Intraoperative hippocampal electrocorticography to predict the extent of hippocampal resection in temporal lobe epilepsy surgery

2000 ◽  
Vol 93 (1) ◽  
pp. 44-52 ◽  
Author(s):  
Guy M. McKhann ◽  
Julie Schoenfeld-McNeill ◽  
Donald E. Born ◽  
Michael M. Haglund ◽  
George A. Ojemann
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Seizure Control ◽  
Epileptiform Activity ◽  
Neuronal Loss ◽  
Mesial Temporal Lobe Epilepsy ◽  
Mesial Temporal Sclerosis ◽  
Content Type ◽  
Pathological Subtype ◽  
Fine Print

Object. Among the variety of surgical procedures that are performed for the treatment of medically refractory mesial temporal lobe epilepsy (TLE), no consensus exists as to how much of the hippocampus should be removed. Whether all patients require a maximal hippocampal resection has not yet been determined.Methods. At the University of Washington, all TLE operations are performed in a tailored fashion, guided by electrocorticography (ECoG). The amount of hippocampal resection is determined intraoperatively by the extent of interictal epileptiform abnormalities on ECoG recorded from that structure, resulting in a hippocampal resection that is individualized for each patient. Using this approach, the authors prospectively observed 140 consecutive patients who underwent surgery for mesial TLE with pathological diagnoses of either mesial temporal sclerosis with neuronal loss (MTS group) or mild gliosis without neuronal loss (non-MTS group) to determine whether the extent of hippocampal resection correlates with outcome when a tailored approach is used. Additionally, the authors analyzed whether the presence of residual interictal epileptiform activity on ECoG following mesial temporal resection predicts poorer seizure control.With at least 18 months of clinical follow up, 67% of the 140 patients were seizure free or had only a single postoperative seizure. There was no correlation between the size of the hippocampal resection and seizure control in the group as a whole or when stratified by pathological subtype. Using an intraoperatively tailored strategy, individuals with a larger hippocampal resection (> 2.5 cm) were not more likely to have seizure-free outcomes than patients with smaller resections (p = 0.9). Additionally, both MTS and non-MTS patients, in whom postoperative ECoG detected residual epileptiform hippocampal (but not cortical or parahippocampal) interictal activity following surgical resection, had significantly worse seizure outcomes (p = 0.01 in the MTS group; p = 0.002 in the non-MTS group).Conclusions. Intraoperative hippocampal ECoG can predict how much hippocampus should be removed to maximize seizure-free outcome, allowing for sparing of possibly functionally important hippocampus.

Acute postoperative seizures following anterior temporal lobectomy for intractable partial epilepsy

1998 ◽  
Vol 89 (2) ◽  
pp. 177-182 ◽  
Author(s):  
Bhaskara Rao Malla ◽  
Terence J. O'Brien ◽  
Gregory D. Cascino ◽  
Elson L. So ◽  
Kurupath Radhakrishnan ◽  
...  
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Seizure Control ◽  
Temporal Lobectomy ◽  
Mesial Temporal Sclerosis ◽  
Anterior Temporal Lobectomy ◽  
Content Type ◽  
Excellent Outcome ◽  
Prognostic Importance ◽  
Fine Print

Object. Recurrence of seizures immediately following epilepsy surgery can be emotionally devastating, and raises concerns about the chances of successfully attaining long-term seizure control. The goals of this study were to investigate the frequency of acute postoperative seizures (APOS) occurring in the 1st postoperative week following anterior temporal lobectomy (ATL) to identify potential risk factors and to determine their prognostic significance. Methods. One hundred sixty consecutive patients who underwent an ATL for intractable nonlesional temporal lobe epilepsy were retrospectively studied. Acute postoperative seizures occurred in 32 patients (20%). None of the following factors were shown to be significantly associated with the occurrence of APOS: age at surgery, duration of epilepsy, side of surgery, extent of neocortical resection, electrocorticography findings, presence of mesial temporal sclerosis, and hippocampal volume measurements (p > 0.05). Patients who suffered from APOS overall had a lower rate of favorable outcome with respect to seizure control at the last follow-up examination than patients without APOS (62.5% compared with 83.6%, p < 0.05). The type of APOS was of prognostic importance, with patients whose APOS were similar to their preoperative habitual seizures having a significantly worse outcome than those whose APOS were auras or were focal motor and/or generalized tonic—clonic seizures (excellent outcome: 14.3%, 77.8%, and 75%, respectively, p < 0.05). Only patients who had APOS similar to preoperative habitual seizures were less likely to have an excellent outcome than patients without APOS (14.3% compared with 75%, p < 0.05). Timing of the APOS and identification of a precipitating factor were of no prognostic importance. Conclusions. The findings of this study may be useful in counseling patients who suffer from APOS following ATL for temporal lobe epilepsy.

Significance of surgery for temporal lobe epilepsy in childhood and adolescence

1970 ◽  
Vol 33 (3) ◽  
pp. 233-252 ◽  
Author(s):  
Murray A. Falconer
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Temporal Lobectomy ◽  
Mesial Temporal Sclerosis ◽  
Childhood And Adolescence ◽  
Content Type ◽  
Pathological Lesion ◽  
Fine Print

✓ The problem of childhood temporal lobe epilepsy is reviewed and illustrated from three cases in which the patients were freed from fits by temporal lobectomy. The pathological lesion (mesial temporal sclerosis) is discussed and the likelihood that many adult cases have gone unrecognized in childhood is emphasized.

Mesial temporal lobe epilepsy: a proton magnetic resonance spectroscopy study and a histopathological analysis

2004 ◽  
Vol 101 (4) ◽  
pp. 613-620 ◽  
Author(s):  
Aaron A. Cohen-Gadol ◽  
Jullie W. Pan ◽  
Jung H. Kim ◽  
Dennis D. Spencer ◽  
Hoby H. Hetherington
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Mr Spectroscopy ◽  
Neuronal Cell ◽  
Cell Loss ◽  
Mesial Temporal Lobe Epilepsy ◽  
Content Type ◽  
Neuronal Cell Loss ◽  
Gfap Immunoreactivity ◽  
Fine Print

Object. Proton magnetic resonance (MR) spectroscopy imaging of the ratio of N-acetylaspartate (NAA) to creatine (Cr) has proved efficacious as a localizing tool in demonstrating the metabolic changes associated with temporal lobe epilepsy. To analyze the significance of these MR spectroscopy findings further, the authors explored the relationship between regional alterations in the NAA/Cr ratio in hippocampi measured preoperatively and histopathological findings in hippocampi resected in patients with intractable mesial temporal lobe epilepsy (MTLE). Methods. Twelve patients in whom the diagnosis of MTLE had been made and 12 healthy volunteers with no known history of neurological disease underwent high-resolution 1H MR spectroscopy imaging of NAA and Cr (0.64 cm3 nominal voxel resolution) in five voxels spanning the anteroposterior length of the hippocampus. The authors correlated the NAA/Cr ratio with neuropathological findings in resected hippocampi, specifically glial fibrillary acidic protein (GFAP) immunoreactivity and pyramidal neuronal loss. A linear regression analysis of the ipsilateral NAA/Cr ratio revealed a statistically significant relation to the extent of hippocampal neuronal loss in only the CA2 sector (correlation coefficient [r] = −0.66, p < 0.03). The ipsilateral NAA/Cr ratio displayed significant regressions with GFAP immunoreactivity from all the CA sectors (r values ranged from −0.69 and p < 0.01 for the CA4 sector to −0.88 and p < 0.001 for the CA2 sector) except for the CA1. The extent of neuronal cell loss in every hippocampal subfield (r = 0.71−0.74, p < 0.007), except the CA2 (p = 0.08), correlated to the extent of neuronal cell loss in the dentate gyrus. There was no significant relationship between the duration or frequency of seizures and the mean ipsilateral NAA/Cr ratio; however, the mean density of GFAP-immunopositive cells correlated with seizure frequency (p < 0.03). Conclusions. The NAA/Cr ratio may not measure the full extent of hippocampal neuronal cell loss. The significant association of the NAA/Cr ratio with the GFAP immunoreactivity of most CA sectors indicates that the NAA/Cr ratio may provide a more accurate measurement of recent neuronal injury caused by epileptic activity. The coupling between neuronal impairment and astroglial GFAP expression may indicate the close association between neuronal and glial dysfunction in patients with epilepsy.

Epileptiform activity extinguished by amygdala infusion of the neurotoxin ibotenate in a rat model of temporal lobe epilepsy

2002 ◽  
Vol 97 (2) ◽  
pp. 450-454 ◽  
Author(s):  
John R. Pace ◽  
Russell R. Lonser ◽  
R. Duncan Kirkby ◽  
Neal Jeffries ◽  
Michael A. Rogawski ◽  
...  
Keyword(s):  
Amino Acid ◽  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Rat Model ◽  
Seizure Activity ◽  
Excitatory Amino Acid ◽  
Epileptiform Activity ◽  
Recurrent Seizure ◽  
Content Type ◽  
Fine Print

Object. The long-term antiseizure effects of local convection-enhanced infusion of the excitotoxin ibotenate were examined in a rat model of temporal lobe epilepsy. Methods. A single injection of kainate, an epileptogenic excitatory amino acid, into the left amygdala elicited chronic spontaneous recurrent seizure activity for at least 36 days after the injection. Two weeks after the injection, infusion of ibotenate, a nonepileptogenic excitatory amino acid that is an axon-sparing neuronal cell toxin, into the left amygdala and piriform lobe induced immediate and permanent extinction of electrical and behavioral seizure activity. Conclusions. Lesioning of an epileptic focus by convective distribution of ibotenate can produce an enduring suppression of seizure activity, indicating a chemical neurosurgical approach for epilepsy therapy.

Gamma knife surgery for mesial temporal lobe epilepsy

2000 ◽  
Vol 93 (supplement_3) ◽  
pp. 141-146 ◽  
Author(s):  
Jean Régis ◽  
Fabrice Bartolomei ◽  
M. Rey ◽  
Motohiro Hayashi ◽  
Patrick Chauvel ◽  
...  
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Gamma Knife ◽  
Temporal Lobe ◽  
Morphological Changes ◽  
Gamma Knife Radiosurgery ◽  
Mesial Temporal Lobe Epilepsy ◽  
Content Type ◽  
Mesial Temporal Lobe ◽  
Fine Print

Object. Gamma knife radiosurgery (GKS) allows precise and complete destruction of chosen target structures containing healthy and/or pathological cells, without causing significant radiation damage to adjacent tissues. Almost all the well-documented cases of radiosurgery for epilepsy are for epilepsies associated with space-occupying lesions. These results prompted the authors to investigate the use of radiosurgery as a new way of treating epilepsy not associated with space-occupying lesions. Methods. To evaluate this new method, 25 patients who presented with drug-resistant mesial temporal lobe epilepsy (MTLE) were selected. A follow up of more than 24 months is now available for 16 patients. The preoperative evaluation was performed as it usually is in patients selected for microsurgery for MTLE. In lieu of microsurgery, the treatment of amygdalohippocampal structures was performed using GKS. Thirteen (81%) of these 16 patients are seizure free, and two are improved. The median latent interval from GKS to seizure cessation was 10.5 months (range 6–21 months). Two patients were immediately seizure free. The median latency in aura cessation was 15.5 months (range 9–22 months). Morphological changes on magnetic resonance imaging were visible at 11 months (median) after GKS (range 7–22 months). During the onset period of these radiological changes, three patients experienced headache associated, in two cases, with nausea and vomiting. In these three patients the signs resolved immediately after prescription of low doses of steroids. No cases of permanent neurological deficit (except three cases of nonsymptomatic visual field deficit), or morbidity, or mortality were observed. Conclusions. This initial experience indicates that there is short- to middle-term efficiency and safety when using GKS to treat MTLE. Further long-term follow up is required. It seems that the introduction of GKS into epilepsy treatment can reduce the invasiveness and morbidity.

scholarly journals Somatosensory aura in mesial temporal lobe epilepsy: semiologic characteristics, MRI findings and differential diagnosis with parietal lobe epilepsy

2006 ◽  
Vol 12 (3) ◽  
pp. 155-160 ◽  
Author(s):  
Márcio Andriani Rahal ◽  
Gerardo Maria de Araújo Filho ◽  
Luís Otávio Sales Ferreira Caboclo ◽  
Vivianne Pellegrino Rosa ◽  
Ricardo da Silva Centeno ◽  
...  
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Parietal Lobe ◽  
Mesial Temporal Lobe Epilepsy ◽  
Mesial Temporal Sclerosis ◽  
Presurgical Evaluation ◽  
Mri Findings ◽  
Tingling Sensation ◽  
Mesial Temporal Lobe ◽  
Prevalent Symptom

INTRODUCTION: Somatosensory auras (SSAs) are more usually described in patients with parietal lobe epilepsy (PLE), producing more commonly a localized cutaneous tingling sensation, involving hands and fingers followed by tonic or clonic focal seizures. These usually originate in the contralateral hemisphere. Etiology includes dysplasias, tumours, ischemic or postencephalitic gliosis. However, other focal epilepsies, such as frontal and temporal, may also originate SSAs. Although this type of aura is reported as rare in patients with mesial temporal lobe epilepsy (MTLE), this association has not been systematically studied. OBJECTIVES: The aim of this article was to describe the cases of four patients with refractory MTLE and SSAs, reporting their clinical characteristics and MRI findings. We discuss the localizing and lateralizing value of SSAs, particularly in the context of MTLE. METHODS AND RESULTS: Four patients with refractory MTLE and SSAs followed-up in the outpatient's clinic at the Epilepsy Section, Universidade Federal de São Paulo, were submitted to presurgical evaluation and corticoamygdalohippocampectomy. MRI in all cases showed unilateral mesial temporal sclerosis (MTS). Regarding seizure semiology, tingling sensation involving the upper extremity was the most prevalent symptom. Three of the four patients had SSAs contralateral to the MTS. Following the SSAs all patients most of the time presented other symptoms such as autonomic or psychic auras evolving to psychomotor seizures. After surgical treatment, two of the patients presented infrequent auras, and two were rendered seizure-free. CONCLUSION: Although rare, SSAs can be present in MTLE. The characteristics of autonomic or psychic auras, psychomotor seizures, neuropsychological deficits, and typical neurophysiologic and MRI findings may help differentiate patients with MTLE from those with PLE.

scholarly journals Anterior temporal lobectomy versus selective amygdalohippocampectomy in patients with mesial temporal lobe epilepsy

2015 ◽  
Vol 74 (1) ◽  
pp. 35-43 ◽  
Author(s):  
Fábio A. Nascimento ◽  
Luana Antunes Maranha Gatto ◽  
Carlos Silvado ◽  
Maria Joana Mäder-Joaquim ◽  
Marlus Sidney Moro ◽  
...  
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Mesial Temporal Lobe Epilepsy ◽  
Temporal Lobectomy ◽  
Mesial Temporal Sclerosis ◽  
Anterior Temporal Lobectomy ◽  
Selective Amygdalohippocampectomy ◽  
Significant Difference ◽  
Mesial Temporal Lobe ◽  
Neuropsychological Outcomes

ABSTRACT Objective To contribute our experience with surgical treatment of patients with mesial temporal lobe epilepsy (mTLE) undergoing anterior temporal lobectomy (ATL) or selective amygdalohippocampectomy (SelAH). Method This is a retrospective observational study. The sample included patients with medically refractory mTLE due to unilateral mesial temporal sclerosis who underwent either ATL or SelAH, at Hospital de Clinicas – UFPR, from 2005 to 2012. We report seizure outcomes, using Engel classification, cognitive outcomes, using measurements of verbal and visuospatial memories, as well as operative complications. Result Sixty-seven patients (33 ATL, 34 SelAH) were studied; median follow-up was 64 months. There was no statistically significant difference in seizure or neuropsychological outcomes, although verbal memory was more negatively affected in ATL operations on patients’ dominant hemispheres. Higher number of major complications was observed in the ATL group (p = 0.004). Conclusion Seizure and neuropsychological outcomes did not differ. ATL appeared to be associated with higher risk of complications.

scholarly journals Efficacy of limited hippocampal radiofrequency thermocoagulation for mesial temporal lobe epilepsy

2019 ◽  
Vol 131 (3) ◽  
pp. 781-789 ◽  
Author(s):  
Ching-Yi Lee ◽  
Han-Tao Li ◽  
Tony Wu ◽  
Mei-Yun Cheng ◽  
Siew-Na Lim ◽  
...  
Keyword(s):  
Adverse Effects ◽  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Seizure Frequency ◽  
Seizure Control ◽  
Mesial Temporal Lobe Epilepsy ◽  
Temporary Increase ◽  
Drug Resistant ◽  
Radiofrequency Thermocoagulation ◽  
Mesial Temporal Lobe

OBJECTIVERadiofrequency thermocoagulation (RFTC), which has been developed for drug-resistant epilepsy patients, involves less brain tissue loss due to surgery, fewer surgical adverse effects, and generally good seizure control. This study demonstrates the effectiveness of RFTC performed at limited hippocampal locations.METHODSDaily seizure diaries were prospectively maintained for at least 6 months by 9 patients (ages 30–59 years) with drug-resistant mesial temporal lobe epilepsy (MTLE) before treatment with RFTC. The limited target for stereotactic RFTC was chosen based on intraoperative electroencephalography (EEG) recording and was initially tested with a Radionics electrode at a low temperature, 45°C, for 60 seconds. The therapeutic RFTC heating parameters were 78°C–80°C for 90 seconds. All patients who received the RFTC treatment underwent both MRI and EEG recording immediately postoperatively and at the 3-month follow-up. Monthly outpatient clinic visits were arranged over 6 months to document seizure frequency and severity to clarify the changes noted in imaging studies and EEG patterns.RESULTSTwo patients were excluded from our analysis because one had undergone multiple seizure surgeries and the other had a poor recording of seizure frequency, before the RFTC surgery. Five and two patients underwent left-sided and right-sided RFTC, respectively. None of the patients had generalized tonic-clonic attacks postoperatively, and no adverse effects or complications occurred. According to MRI data, the effect of coagulation was limited to less than 1.0 cm in diameter and perifocal edema was also in limited range. The seizure frequency within 6 months decreased postoperatively with a mean reduction in seizures of 78% (range 36%–100%). Only two patients had a temporary increase in seizure frequency within 2 weeks of the surgery, and over 50% of all patients showed a decrease in average seizure frequency.CONCLUSIONSThe study results confirm that limited RFTC provides a more effective surgery with similar seizure control but fewer complications than resective surgery for drug-resistant MTLE patients.

scholarly journals Patterns of seizure control in patients with mesial temporal lobe epilepsy with and without hippocampus sclerosis

2015 ◽  
Vol 73 (2) ◽  
pp. 79-82 ◽  
Author(s):  
Ana Carolina Coan ◽  
Brunno M. Campos ◽  
Felipe P.G Bergo ◽  
Bruno Y. Kubota ◽  
Clarissa L. Yasuda ◽  
...  
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Seizure Control ◽  
Hippocampal Sclerosis ◽  
Mesial Temporal Lobe Epilepsy ◽  
Similar Proportion ◽  
Seizure Freedom ◽  
Seizure Recurrence ◽  
Prolonged Seizure ◽  
Mesial Temporal Lobe

Objective Patients with mesial temporal lobe epilepsy (MTLE) may present unstable pattern of seizures. We aimed to evaluate the occurrence of relapse-remitting seizures in MTLE with (MTLE-HS) and without (MTLE-NL) hippocampal sclerosis. Method We evaluated 172 patients with MTLE-HS (122) or MTLE-NL (50). Relapse-remitting pattern was defined as periods longer than two years of seizure-freedom intercalated with seizure recurrence. “Infrequent seizures” was considered as up to three seizures per year and “frequent seizures” as any period of seizures higher than that. Results Thirty-seven (30%) MTLE-HS and 18 (36%) MTLE-NL patients had relapse-remitting pattern (X2, p = 0.470). This was more common in those with infrequent seizures (X2, p < 0.001). Twelve MTLE-HS and one MTLE-NL patients had prolonged seizure remission between the first and second decade of life (X2, p = 0.06). Conclusion Similar proportion of MTLE-HS or MTLE-NL patients present relapse-remitting seizures and this occurs more often in those with infrequent seizures.

scholarly journals Human and Rodent Temporal Lobe Epilepsy is Characterized by Changes in O-GLCNAC Homeostasis that can be Reversed to Dampen Epileptiform Activity

2018 ◽  
Author(s):  
Richard G. Sanchez ◽  
R. Ryley Parrish ◽  
Megan Rich ◽  
William M. Webb ◽  
Roxanne M. Lockhart ◽  
...  
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Energy Supply ◽  
Seizure Control ◽  
Epileptiform Activity ◽  
Protein Composition ◽  
Seizure Duration ◽  
Post Translational Modifications ◽  
Elevated Protein ◽  
Epileptic Spike

AbstractTemporal Lobe Epilepsy (TLE) is frequently associated with changes in protein composition and post-translational modifications (PTM) that exacerbate the disorder. O-linked-β-N-acetyl glucosamine (O-GlcNAc) is a PTM occurring at serine/threonine residues that integrate energy supply with demand. The enzymes O-GlcNActransferase (OGT) and O-GlcNAcase (OGA) mediate the addition and removal, respectively, of the O-GlcNAc modification. The goal of this study was to determine whether changes in OGT/OGA cycling and disruptions in protein O-GlcNAcylation occur in the epileptic hippocampus. We observed reduced global and protein specific O-GlcNAcylation and OGT expression in the kainate rat model of TLE and in human TLE hippocampal tissue. Inhibiting OGA with Thiamet-G elevated protein O-GlcNAcylation, and decreased both seizure duration and epileptic spike events, suggesting that OGA may be a therapeutic target for seizure control. These findings suggest that loss of O-GlcNAc homeostasis in the kainate model and in human TLE can be reversed via targeting of O-GlcNAc related pathways.

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