The predictive value of interictal scalp EEG findings in aiding the detection of malformations of cortical development in temporal lobe epilepsy and impact on surgical planning

Background: Complete resection of focal malformations of cortical development (MCD) has been recognized as crucial for the success of epilepsy surgery. However, many of these lesions escape detection using even state-of-the-art epilepsy protocol MRI imaging. This study evaluates the concurrence of radiographic and histopathologic findings of MCD in patients with refractory temporal lobe epilepsy (TLE) and defines the predictive value of EEG findings in the detection of MCD. Materials and Methods: Pre-operative MRI, scalp VEEG, and post-operative surgical pathology reports from 34 consecutive patients treated for refractory TLE by surgical resection over a ten year period were included in analysis. Radiographic findings of MCD were correlated with histopathologic findings of MCD and compared against pre-operative interictal scalp EEG findings. Results: 66.7% of focal cortical dysplasias (FCD) identified on pathology and all cases of mild MCD (mMCD) were missed on pre-operative MRI. The description of a rhythmic or continuous interictal abnormality on pre-operative VEEG corresponds to a sensitivity of 73.1% and a specificity of 62.5% in detecting either FCD or mMCD. Of the patients who had a radiographically occult FCD, 80% had either a continuous or rhythmic interictal abnormality described in the interpretation of their pre-operative VEEG. Conclusion: This study highlights the high prevalence of MCDs in refractory TLE and the high rate of missed MCDs on pre-operative MRI. Findings here suggest that pre-operative scalp EEG may be able to provide additional information in the pre-operative detection of MCDs and therefore inform surgical decision making.

Download Full-text

The Predictive Value of Interictal Scalp EEG Findings in Aiding the Detection of Malformations of Cortical Development in Temporal Lobe Epilepsy

Neurosurgery ◽

10.1093/neuros/nyz310_363 ◽

2019 ◽

Vol 66 (Supplement_1) ◽

Author(s):

Jeffrey W Fuchs ◽

Nathan A Shlobin ◽

Benjamin Hopkins ◽

Zehra Husain ◽

Michael Cloney ◽

...

Keyword(s):

Minimally Invasive ◽

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Predictive Value ◽

Cortical Development ◽

Malformations Of Cortical Development ◽

Radiographic Findings ◽

Scalp Eeg ◽

Minimally Invasive Surgical ◽

Histopathologic Findings

Abstract INTRODUCTION With the advent of minimally invasive surgical approaches for medically refractory epilepsy, we now have the ability to target specific epileptogenic foci with great precision. Previous studies have recognized the importance of complete resection of malformations of cortical development (MCD) in the success of epilepsy surgery. However, many of these lesions escape detection using standard epilepsy protocol MR imaging. This study seeks to evaluate the concurrence of radiographic and histopathologic findings of MCD in patients with refractory temporal lobe epilepsy (TLE) and describe the predictive value of interictal scalp EEG findings in the detection of MCD in an effort to inform surgical decision-making processes. METHODS We retrospectively identified 34 patients who underwent surgical resection for treatment of medically refractory TLE over a 10 yr period at Northwestern University. Preoperative MRI reports, VEEG reports, and postoperative surgical pathology reports were used to correlate radiographic findings of MCD with histopathologic findings of MCD and identify the predictive value of scalp video EEG (VEEG) abnormalities in the detection of MCD. RESULTS We found that 66.7% of focal cortical dysplasias (FCD) identified on pathology and all cases of histopathologically confirmed mild MCD were missed on preoperative MRI. The finding of a rhythmic or continuous interictal abnormality on preoperative VEEG corresponded to a sensitivity of 73.1% and a specificity of 62.5% in detecting either FCD or mild MCD. Of the patients who had a missed FCD on MRI, 80% had continuous or rhythmic interictal abnormalities on EEG. CONCLUSION MCDs are highly prevalent in medically refractory TLE and many of these MCDs are missed on preoperative MRI. The presence of a continuous and/or rhythmic interictal abnormality on scalp VEEG is suggestive of underlying MCD. The presence of one or both of these interictal findings may support the value of performing an intracranial EEG procedure prior to employing an ultraprecise minimally invasive surgical treatment option such as laser ablation.

Download Full-text

Cortical curvature analysis in MRI-negative temporal lobe epilepsy: A surrogate marker for malformations of cortical development

Epilepsia ◽

10.1111/j.1528-1167.2010.02895.x ◽

2010 ◽

Vol 52 (1) ◽

pp. 28-34 ◽

Cited By ~ 7

Author(s):

Lisa Ronan ◽

Cathy Scanlon ◽

Kevin Murphy ◽

Sinead Maguire ◽

Norman Delanty ◽

...

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Cortical Development ◽

Surrogate Marker ◽

Malformations Of Cortical Development ◽

Curvature Analysis

Download Full-text

Features of scalp EEG in unilateral mesial temporal lobe epilepsy due to hippocampal sclerosis: Determining factors and predictive value for epilepsy surgery

Clinical Neurophysiology ◽

10.1016/j.clinph.2015.06.035 ◽

2016 ◽

Vol 127 (2) ◽

pp. 1081-1087 ◽

Cited By ~ 8

Author(s):

Michael P. Malter ◽

Christina Bahrenberg ◽

Pitt Niehusmann ◽

Christian E. Elger ◽

Rainer Surges

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Epilepsy Surgery ◽

Predictive Value ◽

Hippocampal Sclerosis ◽

Mesial Temporal Lobe Epilepsy ◽

Scalp Eeg ◽

Determining Factors ◽

Mesial Temporal Lobe

Download Full-text

Ictal scalp EEG in temporal lobe epilepsy with unitemporal versus bitemporal interictal epileptiform discharges

Neurology ◽

10.1212/wnl.45.5.889 ◽

1995 ◽

Vol 45 (5) ◽

pp. 889-896 ◽

Cited By ~ 102

Author(s):

B. J. Steinhoff ◽

N. K. So ◽

S. Lim ◽

H. O. Luders

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Scalp Eeg ◽

Epileptiform Discharges ◽

Interictal Epileptiform Discharges

Download Full-text

Localization of epileptogenic zone in temporal lobe epilepsy by ictal scalp EEG

Seizure ◽

10.1053/seiz.2001.0603 ◽

2002 ◽

Vol 11 (3) ◽

pp. 163-168 ◽

Cited By ~ 14

Author(s):

Yuzo Sakai ◽

Hiromi Nagano ◽

Ayumi Sakata ◽

Sachiko Kinoshita ◽

Naotaka Hamasaki ◽

...

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Epileptogenic Zone ◽

Scalp Eeg

Download Full-text

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.

Download Full-text

Ictal Scalp EEG Findings in Patients with Mesial Temporal Lobe Epilepsy

Clinical EEG and Neuroscience ◽

10.1177/155005940803900109 ◽

2008 ◽

Vol 39 (1) ◽

pp. 20-27 ◽

Cited By ~ 16

Author(s):

Nese Dericioglu ◽

Serap Saygi

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Mesial Temporal Lobe Epilepsy ◽

Scalp Eeg ◽

Mesial Temporal Lobe

Download Full-text

False lateralization of seizure onset by scalp EEG in neocortical temporal lobe epilepsy

Seizure ◽

10.1016/j.seizure.2011.01.019 ◽

2011 ◽

Vol 20 (6) ◽

pp. 494-499 ◽

Cited By ~ 9

Author(s):

Bola Adamolekun ◽

Pegah Afra ◽

F.A. Boop

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Seizure Onset ◽

Scalp Eeg

Download Full-text

Surgical Outcomes and EEG Prognostic Factors After Stereotactic Laser Amygdalohippocampectomy for Mesial Temporal Lobe Epilepsy

Frontiers in Neurology ◽

10.3389/fneur.2021.654668 ◽

2021 ◽

Vol 12 ◽

Author(s):

Shasha Wu ◽

Naoum P. Issa ◽

Maureen Lacy ◽

David Satzer ◽

Sandra L. Rose ◽

...

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Surgical Outcomes ◽

Mesial Temporal Lobe Epilepsy ◽

Seizure Freedom ◽

Seizure Recurrence ◽

Factors Associated ◽

Scalp Eeg ◽

Mesial Temporal Lobe

Objective: To assess the seizure outcomes of stereotactic laser amygdalohippocampectomy (SLAH) in consecutive patients with mesial temporal lobe epilepsy (mTLE) in a single center and identify scalp EEG and imaging factors in the presurgical evaluation that correlate with post-surgical seizure recurrence.Methods: We retrospectively reviewed the medical and EEG records of 30 patients with drug-resistant mTLE who underwent SLAH and had at least 1 year of follow-up. Surgical outcomes were classified using the Engel scale. Univariate hazard ratios were used to evaluate the risk factors associated with seizure recurrence after SLAH.Results: The overall Engel class I outcome after SLAH was 13/30 (43%), with a mean postoperative follow-up of 48.9 ± 17.6 months. Scalp EEG findings of interictal regional slow activity (IRSA) on the side of surgery (HR = 4.05, p = 0.005) and non-lateralizing or contra-lateralizing seizure onset (HR = 4.31, p = 0.006) were negatively correlated with postsurgical seizure freedom. Scalp EEG with either one of the above features strongly predicted seizure recurrence after surgery (HR = 7.13, p < 0.001) with 100% sensitivity and 71% specificity.Significance: Understanding the factors associated with good or poor surgical outcomes can help choose the best candidates for SLAH. Of the variables assessed, scalp EEG findings were the most clearly associated with seizure outcomes after SLAH.

Download Full-text