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Janca R, Jezdik P, Ebel M, Kalina A, Kudr M, Jahodova A, Krysl D, Mackova K, Straka B, Marusic P, Krsek P. Distinct patterns of interictal intracranial EEG in focal cortical dysplasia type I and II. Clin Neurophysiol 2023; 151:10-17. [PMID: 37121217 DOI: 10.1016/j.clinph.2023.03.360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 03/13/2023] [Accepted: 03/21/2023] [Indexed: 05/02/2023]
Abstract
OBJECTIVE Focal cortical dysplasia (FCD) is the most common malformation causing refractory focal epilepsy. Surgical removal of the entire dysplastic cortex is crucial for achieving a seizure-free outcome. Precise presurgical distinctions between FCD types by neuroimaging are difficult, mainly in patients with normal magnetic resonance imaging findings. However, the FCD type is important for planning the extent of surgical approach and counselling. METHODS This study included patients with focal drug-resistant epilepsy and definite histopathological FCD type I or II diagnoses who underwent intracranial electroencephalography (iEEG). We detected interictal epileptiform discharges (IEDs) and their recruitment into repetitive discharges (RDs) to compare electrophysiological patterns characterizing FCD types. RESULTS Patients with FCD type II had a significantly higher IED rate (p < 0.005), a shorter inter-discharge interval within RD episodes (p < 0.003), sleep influence on decreased RD periodicity (p < 0.036), and longer RD episode duration (p < 0.003) than patients with type I. A Bayesian classifier stratified FCD types with 82% accuracy. CONCLUSION Temporal characteristics of IEDs and RDs reflect the histological findings of FCD subtypes and can differentiate FCD types I and II. SIGNIFICANCE Presurgical prediction of FCD type can help to plan a more tailored surgical approach in patients with normal magnetic resonance findings.
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Affiliation(s)
- Radek Janca
- Faculty of Electrical Engineering, Department of Circuit Theory, Czech Technical University in Prague, Technicka 2, 166 27 Prague, Czech Republic.
| | - Petr Jezdik
- Faculty of Electrical Engineering, Department of Circuit Theory, Czech Technical University in Prague, Technicka 2, 166 27 Prague, Czech Republic
| | - Matyas Ebel
- Department of Paediatric Neurology, Motol Epilepsy Center, Second Faculty of Medicine, Charles University and Motol University Hospital, V Uvalu 84, 15006, Prague, Czech Republic(2)
| | - Adam Kalina
- Department of Neurology, Motol Epilepsy Center, Second Faculty of Medicine, Charles University and Motol University Hospital, V Uvalu 84, 15006 Prague, Czech Republic(2)
| | - Martin Kudr
- Department of Paediatric Neurology, Motol Epilepsy Center, Second Faculty of Medicine, Charles University and Motol University Hospital, V Uvalu 84, 15006, Prague, Czech Republic(2)
| | - Alena Jahodova
- Department of Paediatric Neurology, Motol Epilepsy Center, Second Faculty of Medicine, Charles University and Motol University Hospital, V Uvalu 84, 15006, Prague, Czech Republic(2)
| | - David Krysl
- Department of Neurology, Motol Epilepsy Center, Second Faculty of Medicine, Charles University and Motol University Hospital, V Uvalu 84, 15006 Prague, Czech Republic(2)
| | - Katerina Mackova
- Faculty of Electrical Engineering, Department of Circuit Theory, Czech Technical University in Prague, Technicka 2, 166 27 Prague, Czech Republic
| | - Barbora Straka
- Department of Paediatric Neurology, Motol Epilepsy Center, Second Faculty of Medicine, Charles University and Motol University Hospital, V Uvalu 84, 15006, Prague, Czech Republic(2)
| | - Petr Marusic
- Department of Neurology, Motol Epilepsy Center, Second Faculty of Medicine, Charles University and Motol University Hospital, V Uvalu 84, 15006 Prague, Czech Republic(2)
| | - Pavel Krsek
- Department of Paediatric Neurology, Motol Epilepsy Center, Second Faculty of Medicine, Charles University and Motol University Hospital, V Uvalu 84, 15006, Prague, Czech Republic(2)
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Shakhatreh L, Janmohamed M, Baker AA, Willard A, Laing J, Rychkova M, Chen Z, Kwan P, O'Brien TJ, Perucca P. Interictal and seizure-onset EEG patterns in malformations of cortical development: A systematic review. Neurobiol Dis 2022; 174:105863. [PMID: 36165814 DOI: 10.1016/j.nbd.2022.105863] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 09/07/2022] [Accepted: 09/17/2022] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVES Malformations of cortical development (MCDs) are common causes of drug-resistant epilepsy. The mechanisms underlying the associated epileptogenesis and ictogenesis remain poorly elucidated. EEG can help in understanding these mechanisms. We systematically reviewed studies reporting scalp or intracranial EEG features of MCDs to characterise interictal and seizure-onset EEG patterns across different MCD types. METHODS We conducted a systematic review in accordance with PRISMA guidelines. MEDLINE, PubMed, and Cochrane databases were searched for studies describing interictal and seizure-onset EEG patterns in MCD patients. A classification framework was implemented to group EEG features into 20 predefined patterns, comprising nine interictal (five, scalp EEG; four, intracranial EEG) and 11 seizure-onset (five, scalp EEG; six, intracranial EEG) patterns. Logistic regression was used to estimate the odds ratios (OR) of each seizure-onset pattern being associated with specific MCD types. RESULTS Our search yielded 1682 studies, of which 27 comprising 936 MCD patients were included. Of the nine interictal EEG patterns, five (three, scalp EEG; two, intracranial EEG) were detected in ≥2 MCD types, while four (rhythmic epileptiform discharges type 1 and type 2 on scalp EEG; repetitive bursting spikes and sporadic spikes on intracranial EEG) were seen only in focal cortical dysplasia (FCD). Of the 11 seizure-onset patterns, eight (three, scalp EEG; five, intracranial EEG) were found in ≥2 MCD types, whereas three were observed only in FCD (suppression on scalp EEG; delta brush on intracranial EEG) or tuberous sclerosis complex (TSC; focal fast wave on scalp EEG). Among scalp EEG seizure-onset patterns, paroxysmal fast activity (OR = 0.13; 95% CI: 0.03-0.53; p = 0.024) and repetitive epileptiform discharges (OR = 0.18; 95% CI: 0.05-0.61; p = 0.036) were less likely to occur in TSC than FCD. Among intracranial EEG seizure-onset patterns, low-voltage fast activity was more likely to be detected in heterotopia (OR = 19.3; 95% CI: 6.22-60.1; p < 0.001), polymicrogyria (OR = 6.70; 95% CI: 2.25-20.0; p = 0.004) and TSC (OR = 4.27; 95% CI: 1.88-9.70; p = 0.005) than FCD. SIGNIFICANCE Different MCD types can share similar interictal or seizure-onset EEG patterns, reflecting common underlying biological mechanisms. However, selected EEG patterns appear to point to distinct MCD types, suggesting certain differences in their neuronal networks.
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Affiliation(s)
- Lubna Shakhatreh
- Department of Neuroscience, The Central Clinical School, Monash University, Melbourne, Australia; Department of Neurology, The Royal Melbourne Hospital, Melbourne, Australia; Department of Neurology, Alfred Health, Melbourne, Australia.
| | - Mubeen Janmohamed
- Department of Neuroscience, The Central Clinical School, Monash University, Melbourne, Australia; Department of Neurology, The Royal Melbourne Hospital, Melbourne, Australia; Department of Neurology, Alfred Health, Melbourne, Australia
| | - Ana Antonic Baker
- Department of Neuroscience, The Central Clinical School, Monash University, Melbourne, Australia
| | - Anna Willard
- Department of Neuroscience, The Central Clinical School, Monash University, Melbourne, Australia; Department of Neurology, The Royal Melbourne Hospital, Melbourne, Australia; Department of Neurology, Alfred Health, Melbourne, Australia
| | - Joshua Laing
- Department of Neuroscience, The Central Clinical School, Monash University, Melbourne, Australia; Department of Neurology, Alfred Health, Melbourne, Australia
| | - Maria Rychkova
- Department of Neuroscience, The Central Clinical School, Monash University, Melbourne, Australia; Department of Neurology, The Royal Melbourne Hospital, Melbourne, Australia
| | - Zhibin Chen
- Department of Neuroscience, The Central Clinical School, Monash University, Melbourne, Australia
| | - Patrick Kwan
- Department of Neuroscience, The Central Clinical School, Monash University, Melbourne, Australia; Department of Neurology, The Royal Melbourne Hospital, Melbourne, Australia; Department of Neurology, Alfred Health, Melbourne, Australia; Department of Medicine (The Royal Melbourne Hospital), The University of Melbourne, Melbourne, Australia
| | - Terence J O'Brien
- Department of Neuroscience, The Central Clinical School, Monash University, Melbourne, Australia; Department of Neurology, The Royal Melbourne Hospital, Melbourne, Australia; Department of Neurology, Alfred Health, Melbourne, Australia; Department of Medicine (The Royal Melbourne Hospital), The University of Melbourne, Melbourne, Australia
| | - Piero Perucca
- Department of Neuroscience, The Central Clinical School, Monash University, Melbourne, Australia; Department of Neurology, The Royal Melbourne Hospital, Melbourne, Australia; Department of Neurology, Alfred Health, Melbourne, Australia; Bladin-Berkovic Comprehensive Epilepsy Program, Department of Neurology, Austin Health, Melbourne, Australia; Epilepsy Research Centre, Department of Medicine (Austin Health), The University of Melbourne, Melbourne, Australia
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Sleep and Epilepsy. Neurol Clin 2022; 40:769-783. [DOI: 10.1016/j.ncl.2022.03.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Jin B, Zhang Z, Wang C, Li H, Zhao X, Wang S, Chen C, He C, Zheng Y, Geng Y, Wang S, Chen G, Aung T. Focal thalamocortical circuit abnormalities in sleep related epilepsy caused by focal cortical dysplasia type II. Seizure 2022; 99:153-158. [DOI: 10.1016/j.seizure.2022.05.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 05/23/2022] [Accepted: 05/24/2022] [Indexed: 11/26/2022] Open
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Zhang X, Yang X, Chen B, Shen K, Liu G, Wang Z, Huang K, Zhu G, Wang T, Lv S, Zhang C, Yang H, Hou Z, Liu S. Glucocorticoid receptors participate in epilepsy in FCDII patients and MP model rats: A potential therapeutic target for epilepsy in patients with focal cortical dysplasia II (FCDII). Expert Opin Ther Targets 2022; 26:171-186. [PMID: 35132930 DOI: 10.1080/14728222.2022.2032650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Glucocorticoid receptors (GRs) and mineralocorticoid receptors (MRs) are involved in neuronal excitability, neurogenesis, and neuroinflammation. However, the roles of GRs and MRs in epilepsy in focal cortical dysplasia II (FCDII) have not been reported. RESEARCH DESIGN AND METHODS We evaluated GRs and MRs expression and distribution in FCDII patients and methylazoxymethanol-pilocarpine-induced epilepsy model rats (MP rats), and the effects of a GR agonist on neurons in human FCDII and investigated the electrophysiological properties of cultured neurons and neurons of MP rats after lentivirus-mediated GR knockdown or overexpression and GR agonist or antagonist administration. RESULTS GR expression (not MR) was decreased in specimens from FCDII patients and model rats. GR agonist dexamethasone reduced neuronal excitatory transmission and increased neuronal inhibitory transmission in FCDII. GR knockdown increased the excitability of cultured neurons, and GR overexpression rescued the hyperexcitability of MP-treated neurons. Moreover, dexamethasone decreased neuronal excitability and excitatory transmission in MP rats, while GR antagonist exerted the opposite effects. Dexamethasone reduced the seizure number and duration by approximately 85% and 60% in MP rats within one to two hours. CONCLUSIONS These results suggested that GRs play an important role in epilepsy in FCDII and GR activation may have protective and antiepileptic effects in FCDII.
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Affiliation(s)
- Xiaoqing Zhang
- National Comprehensive Epilepsy Center, Department of Neurosurgery, Second Affiliated Hospital, Army Medical University, Chongqing, China
| | - Xiaolin Yang
- National Comprehensive Epilepsy Center, Department of Neurosurgery, Second Affiliated Hospital, Army Medical University, Chongqing, China
| | - Bing Chen
- Department of Neurosurgery, Nanchong Central Hospital, Nanchong, Sichuan, China
| | - Kaifeng Shen
- National Comprehensive Epilepsy Center, Department of Neurosurgery, Second Affiliated Hospital, Army Medical University, Chongqing, China
| | - Guolong Liu
- National Comprehensive Epilepsy Center, Department of Neurosurgery, Second Affiliated Hospital, Army Medical University, Chongqing, China
| | - Zhongke Wang
- Department of Neurosurgery, Armed police Hospital, Chongqing, China
| | - Kaixuan Huang
- National Comprehensive Epilepsy Center, Department of Neurosurgery, Second Affiliated Hospital, Army Medical University, Chongqing, China
| | - Gang Zhu
- National Comprehensive Epilepsy Center, Department of Neurosurgery, Second Affiliated Hospital, Army Medical University, Chongqing, China
| | - Tingting Wang
- National Comprehensive Epilepsy Center, Department of Neurosurgery, Second Affiliated Hospital, Army Medical University, Chongqing, China
| | - Shengqing Lv
- National Comprehensive Epilepsy Center, Department of Neurosurgery, Second Affiliated Hospital, Army Medical University, Chongqing, China
| | - Chunqing Zhang
- National Comprehensive Epilepsy Center, Department of Neurosurgery, Second Affiliated Hospital, Army Medical University, Chongqing, China
| | - Hui Yang
- National Comprehensive Epilepsy Center, Department of Neurosurgery, Second Affiliated Hospital, Army Medical University, Chongqing, China
| | - Zhi Hou
- National Comprehensive Epilepsy Center, Department of Neurosurgery, Second Affiliated Hospital, Army Medical University, Chongqing, China
| | - Shiyong Liu
- National Comprehensive Epilepsy Center, Department of Neurosurgery, Second Affiliated Hospital, Army Medical University, Chongqing, China
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Wang Y, He C, Chen C, Wang Z, Ming W, Qiu J, Ying M, Chen W, Jin B, Li H, Ding M, Wang S. Focal cortical dysplasia links to sleep-related epilepsy in symptomatic focal epilepsy. Epilepsy Behav 2022; 127:108507. [PMID: 34968776 DOI: 10.1016/j.yebeh.2021.108507] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 12/11/2021] [Accepted: 12/12/2021] [Indexed: 01/30/2023]
Abstract
OBJECTIVE In sleep-related epilepsy (SRE), epileptic seizures predominantly occur during sleep, but the clinical characteristics of SRE remain elusive. We aimed to identify the clinical features associated with the occurrence of SRE in a large cohort of symptomatic focal epilepsy. METHODS We retrospectively included patients with four etiologies, including focal cortical dysplasia (FCD), low-grade tumors (LGT), temporal lobe epilepsy with hippocampal sclerosis (TLE-HS), and encephalomalacia. SRE was defined as more than 70% of seizures occurring during sleep according to the seizure diary. The correlation between SRE and other clinical variables, such as etiology of epilepsy, pharmacoresistance, seizure frequency, history of bilateral tonic-clonic seizures, and seizure localization was analyzed. RESULTS A total of 376 patients were included. Among them 95 (25.3%) were classified as SRE and the other 281(74.7%) as non-SRE. The incidence of SRE was 53.5% in the FCD group, which was significantly higher than the other three groups (LGT: 19.0%; TLE-HS: 9.9%; encephalomalacia: 16.7%; P < 0.001). The etiology of FCD (p < 0.001) was significantly associated with SRE (OR: 9.71, 95% CI: 3.35-28.14) as an independent risk factor. In addition, small lesion size (p = 0.009) of FCD further increased the risk of SRE (OR: 3.18, 95% CI: 1.33-7.62) in the FCD group. SIGNIFICANCE Our data highlight that FCD markedly increased the risk of sleep-related epilepsy independently of seizure localization. A small lesion of FCD further increased the risk of sleep-related epilepsy by 2.18 times in the FCD group.
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Affiliation(s)
- Yunling Wang
- Department of Neurology, Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China; Department of Neurology, Tongde Hospital of Zhejiang Province, Hangzhou, China
| | - Chenmin He
- Department of Neurology, Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Cong Chen
- Department of Neurology, Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Zhongjin Wang
- Department of Neurology, Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Wenjie Ming
- Department of Neurology, Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Jingjing Qiu
- Department of Neurology, Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Meiping Ying
- Department of Neurology, Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Wei Chen
- Department of Neurology, Linhai Second People's Hospital, Taizhou, China
| | - Bo Jin
- Department of Neurology, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, China
| | - Hong Li
- Department of Radiology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Meiping Ding
- Department of Neurology, Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Shuang Wang
- Department of Neurology, Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
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Nguyen-Michel VH, Herlin B, Gales A, Vaz S, Levy P, Dupont S, Adam C, Navarro V, Frazzini V. Sleep scoring based on video-electroencephalography monitoring in an Epileptology Unit: Comparison with polysomnography. J Sleep Res 2021; 30:e13332. [PMID: 33825252 DOI: 10.1111/jsr.13332] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 01/25/2021] [Accepted: 02/19/2021] [Indexed: 11/30/2022]
Abstract
The aim of the study was to compare the performance of video- electroencephalography (EEG) monitoring and standard polysomnography for sleep scoring in an Epileptology Unit. We calculated the level of agreement between two methods of sleep scoring, using either 27-electrode video-EEG or polysomnography for 1 night in 22 patients admitted to our Epileptology Unit. Independent experts manually scored sleep using the American Academy of Sleep Medicine 2017 guidelines. We evaluated the number of sleep cycles and their distribution on hypnogram, total sleep time, sleep efficiency, sleep and rapid eye movement sleep-onset latency, wake after sleep-onset, and sleep stages. We then extracted sub-samples of recordings to examine the agreement in microarousal and rapid eye movement scoring. We used Bland and Altman plots and Cohen's kappa test to measure agreement. Bland and Altman plots showed at least 95% agreement for all studied sleep parameters with the exception of wake after sleep onset, where there was an 11 min difference. Cohen's kappa test showed an agreement for the recognition of microarousal (0.89) and of rapid eye movements (0.96) in sub-samples. Video-EEG represents an acceptable alternative tool for sleep architecture study in patients admitted to an Epileptology Unit.
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Affiliation(s)
- Vi-Huong Nguyen-Michel
- Department of Clinical Neurophysiology, AP-HP, Hôpital Pitié-Salpêtrière-Charles Foix, Paris, France.,Epileptology Unit, DMU Neuroscience 6, AP-HP, Hôpital Pitié-Salpêtrière-Charles Foix, Paris, France
| | - Bastien Herlin
- Epileptology Unit, DMU Neuroscience 6, AP-HP, Hôpital Pitié-Salpêtrière-Charles Foix, Paris, France.,Rehabilitation Unit, AP-HP, Hôpital Pitié-Salpêtrière-Charles Foix, Paris, France.,Sorbonne Université, Paris, France
| | - Ana Gales
- Epileptology Unit, DMU Neuroscience 6, AP-HP, Hôpital Pitié-Salpêtrière-Charles Foix, Paris, France.,Sleep Disorder Unit, AP-HP, Hôpital Pitié-Salpêtrière-Charles Foix, Paris, France
| | - Soraia Vaz
- Epileptology Unit, DMU Neuroscience 6, AP-HP, Hôpital Pitié-Salpêtrière-Charles Foix, Paris, France
| | - Pierre Levy
- Public Health Department and Clinical Neurophysiology Unit, AP-HP, Hôpital Tenon, Paris, France
| | - Sophie Dupont
- Epileptology Unit, DMU Neuroscience 6, AP-HP, Hôpital Pitié-Salpêtrière-Charles Foix, Paris, France.,Rehabilitation Unit, AP-HP, Hôpital Pitié-Salpêtrière-Charles Foix, Paris, France.,Sorbonne Université, Paris, France
| | - Claude Adam
- Epileptology Unit, DMU Neuroscience 6, AP-HP, Hôpital Pitié-Salpêtrière-Charles Foix, Paris, France
| | - Vincent Navarro
- Department of Clinical Neurophysiology, AP-HP, Hôpital Pitié-Salpêtrière-Charles Foix, Paris, France.,Epileptology Unit, DMU Neuroscience 6, AP-HP, Hôpital Pitié-Salpêtrière-Charles Foix, Paris, France.,Sorbonne Université, Paris, France.,Institut du Cerveau-Paris Brain Institute-ICM, Inserm, CNRS, Paris, France
| | - Valerio Frazzini
- Department of Clinical Neurophysiology, AP-HP, Hôpital Pitié-Salpêtrière-Charles Foix, Paris, France.,Epileptology Unit, DMU Neuroscience 6, AP-HP, Hôpital Pitié-Salpêtrière-Charles Foix, Paris, France.,Institut du Cerveau-Paris Brain Institute-ICM, Inserm, CNRS, Paris, France
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Grigg-Damberger M, Foldvary-Schaefer N. Bidirectional relationships of sleep and epilepsy in adults with epilepsy. Epilepsy Behav 2021; 116:107735. [PMID: 33561767 DOI: 10.1016/j.yebeh.2020.107735] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 11/15/2020] [Accepted: 12/19/2020] [Indexed: 12/14/2022]
Abstract
This targeted review addresses the best accepted and most intriguing recent observations on the complex relationships between sleep and epilepsy. Ten to 15% of all epilepsies are sleep-related. Included in these is sleep-related hypermotor epilepsy, renamed from nocturnal frontal lobe epilepsy by a 2016 consensus conference since 30% of cases are extra-frontal, seizures are related to sleep rather than clock time, and the predominant semiology is hypermotor. Stereo-EEG is providing crucial insights into network activation in sleep-related epilepsies and definition of the epileptogenic zone. Pathologic high-frequency oscillations, a promising biomarker for identifying the epileptogenic zone, are most frequent in NREM sleep, lowest in wakefulness and REM sleep, similar to interictal epileptiform discharges (IEDs). Most sleep-related seizures are followed by awakening or arousal and IEDs cause arousals and increase after arousals, likely contributing to sleep/wake complaints. Sleep/wake disorders are 2-3 times more common in adults with epilepsy than the general population; these comorbidities are associated with poorer quality of life and may impact seizure control. Treatment of sleep apnea reduces seizures in many cases. An emerging area of research is in circadian biology and epilepsy. Over 90% of people with epilepsy have seizures with circadian periodicity, in part related to sleep itself, and the majority of SUDEP cases occur in sleep. Recognizing these bidirectional relationships is important for patient and caregiver education and counseling and optimizing epilepsy outcomes.
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Affiliation(s)
| | - Nancy Foldvary-Schaefer
- Sleep Disorders and Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA.
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