful to the Wolfson Foundation and the Epilepsy Society for supporting the Epilepsy Society MRI scanner. This work was supported by the National Institute for Health Research University College London Hospitals Biomedical Research Centre. FX is funded by a scholarship from China Scholarship Council.