Failed epilepsy surgery for mesial temporal lobe sclerosis: a review of the pathophysiology

Object The object of the current study was to review the electrophysiology and pathological substrate of failed temporal lobe surgery in patients with mesial temporal sclerosis. Methods A systematic review of the literature was performed for the years 1999–2010 to assess the cause of failure and to identify potential reoperation candidates. Results Repeat electroencephalographic evaluation documenting ipsilateral temporal lobe onset was the most frequent cause for recurrent epileptogenesis, followed by contralateral temporal lobe seizures. Less frequently, surgical failures demonstrated an electroencephalogram that was compatible with extratemporal localization. The generation of occult or new epileptogenic zones as well as residual epileptogenic tissue could explain these findings. Conclusions The outcome of temporal lobe surgery for epilepsy is challenged by a somewhat consistent failure rate. Reoperation results in improved seizure control in properly selected patients. A detailed knowledge of the pathophysiology is beneficial for the reevaluation of these patients.

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Transparahippocampal selective amygdalohippocampectomy in children and adolescents: efficacy of the procedure and cognitive morbidity in patients

Journal of Neurosurgery ◽

10.3171/jns.2000.93.3.0402 ◽

2000 ◽

Vol 93 (3) ◽

pp. 402-409 ◽

Cited By ~ 44

Author(s):

Shenandoah Robinson ◽

T. S. Park ◽

Lynn B. Blackburn ◽

Blaise F. D. Bourgeois ◽

Susan T. Arnold ◽

...

Keyword(s):

Children And Adolescents ◽

Temporal Lobe ◽

Seizure Control ◽

Content Type ◽

Clinical Variables ◽

Selective Amygdalohippocampectomy ◽

Significant Difference ◽

Temporal Lobe Seizures ◽

Mesial Temporal Lobe ◽

Fine Print

Object. Unilateral resection of the hippocampus and amygdala can be used to treat medically intractable mesial temporal lobe seizures. To date seizure outcome and the extent of cognitive morbidity have been unknown in children following the transparahippocampal variation of selective amygdalohippocampectomy (TSA), which prompted the present prospective study.Methods. Preoperative examinations and outcomes in 22 consecutive children and adolescents who underwent TSA were studied. Cognitive and psychological morbidity were assessed using standard neuropsychological instruments. The authors evaluated relationships between seizure control and cognitive morbidity and 13 and nine clinical variables, respectively.Seizure control was achieved in 11 (65%) of 17 patients (> 2 years follow up). Among 13 clinical variables, the only preoperative finding that had a significant bearing on seizure control was the presence of unilateral hypometabolism, which could be observed on [18F]fluorodeoxyglucose—positron emission tomography scans (p < 0.001). Patients with seizure control showed significant improvements in verbal and full scale intelligence quotients (both p = 0.05). Patients with longer preoperative durations of seizures exhibited more cognitive impairment that persisted postoperatively. Cognitive outcome analysis based on nine clinical factors revealed no significant difference in cognitive parameters postoperatively, except that significant improvement occurred in rote verbal memory scores among patients who underwent right-sided TSA (p = 0.01). Individually, 81% of the children achieved significant improvement in at least one of seven cognitive parameters, and 52% had stable or improved scores in all parameters.Conclusions. The results indicate that TSA is a safe effective approach for the treatment of medically intractable mesial temporal lobe seizures in children with minimum effect on cognitive morbidity. Given that the literature suggests that children suffer progressive cognitive morbidity from persistent seizures, the results of this study support early surgical intervention for this group of children.

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Functional connectivity of hippocampus in temporal lobe epilepsy depends on hippocampal dominance: a systematic review of the literature

Journal of Neurology ◽

10.1007/s00415-020-10391-8 ◽

2021 ◽

Author(s):

Camille K. Milton ◽

Christen M. O’Neal ◽

Andrew K. Conner

Keyword(s):

Systematic Review ◽

Functional Connectivity ◽

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Review Of The Literature

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

Journal of Epilepsy and Clinical Neurophysiology ◽

10.1590/s1676-26492006000500008 ◽

2006 ◽

Vol 12 (3) ◽

pp. 155-160 ◽

Cited By ~ 4

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.

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

Arquivos de Neuro-Psiquiatria ◽

10.1590/0004-282x20150188 ◽

2015 ◽

Vol 74 (1) ◽

pp. 35-43 ◽

Cited By ~ 12

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.

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Efficacy of limited hippocampal radiofrequency thermocoagulation for mesial temporal lobe epilepsy

Journal of Neurosurgery ◽

10.3171/2018.4.jns184 ◽

2019 ◽

Vol 131 (3) ◽

pp. 781-789 ◽

Cited By ~ 1

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.

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

Arquivos de Neuro-Psiquiatria ◽

10.1590/0004-282x20140199 ◽

2015 ◽

Vol 73 (2) ◽

pp. 79-82 ◽

Cited By ~ 10

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.

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