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Campora N, Princich JP, Nasimbera A, Cordisco S, Villanueva M, Oddo S, Giagante B, Kochen S. Stereo-EEG features of temporal and frontal lobe seizures with loss of consciousness. Neurosci Conscious 2024; 2024:niae003. [PMID: 38618487 PMCID: PMC11015893 DOI: 10.1093/nc/niae003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 12/11/2023] [Accepted: 04/03/2024] [Indexed: 04/16/2024] Open
Abstract
The loss of consciousness (LOC) during seizures is one of the most striking features that significantly impact the quality of life, even though the neuronal network involved is not fully comprehended. We analyzed the intracerebral patterns in patients with focal drug-resistant epilepsy, both with and without LOC. We assessed the localization, lateralization, stereo electroencephalography (SEEG) patterns, seizure duration, and the quantification of contacts exhibiting electrical discharge. The degree of LOC was quantified using the Consciousness Seizure Scale. Thirteen patients (40 seizures) with focal drug-resistant epilepsy underwent SEEG. In cases of temporal lobe epilepsy (TLE, 6 patients and 15 seizures), LOC occurred more frequently in seizures with mesial rather than lateral temporal lobe onset. On the other hand, in cases of frontal lobe epilepsy (7 patients; 25 seizures), LOC was associated with pre-frontal onset, a higher number of contacts with epileptic discharge compared to the onset count and longer seizure durations. Our study revealed distinct characteristics during LOC depending on the epileptogenic zone. For temporal lobe seizures, LOC was associated with mesial seizure onset, whereas in frontal lobe epilepsy, seizure with LOC has a significant increase in contact showing epileptiform discharge and a pre-frontal onset. This phenomenon may be correlated with the broad neural network required to maintain consciousness, which can be affected in different ways, resulting in LOC.
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Affiliation(s)
- Nuria Campora
- Neuroscience Department, El Cruce Hospital, Florencio Varela, Argentina
- Studies in Neuroscience and Complex Systems (ENyS), CONICET, Florencio Varela, Buenos Aires 1888, Argentina
| | - Juan Pablo Princich
- Neuroscience Department, El Cruce Hospital, Florencio Varela, Argentina
- Studies in Neuroscience and Complex Systems (ENyS), CONICET, Florencio Varela, Buenos Aires 1888, Argentina
| | - Alejandro Nasimbera
- Neuroscience Department, El Cruce Hospital, Florencio Varela, Argentina
- Studies in Neuroscience and Complex Systems (ENyS), CONICET, Florencio Varela, Buenos Aires 1888, Argentina
| | - Santiago Cordisco
- Studies in Neuroscience and Complex Systems (ENyS), CONICET, Florencio Varela, Buenos Aires 1888, Argentina
| | - Manuela Villanueva
- Studies in Neuroscience and Complex Systems (ENyS), CONICET, Florencio Varela, Buenos Aires 1888, Argentina
| | - Silvia Oddo
- Neuroscience Department, El Cruce Hospital, Florencio Varela, Argentina
- Studies in Neuroscience and Complex Systems (ENyS), CONICET, Florencio Varela, Buenos Aires 1888, Argentina
| | - Brenda Giagante
- Neuroscience Department, El Cruce Hospital, Florencio Varela, Argentina
| | - Silvia Kochen
- Neuroscience Department, El Cruce Hospital, Florencio Varela, Argentina
- Studies in Neuroscience and Complex Systems (ENyS), CONICET, Florencio Varela, Buenos Aires 1888, Argentina
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2
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Juan E, Górska U, Kozma C, Papantonatos C, Bugnon T, Denis C, Kremen V, Worrell G, Struck AF, Bateman LM, Merricks EM, Blumenfeld H, Tononi G, Schevon C, Boly M. Distinct signatures of loss of consciousness in focal impaired awareness versus tonic-clonic seizures. Brain 2023; 146:109-123. [PMID: 36383415 PMCID: PMC10582624 DOI: 10.1093/brain/awac291] [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: 10/06/2021] [Revised: 05/17/2022] [Accepted: 06/11/2022] [Indexed: 11/17/2022] Open
Abstract
Loss of consciousness is a hallmark of many epileptic seizures and carries risks of serious injury and sudden death. While cortical sleep-like activities accompany loss of consciousness during focal impaired awareness seizures, the mechanisms of loss of consciousness during focal to bilateral tonic-clonic seizures remain unclear. Quantifying differences in markers of cortical activation and ictal recruitment between focal impaired awareness and focal to bilateral tonic-clonic seizures may also help us to understand their different consequences for clinical outcomes and to optimize neuromodulation therapies. We quantified clinical signs of loss of consciousness and intracranial EEG activity during 129 focal impaired awareness and 50 focal to bilateral tonic-clonic from 41 patients. We characterized intracranial EEG changes both in the seizure onset zone and in areas remote from the seizure onset zone with a total of 3386 electrodes distributed across brain areas. First, we compared the dynamics of intracranial EEG sleep-like activities: slow-wave activity (1-4 Hz) and beta/delta ratio (a validated marker of cortical activation) during focal impaired awareness versus focal to bilateral tonic-clonic. Second, we quantified differences between focal to bilateral tonic-clonic and focal impaired awareness for a marker validated to detect ictal cross-frequency coupling: phase-locked high gamma (high-gamma phased-locked to low frequencies) and a marker of ictal recruitment: the epileptogenicity index. Third, we assessed changes in intracranial EEG activity preceding and accompanying behavioural generalization onset and their correlation with electromyogram channels. In addition, we analysed human cortical multi-unit activity recorded with Utah arrays during three focal to bilateral tonic-clonic seizures. Compared to focal impaired awareness, focal to bilateral tonic-clonic seizures were characterized by deeper loss of consciousness, even before generalization occurred. Unlike during focal impaired awareness, early loss of consciousness before generalization was accompanied by paradoxical decreases in slow-wave activity and by increases in high-gamma activity in parieto-occipital and temporal cortex. After generalization, when all patients displayed loss of consciousness, stronger increases in slow-wave activity were observed in parieto-occipital cortex, while more widespread increases in cortical activation (beta/delta ratio), ictal cross-frequency coupling (phase-locked high gamma) and ictal recruitment (epileptogenicity index). Behavioural generalization coincided with a whole-brain increase in high-gamma activity, which was especially synchronous in deep sources and could not be explained by EMG. Similarly, multi-unit activity analysis of focal to bilateral tonic-clonic revealed sustained increases in cortical firing rates during and after generalization onset in areas remote from the seizure onset zone. Overall, these results indicate that unlike during focal impaired awareness, the neural signatures of loss of consciousness during focal to bilateral tonic-clonic consist of paradoxical increases in cortical activation and neuronal firing found most consistently in posterior brain regions. These findings suggest differences in the mechanisms of ictal loss of consciousness between focal impaired awareness and focal to bilateral tonic-clonic and may account for the more negative prognostic consequences of focal to bilateral tonic-clonic.
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Affiliation(s)
- Elsa Juan
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI 53719, USA
- Department of Psychology, University of Amsterdam, Amsterdam, 1018 WS, The Netherlands
| | - Urszula Górska
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI 53719, USA
- Smoluchowski Institute of Physics, Jagiellonian University, 30-348 Krakow, Poland
| | - Csaba Kozma
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI 53719, USA
- Department of Neurology, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Cynthia Papantonatos
- Department of Neurology, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Tom Bugnon
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI 53719, USA
| | - Colin Denis
- Department of Neurology, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Vaclav Kremen
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
- Czech Institute of Informatics, Robotics, and Cybernetics, Czech Technical University in Prague, Prague, 16000, Czech Republic
| | - Greg Worrell
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
| | - Aaron F Struck
- Department of Neurology, University of Wisconsin-Madison, Madison, WI 53705, USA
- Department of Neurology, William S. Middleton Veterans Administration Hospital, Madison, WI 53705, USA
| | - Lisa M Bateman
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Edward M Merricks
- Department of Neurology, Columbia University, New York City, NY 10032, USA
| | - Hal Blumenfeld
- Department of Neurology, Yale School of Medicine, New Haven, CT 06519, USA
| | - Giulio Tononi
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI 53719, USA
| | - Catherine Schevon
- Department of Neurology, Columbia University, New York City, NY 10032, USA
| | - Melanie Boly
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI 53719, USA
- Department of Neurology, University of Wisconsin-Madison, Madison, WI 53705, USA
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3
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Impaired awareness in mesial temporal lobe epilepsy: Network analysis of foramen ovale and scalp EEG. Clin Neurophysiol 2021; 132:3084-3094. [PMID: 34717226 DOI: 10.1016/j.clinph.2021.09.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 08/11/2021] [Accepted: 09/01/2021] [Indexed: 11/22/2022]
Abstract
OBJECTIVE We use co-registration of foramen-ovale and scalp-EEG to investigate network alterations in temporal-lobe epilepsy during focal seizures without (aura) or with impairment of awareness (SIA). METHODS One aura and one SIA were selected from six patients. Temporal dynamic among 4 epochs, as well as the differences between aura and SIA, were analyzed through partial directed coherence and graph theory-based indices of centrality. RESULTS Regarding the auras temporal evolution, fronto-parietal (FP) regions showed decreased connectivity with respect to the interictal period, in both epileptogenic (EH) and non-epileptogenic hemisphere (nEH). During SIAs, temporal dynamic showed more changes than auras: centrality of mesial temporal (mT) regions changes during all conditions, and nEH FP centrality showed the same dynamic trend of the aura (decreased centrality), until the last epoch, close to the impaired awareness, when showed increased centrality. Comparing SIA with aura, in proximity of impaired awareness, increased centrality was found in all the regions, except in nEH mT. CONCLUSIONS Our findings suggested that the impairment of awareness is related to network alterations occurring first in neocortical regions and when awareness is still retained. SIGNIFICANCE The analysis of 'hub' alteration can represent a suitable biomarker for scalp EEG-based prediction of awareness impairment.
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Hanrahan B, Gross RA, Wychowski T, Erba G, Birbeck GL, Liu L. Improved ictal assessment performance in the epilepsy monitoring unit via standardization. Epilepsy Behav 2021; 122:108067. [PMID: 34147022 DOI: 10.1016/j.yebeh.2021.108067] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 04/28/2021] [Accepted: 05/10/2021] [Indexed: 10/21/2022]
Abstract
OBJECTIVE To determine whether the standardization and implementation of an ictal testing protocol in the Epilepsy Monitoring Unit (EMU) leads to improvements in ictal testing performance. METHODS Ictal assessments completed in the EMU from a single center were retrospectively reviewed over a two-month period. Each assessment was evaluated to determine whether 8 high-yield aspects of the ictal assessment were performed. Following observation of performance, a standardized ictal testing protocol was developed based on a root cause analysis and review of consensus guidelines. This protocol was disseminated to staff in conjunction with an annual epilepsy education seminar. Ictal assessment performance was re-assessed during the subsequent two months (short-term follow-up) and again during a five- to seven-month period (long-term follow-up) beyond the initial intervention. For sub-group analysis, event characteristics (event type, time of assessment) and patient characteristics (age, gender) were also evaluated and analyzed in relation to ictal testing performance. RESULTS All eight individual ictal testing elements were more likely to be assessed in short-term and long-term follow-up periods when compared to pre-intervention assessments. The cumulative difference in ictal testing was 20.4% (95% CI 3.7-37.2, p = 0.02) greater for the short-term period and 16.7% (95% CI -0.3% to 33.8%, p = 0.05) greater in the long-term period when compared to baseline testing. CONCLUSIONS Utilization of a standardized ictal testing battery in conjunction with staff education leads to an objective improvement in ictal assessment performance. Further research is warranted to assess the replicability of our findings.
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Affiliation(s)
- Brian Hanrahan
- Department of Neurology, Epilepsy Division, St. Luke's University Health Network, Bethlehem, PA, United States.
| | - Robert A Gross
- Departments of Neurology and Pharmacology and Physiology, Epilepsy Division, University of Rochester Medical Center, Rochester, NY, United States.
| | - Thomas Wychowski
- Departments of Neurology and Pharmacology and Physiology, Epilepsy Division, University of Rochester Medical Center, Rochester, NY, United States.
| | - Giuseppe Erba
- Departments of Neurology and Pharmacology and Physiology, Epilepsy Division, University of Rochester Medical Center, Rochester, NY, United States.
| | - Gretchen L Birbeck
- Departments of Neurology and Pharmacology and Physiology, Epilepsy Division, University of Rochester Medical Center, Rochester, NY, United States.
| | - Lynn Liu
- Departments of Neurology and Pharmacology and Physiology, Epilepsy Division, University of Rochester Medical Center, Rochester, NY, United States.
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5
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Gruenbaum BF. Comparison of anaesthetic- and seizure-induced states of unconsciousness: a narrative review. Br J Anaesth 2021; 126:219-229. [PMID: 32951841 PMCID: PMC7844374 DOI: 10.1016/j.bja.2020.07.056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 06/23/2020] [Accepted: 07/20/2020] [Indexed: 10/23/2022] Open
Abstract
In order to understand general anaesthesia and certain seizures, a fundamental understanding of the neurobiology of unconsciousness is needed. This review article explores similarities in neuronal and network changes during general anaesthesia and seizure-induced unconsciousness. Both seizures and anaesthetics cause disruption in similar anatomical structures that presumably lead to impaired consciousness. Despite differences in behaviour and mechanisms, both of these conditions are associated with disruption of the functionality of subcortical structures that mediate neuronal activity in the frontoparietal cortex. These areas are all likely to be involved in maintaining normal consciousness. An assessment of the similarities in the brain network disruptions with certain seizures and general anaesthesia might provide fresh insights into the mechanisms of the alterations of consciousness seen in these particular unconscious states, allowing for innovative therapies for seizures and the development of anaesthetic approaches targeting specific networks.
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6
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Amorim E, McGraw CM, Westover MB. A Theoretical Paradigm for Evaluating Risk-Benefit of Status Epilepticus Treatment. J Clin Neurophysiol 2020; 37:385-392. [PMID: 32890059 DOI: 10.1097/wnp.0000000000000753] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Aggressive treatment of status epilepticus with anesthetic drugs can provide rapid seizure control, but it might lead to serious medical complications and worse outcomes. Using a decision analysis approach, this concise review provides a framework for individualized decision making about aggressive and nonaggressive treatment in status epilepticus. The authors propose and review the most relevant parameters guiding the risk-benefit analysis of treatment aggressiveness in status epilepticus and present real-world-based case examples to illustrate how these tools could be used at the bedside and serve to guide future research in refractory status epilepticus treatment.
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Affiliation(s)
- Edilberto Amorim
- Department of Neurology, University of California, San Francisco, San Francisco, California, U.S.A.,Neurology Service, Zuckerberg San Francisco General Hospital, San Francisco, California, U.S.A.,Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, U.S.A.; and.,Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts, U.S.A
| | - Chris M McGraw
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, U.S.A.; and
| | - M Brandon Westover
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, U.S.A.; and
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8
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O'Kula SS, Faillace L, Kulick-Soper CV, Reyes-Esteves S, Raab J, Davis KA, Kheder A, Hill CE. Developing and Implementing a Standardized Ictal Examination in the Epilepsy Monitoring Unit. Neurol Clin Pract 2020; 11:127-133. [PMID: 33842065 DOI: 10.1212/cpj.0000000000000815] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 11/23/2019] [Indexed: 11/15/2022]
Abstract
Background The ictal examination is crucial for neuroanatomic localization of seizure onset, which informs medical and neurosurgical treatment of epilepsy. Substantial variation exists in ictal examination performance in epilepsy monitoring units (EMUs). We developed and implemented a standardized examination to facilitate rapid, reliable execution of all testing domains and adherence to patient safety maneuvers. Methods Following observation of examination performance, root cause analysis of barriers, and review of consensus guidelines, an ictal examination was developed and disseminated. In accordance with quality improvement methodology, revisions were enacted following the initial intervention, including differentiation between pathways for convulsive and nonconvulsive seizures. We evaluated ictal examination fidelity, efficiency, and EMU staff satisfaction before and after the intervention. Results We identified barriers to ictal examination performance as confusion regarding ictal examination protocol, inadequate education of the rationale for the examination and its components, and lack of awareness of patient-specific goals. Over an 18-month period, 100 ictal examinations were reviewed, 50 convulsive and 50 nonconvulsive. Ictal examination performance varied during the study period without sustained improvement for convulsive or nonconvulsive seizure examination. The new examination was faster to perform (0.8 vs 1.5 minutes). Postintervention, EMU staff expressed satisfaction with the examination, but many still did not understand why certain components were performed. Conclusion We identified key barriers to EMU ictal assessment and completed real-world testing of a standardized, streamlined ictal examination. We found it challenging to reliably change ictal examination performance in our EMU; further study of implementation is warranted.
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Affiliation(s)
- Susanna S O'Kula
- Department of Neurology (SSO'K), New York University; Department of Neurology (LF, CVK-S, SR-E, KAD), University of Pennsylvania; Department of Neurology (JR), Jefferson Hospital, Philadelphia, PA; Department of Neurology (AK), Emory University, Atlanta, GA; and Department of Neurology (CEH), University of Michigan, Ann Arbor
| | - Lisa Faillace
- Department of Neurology (SSO'K), New York University; Department of Neurology (LF, CVK-S, SR-E, KAD), University of Pennsylvania; Department of Neurology (JR), Jefferson Hospital, Philadelphia, PA; Department of Neurology (AK), Emory University, Atlanta, GA; and Department of Neurology (CEH), University of Michigan, Ann Arbor
| | - Catherine V Kulick-Soper
- Department of Neurology (SSO'K), New York University; Department of Neurology (LF, CVK-S, SR-E, KAD), University of Pennsylvania; Department of Neurology (JR), Jefferson Hospital, Philadelphia, PA; Department of Neurology (AK), Emory University, Atlanta, GA; and Department of Neurology (CEH), University of Michigan, Ann Arbor
| | - Sahily Reyes-Esteves
- Department of Neurology (SSO'K), New York University; Department of Neurology (LF, CVK-S, SR-E, KAD), University of Pennsylvania; Department of Neurology (JR), Jefferson Hospital, Philadelphia, PA; Department of Neurology (AK), Emory University, Atlanta, GA; and Department of Neurology (CEH), University of Michigan, Ann Arbor
| | - Jackie Raab
- Department of Neurology (SSO'K), New York University; Department of Neurology (LF, CVK-S, SR-E, KAD), University of Pennsylvania; Department of Neurology (JR), Jefferson Hospital, Philadelphia, PA; Department of Neurology (AK), Emory University, Atlanta, GA; and Department of Neurology (CEH), University of Michigan, Ann Arbor
| | - Kathryn A Davis
- Department of Neurology (SSO'K), New York University; Department of Neurology (LF, CVK-S, SR-E, KAD), University of Pennsylvania; Department of Neurology (JR), Jefferson Hospital, Philadelphia, PA; Department of Neurology (AK), Emory University, Atlanta, GA; and Department of Neurology (CEH), University of Michigan, Ann Arbor
| | - Ammar Kheder
- Department of Neurology (SSO'K), New York University; Department of Neurology (LF, CVK-S, SR-E, KAD), University of Pennsylvania; Department of Neurology (JR), Jefferson Hospital, Philadelphia, PA; Department of Neurology (AK), Emory University, Atlanta, GA; and Department of Neurology (CEH), University of Michigan, Ann Arbor
| | - Chloe E Hill
- Department of Neurology (SSO'K), New York University; Department of Neurology (LF, CVK-S, SR-E, KAD), University of Pennsylvania; Department of Neurology (JR), Jefferson Hospital, Philadelphia, PA; Department of Neurology (AK), Emory University, Atlanta, GA; and Department of Neurology (CEH), University of Michigan, Ann Arbor
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Kinney MO, Kovac S, Diehl B. Structured testing during seizures: A practical guide for assessing and interpreting ictal and postictal signs during video EEG long term monitoring. Seizure 2019; 72:13-22. [PMID: 31546090 DOI: 10.1016/j.seizure.2019.08.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Revised: 08/01/2019] [Accepted: 08/17/2019] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Ictal and postictal testing carried out in long-term epilepsy monitoring units is often sub-optimal. Recently, a European consensus protocol for testing patients during and after seizures was developed by a joint taskforce of the International League Against Epilepsy - Commission on European Affairs and the European Epilepsy Monitoring Unit Association. AIM Using this recently developed standardised assessment battery as a framework, the goal of this narrative review is to outline the proposed testing procedure in detail and explain the rationale for each individual component, focusing on the underlying neurobiology. This is intended to serve as an educational resource for staff working in epilepsy monitoring units. METHODS A literature review of PubMed was performed; using the search terms "seizure", "ictal", "postictal", "testing", "examination", and "interview". Relevant literature was reviewed and relevant references were chosen. The work is presented as a narrative review. RESULTS The proposed standardised assessment battery provides a comprehensive and user-friendly format for ictal-postictal testing, and examines consciousness, language, motor, sensory, and visual function. CONCLUSION The standardised approach proposed has the potential to make full use of data recorded during video EEG increasing the diagnostic yield with regards to lateralisation and localisation, aiding both presurgical and diagnostic studies.
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Affiliation(s)
- Michael Owen Kinney
- Department of Clinical Neurophysiology, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK.
| | - Stjepana Kovac
- Department of Neurology, University of Münster, Münster, Germany
| | - Beate Diehl
- Department of Clinical Neurophysiology, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK; Department of Clinical and Experimental Epilepsy, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
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10
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Rommens N, Geertsema E, Jansen Holleboom L, Cox F, Visser G. Improving staff response to seizures on the epilepsy monitoring unit with online EEG seizure detection algorithms. Epilepsy Behav 2018; 84:99-104. [PMID: 29758446 DOI: 10.1016/j.yebeh.2018.04.026] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Revised: 04/27/2018] [Accepted: 04/28/2018] [Indexed: 10/16/2022]
Abstract
OBJECTIVE User safety and the quality of diagnostics on the epilepsy monitoring unit (EMU) depend on reaction to seizures. Online seizure detection might improve this. While good sensitivity and specificity is reported, the added value above staff response is unclear. We ascertained the added value of two electroencephalograph (EEG) seizure detection algorithms in terms of additional detected seizures or faster detection time. METHODS EEG-video seizure recordings of people admitted to an EMU over one year were included, with a maximum of two seizures per subject. All recordings were retrospectively analyzed using Encevis EpiScan and BESA Epilepsy. Detection sensitivity and latency of the algorithms were compared to staff responses. False positive rates were estimated on 30 uninterrupted recordings (roughly 24 h per subject) of consecutive subjects admitted to the EMU. RESULTS EEG-video recordings used included 188 seizures. The response rate of staff was 67%, of Encevis 67%, and of BESA Epilepsy 65%. Of the 62 seizures missed by staff, 66% were recognized by Encevis and 39% by BESA Epilepsy. The median latency was 31 s (staff), 10 s (Encevis), and 14 s (BESA Epilepsy). After correcting for walking time from the observation room to the subject, both algorithms detected faster than staff in 65% of detected seizures. The full recordings included 617 h of EEG. Encevis had a median false positive rate of 4.9 per 24 h and BESA Epilepsy of 2.1 per 24 h. CONCLUSIONS EEG-video seizure detection algorithms may improve reaction to seizures by improving the total number of seizures detected and the speed of detection. The false positive rate is feasible for use in a clinical situation. Implementation of these algorithms might result in faster diagnostic testing and better observation during seizures.
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Affiliation(s)
- Nicole Rommens
- Stichting Epilepsie Instellingen Nederland (SEIN), Postbus 540, Hoofddorp 2130 AM, The Netherlands; Technical Medicine, University of Twente, Postbus 217, Enschede 7500 AE, The Netherlands
| | - Evelien Geertsema
- Stichting Epilepsie Instellingen Nederland (SEIN), Postbus 540, Hoofddorp 2130 AM, The Netherlands.
| | - Lisanne Jansen Holleboom
- Stichting Epilepsie Instellingen Nederland (SEIN), Postbus 540, Hoofddorp 2130 AM, The Netherlands; Technical Medicine, University of Twente, Postbus 217, Enschede 7500 AE, The Netherlands
| | - Fieke Cox
- Stichting Epilepsie Instellingen Nederland (SEIN), Postbus 540, Hoofddorp 2130 AM, The Netherlands.
| | - Gerhard Visser
- Stichting Epilepsie Instellingen Nederland (SEIN), Postbus 540, Hoofddorp 2130 AM, The Netherlands.
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11
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Beniczky S, Neufeld M, Diehl B, Dobesberger J, Trinka E, Mameniskiene R, Rheims S, Gil-Nagel A, Craiu D, Pressler R, Krysl D, Lebedinsky A, Tassi L, Rubboli G, Ryvlin P. Testing patients during seizures: A European consensus procedure developed by a joint taskforce of the ILAE - Commission on European Affairs and the European Epilepsy Monitoring Unit Association. Epilepsia 2016; 57:1363-8. [PMID: 27440172 DOI: 10.1111/epi.13472] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/20/2016] [Indexed: 12/01/2022]
Abstract
There is currently no international consensus procedure for performing comprehensive periictal testing of patients in the epilepsy monitoring units (EMUs). Our primary goal was to develop a standardized procedure for managing and testing patients during and after seizures in EMUs. The secondary goal was to assess whether it could be implemented in clinical practice (feasibility). A taskforce was appointed by the International League Against Epilepsy (ILAE)-Commission on European Affairs and the European Epilepsy Monitoring Unit Association, to develop a standardized ictal testing battery (ITB) based on expert opinion and experience with various local testing protocols. ITB contains a comprehensive set of 10 items that evidence the clinically relevant semiologic features, and it is adaptive to the dynamics of the individual seizures. The feasibility of the ITB was prospectively evaluated on 250 seizures from 152 consecutive patients in 10 centers. ITB was successfully implemented in clinical practice in all 10 participating centers and was considered feasible in 93% of the tested seizures. ITB was not feasible for testing seizures of very short duration.
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Affiliation(s)
- Sándor Beniczky
- Department of Clinical Neurophysiology, Danish Epilepsy Center, Dianalund, Denmark.,Aarhus University, Aarhus, Denmark
| | - Miri Neufeld
- The EEG and Epilepsy Unit, Department of Neurology, Tel Aviv Medical Center, Tel Aviv, Israel
| | - Beate Diehl
- Departments of Clinical Neurophysiology and Clinical and Experimental Epilepsy, Institute of Neurology, National Hospital for Neurology and Neurosurgery, University College London, London, United Kingdom
| | - Judith Dobesberger
- Department of Neurology, Christian-Doppler-Klinik, Paracelsus Medical University, and Center for Cognitive Neuroscience, Salzburg, Austria
| | - Eugen Trinka
- Department of Neurology, Christian-Doppler-Klinik, Paracelsus Medical University, and Center for Cognitive Neuroscience, Salzburg, Austria
| | - Ruta Mameniskiene
- Clinic of Neurology and Neurosurgery, Faculty of Medicine, Vilnius University, Vilnius, Lithuania.,Department of Neurology, Vilnius University Hospital, Vilnius, Lithuania
| | - Sylvain Rheims
- Department of Functional Neurology and Epileptology, University Hospital of Lyon and Lyon 1 University, Lyon, France
| | - Antonio Gil-Nagel
- Department of Neurology, Epilepsy Program, Hospital Ruber Internacional, Madrid, Spain
| | - Dana Craiu
- Department of Clinical Neurosciences (No. 6), Pediatric Neurology Clinic, Alexandru Obregia Hospital, "Carol Davila" University of Medicine, Bucharest, Romania
| | - Ronit Pressler
- Department of Clinical Neurophysiology, Great Ormond Street Hospital, London, United Kingdom.,Clinical Neuroscience, UCL Institute of Child Health, London, United Kingdom
| | - David Krysl
- Departments of Clinical Neurophysiology and Neurology, Sahlgrenska University Hospital, Gothenburg, Sweden.,Institute of Neuroscience and Physiology at Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Angelina Lebedinsky
- The EEG and Epilepsy Unit, Department of Neurology, Tel Aviv Medical Center, Tel Aviv, Israel
| | - Laura Tassi
- "Claudio Munari" Epilepsy Surgery Center, Niguarda Hospital, Milan, Italy
| | - Guido Rubboli
- Danish Epilepsy Center and University of Copenhagen, Dianalund, Denmark
| | - Philippe Ryvlin
- Department of Clinical Neurosciences, CHUV, Lausanne, Switzerland.,European Epilepsy Monitoring Association, Lyon, France
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Touloumes G, Morse E, Chen WC, Gober L, Dente J, Lilenbaum R, Katzenstein E, Pacelli A, Johnson E, Si Y, Sivaraju A, Grover E, Khozein R, Cunningham C, Hirsch LJ, Blumenfeld H. Human bedside evaluation versus automatic responsiveness testing in epilepsy (ARTiE). Epilepsia 2015; 57:e28-32. [PMID: 26663137 DOI: 10.1111/epi.13262] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/29/2015] [Indexed: 02/05/2023]
Abstract
Evaluation of behavioral impairment during epileptic seizures is critical for medical decision making, including accurate diagnosis, recommendations for driving, and presurgical evaluation. We investigated the quality of behavioral testing during inpatient video-electroencephalography (EEG) monitoring at an established epilepsy center, and introduce a technical innovation that may improve clinical care. We retrospectively reviewed video-EEG data from 152 seizures in 33 adult or pediatric patients admitted for video-EEG monitoring. Behavioral testing with questions or commands was performed in only 50% of seizures ictally, 73% of seizures postictally, and 80% with either ictal or postictal testing combined. Furthermore, the questions or commands were highly inconsistent and were performed by nonmedical personnel in about one fourth of cases. In an effort to improve this situation we developed and here introduce Automatic Responsiveness Testing in Epilepsy (ARTiE), a series of video-recorded behavioral tasks automatically triggered to play in the patient's room by computerized seizure detection. In initial technical testing using prerecorded or live video-EEG data we found that ARTiE is initiated reliably by automatic seizure detection. With additional clinical testing we hope that ARTiE will succeed in providing comprehensive and reliable behavioral evaluation during seizures for people with epilepsy to greatly improve their clinical care.
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Affiliation(s)
- George Touloumes
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, U.S.A
| | - Elliot Morse
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, U.S.A
| | - William C Chen
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, U.S.A
| | - Leah Gober
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, U.S.A
| | - Jennifer Dente
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, U.S.A
| | - Rachel Lilenbaum
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, U.S.A
| | - Emily Katzenstein
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, U.S.A
| | - Ashley Pacelli
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, U.S.A
| | - Emily Johnson
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, U.S.A
| | - Yang Si
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, U.S.A.,Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Adithya Sivaraju
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, U.S.A
| | - Eric Grover
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, U.S.A
| | | | - Courtney Cunningham
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, U.S.A
| | - Lawrence J Hirsch
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, U.S.A
| | - Hal Blumenfeld
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, U.S.A.,Department of Neuroscience, Yale University School of Medicine, New Haven, Connecticut, U.S.A.,Department of Neurosurgery, Yale University School of Medicine, New Haven, Connecticut, U.S.A
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13
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Blumenfeld H, Meador KJ. Consciousness as a useful concept in epilepsy classification. Epilepsia 2014; 55:1145-50. [PMID: 24981294 DOI: 10.1111/epi.12588] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/01/2014] [Indexed: 11/30/2022]
Abstract
Impaired consciousness has important practical consequences for people living with epilepsy. Recent pathophysiologic studies show that seizures with impaired level of consciousness always affect widespread cortical networks and subcortical arousal systems. In light of these findings and their clinical significance, efforts are underway to revise the International League Against Epilepsy (ILAE) 2010 report to include impaired consciousness in the classification of seizures. Lüders and colleagues have presented one such effort, which we discuss here. We then propose an alternative classification of impaired consciousness in epilepsy based on functional neuroanatomy. Some seizures involve focal cortical regions and cause selective deficits in the content of consciousness but without impaired overall level of consciousness or awareness. These include focal aware conscious seizures (FACS) with lower order cortical deficits such as somatosensory or visual impairment as well as FACS with higher cognitive deficits including ictal aphasia or isolated epileptic amnesia. Another category applies to seizures with impaired level of consciousness leading to deficits in multiple cognitive domains. For this category, we believe the terms "dyscognitive" or "dialeptic" should be avoided because they may create confusion. Instead we propose that seizures with impaired level of consciousness be described based on underlying pathophysiology. Widespread moderately severe deficits in corticothalamic function are seen in absence seizures and in focal impaired consciousness seizures (FICS), including many temporal lobe seizures and other focal seizures with impaired consciousness. Some simple responses or automatisms may be preserved in these seizures. In contrast, generalized tonic-clonic seizures usually produce widespread severe deficits in corticothalamic function causing loss of all meaningful responses. Further work is needed to understand and prevent impaired consciousness in epilepsy, but the first step is to keep this crucial practical and physiologic aspect of seizures front-and-center in our discussions.
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Affiliation(s)
- Hal Blumenfeld
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, U.S.A; Department of Neurobiology, Yale University School of Medicine, New Haven, Connecticut, U.S.A; Department of Neurosurgery, Yale University School of Medicine, New Haven, Connecticut, U.S.A
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14
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15
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Cunningham C, Chen WC, Shorten A, McClurkin M, Choezom T, Schmidt CP, Chu V, Bozik A, Best C, Chapman M, Furman M, Detyniecki K, Giacino JT, Blumenfeld H. Impaired consciousness in partial seizures is bimodally distributed. Neurology 2014; 82:1736-44. [PMID: 24727311 PMCID: PMC4032205 DOI: 10.1212/wnl.0000000000000404] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2013] [Accepted: 01/27/2014] [Indexed: 01/22/2023] Open
Abstract
OBJECTIVE To investigate whether impaired consciousness in partial seizures can usually be attributed to specific deficits in the content of consciousness or to a more general decrease in the overall level of consciousness. METHODS Prospective testing during partial seizures was performed in patients with epilepsy using the Responsiveness in Epilepsy Scale (n = 83 partial seizures, 30 patients). Results were compared with responsiveness scores in a cohort of patients with severe traumatic brain injury evaluated with the JFK Coma Recovery Scale-Revised (n = 552 test administrations, 184 patients). RESULTS Standardized testing during partial seizures reveals a bimodal scoring distribution, such that most patients were either fully impaired or relatively spared in their ability to respond on multiple cognitive tests. Seizures with impaired performance on initial test items remained consistently impaired on subsequent items, while other seizures showed spared performance throughout. In the comparison group, we found that scores of patients with brain injury were more evenly distributed across the full range in severity of impairment. CONCLUSIONS Partial seizures can often be cleanly separated into those with vs without overall impaired responsiveness. Results from similar testing in a comparison group of patients with brain injury suggest that the bimodal nature of Responsiveness in Epilepsy Scale scores is not a result of scale bias but may be a finding unique to partial seizures. These findings support a model in which seizures either propagate or do not propagate to key structures that regulate overall arousal and thalamocortical function. Future investigations are needed to relate these behavioral findings to the physiology underlying impaired consciousness in partial seizures.
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Affiliation(s)
- Courtney Cunningham
- From the Departments of Neurology (C.C., W.C.C., A.S., M.M., T.C., C.P.S., V.C., A.B., C.B., M.C., M.F., K.D., H.B.), Neurobiology (H.B.), and Neurosurgery (H.B.), Yale University School of Medicine, New Haven, CT; and Department of Physical Medicine and Rehabilitation (J.T.G.), Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA
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16
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Chen WC, Chen EY, Gebre RZ, Johnson MR, Li N, Vitkovskiy P, Blumenfeld H. Epilepsy and driving: potential impact of transient impaired consciousness. Epilepsy Behav 2014; 30:50-7. [PMID: 24436967 PMCID: PMC4098969 DOI: 10.1016/j.yebeh.2013.09.024] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Driving is an important part of everyday life for most adults, and restrictions on driving can place a significant burden on individuals diagnosed with epilepsy. Although sensorimotor deficits during seizures may impair driving, decreased level of consciousness often has a more global effect on patients' ability to respond appropriately to the environment. Better understanding of the mechanisms underlying alteration of consciousness in epilepsy is important for decision-making by people with epilepsy, their physicians, and regulators in regard to the question of fitness to drive. Retrospective cohort and cross-sectional studies based on surveys or crash records can provide valuable information about driving in epilepsy. However, prospective objective testing of ictal driving ability during different types of seizures is needed to more fully understand the role of impaired consciousness and other deficits in disrupting driving. Driving simulators adapted for use in the epilepsy video-EEG monitoring unit may be well suited to provide both ictal and interictal data in patients with epilepsy. Objective information about impaired driving in specific types of epilepsy and seizures can provide better informed recommendations regarding fitness to drive, potentially improving the quality of life of people living with epilepsy.
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Affiliation(s)
- William C. Chen
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, Connecticut 06520, USA
| | - Eric Y. Chen
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, Connecticut 06520, USA
| | - Rahiwa Z. Gebre
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, Connecticut 06520, USA
| | - Michelle R. Johnson
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, Connecticut 06520, USA
| | - Ningcheng Li
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, Connecticut 06520, USA
| | - Petr Vitkovskiy
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, Connecticut 06520, USA
| | - Hal Blumenfeld
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, Connecticut 06520, USA,Department of Neurobiology, Yale University School of Medicine, 333 Cedar Street, New Haven, Connecticut 06520, USA,Department of Neurosurgery, Yale University School of Medicine, 333 Cedar Street, New Haven, Connecticut 06520, USA
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17
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Blumenfeld H. What is a seizure network? Long-range network consequences of focal seizures. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 813:63-70. [PMID: 25012367 PMCID: PMC6287499 DOI: 10.1007/978-94-017-8914-1_5] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
What defines the spatial and temporal boundaries of seizure activity in brain networks? To fully answer this question a precise and quantitative definition of seizures is needed, which unfortunately remains elusive. Nevertheless, it is possible to ask under conditions where clearly divergent patterns of activity occur in large-scale brain networks whether certain activity patterns are part of the seizure while others are not. Here we examine brain network activity during focal limbic seizures, including diverse regions such as the hippocampus, subcortical arousal systems and fronto-parietal association cortex. Based on work from patients and from animal models we describe a characteristic pattern of intense increases in neuronal firing, cerebral blood flow, cerebral blood volume, blood oxygen level dependent functional magnetic resonance imaging (BOLD fMRI) signals and cerebral metabolic rate of oxygen consumption in the hippocampus during focal limbic seizures. Similar increases are seen in certain closely linked subcortical structures such as the lateral septal nuclei and anterior hypothalamus, which contain inhibitory neurons. In marked contrast, decreases in all of these parameters are seen in the subcortical arousal systems of the upper brainstem and intralaminar thalamus, as well as in the fronto-parietal association cortex. We propose that the seizure proper can be defined as regions showing intense increases, while those areas showing opposite changes are inhibited by the seizure network and constitute long-range network consequences beyond the seizure itself. Importantly, the fronto-parietal cortex shows sleep-like slow wave activity and depressed metabolism under these conditions, associated with impaired consciousness. Understanding which brain networks are directly involved in seizures versus which sustain secondary consequences can provide new insights into the mechanisms of brain dysfunction in epilepsy, hopefully leading to innovative treatment approaches.
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Affiliation(s)
- Hal Blumenfeld
- Department of Neurology, Neurobiology and Neurosurgery, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA,
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18
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Video-electroencephalography investigation of ictal alterations of consciousness in epilepsy and nonepileptic attack disorder: practical considerations. Epilepsy Behav 2014; 30:24-7. [PMID: 24113568 DOI: 10.1016/j.yebeh.2013.09.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2013] [Accepted: 09/04/2013] [Indexed: 11/24/2022]
Abstract
The ictal assessment of consciousness is of central importance in the differential diagnosis of epilepsy and nonepileptic attack disorder (NEAD). Long-term video-electroencephalography (video-EEG) is currently considered the gold standard investigative technique for the evaluation of patients with recurrent attacks associated with transient alterations of arousal (responsiveness) and/or awareness (experiential states). This paper offers a concise review focusing on the practical aspects of clinical relevance in the video-EEG diagnostic workout of inpatients with suspected epilepsy or NEAD, as outlined in existing guidelines and recommendations. The reviewed literature implies that both implementation of specific procedures (e.g., activation maneuvers) and interpersonal approach (e.g., monitoring protocols) during video-EEG should be tailored to the individual patient's presentation.
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Nani A, Cavanna AE. The quantitative measurement of consciousness during epileptic seizures. Epilepsy Behav 2014; 30:2-5. [PMID: 24113569 DOI: 10.1016/j.yebeh.2013.09.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2013] [Accepted: 09/04/2013] [Indexed: 11/16/2022]
Abstract
The assessment of consciousness is a fundamental element in the classification of epileptic seizures. It is, therefore, of great importance for clinical practice to develop instruments that enable an accurate and reliable measurement of the alteration of consciousness during seizures. Over the last few years, three psychometric scales have been specifically proposed to measure ictal consciousness: the Ictal Consciousness Inventory (ICI), the Consciousness Seizure Scale (CSS), and the Responsiveness in Epilepsy Scale--versions I and II (RES-I and RES-II). The ICI is a self-report psychometric instrument which retrospectively assesses ictal consciousness along the dimensions of the level/arousal and contents/awareness. The CSS has been used by clinicians to quantify the impairment of consciousness in order to establish correlations with the brain mechanisms underlying alterations of consciousness during temporal lobe seizures. The most recently developed observer-rated instrument is the RES-I, which has been used to assess responsiveness during epileptic seizures in patients undergoing video-EEG. The implementation of standardized psychometric tools for the assessment of ictal consciousness can complement clinical observations and contribute to improve accuracy in seizure classification.
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Affiliation(s)
- Andrea Nani
- Michael Trimble Neuropsychiatry Research Group, BSMHFT, UK; Section of Neuropharmacology and Neurobiology, School of Clinical and Experimental Medicine, University of Birmingham, UK
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Detyniecki K, Blumenfeld H. Consciousness of seizures and consciousness during seizures: are they related? Epilepsy Behav 2014; 30:6-9. [PMID: 24126026 PMCID: PMC6287500 DOI: 10.1016/j.yebeh.2013.09.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 09/13/2013] [Indexed: 10/26/2022]
Abstract
Recent advances have been made in the network mechanisms underlying impairment of consciousness during seizures. However, less is known about patient awareness of their own seizures. Studying patient reports or documentation of their seizures is currently the most commonly utilized mechanism to scientifically measure patient awareness of seizures. The purpose of this review is to summarize the available evidence regarding the accuracy of patient seizure counts and identify the variables that may influence unreliable seizure reporting. Several groups looking at patient documentation of seizures during continuous EEG monitoring show that patients do not report as many as 50% of their seizures. These studies also suggest that seizures accompanied by loss of consciousness, arising from the left hemisphere or the temporal lobe, or occurring during sleep are associated with significantly reduced reporting. Baseline memory performance does not appear to have a major influence on the accuracy of seizure report. Further prospective studies using validated ictal behavioral testing as well as using correlation with newer electrophysiological and neuroimaging techniques for seizure localization are needed to more fully understand the mechanisms of underreporting of seizures. Better methods to alert caregivers about unrecognized seizures and to improve seizure documentation are under investigation.
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Affiliation(s)
- Kamil Detyniecki
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA.
| | - Hal Blumenfeld
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA,Department of Neurobiology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA,Department of Neurosurgery, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
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21
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Blumenfeld H, Jackson GD. Should consciousness be included in the classification of focal (partial) seizures? Epilepsia 2013; 54:1125-30. [PMID: 23731397 DOI: 10.1111/epi.12157] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The ILAE 2010 report does not classify focal seizures and instead uses “descriptors” to distinguish focal seizures with versus without impaired consciousness. Below, we recall a recent informal conversation that took place while traveling a back road in Australia (true story), discussing problems with the old terms as well as new biological and practical evidence separating events formerly known as complex partial versus simple partial seizures. Impaired level of consciousness is a core distinguishing feature of focal seizures, which arises from established physiological mechanisms and can be readily determined based on behavior in most cases. After some debate, we arrive at succinct terms compatible with the old as well as the new ILAE classification report: Focal Impaired Consciousness Seizures (FICS), and Focal Aware Conscious Seizures (FACS). We hope that this discussion will bring impaired consciousness off the back roads of epilepsy classification, and provide useful names for these two very common seizure types.
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Affiliation(s)
- Hal Blumenfeld
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA.
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Abstract
Consciousness is essential to normal human life. In epileptic seizures consciousness is often transiently lost, which makes it impossible for the individual to experience or respond. These effects have huge consequences for safety, productivity, emotional health, and quality of life. To prevent impaired consciousness in epilepsy, it is necessary to understand the mechanisms that lead to brain dysfunction during seizures. Normally the consciousness system-a specialised set of cortical-subcortical structures-maintains alertness, attention, and awareness. Advances in neuroimaging, electrophysiology, and prospective behavioural testing have shed light on how epileptic seizures disrupt the consciousness system. Diverse seizure types, including absence, generalised tonic-clonic, and complex partial seizures, converge on the same set of anatomical structures through different mechanisms to disrupt consciousness. Understanding of these mechanisms could lead to improved treatment strategies to prevent impairment of consciousness and improve the quality of life of people with epilepsy.
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Affiliation(s)
- Hal Blumenfeld
- Departments of Neurology, Neurobiology, and Neurosurgery, Yale University School of Medicine, New Haven, CT 06520, USA.
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