Clinical utility of flumazenil-PET versus [18F]fluorodeoxyglucose-PET and MRI in refractory partial epilepsy. A prospective study in 100 patients

Abstract

We assessed the clinical utility of [11C]flumazenil-PET (FMZ-PET) prospectively in 100 epileptic patients undergoing a pre-surgical evaluation, and defined the specific contribution of this neuro-imaging technique with respect to those of MRI and [18F]fluorodeoxyglucose-PET (FDG-PET). All patients benefited from a long term video-EEG monitoring, whereas an intracranial EEG investigation was performed in 40 cases. Most of our patients (73%) demonstrated a FMZ-PET abnormality; this hit rate was significantly higher in temporal lobe epilepsy (94%) than in other types of epilepsy (50%) (P < 0.001). Most FMZ-PET findings coexisted with a MRI abnormality (81%), including hippocampal atrophy (35%) and focal hypometabolism on FDG-PET (89%). The area of decreased FMZ binding was often smaller than that of glucose hypometabolism (48%) or larger than that of the MRI abnormality (28%). FMZ-PET did not prove superior to FDG-PET in assessing the extent of the ictal onset zone, as defined by intracranial EEG recordings. However, it provided useful data which were complementary to those of MRI and FDG-PET in three situations: (i) in temporal lobe epilepsy associated with MRI signs of hippocampal sclerosis, FMZ-PET abnormalities delineated the site of seizure onset precisely, whenever they were coextensive with FDG-PET abnormalities; (ii) in bi-temporal epilepsy, FMZ-PET helped to confirm the bilateral origin of seizures by showing a specific pattern of decreased FMZ binding in both temporal lobes in 33% of cases; (iii) in patients with a unilateral cryptogenic frontal lobe epilepsy, FMZ-PET provided further evidence of the side and site of seizure onset in 55% of cases. Thus, FMZ-PET deserves to be included in the pre-surgical evaluation of these specific categories of epileptic patients, representing approximately half of the population considered for epilepsy surgery.

Multimodal computational neocortical anatomy in pediatric hippocampal sclerosis

“…This is in line with the literature, which reports that temporopolar blurring is present in 32‐66% of adults with TLE and HS39 and in 57% of children 42. It has previously been postulated to be caused by vasculometabolic changes,43 cortical dysplasia,44 inflammatory changes,45 increased perivascular spaces, abnormal water content,46 widespread gliosis45 as well as myelin loss 45. A recent study by Garbelli and colleagues relating histopathology to high‐field imaging carefully attempted to disentangle these factors and found that blurring was associated with axonal degeneration and reduced axonal numbers in the white matter 39.…”

A systematic review of the effectiveness and cost-effectiveness of neuroimaging assessments used to visualise the seizure focus in people with refractory epilepsy being considered for surgery

“…did not specify the type of EEG used in all patients. 102 A combination reference standard where patients received a variety of reference tests was considered acceptable. All studies avoided differential verification bias, but partial verification bias was a potential problem in three studies.…”

“…102 The final study reported that EEG was used as the reference standard without providing further details; therefore, it was unclear whether an appropriate reference standard had been used. 31 Partial verification bias did not appear to be a problem in any of these studies.…”

“…64 Two studies included an appropriate patient spectrum. 29,106 The results of these studies are presented in 29,51,79,102,106 and one pathology at the site of surgery. 53 Partial verification bias may have been a problem in two studies which only reported results on patients who underwent surgery, which was also the reference standard.…”

L’enzyme de la glycolyse GAPDH joue un double rôle dans la neurotransmission GABAergique et l’épilepsie humaine

“…La génération de divers types cellulaires via un processus de division asymétrique qui sépare inégalement les déterminants cellulaires est un mécanisme conservé dans l'évolution, depuis Caenorhabditis elegans et Drosophila melanogaster [8,9] Figure 1A). La phosphorylation endogène a-t-elle un rôle fonctionnel ?…”