Impact of mesial temporal lobe resection on brain structure in medically refractory epilepsy

OBJECTIVERecent trials for temporal lobe epilepsy (TLE) highlight the challenges of investigating surgical outcomes using randomized controlled trials (RCTs). Although several reviews have examined seizure-freedom outcomes from existing data, there is a need for an overall seizure-freedom rate estimated from level I data as investigators consider other methods besides RCTs to study outcomes related to new surgical interventions.METHODSThe authors performed a systematic review and meta-analysis of the 3 RCTs of TLE in adults and report an overall surgical seizure-freedom rate (Engel class I) composed of level I data. An overall seizure-freedom rate was also collected from level II data (prospective cohort studies) for validation. Eligible studies were identified by filtering a published Cochrane meta-analysis of epilepsy surgery for RCTs and prospective studies, and supplemented by searching indexed terms in MEDLINE (January 1, 2012–April 1, 2018). Retrospective studies were excluded to minimize heterogeneity in patient selection and reporting bias. Data extraction was independently reverified and pooled using a fixed-effects model. The primary outcome was overall seizure freedom following surgery. The historical benchmark was applied in a noninferiority study design to compare its power to a single-study cohort.RESULTSThe overall rate of seizure freedom from level I data was 72.4% (55/76 patients, 3 RCTs), which was nearly identical to the overall seizure-freedom rate of 71.7% (1325/1849 patients, 18 studies) from prospective cohorts (z = 0.134, p = 0.89; z-test). Seizure-freedom rates from level I and II studies were consistent over the years of publication (R2< 0.01, p = 0.73). Surgery resulted in markedly improved seizure-free outcomes compared to medical management (RR 10.82, 95% CI 3.93–29.84, p < 0.01; 2 RCTs). Noninferiority study designs in which the historical benchmark was used had significantly higher power at all difference margins compared to using a single cohort alone (p < 0.001, Bonferroni’s multiple comparison test).CONCLUSIONSThe overall rate of seizure freedom for temporal lobe surgery is approximately 70% for medically refractory epilepsy. The small sample size of the RCT cohort underscores the need to move beyond standard RCTs for epilepsy surgery. This historical seizure-freedom rate may serve as a useful benchmark to guide future study designs for new surgical treatments for refractory TLE.

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Distinguishing the precision of spatial recollection from its success: Evidence from healthy aging and unilateral mesial temporal lobe resection

Neuropsychologia ◽

10.1016/j.neuropsychologia.2018.07.035 ◽

2018 ◽

Vol 119 ◽

pp. 101-106 ◽

Cited By ~ 11

Author(s):

Aneesha S. Nilakantan ◽

Donna J. Bridge ◽

Stephen VanHaerents ◽

Joel L. Voss

Keyword(s):

Temporal Lobe ◽

Healthy Aging ◽

Temporal Lobe Resection ◽

Mesial Temporal Lobe

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Neurocysticercosis and microscopic hippocampal dysplasia in a patient with refractory mesial temporal lobe epilepsy

Arquivos de Neuro-Psiquiatria ◽

10.1590/s0004-282x2006000200026 ◽

2006 ◽

Vol 64 (2a) ◽

pp. 309-313 ◽

Cited By ~ 14

Author(s):

Alexandre Valotta da Silva ◽

Heloise Helena Martins ◽

Carolina Mattos Marques ◽

Elza Marcia Targas Yacubian ◽

Américo Ceiki Sakamoto ◽

...

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Refractory Epilepsy ◽

Hippocampal Formation ◽

Granular Cell ◽

Mesial Temporal Lobe Epilepsy ◽

Epidemiologic Studies ◽

Neuronal Markers ◽

Symptomatic Epilepsy ◽

Mesial Temporal Lobe

Epidemiologic studies suggest that neurocysticercosis (NC) is the main cause of symptomatic epilepsy in developing countries. The association between NC and mesial temporal lobe epilepsy (MTLE) has been reported by several authors. Recent data have shown that the presence of NC does not influence the clinical and pathological profile in MTLE patients and suggest that not all cysticercotic lesions are inevitably epileptogenic. We describe a 50-years-old woman with partial seizures due to NC which evolve to MTLE. The patient was submitted to a corticoamygdalohippocampectomy to treat refractory epilepsy. An immunohistochemical study using neuronal markers was made on hippocampal formation. Besides the typical aspects of Ammon's horn sclerosis (AHS), the microscopic examination demonstrates cellular features of hippocampal malformation including dysmorphic neurons and focal bilamination of granular cell layer. We suggest that, in this case, a developmental disorder lowered the threshold for the NC-induced seizures and contributed to the establishment of refractory epilepsy.

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Reactivation of occult herpes simplex meningoencephalitis after temporal lobe resection for refractory epilepsy – A case report

Seizure ◽

10.1016/j.seizure.2014.01.010 ◽

2014 ◽

Vol 23 (4) ◽

pp. 321-323 ◽

Cited By ~ 5

Author(s):

Einar Osland Vik-Mo ◽

Bård K. Krossnes ◽

Milo Stanisic ◽

Arild Egge ◽

Ellen Holter ◽

...

Keyword(s):

Case Report ◽

Herpes Simplex ◽

Temporal Lobe ◽

Refractory Epilepsy ◽

Temporal Lobe Resection

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Temporal lobe surgery in medically refractory epilepsy: A comparison between populations based on MRI findings

Seizure ◽

10.1016/j.seizure.2013.09.004 ◽

2014 ◽

Vol 23 (1) ◽

pp. 20-24 ◽

Cited By ~ 10

Author(s):

Tsz Lau ◽

Timothy Miller ◽

Travis Klein ◽

Selim R. Benbadis ◽

Fernando L. Vale

Keyword(s):

Temporal Lobe ◽

Refractory Epilepsy ◽

Mri Findings ◽

Medically Refractory Epilepsy

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Case Report: Late-Onset Temporal Lobe Epilepsy Following Subarachnoid Hemorrhage: An Interplay Between Pre-existing Cortical Development Abnormality and Tissue Damage

Frontiers in Neurology ◽

10.3389/fneur.2021.599130 ◽

2021 ◽

Vol 12 ◽

Author(s):

Anna Ikawa ◽

Ayataka Fujimoto ◽

Yoshifumi Arai ◽

Yoshiro Otsuki ◽

Toshiki Nozaki ◽

...

Keyword(s):

Subarachnoid Hemorrhage ◽

Temporal Lobe ◽

Refractory Epilepsy ◽

Late Onset ◽

Focal Cortical Dysplasia ◽

Left Temporal Lobe ◽

Temporal Lobes ◽

Temporal Lobe Resection ◽

Secondary Epilepsy ◽

Hemosiderin Deposits

Epileptogenicity following brain insult depends on various factors including severity of the resulting lesion and extent of brain damage. We report a 54-year-old female patient who developed medically refractory epilepsy resulting from the interplay of pre-existing and post-insult pathologies. She presented with subarachnoid hemorrhage (SAH) due to a ruptured aneurysm and underwent clipping surgery. Seizures started 3 months post-operatively. MRI revealed cerebral ischemia and hemosiderin deposits in the left temporal lobes, and left hippocampal atrophy was suspected. As anti-seizure medications and vagus nerve stimulation failed to control her seizures, she underwent left temporal lobe resection and placement of a ventriculoperitoneal shunt for the post-operative complication of hydrocephalus. She remains seizure-free to date. Neuropathology revealed a previously undiagnosed focal cortical dysplasia (FCD) type 1a. Brain insult likely had a second hit effect in the late onset of epilepsy in this patient with pre-existing mild MCD, in whom secondary epilepsy can be attributed to the interplay of multiple underlying pathologies.

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Role of Electroencephalography in Presurgical Evaluation of Temporal Lobe Epilepsy

Epilepsy Research and Treatment ◽

10.1155/2012/204693 ◽

2012 ◽

Vol 2012 ◽

pp. 1-18 ◽

Cited By ~ 2

Author(s):

Seetharam Raghavendra ◽

Javeria Nooraine ◽

Seyed M. Mirsattari

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Refractory Epilepsy ◽

Therapeutic Option ◽

Presurgical Evaluation ◽

Video Eeg ◽

Medically Refractory Epilepsy

Surgery remains a therapeutic option for patients with medically refractory epilepsy. Comprehensive presurgical evaluation includes electroencephalography (EEG) and video EEG in identifying patients who are likely to benefit from surgery. Here, we discuss in detail the utility of EEG in presurgical evaluation of patients with temporal lobe epilepsy along with illustrative cases.

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Medial Temporal Encephalocele and Medically Intractable Epilepsy: A Tailored Inferior Temporal Lobectomy and Case Report

Operative Neurosurgery ◽

10.1093/ons/opz098 ◽

2019 ◽

Vol 18 (1) ◽

pp. E19-E22 ◽

Cited By ~ 1

Author(s):

Anthony L Mikula ◽

Karim ReFaey ◽

Sanjeet S Grewal ◽

Jeffrey W Britton ◽

Jamie J Van Gompel

Keyword(s):

Case Report ◽

Temporal Lobe ◽

Refractory Epilepsy ◽

Statistical Parametric Mapping ◽

Intractable Epilepsy ◽

Middle Cranial Fossa ◽

Temporal Lobectomy ◽

Seizure Freedom ◽

Temporal Region ◽

Medically Refractory Epilepsy

AbstractBACKGROUND AND IMPORTANCETemporal lobe encephaloceles are increasingly recognized as a potential cause of medically refractory epilepsy and surgical treatment has proven effective. Resection of the encephalocele and associated cortex is often sufficient to provide seizure control. However, it is difficult to determine the extent of adjacent temporal lobe that should be resected. We present a case report and our technique of a tailored inferior temporal pole resection.CLINICAL PRESENTATIONA 32-yr-old man with an 11-yr history of medically refractory epilepsy. Prolonged electroencephalography (EEG) revealed frequent left and rare right frontotemporal sharp waves. Numerous seizures were captured with EEG, all of which originated from the left temporal region. Statistical parametric mapping (SPM) subtraction ictal–interictal SPECT coregistered with magnetic resonance imaging (MRI) (SISCOM) demonstrated ictal hyperperfusion in the anterior left temporal lobe. MRI showed 2 encephaloceles in the left anterior temporal lobe with the accompanying bony defects in the floor of the middle cranial fossa apparent on the computed tomography scan. The patient underwent left temporal craniotomy with intraoperative electrocorticography, resection of the encephaloceles, and a tailored inferior temporal lobectomy (IFTL) and repair of the middle fossa defects. At 7 mo follow up he reported seizure-freedom since surgery.CONCLUSIONResection of temporal encephalocele and adjacent cortex is safe and effective procedure for select patients with medically refractory epilepsy. This video demonstrates our technique which provides a more standardized approach to the resection.

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Impact of focal cortical dysplasia Type IIIa on seizure outcome following anterior mesial temporal lobe resection for the treatment of epilepsy

Journal of Neurosurgery ◽

10.3171/2017.2.jns161295 ◽

2018 ◽

Vol 128 (6) ◽

pp. 1668-1673 ◽

Cited By ~ 6

Author(s):

Lasse Dührsen ◽

Thomas Sauvigny ◽

Patrick M. House ◽

Stefan Stodieck ◽

Brigitte Holst ◽

...

Keyword(s):

Temporal Lobe ◽

Focal Cortical Dysplasia ◽

Cortical Dysplasia ◽

Seizure Outcome ◽

Histopathological Analysis ◽

Type Iiia ◽

Temporal Pole ◽

Temporal Lobe Resection ◽

Mesial Temporal Lobe ◽

The Impact

OBJECTIVETemporal lobe epilepsy (TLE) is the most common type of pharmacoresistant focal epilepsy, for which anterior mesial temporal lobe resection (AMTLR) is a treatment option. Focal cortical dysplasia Type IIIa (FCD IIIa), a developmental lesion resulting from defects in neuronal formation and migration into the temporal pole (FCD I) combined with hippocampal sclerosis (HS), can be a neuropathological finding. In this study, the authors investigate the impact of FCD IIIa on seizure outcome in patients with TLE who underwent AMTLR.METHODSThe authors performed a retrospective analysis of all patients with TLE who underwent AMTLR at their institution between June 2011 and April 2014. Histopathological analysis was used to determine whether patients had HS together with FCD I (FCD IIIa) or HS alone. The groups were compared with regard to age, sex, years of epilepsy, and seizure outcome using the Engel classification.RESULTSA total of 51 patients with TLE underwent AMTLR at the authors’ institution. FCD IIIa was diagnosed in 13 cases. The patients experienced seizures for a mean duration of 31.1 years. The mean length of follow-up after the procedure was 18 months. All patients with FCD IIIa had a favorable seizure outcome (Engel Class I or II) compared with 71% of the patients with no pathological findings in the temporal pole (p < 0.01).CONCLUSIONSPatients with histopathologically proven FCD IIIa had a significantly better seizure outcome after AMTLR than patients with HS alone. Further effort should be made during presurgical evaluation to detect FCD IIIa so that the most suitable resection technique can be chosen and postoperative seizure outcome can be predicted for patient counseling.

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