Mesial Temporal Sclerosis

Temporal lobe epilepsy (TLE), the most common form of partial epilepsy in adults is often refractory to medical treatment and in these patients epilepsy surgery is considered. Successful surgery is dependent on accurate localisation and lateralisation of the epileptogenic zone. The preoperative evaluation involves a series of assessments and investigations including detailed clinical history, interictal EEG, video-EEG monitoring, MRI, PET,

Mesial temporal sclerosis syndrome in adult patients. Magnetic resonance imaging (MRI) has be- come an essential tool in the work-up of epilepsy. Since its appearance it has been possible to identify pathologies, such as hippocampal sclerosis (HS), that had previously only been detected by histopathological assays. The aim of this study was to analyze the clinical manifestations, EEG and the

PURPOSE: The purpose of our study was to determine the significance of the loss of visualization of digitations in the hippocampal head on high-resolution fast spin-echo MR images in the diagnosis of mesial temporal sclerosis (MTS). METHODS: MR examinations of 193 patients with intractable epilepsy were evaluated retrospectively for atrophy and/or T2 signal changes of the hippocampi. On the basis

Extensive metabolic impairments have been reported in association with mesial temporal lobe epilepsy (mTLE). We investigated whether proton MR spectroscopy ((1)H-MRS) depicts metabolic changes beyond the hippocampus in cases of mTLE and whether these changes help lateralize the seizure focus. MR imaging and (1)H-MRS were performed in 15 patients with mTLE with a postoperative diagnosis of mesial temporal sclerosis and in 12 control volunteers. Point-resolved spectroscopy and multisection (1)H-MRS measured N-acetylaspartate (NAA), creatine (Cr), and choline (Cho) in the hippocampus, temporal opercular and lateral cortices, insula and cerebellum, and frontal, parietal, and occipital lobes. Metabolites were assessed as ratios to Cr and in absolute units. Twelve patients had ipsilateral hippocampal atrophy; three had negative imaging results. In the ipsilateral hippocampus, absolute NAA (/NAA/) was 27.3% lower in patients compared with that in control volunteers (P <.001) and 18.5% l...

Objective To investigate the outcome of temporal lobe epilepsy surgery and identify the variables which predict a good prognosis with respect to seizures in postoperative follow-up after two and four years. Methods This retrospective study included 115 selected patients who underwent surgery for temporal lobe epilepsy between 1996 and 2007. Results In the second year after surgery 86.1% of patients had a good prognosis for seizure control (73.9% Engel class I and 12.2% Engel class II) and 89.2% (76.3% Engel class I and 12.9% Engel class II) in the fourth year. Sixty-four of 93 (68.8%) patients were free of disabling seizures (Engel class I) during the entire period and 78 (83.8%) had good prognosis (Engel class I and II). For the second year, logistic regression analysis revealed the following variables to be independently predictive of good seizure control: absence of two or more seizure episodes in the first year after surgery, normal postoperative video-EEG, and age at surgery of less than 35 years. In the fourth year, mesial temporal sclerosis, female sex and normal postoperative video-EEG were the predictive factors. For the group with a good prognosis in both the second and the fourth year, the predictive variables were: absence of two or more seizure episodes in the first year after surgery (OR: 13.762, CI 95%: 2.566–73.808, p Discussion This study illustrates the sustained benefit of temporal lobe epilepsy surgery. The multivariate logistic regression analysis failed to identify a good predictive model composed of preoperative variables alone, although it was possible to build such a model with either pre- and postoperative variables or only postoperative variables.

Seizures in patients presenting with mesial temporal lobe epilepsy result from the interaction among neuronal networks in limbic structures such as the hippocampus, amygdala and entorhinal cortex. Mesial temporal lobe epilepsy, one of the most common forms of partial epilepsy in adulthood, is generally accompanied by a pattern of brain damage known as mesial temporal sclerosis. Limbic seizures can be mimicked in vitro using preparations of combined hippocampus–entorhinal cortex slices perfused with artificial cerebrospinal fluid containing convulsants or nominally zero Mg2+, in order to produce epileptiform synchronization. Here, we summarize experimental evidence obtained in such slices from rodents. These data indicate that in control animals: (i) prolonged, NMDA receptor-dependent epileptiform discharges, resembling electrographic limbic seizures, originate in the entorhinal cortex from where they propagate to the hippocampus via the perforant path–dentate gyrus route; (ii) the initiation and maintenance of these ictal discharges is paradoxically contributed by GABA (mainly type A) receptor-mediated mechanisms; and (iii) CA3 outputs, which relay a continuous pattern of interictal discharge at approximately 1 Hz, control rather than sustain ictal discharge generation in entorhinal cortex. Recent work indicates that such a control is weakened in the pilocarpine model of epilepsy (presumably as a result of CA3 cell damage). In addition, in these experiments electrographic seizure activity spreads directly to the CA1–subiculum regions through the temporoammonic pathway. Studies reviewed here indicate that these changes in network interactions, along with other mechanisms of synaptic plasticity (e.g. axonal sprouting, decreased activation of interneurons, upregulation of bursting neurons) can confer to the epileptic, damaged limbic system, the ability to produce recurrent limbic seizures as seen in patients with mesial temporal lobe epilepsy.

The authors report the experience in treatment of pediatric epilepsy in a referral university hospital located in Bangkok, Thailand. After the reactivation of program of surgical treatment for epilepsy in the Institute in October 2005, seven Thai children under 17 years with intractable epilepsy received surgical treatment. Presurgical evaluation for each patient includes 1.5-tesla magnetic resonance imaging of brain, interictal

Twenty-two patients, followed with the diagnosis of epilepsy between the ages of 8.5 and 19 years who were found to have mesial temporal sclerosis (MTS) on brain magnetic resonance imaging (MRI) were evaluated according to their clinical, electrophysiological and neuropsychological characteristics, and assessed for the significance of neuropsychological tests on lateralization. In both MTS groups, a remarkable number of patients had their intial seizure before one year of age (45.5% in the right MTS group, and 36.4% in the left MTS group). Half of the patients were seizure-free for a period of two months-9.5 years (average 3.9 years). The duration between the febrile seizure and first non-febrile seizure was 6.2 years. Eleven patients had MTS on the left temporal lobe. Interictal EEG was normal in five (22.5%) patients; 10 (45.5%) had temporal spike on the corresponding side with MTS. Six (27.3%) patients had paroxysmal activity and voltage asymmetry on cortical areas other than tem...