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Sharma S, Nunes M, Alkhachroum A. Adult Critical Care Electroencephalography Monitoring for Seizures: A Narrative Review. Front Neurol 2022; 13:951286. [PMID: 35911927 PMCID: PMC9334872 DOI: 10.3389/fneur.2022.951286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 06/22/2022] [Indexed: 11/13/2022] Open
Abstract
Electroencephalography (EEG) is an important and relatively inexpensive tool that allows intensivists to monitor cerebral activity of critically ill patients in real time. Seizure detection in patients with and without acute brain injury is the primary reason to obtain an EEG in the Intensive Care Unit (ICU). In response to the increased demand of EEG, advances in quantitative EEG (qEEG) created an approach to review large amounts of data instantly. Finally, rapid response EEG is now available to reduce the time to detect electrographic seizures in limited-resource settings. This review article provides a concise overview of the technical aspects of EEG monitoring for seizures, clinical indications for EEG, the various available modalities of EEG, common and challenging EEG patterns, and barriers to EEG monitoring in the ICU.
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Affiliation(s)
- Sonali Sharma
- Department of Neurology, University of Miami, Miami, FL, United States
- Department of Neurology, Jackson Memorial Hospital, Miami, FL, United States
| | - Michelle Nunes
- Department of Neurology, University of Miami, Miami, FL, United States
- Department of Neurology, Jackson Memorial Hospital, Miami, FL, United States
| | - Ayham Alkhachroum
- Department of Neurology, University of Miami, Miami, FL, United States
- Department of Neurology, Jackson Memorial Hospital, Miami, FL, United States
- *Correspondence: Ayham Alkhachroum
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Fernández-Torre JL, Kaplan PW. Atypical or Typical Triphasic Waves-Is There a Difference? A Review. J Clin Neurophysiol 2021; 38:384-398. [PMID: 34155183 DOI: 10.1097/wnp.0000000000000731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
SUMMARY The entity of triphasic waves (TWs) and TW encephalopathy has derived from the subjective art of EEG interpretation. Indeed, there are few if any guidelines regarding many different aspects of TWs. The authors seek to shed light on the nature and the diagnostic characteristics of various types of TWs, differentiating "typical" from "atypical" forms. The authors conclude that morphologies in the form of bursts of well-formed, smoothly contoured, negative-positive-negative, bilateral, symmetrical and synchronous, regular, reactive, periodic or rhythmic, 1.5 to 2.0 Hz, fronto-central, triphasic complexes with fronto-occipital lag meet the criteria for typical TWs and are highly suggestive of toxic-metabolic encephalopathies. These are most frequently hepatic, uremic, or sepsis-associated encephalopathies with multi-organ failure. In such cases, atypical TWs (frontopolar or parieto-occipital maximum, negative-positive or negative-positive-negative, asymmetric and asynchronous, unreactive, irregular, multifocal, continuous with spatiotemporal evolution, sharper and without fronto-occipital/occipito-frontal lag, or triphasic delta waves) are rarely seen. Atypical TWs are encountered in Angelman syndrome, toxic encephalopathies, hyperthyroidism/hypothyroidism, Hashimoto encephalopathy, nonconvulsive status epilepticus, dementia, sepsis-associated encephalopathy, cerebrovascular disorders, and certain boundary syndromes. Investigations describing TWs with uncommon etiologies revealed few with typical TWs, suggesting that the term "TWs" has been overused in the past. Triphasic waves arise from the interaction of multiple factors including toxic, metabolic, infectious, and structural disorders that affect circuits between thalamus and cortex. The patient's metabolic status, presence of potentially neurotoxic drugs, cerebral atrophy, white matter disease, dementia, or seizures help differentiate typical from typical TWs. Future studies will determine whether this dichotomy is heuristically and clinically helpful.
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Affiliation(s)
- José L Fernández-Torre
- Clinical Neurophysiology Department, Marqués de Valdecilla University Hospital, Santander, Cantabria, Spain
- Biomedical Research Institute (IDIVAL), Santander, Cantabria, Spain; and
| | - Peter W Kaplan
- Department of Neurology, Johns Hopkins Bayview Medical Center, Baltimore, Maryland, U.S.A
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Abstract
SUMMARY Generalized periodic patterns with triphasic wave morphology, long referred to as triphasic waves [TWs], had been associated with metabolic encephalopathies, although other neurologic and systemic causes have since been identified. In a recent classification of periodic patterns, TWs were formally grouped with the generalized periodic discharges, which are often associated with ictal activity. The interpretation of generalized periodic patterns with TWs as nonictal can have significant implications in the management of comatose patients in nonconvulsive status epilepticus. Electrographic characteristics that help distinguish nonictal periodic patterns with TWs from generalized periodic discharge ictal patterns include (1) TWs in long runs of periodic bilaterally synchronous and symmetric discharges, maximal in frontocentral or posterior head regions with and without a frontal-to-occipital lag or posterior-to-anterior lag, respectively; (2) recurrent spontaneous and/or low-dose benzodiazepine-induced attenuation and/or suppression of the periodic pattern and replacement with a diffuse slow wave activity throughout a prolonged EEG recording; and (3) stimulation-induced activation and/or increase in frequency and/or organization of TWs. We coined the term of status triphasicus to describe the electrographic periodic pattern of TWs with these three distinct characteristics. In this article, we discuss the advantages and limitations of keeping the status triphasicus pattern as a distinct electrographic entity different from periodic ictal generalized periodic discharge patterns. We discuss the circumstances in which a status triphasicus pattern can be associated with ictal activity and propose a simple pragmatic classification of status triphasicus that encompasses the different clinical scenarios it can be associated with.
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Affiliation(s)
- Manuel M Bicchi
- Department of Neurology, Miller School of Medicine, University of Miami, Miami, Florida, U.S.A.; and
- Neurology Services, University of Miami Hospital and Clinics and Jackson Memorial Hospital, Miami, Florida, U.S.A
| | - Ayham Alkhachroum
- Department of Neurology, Miller School of Medicine, University of Miami, Miami, Florida, U.S.A.; and
- Neurology Services, University of Miami Hospital and Clinics and Jackson Memorial Hospital, Miami, Florida, U.S.A
| | - Andres M Kanner
- Department of Neurology, Miller School of Medicine, University of Miami, Miami, Florida, U.S.A.; and
- Neurology Services, University of Miami Hospital and Clinics and Jackson Memorial Hospital, Miami, Florida, U.S.A
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Freund B, Kotchetkov IS, Kaplan PW. White Matter Disease-The True Source of Triphasic Waves? J Clin Neurophysiol 2021; 38:359-361. [PMID: 34155178 DOI: 10.1097/wnp.0000000000000745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
SUMMARY Triphasic waves are EEG phenomena typically seen in patients with acute encephalopathy and have importance in diagnosis and prognosis in these cases. The underlying metabolic disturbances associated with their incidence have been described previously, but neuroimaging characteristics are not well delineated. There are a few small studies that define neuroimaging results in patients with triphasic waves. This review highlights the most common neuroimaging findings in these patients, including subcortical white matter disease, which itself may be a risk factor for triphasic waves.
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Affiliation(s)
- Brin Freund
- Department of Neurology, Johns Hopkins Bayview Medical Center, Baltimore, Maryland, U.S.A. ; and
| | - Ivan S Kotchetkov
- Department of Neurology, Memorial Sloan Kettering Cancer Center, New York, New York, U.S.A
| | - Peter W Kaplan
- Department of Neurology, Johns Hopkins Bayview Medical Center, Baltimore, Maryland, U.S.A. ; and
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Kaplan PW, Gélisse P, Sutter R. An EEG Voyage in Search of Triphasic Waves-The Sirens and Corsairs on the Encephalopathy/EEG Horizon: A Survey of Triphasic Waves. J Clin Neurophysiol 2021; 38:348-358. [PMID: 34155177 DOI: 10.1097/wnp.0000000000000725] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
SUMMARY Generalized periodic discharges with triphasic wave (TW) morphology, long referred to as TWs, are typical of many toxic, metabolic, infectious, and cerebral structural problems, often in concert. Identifying TWs has been challenging for the electroencephalographer and clinician, as has been their cause, significance, prognosis, and treatment. This review highlights the many different patterns of TWs with commentary on their various causes and etiologies, characteristics, different morbidities, differentiation from nonconvulsive status epilepticus, and their prognosis. The articles in this Journal of Clinical Neurophysiology special issue on TWs will review the many challenges the clinician face when TWs are sighted.
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Affiliation(s)
- Peter W Kaplan
- Department of Neurology, Johns Hopkins Bayview Medical Center, Baltimore, Maryland, U.S.A
| | - Philippe Gélisse
- Department of Neurology, Epilepsy Unit Montpellier, Montpellier, France
| | - Raoul Sutter
- Intensive Care Units and Department of Neurology, University Hospital Basel, Basel, Switzerland; and
- University of Basel, Basel, Switzerland
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Fernández-Torre JL, Kaplan PW. Triphasic Waves: Historical Overview of an Unresolved Mystery. J Clin Neurophysiol 2021; 38:399-409. [PMID: 34155180 DOI: 10.1097/wnp.0000000000000809] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
SUMMARY Triphasic waves are a fascinating and mysterious EEG feature. We now have to accept that, at times, epileptiform discharges may have a blunted "triphasic morphology," and that there may be great difficulty in distinguishing between these often similar forms. The aim of this review was to describe the evolution in our understanding of triphasic waves that has occurred regarding the pathophysiology of triphasic waves, their most frequent causes, and the diagnostic difficulties involved in interpretation and differentiation from nonconvulsive status epilepticus.
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Affiliation(s)
- José L Fernández-Torre
- Clinical Neurophysiology Department, Marqués de Valdecilla University Hospital, Santander, Cantabria, Spain
- Biomedical Research Institute (IDIVAL), Santander, Cantabria, Spain; and
| | - Peter W Kaplan
- Department of Neurology, Johns Hopkins Bayview Medical Center, Baltimore, Maryland, U.S.A
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Rahwan M, Edwards JC. Neuroimaging in Triphasic Waves. J Clin Neurophysiol 2021; 38:410-414. [PMID: 34155179 DOI: 10.1097/wnp.0000000000000778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
SUMMARY Triphasic waves can be seen in a wide range of medical conditions, particularly in metabolic encephalopathies. Neuroimaging studies provide valuable diagnostic information for neurological conditions and can also help in our understanding of anatomical substrates for these conditions. Because of practical challenges and the fact that most encephalopathies with triphasic waves are presumed to be metabolic in etiology, large studies of imaging findings associated with triphasic waves are limited. We present a summary of studies that are currently available and a discussion of insights that these studies provide.
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Affiliation(s)
- Mohamad Rahwan
- Department of Neurology, The Medical University of South Carolina, Charleston, South Carolina, U.S.A
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Hartshorn JA, Foreman B. Generalized periodic discharges with triphasic morphology. JOURNAL OF NEUROCRITICAL CARE 2019. [DOI: 10.18700/jnc.190079] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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Affiliation(s)
- Francesco Brigo
- Department of Neurological, Neuropsychological, Morphological and Movement Sciences Section of Neurology University of Verona Verona, Italy
| | - Monica Storti
- Department of Medicine Section of Gastroenterology University of Verona Verona, Italy
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Jadav R, Sinha S, Nagarathna S, Bindu P, Mahadevan A, Bharath R, Shankar S, Taly A. Carcinomatous meningitis: Yet another cause for rapidly progressive dementia and triphasic waves in electroencephalograph! J Neurosci Rural Pract 2012; 3:207-9. [PMID: 22865984 PMCID: PMC3410003 DOI: 10.4103/0976-3147.98253] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
We report a 65-year-old woman who manifested with progressive cognitive impairment, abnormal behavior, slurred speech, inability to carry out activities with right upper limb, gait disturbances, emotional liability, and double incontinence that evolved progressively over the last 8 months. A clinical syndrome of “rapidly progressive dementia” was considered. The MRI of brain was unremarkable except for small para third ventricular enhancing lesion was detected in the left thalamic region. There was bi/tri-phasic sharp waves in the routine scalp EEG occurring at periodically 1.5–2.0 Hz, mimicking Creutzfeldt–Jakob disease (CJD). She was later diagnosed to have carcinomatous meningitis based on cerebrospinal fluid (CSF) cytology. This case is being discussed for rarity and interesting EEG observations in patients with carcinomatous meningitis and to highlight the importance of CSF cytology in an appropriate clinical setting. One needs to be careful in concluding CJD as possible diagnosis in such scenario.
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Affiliation(s)
- R Jadav
- Department of Neurology, NIMHANS, Bangalore, India
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Rosenthal ES. The utility of EEG, SSEP, and other neurophysiologic tools to guide neurocritical care. Neurotherapeutics 2012; 9:24-36. [PMID: 22234455 PMCID: PMC3271154 DOI: 10.1007/s13311-011-0101-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Neuromonitoring is an emerging field that aims to characterize real-time neurophysiology to tailor therapy for acute injuries of the central nervous system. While cardiac telemetry has been used for decades among patients requiring critical care of all kinds, neurophysiology and neurotelemetry has only recently emerged as a routine screening tool in comatose patients. The increasing utilization of electroencephalography in comatose patients is primarily due to the recognition of the common occurrence of nonconvulsive seizures among comatose patients, the development of quantitative measures to detect regional ischemia, and the appreciation of electroencephalography phenotypes that indicate prognosis after cardiac arrest. Other neuromonitoring tools, such as somatosensory evoked potentials have a complementary role, surveying the integrity of the neuroaxis as an indicator of prognosis or illness progression in both acute brain and spinal injuries.
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Affiliation(s)
- Eric S Rosenthal
- Department of Neurology, Division of Neurocritical Care and Emergency Neurology, Massachusetts General Hospital, Boston, MA 02114, USA.
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Konno S, Sugimoto H, Nemoto H, Kitazono H, Murata M, Toda T, Nakazora H, Nomoto N, Wakata N, Kurihara T, Fujioka T. Triphasic waves in a patient with tuberculous meningitis. J Neurol Sci 2010; 291:114-7. [DOI: 10.1016/j.jns.2009.12.027] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2009] [Revised: 12/22/2009] [Accepted: 12/23/2009] [Indexed: 11/16/2022]
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Kaya D, Bingol CA. Significance of atypical triphasic waves for diagnosing nonconvulsive status epilepticus. Epilepsy Behav 2007; 11:567-77. [PMID: 17942373 DOI: 10.1016/j.yebeh.2007.07.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Revised: 07/20/2007] [Accepted: 07/30/2007] [Indexed: 10/22/2022]
Abstract
The aim of the study described here was to analyze findings in 15 cases who were admitted with nonconvulsive status epilepticus (NCSE) and whose EEGs featured atypical triphasic waves (ATWs). We also investigated whether ATWs are useful for diagnosing this condition. Mental status was assessed, and EEGs were recorded during/after the antiepileptic drug treatment. Eight patients had metabolic disorders and nine had intracranial pathology. The ATWs were unilateral focal in 5 cases and bilaterally asymmetrical focal in 10 cases. In 11 of the 15 cases, the ATWs disappeared and mental status improved after treatment. NCSE should be considered in any individual who presents in an acute confusional state and whose EEG reveals either unilateral or bilaterally asymmetric ATWs.
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Affiliation(s)
- Dilaver Kaya
- Department of Neurology, Marmara University Hospital, Istanbul, Turkey.
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Abstract
We describe a case of encephalopathy in which the clinical picture and triphasic waves in the EEG indicated a metabolic cause. However, the illness was caused by neuroborreliosis. The occurrence of triphasic waves in the EEG is a strong evidence of metabolic encephalopathy, but triphasic waves are not specific for metabolic encephalopathy. Triphasic waves have been described in a number of non-metabolic encephalopaties and structural brain lesions. To our knowledge, this is the first report of triphasic waves in Borrelia burgdorferi meningoencephalitis.
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Affiliation(s)
- B Eriksson
- Division of Clinical Neurology, Lund University Hospital, Lund, Sweden.
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Kwon OY, Jung KY, Park KJ, Kang JK, Shon YM, Lee IK, Yum MK. Source localization of triphasic waves: implications for the pathophysiological mechanism. Clin EEG Neurosci 2007; 38:161-7. [PMID: 17844946 DOI: 10.1177/155005940703800313] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
To investigate the current source location from the electroencephalograms (EEGs) of 12 patients who showed typical triphasic waves attributable to various causes, using the combination of a dipole source model and a distributed source model. The triphasic waves were explained by a single main dipole in 10 of the 12 patients, and 2 patients had two dipoles responsible for the triphasic waves. All the main dipoles had a radial orientation with respect to the frontal pole. The current density of the triphasic waves was distributed mainly in the bilateral medial frontal regions along the cingulate cortices. These findings suggest that current sources located in the medial frontal area are crucial for generating triphasic waves. The source localization may be useful for elucidating the pathophysiologic mechanism of generalized non-epileptic EEG activities, such as triphasic waves.
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Affiliation(s)
- Oh-Young Kwon
- Department of Neurology and Gyeongsang Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, South Korea
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Cherian PJ, Radhakrishnan K. Triphasic waves in a patient with brainstem hemorrhage modified by hemispheric infarct. Eur J Neurol 2004; 11:789-90. [PMID: 15525303 DOI: 10.1111/j.1468-1331.2004.00963.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Abstract
Refractory epileptic state (RES) is defined by severe seizures that are resistant to antiepileptic drug treatment. Diagnostic errors such as pseudo-seizures and encephalopathies with triphasic waves must be distinguished at an early stage from cases of RES. The latter are symptomatic of a focal brain lesion or severe systemic disease, most frequently metabolic in origin. The treatment of such conditions is aimed at correction of the underlying cause. A nosographic issue that is still a subject of discussion and which requires further study, i.e., PLEDS, will also be discussed in this article.
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Affiliation(s)
- F Assal
- Unité d'EEG, clinique de neurologie, hôpital cantonal universitaire, Genève, Suisse
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Abstract
BACKGROUND The term, "triphasic wave" originally described an EEG pattern believed to be a marker for a specific stage of hepatic coma. For 4 decades, the diagnostic and prognostic specificity of the pattern remains controversial. Its pathophysiology also continues to be elusive. METHODS EEG recordings were obtained in three patients known or suspected to have primary generalized epilepsy. In 2 patients, the EEGs were part of long-term monitoring using simultaneous video-EEG telemetry. For the third patient, the EEG was secured only during the post-ictal unconsciousness. These 3 patients were specifically selected because of the presence of triphasic waves in their EEGs. RESULTS Triphasic waves were observed in the EEG of the 3 patients only during post-ictal unconsciousness. The pattern was transient, being preceded by generalized suppression and delta slow waves and followed by theta activities. Alpha rhythms supervened when the patients became fully alert. CONCLUSION A post-ictal state should be considered in unconscious patients with triphasic EEG waves.
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Affiliation(s)
- A Ogunyemi
- Division of Neurology, Memorial University, St. John's, Newfoundland, Canada
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Nowack WJ, King JA. Triphasic waves and spike wave stupor. CLINICAL EEG (ELECTROENCEPHALOGRAPHY) 1992; 23:100-4. [PMID: 1582047 DOI: 10.1177/155005949202300210] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Triphasic waves are usually thought of as indicating a metabolic encephalopathy. Recent investigations have added nonmetabolic etiologies to the differential diagnosis of triphasic waves. Seizures are not generally thought of as associated with triphasic waves. Similarities in the appearance of records with encephalopathies and continuous triphasic waves and those of some patients with the Lennox-Gastaut syndrome have been noted. We presented a case which suggests that the presence of TW in a patient with a metabolic encephalopathy might suggest petit mal status epilepticus.
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Affiliation(s)
- W J Nowack
- Department of Neurology, University of South Alabama, Mobile 36617
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