In order to investigate the factors influencing interhemispheric hippocampal connectivity we used fMRI to assess the time course of hippocampal activity during a spatial memory task. Data were obtained from 14 patients with unilateral hippocampal sclerosis and focal unilateral medial temporal lobe epilepsy. Correlation coefficients between left and right hippocampal BOLD signal fluctuations wer...

OBJECTIVE To analyze retrospectively a series of patients with temporal lobe epilepsy (TLE) and mesial temporal sclerosis (MTS), and the association of patterns of hippocampal sclerosis with clinical data and surgical prognosis. METHOD Sixty-six patients with medically refractory TLE with unilateral MTS after anterior temporal lobectomy were included. Quantitative neuropathological evaluation...

OBJECTIVE The exact role of calcified neurocysticercotic lesions (CNLs) in epilepsy is yet unknown and controversial. Although the relationship between CNLs, epilepsy and mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) has already been addressed, to our knowledge, no study has actually provided strong statistical evidence, nor reported the ODDS ratio for these associations. T...

The aim of this study was to explore the effects of preoperative and postoperative lateralized mesial temporal damage on three measures of spatial learning: navigation, object location and plan drawing, and to determine the relationship between volumetry of the hippocampus and memory performance. Fifteen patients with well-characterized unilateral hippocampal sclerosis, 15 patients who had unde...

OBJECTIVE To determine the frequency and regional involvement of temporal pole signal abnormality (TPA) in patients with hippocampal sclerosis (HS) using fluid-attenuated inversion-recovery (FLAIR) MR imaging, and to correlate this feature with history. METHOD Coronal FLAIR images of the temporal pole were assessed in 120 patients with HS and in 30 normal subjects, to evaluate gray-white matt...

Mesial temporal lobe epilepsy (MTLE) is hypothesized to involve derangement of long-range limbic connectivity, but in vivo evidence is lacking. We used diffusion tractography to investigate the relationship between hippocampal atrophy and connectivity in MTLE patients with hippocampal sclerosis (HS). Atrophy was correlated with relatively decreased connectivity density but increased connectivit...

PURPOSE Semi-quantitative analysis of hippocampal internal architecture (HIA) on MRI has been shown to be a reliable predictor of the side of seizure onset in patients with temporal lobe epilepsy (TLE). In the present study, we investigated the relationship between postoperative seizure outcome and preoperative semi-quantitative measures of HIA. METHODS We determined HIA on high in-plane reso...

PURPOSE To investigate factors determining the presence of bilateral interictal epileptiform discharges (IEDs) in temporal lobe epilepsy (TLE) with unilateral hippocampal sclerosis (HS). METHODS We analysed data of 243 TLE patients with unilateral HS who had long-term video-EEG. Eighty-one patients (33%) had bitemporal IEDs. RESULTS We categorised patients into a unilateral group (UG), a bi...

PURPOSE Neuroimaging is critical in deciding candidacy for epilepsy surgery. Currently imaging is primarily assessed qualitatively, which may affect patient selection and outcomes. METHOD The epilepsy surgery database at MGH was reviewed for temporal lobectomy patients from the last 10 years. Radiology reports for MRI and FDG-PET were compared to the epilepsy conference consensus. First, spec...

PURPOSE Our goal was to compare the diagnostic accuracy of subjective visual assessment versus MR volumetry in evaluating hippocampal sclerosis and to determine whether MR volumetry is needed in the lateralization of this disease process. METHODS MR imaging findings were studied retrospectively in 48 patients who underwent surgery for temporal lobe epilepsy and were compared with findings at ...