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Kalss G, Pelliccia V, Zimmermann G, Trinka E, Tassi L. The Fingerprint of Scalp-EEG in Drug-Resistant Frontal Lobe Epilepsies. J Clin Neurophysiol 2024:00004691-990000000-00162. [PMID: 39042052 DOI: 10.1097/wnp.0000000000001106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/24/2024] Open
Abstract
PURPOSE Scalp-EEG incompletely covers the frontal lobe cortex. Underrepresentation of frontobasal or frontomesial structures, fast ictal spreading, and false lateralization impede scalp-EEG interpretation. Hence, we investigated the significance of scalp-EEG in the presurgical workup of frontal lobe epilepsy. METHODS Using descriptive statistical methods and Pearson chi-squared test for group comparisons, we retrospectively investigated postsurgical outcome, interictal epileptiform discharges (iiEDs), and electrographic seizure patterns on scalp-EEG in 81 consecutive patients undergoing resective epilepsy surgery within the margins of the frontal lobe. RESULTS Postoperatively, patients with frontopolar iiEDs (n = 7) or concordant frontopolar iiED focus and seizure-onset (n = 2) were seizure free (n = 7/7, Engel Ia). MRI-positive patients with frontopolar iiEDs or frontopolar seizure-onset (n = 1/8 Engel Id, n = 7/8 Engel Ia) underwent surgery without stereo-EEG. Thirteen of 16 patients with frontolateral (n = 8/10, Engel Ia), or left frontobasal (n = 5/6, Engel Ia) seizure-onset undergoing further stereo-EEG, were seizure-free postoperatively. Seizure-onset prevalent over one electrode (n = 37/44 Engel I, p = 0.02), fast activity (FA)/flattening at seizure-onset (n = 29/33 Engel I, p = 0.02), FA/flattening during the seizure (n = 38/46 Engel I, p = 0.05), or focal rhythmic sharp-/spike-/polyspike-and-slow waves during the seizure (n = 24/31, Engel Ia, p = 0.05) were favorable prognostic markers. Interictal polyspike waves (p = 0.006 for Engel Ia) and interictal paroxysmal FA (p = 0.02 for Engel I) were unfavorable prognostic markers. CONCLUSIONS Frontopolar scalp-EEG findings serve as biomarkers for predicting favorable surgical outcome in lesional frontal lobe epilepsy. Consequently, careful analysis of scalp-EEG assists in bypassing stereo-EEG in these patients.
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Affiliation(s)
- Gudrun Kalss
- Department of Neurology and Centre for Cognitive Neurosciences, Christian Doppler University Hospital, Paracelsus Medical University, Member of the European Reference Network EpiCARE, Salzburg, Austria
| | - Veronica Pelliccia
- "Claudio Munari" Epilepsy Surgery Centre, ASST GOM Niguarda, Milan, Italy
| | - Georg Zimmermann
- Department of Neurology and Centre for Cognitive Neurosciences, Christian Doppler University Hospital, Paracelsus Medical University, Member of the European Reference Network EpiCARE, Salzburg, Austria
- Department of Mathematics, Paris-Lodron-University of Salzburg, Salzburg, Austria
- Team Biostatistics and Big Medical Data, IDA Lab Salzburg, Paracelsus Medical University, Salzburg, Austria; and
| | - Eugen Trinka
- Department of Neurology and Centre for Cognitive Neurosciences, Christian Doppler University Hospital, Paracelsus Medical University, Member of the European Reference Network EpiCARE, Salzburg, Austria
- Neuroscience Institute, Centre for Cognitive Neurosciences, Christian Doppler University Hospital, Paracelsus Medical University, Salzburg, Austria
| | - Laura Tassi
- "Claudio Munari" Epilepsy Surgery Centre, ASST GOM Niguarda, Milan, Italy
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Macdonald-Laurs E, Warren AEL, Francis P, Mandelstam SA, Lee WS, Coleman M, Stephenson SEM, Barton S, D'Arcy C, Lockhart PJ, Leventer RJ, Harvey AS. The clinical, imaging, pathological and genetic landscape of bottom-of-sulcus dysplasia. Brain 2024; 147:1264-1277. [PMID: 37939785 DOI: 10.1093/brain/awad379] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 09/20/2023] [Accepted: 10/22/2023] [Indexed: 11/10/2023] Open
Abstract
Bottom-of-sulcus dysplasia (BOSD) is increasingly recognized as a cause of drug-resistant, surgically-remediable, focal epilepsy, often in seemingly MRI-negative patients. We describe the clinical manifestations, morphological features, localization patterns and genetics of BOSD, with the aims of improving management and understanding pathogenesis. We studied 85 patients with BOSD diagnosed between 2005-2022. Presenting seizure and EEG characteristics, clinical course, genetic findings and treatment response were obtained from medical records. MRI (3 T) and 18F-FDG-PET scans were reviewed systematically for BOSD morphology and metabolism. Histopathological analysis and tissue genetic testing were performed in 64 operated patients. BOSD locations were transposed to common imaging space to study anatomical location, functional network localization and relationship to normal MTOR gene expression. All patients presented with stereotyped focal seizures with rapidly escalating frequency, prompting hospitalization in 48%. Despite 42% patients having seizure remissions, usually with sodium channel blocking medications, most eventually became drug-resistant and underwent surgery (86% seizure-free). Prior developmental delay was uncommon but intellectual, language and executive dysfunction were present in 24%, 48% and 29% when assessed preoperatively, low intellect being associated with greater epilepsy duration. BOSDs were missed on initial MRI in 68%, being ultimately recognized following repeat MRI, 18F-FDG-PET or image postprocessing. MRI features were grey-white junction blurring (100%), cortical thickening (91%), transmantle band (62%), increased cortical T1 signal (46%) and increased subcortical FLAIR signal (26%). BOSD hypometabolism was present on 18F-FDG-PET in 99%. Additional areas of cortical malformation or grey matter heterotopia were present in eight patients. BOSDs predominated in frontal and pericentral cortex and related functional networks, mostly sparing temporal and occipital cortex, and limbic and visual networks. Genetic testing yielded pathogenic mTOR pathway variants in 63% patients, including somatic MTOR variants in 47% operated patients and germline DEPDC5 or NPRL3 variants in 73% patients with familial focal epilepsy. BOSDs tended to occur in regions where the healthy brain normally shows lower MTOR expression, suggesting these regions may be more vulnerable to upregulation of MTOR activity. Consistent with the existing literature, these results highlight (i) clinical features raising suspicion of BOSD; (ii) the role of somatic and germline mTOR pathway variants in patients with sporadic and familial focal epilepsy associated with BOSD; and (iii) the role of 18F-FDG-PET alongside high-field MRI in detecting subtle BOSD. The anatomical and functional distribution of BOSDs likely explain their seizure, EEG and cognitive manifestations and may relate to relative MTOR expression.
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Affiliation(s)
- Emma Macdonald-Laurs
- Department of Neurology, The Royal Children's Hospital, Parkville, Victoria 3052Australia
- Department of Neuroscience, Murdoch Children's Research Institute, Parkville 3052, Australia
- Department of Paediatrics, The University of Melbourne, Parkville 3052, Australia
| | - Aaron E L Warren
- Department of Neuroscience, Murdoch Children's Research Institute, Parkville 3052, Australia
- Department of Medicine (Austin Health), The University of Melbourne, Heidelberg 3084, Australia
| | - Peter Francis
- Department of Medical Imaging, The Royal Children's Hospital, Parkville 3052, Australia
| | - Simone A Mandelstam
- Department of Neuroscience, Murdoch Children's Research Institute, Parkville 3052, Australia
- Department of Paediatrics, The University of Melbourne, Parkville 3052, Australia
- Department of Medical Imaging, The Royal Children's Hospital, Parkville 3052, Australia
| | - Wei Shern Lee
- Department of Paediatrics, The University of Melbourne, Parkville 3052, Australia
- Department of Genomic Medicine, Bruce Lefroy Centre, Murdoch Children's Research Institute, Parkville 3052, Australia
| | - Matthew Coleman
- Department of Paediatrics, The University of Melbourne, Parkville 3052, Australia
- Department of Genomic Medicine, Bruce Lefroy Centre, Murdoch Children's Research Institute, Parkville 3052, Australia
| | - Sarah E M Stephenson
- Department of Paediatrics, The University of Melbourne, Parkville 3052, Australia
- Department of Genomic Medicine, Bruce Lefroy Centre, Murdoch Children's Research Institute, Parkville 3052, Australia
| | - Sarah Barton
- Department of Neurology, The Royal Children's Hospital, Parkville, Victoria 3052Australia
- Department of Neuroscience, Murdoch Children's Research Institute, Parkville 3052, Australia
- Department of Paediatrics, The University of Melbourne, Parkville 3052, Australia
| | - Colleen D'Arcy
- Department of Pathology, The Royal Children's Hospital, Parkville 3052, Australia
| | - Paul J Lockhart
- Department of Paediatrics, The University of Melbourne, Parkville 3052, Australia
- Department of Genomic Medicine, Bruce Lefroy Centre, Murdoch Children's Research Institute, Parkville 3052, Australia
| | - Richard J Leventer
- Department of Neurology, The Royal Children's Hospital, Parkville, Victoria 3052Australia
- Department of Neuroscience, Murdoch Children's Research Institute, Parkville 3052, Australia
- Department of Paediatrics, The University of Melbourne, Parkville 3052, Australia
| | - A Simon Harvey
- Department of Neurology, The Royal Children's Hospital, Parkville, Victoria 3052Australia
- Department of Neuroscience, Murdoch Children's Research Institute, Parkville 3052, Australia
- Department of Paediatrics, The University of Melbourne, Parkville 3052, Australia
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Castillo Rodriguez MDLA, Brandt A, Schulze-Bonhage A. Differentiation of subclinical and clinical electrographic events in long-term electroencephalographic recordings. Epilepsia 2023; 64 Suppl 4:S47-S58. [PMID: 36008142 DOI: 10.1111/epi.17401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 08/22/2022] [Accepted: 08/22/2022] [Indexed: 11/28/2022]
Abstract
OBJECTIVE With the advent of ultra-long-term recordings for monitoring of epilepsies, the interpretation of results of isolated electroencephalographic (EEG) recordings covering only selected brain regions attracts considerable interest. In this context, the question arises of whether detected ictal EEG patterns correspond to clinically manifest seizures or rather to purely electrographic events, that is, subclinical events. METHODS EEG patterns from 268 clinical seizures and 252 subclinical electrographic events from 50 patients undergoing video-EEG monitoring were analyzed. Features extracted included predominant frequency band, duration, association with rhythmic muscle artifacts, spatial extent, and propagation patterns. Classification using logistic regression was performed based on data from the whole dataset of 10-20 system EEG recordings and from a subset of two temporal electrode contacts. RESULTS Correct separation of clinically manifest and purely electrographic events based on 10-20 system EEG recordings was possible in up to 83.8% of events, depending on the combination of features included. Correct classification based on two-channel recordings was only slightly inferior, achieving 78.6% accuracy; 74.4% and 74.8%, respectively, of events could be correctly classified when using duration alone with either electrode set, although classification accuracies were lower for some subgroups of seizures, particularly focal aware seizures and epileptic arousals. SIGNIFICANCE A correct classification of subclinical versus clinical EEG events was possible in 74%-83% of events based on full EEG recordings, and in 74%-78% when considering only a subset of two electrodes, matching the channel number available from new implantable diagnostic devices. This is a promising outcome, suggesting that ultra-long-term low-channel EEG recordings may provide sufficient information for objective seizure diaries. Intraindividual optimization using high numbers of ictal events may further improve separation, provided that supervised learning with external validation is feasible.
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Affiliation(s)
| | - Armin Brandt
- Epilepsy Center, University Medical Center Freiburg, Freiburg, Germany
| | - Andreas Schulze-Bonhage
- Epilepsy Center, University Medical Center Freiburg, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine, Freiburg, Germany
- European Reference Network EpiCare, Freiburg, Germany
- NeuroModulBasic, Freiburg, Germany
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Yeh WC, Hsu CY, Li KY, Chien CF, Huang LC, Yang YH. Association between subclinical epileptiform discharge and the behavioral and psychological symptoms in patients with Alzheimer's dementia. Int J Geriatr Psychiatry 2023; 38:e6013. [PMID: 37817385 DOI: 10.1002/gps.6013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 09/25/2023] [Indexed: 10/12/2023]
Abstract
OBJECTIVES Behavioral and psychological symptoms of dementia (BPSD) are highly prevalent in patients with Alzheimer's disease (AD), causing burdens on caregivers. Behavioral and psychological symptoms of dementia and subclinical epileptiform discharge (SED) increased with the disease course of AD. However, the interaction between them was still unknown. The present study aimed to evaluate the associations between SED and BPSD. METHODS/DESIGN Patients with AD from Kaohsiung Municipal Ta-tung Hospital were included in this study. International 10-20 system scalp electroencephalography (EEG) for 13 min was performed to detect SED. Behavioral and psychological symptoms of dementia was assessed by neuropsychiatric inventory (NPI) questionnaires. The occurrence of BPSD subsyndromes was compared between patients with and without SED. RESULTS Two hundred sixty-three adult patients qualified for the inclusion criteria and were enrolled in this study. The mean age of patients was 80.2 years, and approximately 62% were women. 17.1% of patients showed SED on EEG. Apathy was the most commonly reported BPSD subsyndrome in this cohort. There was no significant difference in the prevalence of BPSD between patients with and without SED. (75.6% vs. 67.4%, p = 0.2806). However, the NPI score of irritability subsyndrome was significantly higher in the SED (+) group (2.6 ± 3.7 vs. 1.2 ± 2.7, p = 0.0028). In addition, subclinical epileptiform discharge in the frontal lobe was associated with a considerably higher occurrence of hyperactivity subsyndrome, including irritability. CONCLUSIONS SED may not be a direct cause of BPSD, but the presence of SED may affect the manifestation of BPSD.
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Affiliation(s)
- Wei-Chih Yeh
- Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Neurology, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chung-Yao Hsu
- Department of Neurology, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Neurology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
| | - Kuan-Ying Li
- Department of Neurology, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
- Neuroscience Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Ching-Fang Chien
- Department of Neurology, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
- Neuroscience Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Ling-Chun Huang
- Department of Neurology, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
- Neuroscience Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yuan-Han Yang
- Department of Neurology, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
- Neuroscience Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan
- Post-baccalaureate Medicine, Kaohsiung Medical, University, Kaohsiung, Taiwan
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