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Bencsik C, Josephson C, Soo A, Ainsworth C, Savard M, van Diepen S, Kramer A, Kromm J. The Evolving Role of Electroencephalography in Postarrest Care. Can J Neurol Sci 2024:1-13. [PMID: 38572611 DOI: 10.1017/cjn.2024.55] [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: 04/05/2024]
Abstract
Electroencephalography is an accessible, portable, noninvasive and safe means of evaluating a patient's brain activity. It can aid in diagnosis and management decisions for post-cardiac arrest patients with seizures, myoclonus and other non-epileptic movements. It also plays an important role in a multimodal approach to neuroprognostication predicting both poor and favorable outcomes. Individuals ordering, performing and interpreting these tests, regardless of the indication, should understand the supporting evidence, logistical considerations, limitations and impact the results may have on postarrest patients and their families as outlined herein.
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Affiliation(s)
- Caralyn Bencsik
- Department of Critical Care Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Health Services, Calgary, AB, Canada
| | - Colin Josephson
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
- O'Brien Institute for Public Health, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Centre for Health Informatics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Andrea Soo
- Department of Critical Care Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Health Services, Calgary, AB, Canada
| | - Craig Ainsworth
- Division of Cardiology, Department of Medicine, McMaster University, Hamilton, ON, Canada
| | - Martin Savard
- Département de Médecine, Université Laval, Quebec City, QC, Canada
| | - Sean van Diepen
- Department of Critical Care Medicine, University of Alberta, Edmonton, AB, Canada
- Division of Cardiology, Department of Medicine, University of Alberta, Edmonton, AB, Canada
| | - Andreas Kramer
- Department of Critical Care Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Health Services, Calgary, AB, Canada
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Julie Kromm
- Department of Critical Care Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Health Services, Calgary, AB, Canada
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
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Morris H, Kaplan PW, Kane N. Electroencephalography in encephalopathy and encephalitis. Pract Neurol 2024; 24:2-10. [PMID: 38050141 DOI: 10.1136/pn-2023-003798] [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] [Accepted: 09/23/2023] [Indexed: 12/06/2023]
Abstract
Electroencephalography (EEG) is a useful adjunct to clinical neurological examination, particularly as it may detect subtle or subclinical disturbance of cerebral function and it allows monitoring of cerebral activity over time. Continuous EEG combined with quantitative analysis and machine learning may help identify changes in real time, before the emergence of clinical signs and response to interventions. EEG is rarely pathognomonic in encephalopathy/encephalitis but when interpreted correctly and within the clinical context, certain phenotypes may indicate a specific pathophysiology (eg, lateralised periodic discharges in HSV-1, generalised periodic discharges in sporadic Creutzfeldt-Jakob disease, and extreme delta brushes in anti-n-methyl-D-aspartate receptor autoimmune encephalitis). EEG is included in some specialist guidelines for disease assessment, monitoring and prognostication (ie, hepatic, cancer immunotherapy, viral, prion, autoimmune encephalitis and hypoxic ischaemic encephalopathy). EEG is invaluable for confirming or excluding non-convulsive seizures or status epilepticus, particularly in critically ill patients, and in understanding new concepts such as epileptic encephalopathy and the ictal-interictal continuum.
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Affiliation(s)
- Hollie Morris
- Grey Walter Dept of Clinical Neurophysiology, North Bristol NHS Trust, Bristol, UK
| | - Peter W Kaplan
- Johns Hopkins Bayview Medical Center, Baltimore, Maryland, USA
| | - Nick Kane
- Grey Walter Dept of Clinical Neurophysiology, North Bristol NHS Trust, Westbury on Trym, UK
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Greenblatt AS, Beniczky S, Nascimento FA. Pitfalls in scalp EEG: Current obstacles and future directions. Epilepsy Behav 2023; 149:109500. [PMID: 37931388 DOI: 10.1016/j.yebeh.2023.109500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Revised: 10/15/2023] [Accepted: 10/17/2023] [Indexed: 11/08/2023]
Abstract
Although electroencephalography (EEG) serves a critical role in the evaluation and management of seizure disorders, it is commonly misinterpreted, resulting in avoidable medical, social, and financial burdens to patients and health care systems. Overinterpretation of sharply contoured transient waveforms as being representative of interictal epileptiform abnormalities lies at the core of this problem. However, the magnitude of these errors is amplified by the high prevalence of paroxysmal events exhibited in clinical practice that compel investigation with EEG. Neurology training programs, which vary considerably both in the degree of exposure to EEG and the composition of EEG didactics, have not effectively addressed this widespread issue. Implementation of competency-based curricula in lieu of traditional educational approaches may enhance proficiency in EEG interpretation amongst general neurologists in the absence of formal subspecialty training. Efforts in this regard have led to the development of a systematic, high-fidelity approach to the interpretation of epileptiform discharges that is readily employable across medical centers. Additionally, machine learning techniques hold promise for accelerating accurate and reliable EEG interpretation, particularly in settings where subspecialty interpretive EEG services are not readily available. This review highlights common diagnostic errors in EEG interpretation, limitations in current educational paradigms, and initiatives aimed at resolving these challenges.
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Affiliation(s)
- Adam S Greenblatt
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA
| | - Sándor Beniczky
- Department of Clinical Neurophysiology, Danish Epilepsy Center, Dianalund and Aarhus University Hospital, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Fábio A Nascimento
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA.
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Tedrus GMAS. Focal nonconvulsive status epilepticus with impaired consciousness in older adults: Prognosis-related variables. Epilepsy Behav 2023; 144:109257. [PMID: 37271017 DOI: 10.1016/j.yebeh.2023.109257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 05/05/2023] [Accepted: 05/07/2023] [Indexed: 06/06/2023]
Abstract
OBJECTIVE To assess the prognosis-related clinical-EEG characteristics in older adults with focal nonconvulsive status epilepticus with impaired consciousness (focal NCSE). METHODOLOGY We prospectively assessed clinical variables and EEG data at diagnosis and after an initial pharmacological protocol (within 24 hours) and their relationship with prognosis in older adults with focal NCSE treated at the emergency room. RESULTS The clinical presentation of focal NCSE in 45 adults (mean age 73.5 ± 9.1 years) was characterized by decreased consciousness and the presence of subtle ictal phenomena in 24 cases. On the initial EEG, there were lateralized periodic discharges (LPDs) and lateralized rhythmic delta activity (RDA) in 25 cases and epileptiform discharges (EDs > 2.5 Hz) in 32 cases. After the drug protocol, 33 (73.3%) cases had effective clinical improvement. Death after 30 days occurred in 10 (22.2%) cases. In simple and multiple logistic regression, it was observed that older adults with a history of epilepsy/seizures have a greater chance of clinical improvement. The occurrence of death was associated with the presence of RDA in the initial EEG and its subsequent disappearance (OR 6.93, 95% CI 1.20-46.01, p = 0.033). Higher mortality was associated with the presence of LPDs in the initial EEG and with the presence of LPDs/EDs > 2.5 Hz in the EEG after treatment. CONCLUSION The presence of ED > 2.5 Hz in the initial EEG was the most frequent pattern at focal NCSE. Clinical improvement was associated with a history of epilepsy/seizures. Mortality in the focal NCSE was high and was associated with the presence of RDA in the initial EEG and the occurrence of LPDs/ED > 2.5 Hz after treatment.
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Affiliation(s)
- Gloria M A S Tedrus
- Postgraduate Program in Health Sciences, Pontifical Catholic University of Campinas. PUC-Campinas, Av. John Boyd Dunlop s/n - Jardim Ipaussurama, Campinas, SP, Brazil.
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Knipe MF, Bush WW, Thomas KE, Williams DC. Periodic discharges in veterinary electroencephalography-A visual review. Front Vet Sci 2023; 10:1037404. [PMID: 36777678 PMCID: PMC9909489 DOI: 10.3389/fvets.2023.1037404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 01/03/2023] [Indexed: 01/27/2023] Open
Abstract
First described in human EEG over 60 years ago, there are very few examples of periodic discharges in the veterinary literature. They are associated with a wide variety of etiologies, both intracranial and systemic, making interpretation challenging. Whether these patterns are indicative of ictal, interictal, or postictal activity is a matter of debate and may vary depending on the clinical features in an individual patient. Periodic discharges have a repeated waveform occurring at nearly regular intervals, with varying morphology of individual discharges from simple sharp waves or slow waves to more complex events. Amplitudes, frequencies, and morphologies of the discharges can fluctuate, occasionally evolving, or resolving over time. This study presents a visual review of several veterinary cases with periodic discharges on EEG similar to those described in human EEG, and discusses the current known pathophysiology of these discharges.
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Affiliation(s)
- Marguerite F. Knipe
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States,*Correspondence: Marguerite F. Knipe ✉
| | - William W. Bush
- Bush Veterinary Neurology Service, Leesburg, VA, United States
| | | | - D. Colette Williams
- School of Veterinary Medicine, William R. Pritchard Veterinary Medical Teaching Hospital, University of California, Davis, Davis, CA, United States
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Malter MP, Neuneier J. Super-refractory status epilepticus in adults. Neurol Res Pract 2022; 4:35. [PMID: 35989337 PMCID: PMC9394073 DOI: 10.1186/s42466-022-00199-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 06/10/2022] [Indexed: 11/13/2022] Open
Abstract
Introduction Super-refractory status epilepticus (SRSE) represents the culmination of refractory status epilepticus (RSE) and carries a significant risk of poor neurological outcome and high mortality. RSE is not defined primarily by seizure duration, but by failure to respond to appropriate antiseizure treatment. SRSE is present when a RSE persists or recurs after more than 24 h of treatment with anesthetics. No evidence-based treatment algorithms can be provided for SRSE. Therefore, we propose a pragmatic standard operating procedure (SOP) for the management of SRSE that addresses the existing uncertainties in the treatment of SRSE and provides options for resolution and decision-making.
Comments First, we recommend the assessment of persistent seizure activity and the evaluation of differential diagnoses to confirm correct diagnosis. Relevant differential diagnoses include psychogenic non-epileptic seizures, hypoxic, metabolic, or toxic encephalopathies, and tetanus. During SE or in severe encephalopathies, a so-called electroclinical ictal-interictal continuum may occur, which denotes an intermediate stage that cannot be defined with certainty as ictal or interictal by EEG and should not lead to harmful overtreatment. Because both prognosis and specific treatment options depend crucially on the etiology of SRSE, the etiological evaluation should be performed rapidly. When SRSE is confirmed, various pharmacological and non-pharmacological treatment options are available. Conclusion We provide a pragmatical SOP for adult people with SRSE.
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Grigg-Damberger MM, Hussein O, Kulik T. Sleep Spindles and K-Complexes Are Favorable Prognostic Biomarkers in Critically Ill Patients. J Clin Neurophysiol 2022; 39:372-382. [PMID: 35239561 DOI: 10.1097/wnp.0000000000000830] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
SUMMARY In this narrative review, we summarize recent research on the prognostic significance of biomarkers of sleep in continuous EEG and polysomnographic recordings in intensive care unit patients. Recent studies show the EEG biosignatures of non-rapid eye movement 2 sleep (sleep spindles and K-complexes) on continuous EEG in critically ill patients better predict functional outcomes and mortality than the ictal-interictal continuum patterns. Emergence of more complex and better organized sleep architecture has been shown to parallel neurocognitive recovery and correlate with functional outcomes in traumatic brain injury and strokes. Particularly interesting are studies which suggest intravenous dexmedetomidine may induce a more biomimetic non-rapid eye movement sleep state than intravenous propofol, potentially providing more restorative sleep and lessening delirium. Protocols to improve intensive care unit sleep and neurophysiological studies evaluating the effect of these on sleep and sleep architecture are here reviewed.
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Pinto LF, Oliveira JPSD, Midon AM. Status epilepticus: review on diagnosis, monitoring and treatment. ARQUIVOS DE NEURO-PSIQUIATRIA 2022; 80:193-203. [PMID: 35976303 PMCID: PMC9491413 DOI: 10.1590/0004-282x-anp-2022-s113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 04/29/2022] [Indexed: 06/15/2023]
Abstract
Status epilepticus (SE) is a frequent neurological emergency associated with high morbidity and mortality. According to the new ILAE 2015 definition, SE results either from the failure of the mechanisms responsible for seizure termination or initiation, leading to abnormally prolonged seizures. The definition has different time points for convulsive, focal and absence SE. Time is brain. There are changes in synaptic receptors leading to a more proconvulsant state and increased risk of brain lesion and sequelae with long duration. Management of SE must include three pillars: stop seizures, stabilize patients to avoid secondary lesions and treat underlying causes. Convulsive SE is defined after 5 minutes and is a major emergency. Benzodiazepines are the initial treatment, and should be given fast and an adequate dose. Phenytoin/fosphenytoin, levetiracetam and valproic acid are evidence choices for second line treatment. If SE persists, anesthetic drugs are probably the best option for third line treatment, despite lack of evidence. Midazolam is usually the best initial choice and barbiturates should be considered for refractory cases. Nonconvulsive status epilepticus has a similar initial approach, with benzodiazepines and second line intravenous (IV) agents, but after that, aggressiveness should be balanced considering risk of lesion due to seizures and medical complications caused by aggressive treatment. Usually, the best approach is the use of sequential IV antiepileptic drugs (oral/tube are options if IV options are not available). EEG monitoring is crucial for diagnosis of nonconvulsive SE, after initial control of convulsive SE and treatment control. Institutional protocols are advised to improve care.
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Affiliation(s)
- Lecio Figueira Pinto
- Universidade de São Paulo, Faculdade de Medicina, Hospital das Clínicas, Departamento de Neurologia, Grupo de Epilepsia, São Paulo SP, Brazil
| | | | - Aston Marques Midon
- Universidade de São Paulo, Faculdade de Medicina, Hospital das Clínicas, Departamento de Neurologia, São Paulo SP, Brazil
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Husari KS, Johnson EL, Ritzl EK. Acute and Long-Term Outcomes of Lateralized Rhythmic Delta Activity (LRDA) Versus Lateralized Periodic Discharges (LPDs) in Critically Ill Patients. Neurocrit Care 2021; 34:201-208. [PMID: 32556854 DOI: 10.1007/s12028-020-01017-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
BACKGROUND To assess the acute and long-term outcomes for patients with lateralized rhythmic delta activity (LRDA) compared to patients with lateralized periodic discharges (LPDs). METHODS A single-center retrospective study examining consecutive patients older than 10 years who had LRDA, LPDs, or both on continuous electroencephalographic (cEEG) between 12/01/2015 and 12/31/2017. Outcomes included inpatient mortality, functional outcome at follow-up, inpatient electrographic seizures, and the presence of new epilepsy at follow-up. Patients were classified into 4 groups: LRDA-only (without LPDs), LPDs-only (without LRDA), LRDA/LPDs, and control (without LRDA or LPDs). RESULTS Twenty-nine patients (2.7%) were in the LRDA-only group, 76 (7%) patients were in the LPDs-only group, and 25 (2.3%) patients had both patterns (LRDA/LPDs group). 68 patients were identified as a control group. Only one patient (3%) in the LRDA-only group died during their hospitalization, compared to 21 patients (28%) in the LPDs-only group, 2 (8%) LRDA/LPDs group and 7 (10%) in the control group (p 0.003). Patients in the LPDs-only group had three times higher odds of adjusted mortality compared to the control group (p 0.05), while there was no difference in the mortality odds between the LRDA-only and control groups. Patients with LRDA-only had higher odds of good functional outcome at clinic follow-up (p 0.04). When compared to control, patients with both IIC patterns (LRDA/LPDs group) had 24.3 higher odds of acute electrographic seizures (p < 0.001), followed by patients in LPDs-only (OR 12.6, p < 0.001) and then LRDA-only (OR 9.4, p = 0.002). The odds of developing epilepsy following discharge were not increased in patients with either LRDA or LPDs (p = 0.9). CONCLUSIONS Patients with LRDA had superior functional outcome compared to a higher mortality for patients with LPDs. Patients with both patterns had the highest odds of acute seizures, followed by those with only LPDs and then patients with only LRDA. There was no difference in the odds of developing new epilepsy compared to control with any IIC pattern. We hypothesize different underlying mechanisms of injury leading to the observed electrographic patterns.
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Affiliation(s)
- Khalil S Husari
- Department of Neurology, Comprehensive Epilepsy Center, Johns Hopkins University, 600 N. Wolfe St, Meyer 2-147, Baltimore, MD, USA.
| | - Emily L Johnson
- Department of Neurology, Comprehensive Epilepsy Center, Johns Hopkins University, 600 N. Wolfe St, Meyer 2-147, Baltimore, MD, USA
| | - Eva K Ritzl
- Department of Neurology, Comprehensive Epilepsy Center, Johns Hopkins University, 600 N. Wolfe St, Meyer 2-147, Baltimore, MD, USA
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Winslow N, George M, Michalos A, Wang H, Ergene E, Xu M. Hemodynamic Changes Associated with Lateralized Periodic Discharges: A Near-Infrared Spectroscopy and Continuous EEG Study. Neurocrit Care 2020; 35:153-161. [PMID: 33263144 DOI: 10.1007/s12028-020-01154-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 11/12/2020] [Indexed: 11/24/2022]
Abstract
BACKGROUND Lateral periodic discharges (LPDs) have been recognized as a common electroencephalographic (EEG) pattern in critically ill patients. However, management decisions in these patients are still a challenge for clinicians. This study investigates hemodynamic changes associated with LPDs and evaluates if this pattern is likely to represent an ictal, interictal, or ictal-interictal continuum phenomenon via non-invasive near infra-red spectroscopy (NIRS) with concurrent with continuous EEG. METHODS Seventeen patients admitted to the intensive care unit with LPDs on continuous electroencephalogram (EEG) were included. Participants engaged in NIRS recording-with scalp probes on right and left frontal regions simultaneously. Associations between LPDs laterality, primary frequency, NIRS a of cerebral oxygen saturation (SO2), total hemoglobin concentration (tHb), oxygenated hemoglobin concentration (O2Hb), de-oxygenated hemoglobin concentration (HHb), and variables in participant medical history were studied. RESULTS Hemispheres with LPDs showed higher overall SO2 when compared to non-LPDs hemispheres (57% vs 52%, p = 0.03). Additionally, mildly increased tHb, O2Hb, and mildly decreased HHb concentrations were detected in the hemisphere showing LPDs, but changes were not statistically significant. A higher primary frequency of LPDs was associated with lower cerebral SO2 (Pearson correlation r = - 0.55, p = 0.022) and O2Hb (Pearson correlation r = - 0.52, p = 0.033). In patients with seizure during their EEG recording (64.7%), lower tHb (28.2 μmol/L vs 37.8 μmol/L, p = 0.049) and O2Hb (15.5 μmol/L vs 24.2 μmol/L, p = 0.033) were recorded in the LPDs hemisphere. CONCLUSIONS This study demonstrates an increased cerebral SO2 in the hemisphere with LPDs, and decreased SO2 and O2Hb when the frequency of LPDs increases. The findings indicate that LPDs increase oxygen demand on the ipsilateral hemisphere. We infer that a threshold of LPDs frequency might exit, when the cerebral oxygen demand begins to supersede the ability of delivery, and saturation decreases.
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Affiliation(s)
- Nolan Winslow
- Department of Neurosurgery, OSF Illinois Neurological Institute, 200 E Pennsylvania Ave, Peoria, IL, 61603, USA
| | - Mebin George
- Department of Engineering, University of Illinois Urbana-Champaign, 1206 W. Clark Street, Urbana, IL, 61801, USA
| | - Antonios Michalos
- Health Care Engineering Systems Center, University of Illinois Urbana-Champaign, 1206 W. Clark Street, Urbana, IL, 61801, USA
| | - Huaping Wang
- University of Illinois College of Medicine, One Illini Drive, Peoria, IL, 61656, USA
| | - Erhan Ergene
- Department of Neurology, OSF Illinois Neurological Institute, 200 E Pennsylvania Ave, Peoria, IL, 61603, USA
| | - Michael Xu
- Department of Neurology, OSF Illinois Neurological Institute, 200 E Pennsylvania Ave, Peoria, IL, 61603, USA.
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Abstract
The neurological application of long-term electroencephalography (EEG) monitoring in the intensive care unit (ICU) has been implemented in many healthcare institutions. The use of EEG as a monitoring tool in the ICU affords many potential benefits. Uses include the identification of seizures, vasospasm following subarachnoid hemorrhage (SAH), the assessment of coma and the determination of brain death. Neurologic critical care is focused on recognition and treatment of secondary insults. Often treatment is withheld because these insults are not recognized early enough until an irreversible deficit manifest. Continuous EEG (cEEG) monitoring provides a unique potential to recognize these insults and offers an opportunity for early intervention. Why should we continuously monitor the brain with EEG in the ICU? Nonconvulsive seizures (NCS) are common in comatose patients. Nonconvulsive Status Epilepticus (NCSE) and NCS 1 are damaging to brain tissue; thus, rapid control of seizures is essential to preserving brain function. With the increased use of cEEG in critical care areas, the purpose of this paper is to examine the use and benefits of EEG monitoring of ICU patients, review the indications for the use of cEEG and discuss technical issues and concerns when performing cEEG monitoring. This article has been divided into six distinct sections: (1) Seizures, NCS, and NCSE (2) Periodic Discharges 2 and Patterns on the Ictal-interictal Continuum, (3) Cerebral Ischemia, SAH, and Delayed Cerebral Ischemia (DCI), (4) Encephalopathy and Coma (5) ECI and Brain Death, and (6) ICU-cEEG Monitoring Techniques.
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Affiliation(s)
- Walt Banoczi
- Professor Emeritus, Orange Coast College , Costa Mesa, California
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Kamousi B, Karunakaran S, Gururangan K, Markert M, Decker B, Khankhanian P, Mainardi L, Quinn J, Woo R, Parvizi J. Monitoring the Burden of Seizures and Highly Epileptiform Patterns in Critical Care with a Novel Machine Learning Method. Neurocrit Care 2020; 34:908-917. [PMID: 33025543 PMCID: PMC8021593 DOI: 10.1007/s12028-020-01120-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 09/17/2020] [Indexed: 12/18/2022]
Abstract
INTRODUCTION Current electroencephalography (EEG) practice relies on interpretation by expert neurologists, which introduces diagnostic and therapeutic delays that can impact patients' clinical outcomes. As EEG practice expands, these experts are becoming increasingly limited resources. A highly sensitive and specific automated seizure detection system would streamline practice and expedite appropriate management for patients with possible nonconvulsive seizures. We aimed to test the performance of a recently FDA-cleared machine learning method (Claritγ, Ceribell Inc.) that measures the burden of seizure activity in real time and generates bedside alerts for possible status epilepticus (SE). METHODS We retrospectively identified adult patients (n = 353) who underwent evaluation of possible seizures with Rapid Response EEG system (Rapid-EEG, Ceribell Inc.). Automated detection of seizure activity and seizure burden throughout a recording (calculated as the percentage of ten-second epochs with seizure activity in any 5-min EEG segment) was performed with Claritγ, and various thresholds of seizure burden were tested (≥ 10% indicating ≥ 30 s of seizure activity in the last 5 min, ≥ 50% indicating ≥ 2.5 min of seizure activity, and ≥ 90% indicating ≥ 4.5 min of seizure activity and triggering a SE alert). The sensitivity and specificity of Claritγ's real-time seizure burden measurements and SE alerts were compared to the majority consensus of at least two expert neurologists. RESULTS Majority consensus of neurologists labeled the 353 EEGs as normal or slow activity (n = 249), highly epileptiform patterns (HEP, n = 87), or seizures [n = 17, nine longer than 5 min (e.g., SE), and eight shorter than 5 min]. The algorithm generated a SE alert (≥ 90% seizure burden) with 100% sensitivity and 93% specificity. The sensitivity and specificity of various thresholds for seizure burden during EEG recordings for detecting patients with seizures were 100% and 82% for ≥ 50% seizure burden and 88% and 60% for ≥ 10% seizure burden. Of the 179 EEG recordings in which the algorithm detected no seizures, seizures were identified by the expert reviewers in only two cases, indicating a negative predictive value of 99%. DISCUSSION Claritγ detected SE events with high sensitivity and specificity, and it demonstrated a high negative predictive value for distinguishing nonepileptiform activity from seizure and highly epileptiform activity. CONCLUSIONS Ruling out seizures accurately in a large proportion of cases can help prevent unnecessary or aggressive over-treatment in critical care settings, where empiric treatment with antiseizure medications is currently prevalent. Claritγ's high sensitivity for SE and high negative predictive value for cases without epileptiform activity make it a useful tool for triaging treatment and the need for urgent neurological consultation.
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Affiliation(s)
- Baharan Kamousi
- Ceribell Inc., 2483 Old Middlefield Way, Suite 120, Mountain View, CA, USA
| | | | - Kapil Gururangan
- Department of Neurology, The Mount Sinai Hospital, New York, NY, USA
| | - Matthew Markert
- Department of Neurology and Neurological Sciences, Stanford University Medical Center, 300 Pasteur Drive, Stanford, CA, 94305, USA
| | - Barbara Decker
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Pouya Khankhanian
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Laura Mainardi
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - James Quinn
- Department of Emergency Medicine, Stanford University Medical Center, Stanford, CA, USA
| | - Raymond Woo
- Ceribell Inc., 2483 Old Middlefield Way, Suite 120, Mountain View, CA, USA
| | - Josef Parvizi
- Department of Neurology and Neurological Sciences, Stanford University Medical Center, 300 Pasteur Drive, Stanford, CA, 94305, USA.
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Westover MB, Gururangan K, Markert MS, Blond BN, Lai S, Benard S, Bickel S, Hirsch LJ, Parvizi J. Diagnostic Value of Electroencephalography with Ten Electrodes in Critically Ill Patients. Neurocrit Care 2020; 33:479-490. [PMID: 32034656 PMCID: PMC7416437 DOI: 10.1007/s12028-019-00911-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND In critical care settings, electroencephalography (EEG) with reduced number of electrodes (reduced montage EEG, rm-EEG) might be a timely alternative to the conventional full montage EEG (fm-EEG). However, past studies have reported variable accuracies for detecting seizures using rm-EEG. We hypothesized that the past studies did not distinguish between differences in sensitivity from differences in classification of EEG patterns by different readers. The goal of the present study was to revisit the diagnostic value of rm-EEG when confounding issues are accounted for. METHODS We retrospectively collected 212 adult EEGs recorded at Massachusetts General Hospital and reviewed by two epileptologists with access to clinical, trending, and video information. In Phase I of the study, we re-configured the first 4 h of the EEGs in lateral circumferential montage with ten electrodes and asked new readers to interpret the EEGs without access to any other ancillary information. We compared their rating to the reading of hospital clinicians with access to ancillary information. In Phase II, we measured the accuracy of the same raters reading representative samples of the discordant EEGs in full and reduced configurations presented randomly by comparing their performance to majority consensus as the gold standard. RESULTS Of the 95 EEGs without seizures in the selected fm-EEG, readers of rm-EEG identified 92 cases (97%) as having no seizure activity. Of 117 EEGs with "seizures" identified in the selected fm-EEG, none of the cases was labeled as normal on rm-EEG. Readers of rm-EEG reported pathological activity in 100% of cases, but labeled them as seizures (N = 77), rhythmic or periodic patterns (N = 24), epileptiform spikes (N = 7), or burst suppression (N = 6). When the same raters read representative epochs of the discordant EEG cases (N = 43) in both fm-EEG and rm-EEG configurations, we found high concordance (95%) and intra-rater agreement (93%) between fm-EEG and rm-EEG diagnoses. CONCLUSIONS Reduced EEG with ten electrodes in circumferential configuration preserves key features of the traditional EEG system. Discrepancies between rm-EEG and fm-EEG as reported in some of the past studies can be in part due to methodological factors such as choice of gold standard diagnosis, asymmetric access to ancillary clinical information, and inter-rater variability rather than detection failure of rm-EEG as a result of electrode reduction per se.
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Affiliation(s)
- M Brandon Westover
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA.
| | | | | | | | - Saien Lai
- Kaiser Permanente Medical Center, Panorama City, CA, USA
| | - Shawna Benard
- Keck Hospital of University of Southern California, Los Angeles, CA, USA
| | - Stephan Bickel
- Zucker School of Medicine at Hofstra/Northwell, Long Island, NY, USA
| | | | - Josef Parvizi
- Stanford University Medical Center, Stanford, CA, USA
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Abstract
AbstractContinuous electroencephalogram (cEEG) has become an indispensable technique in the management of critically ill patients for early detection and treatment of non-convulsive seizures (NCS) and non-convulsive status epilepticus (NCSE). It has also brought about a renaissance in a wide range of rhythmic and periodic patterns with heterogeneous frequency and morphology. These patterns share the rhythmic and sharp appearances of electrographic seizures, but often lack the necessary frequency, spatiotemporal evolution and clinical accompaniments to meet the definitive criteria for ictal patterns. They may be associated with cerebral metabolic crisis and neuronal injury, therefore not clearly interictal either, but lie along an intervening spectrum referred to as ictal-interictal continuum (IIC). Generally speaking, rhythmic and periodic patterns are categorized as interictal patterns when occurring at a rate of <1Hz, and are categorized as NCS and NCSE when occurring at a rate of >2.5 Hz with spatiotemporal evolution. As such, IIC commonly includes the rhythmic and periodic patterns occurring at a rate of 1–2.5 Hz without spatiotemporal evolution and clinical correlates. Currently there are no evidence-based guidelines on when and if to treat patients with IIC patterns, and particularly how aggressively to treat, presenting a challenging electrophysiological and clinical conundrum. In practice, a diagnostic trial with preferably a non-sedative anti-seizure medication (ASM) can be considered with the end point being both clinical and electrographic improvement. When available and necessary, correlation of IIC with biomarkers of neuronal injury, such as neuronal specific enolase (NSE), neuroimaging, depth electrode recording, cerebral microdialysis and oxygen measurement, can be assessed for the consideration of ASM treatment. Here we review the recent advancements in their clinical significance, risk stratification and treatment algorithm.
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Poststroke seizures as stroke mimics: Clinical assessment and management. Epilepsy Behav 2020; 104:106297. [PMID: 31303444 DOI: 10.1016/j.yebeh.2019.04.050] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 04/27/2019] [Accepted: 04/27/2019] [Indexed: 11/23/2022]
Abstract
Epileptic seizures with postictal negative symptoms represent 20% of all suspected strokes and should be considered in the differential diagnosis of stroke in any patient presenting with an acute neurological deficit, mostly in absence of convulsions. Seizures may also occur at stroke onset, and the latter need to be promptly recognized in order to timely administer reperfusion therapies and reduce the risk of irreversible brain injury. Neuroimaging is essential in differentiating between postictal negative symptoms and deficits due to stroke. After the acute phase, poststroke seizures may worsen or cause the reappearance of neurological deficits and consciousness impairment; they can be also misinterpreted as stroke recurrence and lead to delayed treatment with antiepileptic drugs. It is mandatory to maintain a low threshold for suspecting epileptic seizures, and require appropriate electroencephalographic and neuroimaging investigations to promptly ascertain the etiology of any unexplained change in the neurological status and provide the most adequate treatment. This article is part of the Special Issue "Seizures & Stroke".
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Tatum WO, McKay JH, ReFaey K, Feyissa AM, Ryan D, Ritaccio A, Middlebrooks E, Yelvington K, Roth G, Acton E, Grewal S, Chaichana K, Quinones-Hinojosa A. Detection of after-discharges during intraoperative functional brain mapping in awake brain tumor surgery using a novel high-density circular grid. Clin Neurophysiol 2020; 131:828-835. [PMID: 32066101 DOI: 10.1016/j.clinph.2019.12.416] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 11/21/2019] [Accepted: 12/14/2019] [Indexed: 12/13/2022]
Abstract
OBJECTIVE To evaluate intraoperative use of a novel high-density circular grid in detecting after-discharges (AD) on electrocorticography (ECoG) during functional brain mapping (FBM). METHODS FBM during glioma surgery (10/2016 to 5/2019) recorded ADs using a 22-channel circular grid compared to conventional strip electrodes. ADs were analyzed for detection, duration, amplitude, morphology, histology, direction, and clinical signs. RESULTS Thirty-two patients (mean age 54.2 years; r = 30-75) with glioma (WHO grade II-IV; 20 grade IV) had surgery. ADs during FBM were more likely in patients with wild-type as opposed to IDH-1 mutants (p < 0.0001) using more contacts compared with linear strip electrodes (p = 0.0001). More sensors tended to be involved in ADs detected by the circular grid vs strips (6.61 vs 3.43; p = 0.16) at lower stimulus intensity (3.14 mA vs 4.13 mA; p = 0.09). No difference in the number of cortical stimulations before resection was present (38.9 mA vs 47.9 mA; p = 0.26). ADs longer than 10 seconds were 32.5 seconds (circular grid) vs 58.4 (strips) (p = 0.12). CONCLUSIONS High-density circular grids detect ADs in 360 degrees during FBM for glioma resection. Provocation of ADs was more likely in patients with wild-type than IDH-1 mutation. SIGNIFICANCE Circular grids offer high-resolution ECoG during intraoperative FBM for detection of ADs.
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Affiliation(s)
- William O Tatum
- Department of Neurology, Mayo Clinic, Jacksonville, FL, USA.
| | - Jake H McKay
- Department of Neurology, Mayo Clinic, Jacksonville, FL, USA
| | - Karim ReFaey
- Department of Neurosurgery, Mayo Clinic, Jacksonville, FL, USA
| | | | - Dan Ryan
- Department of Neurology, Mayo Clinic, Jacksonville, FL, USA
| | | | | | - Kirsten Yelvington
- Department of Clinical Neurophysiology, Mayo Clinic, Jacksonville, FL, USA
| | | | - Emily Acton
- University of Pennsylvania, Philadelphia, PA, USA
| | - Sanjeet Grewal
- Department of Neurosurgery, Mayo Clinic, Jacksonville, FL, USA
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Conventional and quantitative EEG in status epilepticus. Seizure 2018; 68:38-45. [PMID: 30528098 DOI: 10.1016/j.seizure.2018.09.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 09/11/2018] [Accepted: 09/14/2018] [Indexed: 01/10/2023] Open
Abstract
PURPOSE To summarize the use of continuous electroencephalographic monitoring (cEEG) in the diagnosis and management of pediatric convulsive status epilepticus (CSE) and subsequent non-convulsive seizures (NCS) with a focus on available guidelines and infrastructure. In addition, we provide an overview of quantitative EEG (QEEG) for the identification of NCS in critically ill children. METHODS We performed a review of the medical literature on the use of cEEG and QEEG in pediatric CSE. This included published guideline, consensus statements, and literature focused on the use of cEEG and QEEG to detect NCS. RESULTS cEEG monitoring is recommended for prompt recognition of ongoing seizures that may be subtle, masked by pharmacologic paralysis, and or converted from convulsive seizures to NCS after administration of anti-seizure medications. Evidence indicating that high seizure burden is associated with worse outcome has motivated prompt recognition and management of NCS. The American Clinical Neurophysiology Society's consensus statement recommends a minimum of 24 h to exclude electrographic seizures, while the Neurocritical Care Society's guideline suggests 48 h in patients that are comatose. The use of QEEG amongst electroencephalographers and critical care medicine providers is increasing for NCS detection in critically ill children. The sensitivity and specificity of QEEG to detect NCS ranges from 65 to 83% and 65-92%, respectively. CONCLUSION The use of cEEG is important to the diagnosis and treatment of NCS or subtle clinical seizures after pediatric CSE. QEEG allows cEEG data to be reviewed and interpreted quickly and is a useful tool for detection of NCS after CSE.
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