Abstracts

Rationale: Modern imaging tools provide an unprecedented opportunity to understand aberrant brain connectivity in epilepsy. The NIH-sponsored Epilepsy Connectome Project aims to characterize connectivity changes in people with temporal lobe epilepsy (TLE); correlate these changes with disease duration and severity, cognitive and behavioral deficits, and medication resistance; and measure longitudinal changes in the TLE connectome and their relationship with seizure frequency and cognitive decline. Methods: 200 people with non-lesional TLE of varying duration and severity will be recruited. Participants must have 2 or more of the following: seizure semiology consistent with TLE, interictal temporal lobe discharges or rhythmic delta activity on EEG, temporal lobe seizure onset on EEG, or MRI evidence of mesial temporal sclerosis. 60 healthy controls will also participate in each phase of the protocol. MRI protocols follow those used in the Human Connectome Project (HCP), and include 40 minutes of resting-state fMRI; 4 task-activation fMRI scans examining language lateralization, semantic memory, emotion processing, and social cognition; high-resolution diffusion tensor imaging; and T1- and T2-weighted structural scans. FMRI data are acquired at 3T using 8-band multiband imaging for full brain 2-mm isotropic coverage every 800 ms. In addition to MRI, connectivity will be examined using magnetoencephalography (MEG, with simultaneous EEG) obtained during rest and under 6 task-evoked activation conditions (single-word semantic decision, picture naming, story comprehension, and 3 control conditions). Participants also undergo a 6-hour behavioral assessment that includes a medical and seizure history interview; selected cognitive and sensory-motor tests from the Epilepsy Common Data Elements and NIH Toolbox batteries; and a range of self-report inventories covering psychiatric state, quality-of-life, and sleep quality. Data are acquired over 3-4 visits. Participants return after 1 year for a single visit that includes resting-state and DTI MRI, seizure history interview, and an abbreviated battery of cognitive measures. Results: HCP multi-band MRI protocols were implemented for the first time on GE 750 scanners at the two participating sites. Example high-resolution resting-state connectivity and language lateralization results are shown in the Figure. Since enrollment began in March 2016, 62 TLE participants have completed the protocol, as well as 43 MRI control, 28 MEG control, and 60 behavioral battery control participants. MRI signal-noise ratio and head motion quality control metrics, determined using the standard HCP processing pipeline, are well within 90% confidence intervals established by the HCP. Conclusions: The Epilepsy Connectome Project will provide the research community with an unusually large and rich dataset for studying functional and structural connectivity at the network level in TLE. De-identified data will be uploaded at yearly intervals to the Connectome Coordinating Facility (www.humanconnectome.org/ccf/) for sharing worldwide. Funding: Funded by NINDS grant U01 NS093650