Attentional control in patients with temporal lobe epilepsy

Across different studies, patients with temporal lobe epilepsy (TLE) demonstrate impairments on numerous measures of attentional control that are classically associated with frontal lobe functioning. One aspect of attentional control that has not been examined in TLE is the ability to execute two modality-specific tasks concurrently. We sought to examine the status of dual-task coordination in TLE. We further examined the cohorts’ performance on a range of traditional measures of attentional control. Eighteen TLE patients and 22 healthy controls participated in the study. Dual-task performance involved comparing the capacity to execute a tracking and a digit recall task simultaneously with the capacity to execute the tasks separately. We also administered measures of: set shifting (odd-man-out test), sustained attention (elevator counting), selective attention (elevator counting with distraction), and divided attention (trail making test). We found that the proportional decrement in dual-task performance relative to single-task performance did not vary between the groups (TLE = 92.48%; controls = 93.70%), nor was there a significant difference in sustained attention (p > .10). Patients with TLE did demonstrate marked deficits in selective attention (p < .0001), divided attention (p < .01), and set shifting (p < .01). These findings add to the knowledge about cognitive dysfunction in TLE, indicating that impairments in attentional control in TLE tend to be selective. The greatest deficits appear to be on tasks that invoke a high level of processing resources. In contrast, sustained attention is less compromised and the capacity to allocate cognitive resources appears to be normal in patients with TLE

Noyau amygdalien et automatisme gestuel de frottement de nez (étude anatomo-électro-clinique en SEEG chez 32 patients)

LYON1-BU Santé (693882101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Periventricular [11C]flumazenil binding for predicting postoperative outcome in individual patients with temporal lobe epilepsy and hippocampal sclerosis

AbstractA third of patients with intractable temporal lobe epilepsy and hippocampal sclerosis (HS) are not seizure free (NSF) after surgery. Increased periventricular [11C]flumazenil (FMZ) binding, reflecting heterotopic neuron concentration, has been described as one predictor of NSF outcome at the group level. We aimed to replicate this finding in an independent larger cohort and investigated whether NSF outcome can be predicted in individuals.Preoperative [11C]FMZ summed radioactivity images were available for 16 patients with HS and 41 controls. Images were analyzed using SPM8, explicitly including the white matter, and correction for global radioactivity via group-specific ANCOVA. Periventricular increases were assessed with a mask and different cutoffs for distinguishing NSF and seizure free (SF) patients.NSF patients had increased [11C]FMZ binding around the posterior horn of the ventricles ipsilaterally (z=2.53) and contralaterally (z=4.44) to the seizure focus compared with SF patients. Compared with controls, SF patients had fewer periventricular increases (two clusters, total volume 0.87cm3, zmax=3.8) than NSF patients (two ipsilateral and three contralateral clusters, 6.15cm3, zmax=4.8). In individuals and at optimized cutoffs, five (63%) of eight NSF patients and one (13%) of eight SF patients showed periventricular increases compared with controls (accuracy 75%). Only one (2%) of the 41 controls had increases at the same cutoff.The association between periventricular [11C]FMZ increases and NSF outcome after temporal lobe resection for HS has been confirmed in an independent cohort on simple summed activity images. [11C]FMZ-PET may be useful for individual preoperative counseling with clinically relevant accuracy

Planning and management of SEEG

International audienceStereoelectroencephalography (SEEG) aims to define the epileptogenic zone (EZ), to study its relationship with functional areas and the causal lesion and to evaluate the possibility of surgical therapy. Planning of exploration is based on the validity of the hypotheses developed from electroclinical and imaging correlations. Further investigations can refine the implantation plan (e.g. fluorodeoxyglucose positron emission tomography [FDG-PET], single photon emission computerized tomography [SPECT], magnetoencephalography [MEG] and high resolution electroencephalography [EEG-HR]). The scheme is individualized according to the features of each clinical case, but a general approach can be systematized according to the regions involved (temporal versus extra-temporal), the existence of a lesion, its type and extent. It takes account of the hemispheric dominance for language if this can be determined. In "temporal plus" epilepsies, perisylvian and insular regions are among the key structures to investigate in addition to mesial and neocortical temporal areas. In frontal lobe epilepsies, determining the functional and anatomical organization of seizures (anterior versus posterior, mesial versus dorsolateral) allows better targeting of the implantation. Posterior epilepsies tend to have a complex organization leading to multilobar and often bilateral explorations. In lesional cases, it may be useful to implant one or several intralesional electrode(s), except in cases of vascular lesions or cyst. The strategy of implantation can be modified if thermocoagulations are considered. The management of SEEG implies continuous monitoring in a dedicated environment to determine the EZ with optimal safety conditions. This methodology includes spontaneous seizure recordings, low and high frequency stimulations and, if possible, sleep recording. SEEG is applicable in children, even the very young. Specific training of medical and paramedical teams is required