Cortical Excitability in Post-traumatic Epilepsy

To test whether measures of cortical excitability derived from motor cortex transcranial magnetic stimulation (TMS) in patients with traumatic brain injury reflect heightened excitability relative to healthy controls and whether such measures can be used to distinguish patients with post-traumatic epilepsy from patients with head trauma but no epilepsy

This is a pilot a pilot cross-sectional study to evaluate the utility of TMS-derived biomarkers in PTE prediction and detection. We will measure motor cortex excitability and intracortical inhibition (see below) in TBI patients with PTE (Group 1), TBI patients with average 30% risk of developing PTE who have not yet developed PTE (Group 2) and healthy age- and sex-matched control participants (group 3). 10 adult subjects aged 18-70 will be recruited into each group. We shall obtain a range of TMS metrics in each individual (see below), and, per metric, compare average values among groups by 1-way ANOVA. Our specific hypothesis is that, relative to healthy control, motor cortex TMS measures will indicate increased cortical excitability in participants with PTE, and a trend toward same in patients with TBI who have not developed PTE For subjects in groups 2 and 3, all antiseizure treatments will be stable (unchanged) for 4 weeks prior to evaluation. Subjects will undergo two ppTMS testing separated by 1-2 weeks. Per participant, TMS metrics (see below), will be evaluated for test-retest reliability (our secondary outcome measure)