2.1. Participants

All patients in this study were medically-refractory, under evaluation for surgical treatment at the UC San Diego or UC San Francisco Epilepsy Center, and diagnosed by board-certified neurologists with expertise in epileptology²⁰. A total of 28 patients were recruited at UC San Diego, and a total of 18 patients were recruited at UC San Francisco. Patients were classified as either LTLE or RTLE based on seizure onsets recorded by video-EEG telemetry and supported by seizure semiology and neuroimaging results at each site. MRIs were visually inspected by a board-certified neuroradiologist for detection of mesial temporal sclerosis (MTS) and exclusion of contralateral temporal lobe structural abnormalities. Control participants were all recruited at UC San Diego and were included if they had no reported history of neurological or psychiatric conditions. Twenty-six patients with a diagnosis of LTLE, twenty patients with a diagnosis of RTLE, and thirty-three healthy controls were included in this study.

Demographic and clinical characteristics of patients with LTLE and RTLE and healthy controls are presented in Table 1. The mean ages and distributions of handedness and sex of the LTLE and RTLE groups were not statistically different from the control group. However, healthy controls attained more years of education than both patient groups.

Demographic and clinical information.

Note: Age, years of education, age of seizure onset, year of seizure duration, and number of medications were presented in mean ± SD; Handedness (L/R/A) = handedness (Left/Right/Ambidextrous); Presence of MTS = number of patients with mesial temporal sclerosis; Wilcoxon-Mann-Whitney tests were performed for the continuous variables, whereas chi-square tests were performed for the categorical variables.

Due to excessive head motion (i.e. mean framewise displacement > 0.5 mm), rs-fMRI was removed for two patients with RTLE and one control. The mean head motion parameters (i.e., head-to-head, translation, and rotation) of the LTLE (t(56) = 0.2, p = .845, t(56) = 0.53, p = .595, and t(56) = −1.03, p = .307, respectively) and RTLE (t(48) = −1.45, p = .154, t(48) = −1.38, p = .174, and t(48) = −1.46, p = .15, respectively) groups were not statistically different from the control group. Due to the absence of B0 scans to correct for geometric distortions, diffusion data were removed for six patients with LTLE and two patients with RTLE.