Temporal pole abnormalities detected by 3 T MRI in temporal lobe epilepsy due to hippocampal sclerosis: No influence on seizure outcome after surgery

ABSTRACT BACKGROUND Treatment of patients with pharmacoresistant temporal lobe epilepsy with hippocampal sclerosis and nonspecific pathology who failed initial resection is challenging, although selected patients may benefit from repeated surgery. OBJECTIVE To determine seizure outcome, postoperative morbidity, and possible predictors of seizure freedom after repeated ipsitemporal resection. METHODS We reviewed the results of comprehensive epilepsy evaluations performed before the initial and repeated resections in 10 patients with hippocampal sclerosis and 13 with nonspecific pathology. We assessed the Engel classification of seizure outcome 2 yr after repeated resection, evaluated postoperative morbidity, and examined the association of epilepsy and surgical characteristics with seizure freedom before and after reoperation. RESULTS After reoperation, in patients with hippocampal sclerosis, seizure freedom (Engel class I) was achieved in 2 (20%), 1 (10%) experienced surgical complications, and 1 (10%) experienced permanent neurological impairment. Following reoperation in patients with nonspecific pathology, seizure freedom was achieved in 1 (8%), 3 (23%) experienced surgical complications, and 4 (31%) experienced permanent neurological impairment. Epilepsy and surgical characteristics before and after reoperation were not associated with seizure freedom. CONCLUSION Patients with hippocampal sclerosis and nonspecific pathology who underwent a comprehensive initial work-up and failed original temporal lobe resection rarely become seizure-free after repeated ipsitemporal reoperation. Reoperations carry a high risk of surgical complications and neurological impairment. Predictors for seizure freedom could not be defined.

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Antiepileptic drugs management and long-term seizure outcome in post surgical mesial temporal lobe epilepsy with hippocampal sclerosis

Epilepsy Research ◽

10.1016/j.eplepsyres.2012.01.010 ◽

2012 ◽

Vol 100 (1-2) ◽

pp. 55-58 ◽

Cited By ~ 10

Author(s):

José Pimentel ◽

Ana Rita Peralta ◽

Alexandre Campos ◽

Carla Bentes ◽

António G. Ferreira

Keyword(s):

Temporal Lobe Epilepsy ◽

Antiepileptic Drugs ◽

Temporal Lobe ◽

Hippocampal Sclerosis ◽

Mesial Temporal Lobe Epilepsy ◽

Seizure Outcome ◽

Mesial Temporal Lobe

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Memory outcome after temporal lobe epilepsy surgery: corticoamygdalohippocampectomy versus selective amygdalohippocampectomy

Journal of Neurosurgery ◽

10.3171/2009.10.jns09677 ◽

2010 ◽

Vol 113 (6) ◽

pp. 1164-1175 ◽

Cited By ~ 54

Author(s):

Taner Tanriverdi ◽

Roy William Roland Dudley ◽

Alya Hasan ◽

Ahmed Al Jishi ◽

Qasim Al Hinai ◽

...

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Verbal Memory ◽

Hippocampal Sclerosis ◽

Surgical Approaches ◽

Seizure Outcome ◽

Nonverbal Memory ◽

Selective Amygdalohippocampectomy ◽

Significant Difference

Object The aim of this study was to compare IQ and memory outcomes at the 1-year follow-up in patients with medically refractory mesial temporal lobe epilepsy (MTLE) due to hippocampal sclerosis. All patients were treated using a corticoamygdalohippocampectomy (CAH) or a selective amygdalohippocampectomy (SelAH). Methods The data of 256 patients who underwent surgery for MTLE were retrospectively evaluated. One hundred twenty-three patients underwent a CAH (63 [right side] and 60 [left side]), and 133 underwent an SelAH (61 [right side] and 72 [left side]). A comprehensive neuropsychological test battery was assessed before and 1 year after surgery, and the results were compared between the surgical procedures. Furthermore, seizure outcome was compared using the Engel classification scheme. Results At 1-year follow-up, there was no statistically significant difference between the surgical approaches with respect to seizure outcome. Overall, IQ scores showed improvement, but verbal IQ decreased after left SelAH. Verbal memory impairment was seen after left-sided resections especially in cases of SelAH, and nonverbal memory decreased after right-sided resection, especially for CAH. Left-sided resections produced some improvement in nonverbal memory. Older age at surgery, longer duration of seizures, greater seizure frequency before surgery, and poor seizure control after surgery were associated with poorer memory. Conclusions Both CAH and SelAH can lead to several cognitive impairments depending on the side of the surgery. The authors suggest that the optimal type of surgical approach should be decided on a case-by-case basis.

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Multiple hippocampal transections for refractory pediatric mesial temporal lobe epilepsy: seizure and neuropsychological outcomes

Journal of Neurosurgery Pediatrics ◽

10.3171/2020.4.peds19760 ◽

2020 ◽

Vol 26 (4) ◽

pp. 379-388

Author(s):

Ahmad Marashly ◽

Jennifer Koop ◽

Michelle Loman ◽

Irene Kim ◽

Mohit Maheshwari ◽

...

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Verbal Memory ◽

Focal Epilepsy ◽

Hippocampal Sclerosis ◽

Neuropsychological Functioning ◽

Memory Function ◽

Seizure Outcome ◽

Epileptogenic Zone ◽

Seizure Propagation

OBJECTIVETemporal lobe epilepsy (TLE) is the most common focal epilepsy across adult and pediatric age groups. It is also the most amenable to surgery, with excellent long-term seizure outcome. Most TLE cases have an epileptogenic zone in the mesial temporal structures, namely the hippocampus. Resecting the dominant hippocampus has been shown to be associated with significant verbal memory deficits, especially in patients with intact verbal memory scores presurgically. Multiple hippocampal transection (MHT) is a relatively new surgical technique designed to interrupt the longitudinal hippocampal circuitry involved in seizure propagation yet preserve the circular fibers involved in memory function. This technique has been used to treat mesial TLE in both dominant- and nondominant-hemisphere cases, almost exclusively in adults. It has been applied to normal and sclerotic hippocampi.METHODSIn this study, information on 3 pediatric patients who underwent MHT for mesial TLE at Children’s Wisconsin between 2017 and 2018 is included. Clinical, electroencephalographic, and neuropsychological features and outcomes are described in detail.RESULTSMRI revealed a tumor in the amygdala with a normal hippocampus in 1 patient and hippocampal sclerosis in 2 patients. All patients underwent stereoelectroencephalography confirming the involvement of the hippocampus in seizure onset. MHTs were completed under intraoperative monitoring, with amygdala and temporal tip resection in all patients due to early spread to these regions. All patients had excellent seizure outcomes at 1 year, and 2 of the 3 patients remain seizure free at last follow-up (range 20–36 months), all with stable or improved neuropsychological profiles, including verbal memory.CONCLUSIONSMHT is a relatively new surgical procedure designed to preserve essential memory circuitry while disrupting seizure propagation pathways in the hippocampus. A growing body of literature shows good seizure and neuropsychological results, but mainly in adults. This is the first series of MHTs used exclusively in children at one medical center, showcasing excellent seizure control and preservation of neuropsychological functioning. One of the patients is also the first described to have MHT in the setting of an amygdalar tumor abutting the hippocampus, further expanding the pathological setting in which MHT can be used effectively.

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HIPPOCAMPAL INTERNAL ARCHITECTURE AND POSTOPERATIVE OUTCOME IN TEMPORAL LOBE EPILEPSY

Journal of Neurology Neurosurgery & Psychiatry ◽

10.1136/jnnp-2015-312379.56 ◽

2015 ◽

Vol 86 (11) ◽

pp. e4.147-e4

Author(s):

Samia Elkommos ◽

Bernd Weber ◽

Pitt Niehusmann ◽

Elisa Volmering ◽

Mark Richardson ◽

...

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Hippocampal Sclerosis ◽

Postoperative Outcome ◽

Mesial Temporal Lobe Epilepsy ◽

University Hospital ◽

Seizure Outcome ◽

Postoperative Seizure ◽

The Relationship ◽

Internal Architecture

IntroductionIt is unknown why over one-third of patients with mesial temporal lobe epilepsy (mTLE) and hippocampal sclerosis (HS) continue to experience seizures despite temporal lobe surgery. We investigated the relationship between hippocampal internal architecture (HIA) on preoperative MRI, and postoperative seizure outcome in patients with refractory mTLE and HS.MethodsHIA was assessed on preoperative T2-STIR MR images using a published scoring system1 for 79 patients undergoing evaluation at University Hospital Bonn, Germany. Patients underwent amygdalohippocampectomy and received postoperative outcome assessment using the International League Against Epilepsy (ILAE) classification. Hippocampal volumes were obtained using 3D T1-weighted images. Quantitative histopathological assessment was performed on resected hippocampal specimens.ResultsNo significant differences in ipsilateral or contralateral HIA ratings, or HIA score asymmetry, were found between patients rendered seizure free (ILAE I) compared to those continuing to experience postoperative seizures (ILAE II-VI). HIA significantly correlated with neuronal density in CA3 and CA4 in the pathologic hippocampus, and hippocampal volumes bilaterally. There was no significant correlation between HIA and clinical variables.ConclusionAlthough valuable in determining seizure laterality, HIA does not predict postoperative outcome.AcknowledgementsThis work was supported by a UK MRC grant awarded to SSK (Grant Number: MR/K023152/1). References:1Ver Hoef 2013

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Faculty Opinions recommendation of Optimized SEEG-guided radiofrequency thermocoagulation for mesial temporal lobe epilepsy with hippocampal sclerosis.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.736604573.793566615 ◽

2019 ◽

Author(s):

John Paul Leach

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Hippocampal Sclerosis ◽

Mesial Temporal Lobe Epilepsy ◽

Radiofrequency Thermocoagulation ◽

Mesial Temporal Lobe

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Synaptic Reshaping and Neuronal Outcomes in the Temporal Lobe Epilepsy

International Journal of Molecular Sciences ◽

10.3390/ijms22083860 ◽

2021 ◽

Vol 22 (8) ◽

pp. 3860

Author(s):

Elisa Ren ◽

Giulia Curia

Keyword(s):

Animal Models ◽

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Current Knowledge ◽

Focal Epilepsy ◽

Ex Vivo ◽

Hippocampal Sclerosis ◽

Control Group ◽

Epileptogenic Zone ◽

Epileptiform Discharges

Temporal lobe epilepsy (TLE) is one of the most common types of focal epilepsy, characterized by recurrent spontaneous seizures originating in the temporal lobe(s), with mesial TLE (mTLE) as the worst form of TLE, often associated with hippocampal sclerosis. Abnormal epileptiform discharges are the result, among others, of altered cell-to-cell communication in both chemical and electrical transmissions. Current knowledge about the neurobiology of TLE in human patients emerges from pathological studies of biopsy specimens isolated from the epileptogenic zone or, in a few more recent investigations, from living subjects using positron emission tomography (PET). To overcome limitations related to the use of human tissue, animal models are of great help as they allow the selection of homogeneous samples still presenting a more various scenario of the epileptic syndrome, the presence of a comparable control group, and the availability of a greater amount of tissue for in vitro/ex vivo investigations. This review provides an overview of the structural and functional alterations of synaptic connections in the brain of TLE/mTLE patients and animal models.

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