Nonconvulsive Status Epilepticus: How can you tell? What do you do?
0

Nonconvulsive Status Epilepticus: Overlooked and Undertreated

Below is a free preview. Log in or subscribe for full access. Or, get a free sample article Emergency Department Management of Abnormal Uterine Bleeding in the Nonpregnant Patient:
Please provide a valid email address.

*NEW* Quick Search this issue!

Table of Contents
 
About This Issue

When a patient presents to the ED with new-onset altered mental status or unusual behavior without visible convulsive activity, how can you tell if it is nonconvulsive status epilepticus? Prompt treatment can prevent neurologic sequelae.

Definitive diagnosis is by EEG, but what are the clinical clues that will help determine what’s causing the behavior changes if EEG is unavailable?

Do patients in NCSE always have impaired consciousness?

What are the possible causes of NCSE?

What are the risk factors that could point to NCSE?

Is CT scan recommended for all patients who have a seizure?

What are the first-line, second-line, and third-line drugs to use?

How should you manage alcoholic patients who present with seizure?

What are the cautions you should exercise when managing elderly patients with NCSE?

Table of Contents
  1. Abstract
  2. Case Presentations
  3. Abbreviations of Types of Status Epilepticus
  4. Introduction
  5. Classification and Taxonomy of Status Epilepticus
  6. Critical Appraisal of the Literature
  7. Etiology and Pathophysiology
  8. Differential Diagnosis
  9. Prehospital Care
  10. Emergency Department Evaluation
    1. History
    2. Physical Examination
  11. Diagnostic Studies
    1. Laboratory Studies
    2. Neuroimaging
    3. Lumbar Puncture
    4. Electroencephalography
  12. Treatment
    1. Pharmacologic Therapy
      1. First-Line Treatment
      2. Second-Line Treatment
      3. Third-Line Treatment
  13. Special Populations
    1. Patients Abusing Alcohol
    2. Elderly Patients
  14. Controversies and Cutting Edge
    1. Bedside Electroencephalography
    2. Additional Treatment Options
  15. Disposition
  16. Summary
  17. Time- and Cost-Effective Strategies
  18. Risk Management Pitfalls for Patients With Nonconvulsive Status Epilepticus in the Emergency Department
  19. Case Conclusions
  20. Clinical Pathway for Management of Nonconvulsive Status Epilepticus
  21. Tables
    1. Table 1. Clinical Features of Nonconvulsive Status Epilepticus
    2. Table 2. Clinical Subtypes and Features of Nonconvulsive Status Epilepticus
    3. Table 3. Common Etiologies of Nonconvulsive Status Epilepticus
    4. Table 4. Differential Diagnosis for Nonconvulsive Status Epilepticus
    5. Table 5. Clinical Findings and Risk Factors in Nonconvulsive Status Epilepticus
    6. Table 6. Treatment Approach in Nonconvulsive Status Epilepticus, by Subtype
    7. Table 7. Pharmacotherapy for Nonconvulsive Status Epilepticus
    8. Table 8. Indications for Continuous EEG to Diagnose Nonconvulsive Status Epilepticus in the Critically Ill Patient
  22. References

Abstract

Nonconvulsive status epilepticus (NCSE) is characterized by persistent change in mental status from baseline lasting more than 5 minutes, generally with epileptiform activity seen on EEG monitoring and subtle or no motor abnormalities. NCSE can be a difficult diagnosis to make in the emergency department setting, but the key to diagnosis is a high index of suspicion coupled with rapid initiation of continuous EEG and early involvement of neurology. Benzodiazepines are the mainstay of first-line therapy, with antiepileptic drugs and anesthetics as second- and third-line therapies, respectively. The few established guidelines on the treatment of NCSE are highly variable, and the objective of this comprehensive review is to create a standardized evidence-based protocol for the diagnosis and treatment of NCSE.

Case Presentations

An 81-year-old woman presents with 1 day of behavioral changes. On examination, she is disoriented, with no focal neurologic findings and no evidence of seizure activity. Her medical history is remarkable for anxiety, arthritis, and hypertension; she has no history of stroke, trauma, or immunocompromise. Her medications include furosemide, lorazepam, and acetaminophen. After an extensive workup in the ED including ECG, CBC, CMP, UA, and brain CT, all of which were normal, she was admitted to the floor. You wonder: Is there something you forgot to consider in your differential diagnosis?

A 35-year-old man with unknown history is brought to the ED following a 10-minute witnessed seizure. EMS administered 4 mg of lorazepam IV and fosphenytoin 1200 PE IVPB, which terminated the seizure; however, the patient remained altered. Brain CT was normal. ECG, CBC, CMP, VBG, UDS, and UA were unremarkable other than an elevated lactate that quickly cleared. You admit him to the ICU, but wonder: Is he is altered because he is postictal? Is it from the lorazepam, or could there be another etiology to consider?

A 42-year-old homeless man with bipolar disorder arrives by EMS after being found on a park bench. He has a temperature of 38.1°C (100.6°F) but otherwise normal vital signs. He smells of alcohol and has abrasions on his hands and face. GCS score is 10, and he is mumbling inappropriate but comprehensible words. Brain CT and cervical spine were normal. Laboratory testing demonstrated elevated BUN, Cr, CPK, and alcohol levels; mild leukocytosis; and normal UA and UDS. When his mental status did not improve, you order a lumbar puncture, but you wonder: Could another test could be diagnostic?

Abbreviations of Types of Status Epilepticus

ASE Absence status epilepticus
CPSE Complex partial status epilepticus
GCSE Generalized convulsive status epilepticus
NCSE Nonconvulsive status epilepticus
sCSE Subtle convulsive status epilepticus
SE Status epilepticus
SPSE Simple partial status epilepticus
SSE Subtle status epilepticus

Introduction

Seizures are classified as partial or generalized, and they can generate motor, sensory, psychiatric, or autonomic disturbances. A partial seizure denotes abnormal neuronal firing within a limited area of 1 brain hemisphere, whereas a generalized seizure constitutes abnormal firing diffusely across both hemispheres. Partial seizures are simple when they do not involve a change in mental status, and complex when consciousness is impaired. Seizures with altered mental status (AMS) but without motor activity are classified as nonconvulsive seizures.

Status epilepticus has been traditionally defined as a continuous seizure that lasts > 30 minutes, or multiple seizures in a 30-minute period without return to baseline. This definition was based largely on pathophysiologic observations that long-term consequences, including neuronal injury and death, result from seizures that last > 30 minutes. In practice, individual seizures that last > 5 minutes are prone to persist or recur before full recovery is made and, in all likelihood, represent status epilepticus.1

By definition, nonconvulsive status epilepticus (NCSE) presents with a persistent alteration in behavior or consciousness in the absence of convulsive activity, but the range of possible symptoms is broad. (See Table 1 and Table 2.) Although overt convulsions are absent, subtle motor signs such as twitching or blinking, extrapyramidal signs, or myoclonus may be seen.2 Despite the lack of convulsive activity, NCSE may still result in neuronal injury, making early recognition and treatment critically important.

Table 1. Clinical Features of Nonconvulsive Status Epilepticus
Table 2. Clinical Subtypes and Features of Nonconvulsive Status Epilepticus

NCSE is underdiagnosed, especially in patients without antecedent convulsive seizures.3 Many of these patients are not diagnosed in the emergency department (ED), either due to failure to consider the diagnosis or to lack of access to emergent encephalography (EEG), which confirms NCSE.4,5 The role of EEG in the ED is evolving, and newer portable technologies are being developed that may increase access and allow rapid confirmation of suspected NCSE.6

This issue of Emergency Medicine Practice provides an evidence-based review of the diagnosis and management of NCSE. An emphasis is placed on increasing awareness in order to initiate timely therapy and prevent neurologic sequelae.

Risk Management Pitfalls for Patients With Nonconvulsive Status Epilepticus in the Emergency Department

3. “Benzos didn’t work. I was starting a second-line agent, and the nurse came to tell me that the sodium was 118.”

NCSE represents a final common pathway for numerous pathologies. Seizures can be precipitated by various chemical and metabolic insults, with or without structural central nervous system abnormality. It is important to consider all possible causes and focus medical management on identifying a correctable etiology before escalating therapy (ie, seizures brought on by hypoglycemia, pre-eclampsia, isoniazid overdose, and drug toxicity).

6. “Everything is back and all the tests are normal, but the patient is still altered. We can’t get an EEG. Should we give a benzo?”

When NCSE is suspected and EEG is unavailable, consider an early trial of benzodiazepines and observe for clinical improvement. Benzodiazepine efficacy decreases the longer a seizure persists, so the initial agent should be started as quickly as possible; however prior to empiric treatment, coordination with neurology is ideal.

10. “He stopped convulsing, but I’m not sure whether he is still seizing.”

The only way to truly know whether a patient is in NCSE is to monitor brain activity with cEEG. Failure to initiate cEEG early can lead to delayed recognition of clinical deterioration and diminished efficacy of antiepileptic therapy. Emergency clinicians must advocate at an institutional and specialty level for timely access to cEEG, initiated as soon as possible when the diagnosis of NCSE is considered.

Tables

Table 1. Clinical Features of Nonconvulsive Status Epilepticus
Table 2. Clinical Subtypes and Features of Nonconvulsive Status Epilepticus

References

Evidence-based medicine requires a critical appraisal of the literature based upon study methodology and number of subjects. Not all references are equally robust. The findings of a large, prospective, randomized, and blinded trial should carry more weight than a case report.

To help the reader judge the strength of each reference, pertinent information about the study, such as the type of study and the number of patients in the study is included in bold type following the references, where available. In addition, the most informative references cited in this paper, as determined by the author, are highlighted.

  1. Brophy GM, Bell R, Claassen J, et al. Guidelines for the evaluation and management of status epilepticus. Neurocrit Care. 2012;17(1):3-23. (Guidelines)
  2. Fountain NB, Lothman EW. Pathophysiology of status epilepticus. J Clin Neurophysiol. 1995;12(4):326-342. (Review)
  3. Shneker BF, Fountain NB. Assessment of acute morbidity and mortality in nonconvulsive status epilepticus. Neurology. 2003;61(8):1066-1073. (Retrospective case series; 100 patients)
  4. Kaplan PW. Nonconvulsive status epilepticus in the emergency room. Epilepsia. 1996;37(7):643-650. (Retrospective case series; 23 patients)
  5. Ziai WC, Schlattman D, Llinas R, et al. Emergent EEG in the emergency department in patients with altered mental states. Clin Neurophysiol. 2012;123(5):910-917. (Single-center prospective cohort intervention study; 82 patients)
  6. Does the Use of Rapid Response EEG Impact Clinical Decision Making (DECIDE). (Prospective nonrandomized observational multicenter clinical trial)
  7. Hesdorffer DC, Logroscino G, Cascino G, et al. Incidence of status epilepticus in Rochester, Minnesota, 1965-1984. Neurology. 1998;50(3):735-741. (Epidemiological study)
  8.  Trinka E, Cock H, Hesdorffer D, et al. A definition and classification of status epilepticus--report of the ILAE Task Force on Classification of Status Epilepticus. Epilepsia. 2015;56(10):1515-1523. (Review)
  9. Holtkamp M, Meierkord H. Nonconvulsive status epilepticus: a diagnostic and therapeutic challenge in the intensive care setting. Ther Adv Neurol Disord. 2011;4(3):169-181. (Review)
  10. Privitera M, Hoffman M, Moore JL, et al. EEG detection of nontonic-clonic status epilepticus in patients with altered consciousness. Epilepsy Res. 1994;18(2):155-166. (Prospective clinical trial; 198 patients)
  11.  Zehtabchi S, Abdel Baki SG, Grant AC. Electroencephalographic findings in consecutive emergency department patients with altered mental status: a preliminary report. Eur J Emerg Med. 2013;20(2):126-129. (Prospective observational study; 50 patients)
  12. Kanich W, Brady WJ, Huff JS, et al. Altered mental status: evaluation and etiology in the ED. Am J Emerg Med. 2002;20(7):613-617. (Prospective cohort study; 317 patients)
  13. Meierkord H, Holtkamp M. Non-convulsive status epilepticus in adults: clinical forms and treatment. Lancet Neurol. 2007;6(4):329-339. (Review)
  14. Kinney MO, Craig JJ, Kaplan PW. Hidden in plain sight: non-convulsive status epilepticus-recognition and management. Acta Neurol Scand. 2017;136(4):280-292. (Review)
  15.  Huff JS, Melnick ER, Tomaszewski CA, et al. Clinical policy: critical issues in the evaluation and management of adult patients presenting to the emergency department with seizures. Ann Emerg Med. 2014;63(4):437-447. (Clinical policy)
  16.  Glauser T, Shinnar S, Gloss D, et al. Evidence-based guideline: treatment of convulsive status epilepticus in children and adults: report of the Guideline Committee of the American Epilepsy Society. Epilepsy Curr. 2016;16(1):48-61. (Guideline)
  17. Harden CL, Hopp J, Ting TY, et al. Practice parameter update: management issues for women with epilepsy--focus on pregnancy (an evidence-based review): obstetrical complications and change in seizure frequency: report of the Quality Standards Subcommittee and Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology and American Epilepsy Society. Neurology. 2009;73(2):126-132. (Consensus statement)
  18. Le Roux P, Menon DK, Citerio G, et al. The International Multidisciplinary Consensus Conference on Multimodality Monitoring in Neurocritical Care: a list of recommendations and additional conclusions: a statement for healthcare professionals from the Neurocritical Care Society and the European Society of Intensive Care Medicine. Neurocrit Care. 2014;21 Suppl 2:S282-S296. (Consensus statement)
  19.  Meierkord H, Boon P, Engelsen B, et al. EFNS guideline on the management of status epilepticus in adults. Eur J Neurol. 2010;17(3):348-355. (Guideline)
  20. Lado FA, Moshe SL. How do seizures stop? Epilepsia. 2008;49(10):1651-1664. (Review)
  21. Meldrum BS. Concept of activity-induced cell death in epilepsy: historical and contemporary perspectives. Prog Brain Res. 2002;135:3-11. (Review)
  22. Jones-Davis DM, Macdonald RL. GABA(A) receptor function and pharmacology in epilepsy and status epilepticus. Curr Opin Pharmacol. 2003;3(1):12-18. (Review)
  23. Chen JW, Wasterlain CG. Status epilepticus: pathophysiology and management in adults. Lancet Neurol. 2006;5(3):246-256. (Systematic review)
  24. Wasterlain CG, Niquet J, Thompson KW, et al. Seizure-induced neuronal death in the immature brain. Prog Brain Res. 2002;135:335-353. (Review)
  25. Hosford DA. Animal models of nonconvulsive status epilepticus. J Clin Neurophysiol. 1999;16(4):306-313. (Review)
  26. Drislane FW. Evidence against permanent neurologic damage from nonconvulsive status epilepticus. J Clin Neurophysiol. 1999;16(4):323-331. (Review)
  27. Huguenard JR, Prince DA. Clonazepam suppresses GABAB-mediated inhibition in thalamic relay neurons through effects in nucleus reticularis. J Neurophysiol. 1994;71(6):2576-2581. (In vitro animal study; rats)
  28. Meldrum BS, Vigouroux RA, Brierley JB. Systemic factors and epileptic brain damage. Prolonged seizures in paralyzed, artificially ventilated baboons. Arch Neurol. 1973;29(2):82-87. (Review)
  29. Sloviter RS. Decreased hippocampal inhibition and a selective loss of interneurons in experimental epilepsy. Science. 1987;235(4784):73-76. (In vitro animal study)
  30. Young GB, Jordan KG. Do nonconvulsive seizures damage the brain?--Yes. Arch Neurol. 1998;55(1):117-119. (Expert commentary)
  31. Wasterlain CG, Fujikawa DG, Penix L, et al. Pathophysiological mechanisms of brain damage from status epilepticus. Epilepsia. 1993;34 Suppl 1:S37-S53. (Review)
  32. Krumholz A, Sung GY, Fisher RS, et al. Complex partial status epilepticus accompanied by serious morbidity and mortality. Neurology. 1995;45(8):1499-1504. (Case series; 10 patients)
  33. Fujikawa DG, Itabashi HH, Wu A, et al. Status epilepticus-induced neuronal loss in humans without systemic complications or epilepsy. Epilepsia. 2000;41(8):981-991. (Case series; 3 patients)
  34. Parmar H, Lim SH, Tan NC, et al. Acute symptomatic seizures and hippocampus damage: DWI and MRS findings. Neurology. 2006;66(11):1732-1735. (Case series; 12 patients)
  35. Bauer G, Gotwald T, Dobesberger J, et al. Transient and permanent magnetic resonance imaging abnormalities after complex partial status epilepticus. Epilepsy Behav. 2006;8(3):666-671. (Case report)
  36. Vespa PM, McArthur DL, Xu Y, et al. Nonconvulsive seizures after traumatic brain injury are associated with hippocampal atrophy. Neurology. 2010;75(9):792-798. (Prospective case series; 16 patients)
  37. Fernandez-Torre JL. Status epilepticus in idiopathic generalized epilepsy. Epilepsia. 2006;47(4):805-806. (Review)
  38. Ruegg S. Nonconvulsive status epilepticus in adults: types, pathophysiology, epidemiology, etiology, and diagnosis. Neurology International OPEN. 2017;01(03):E189-E203. (Review)
  39. Barry E, Hauser WA. Status epilepticus: the interaction of epilepsy and acute brain disease. Neurology. 1993;43(8):1473-1478. (Prospective cohort; 217 patients)
  40. Kaplan PW. Nonconvulsive status epilepticus. Semin Neurol. 1996;16(1):33-40. (Review)
  41. Patsalos PN, Froscher W, Pisani F, et al. The importance of drug interactions in epilepsy therapy. Epilepsia. 2002;43(4):365-385. (Review)
  42. Husain AM, Horn GJ, Jacobson MP. Non-convulsive status epilepticus: usefulness of clinical features in selecting patients for urgent EEG. J Neurol Neurosurg Psychiatry. 2003;74(2):189-191. (Prospective case series; 48 patients)
  43. Chicharro AV, Kanner KA. Psychiatric manifestations of NCSE. In: Kaplan PW, Drislane FW, eds. Nonconvulsive Status Epilepticus. New York, NY: Demos Medical; 2009:203-215. (Textbook chapter)
  44. Elliott B, Joyce E, Shorvon S. Delusions, illusions and hallucinations in epilepsy: 2. Complex phenomena and psychosis. Epilepsy Res. 2009;85(2-3):172-186. (Review)
  45. Takaya S, Matsumoto R, Namiki C, et al. Frontal nonconvulsive status epilepticus manifesting somatic hallucinations. J Neurol Sci. 2005;234(1-2):25-29. (Case report)
  46. Ng YT, Rekate HL. Coining of a new term, “status gelasticus”. Epilepsia. 2006;47(3):661-662. (Case report)
  47. Brigo F, Ferlisi M, Fiaschi A, et al. Fear as the only clinical expression of affective focal status epilepticus. Epilepsy Behav. 2011;20(1):107-110. (Case report)
  48. Kaplan PW. Behavioral manifestations of nonconvulsive status epilepticus. Epilepsy Behav. 2002;3(2):122-139. (Review)
  49. Thomas P, Beaumanoir A, Genton P, et al. ‘De novo’ absence status of late onset: report of 11 cases. Neurology. 1992;42(1):104-110. (Case series; 11 patients)
  50. Trimble M, Kanner A, Schmitz B. Postictal psychosis. Epilepsy Behav. 2010;19(2):159-161. (Review)
  51. DeLorenzo RJ, Hauser WA, Towne AR, et al. A prospective, population-based epidemiologic study of status epilepticus in Richmond, Virginia. Neurology. 1996;46(4):1029-1035. (Prospective population-based study)
  52. Sutter R, Semmlack S, Kaplan PW. Nonconvulsive status epilepticus in adults - insights into the invisible. Nat Rev Neurol. 2016;12(5):281-293. (Review)
  53.  Treiman DM, Meyers PD, Walton NY, et al. A comparison of four treatments for generalized convulsive status epilepticus. Veterans Affairs Status Epilepticus Cooperative Study Group. N Engl J Med. 1998;339(12):792-798. (Randomized double-blind study; 384 patients)
  54. Shorvon S. Clinical forms of status epilepticus. In: Shorvon S, ed. Status Epilepticus: Its Clinical Features and Treatment in Children and Adults. New York, NY: Cambridge University Press; 1994:34-138. (Textbook chapter)
  55. American College of Emergency Physicians. Clinical policy for the initial approach to patients presenting with altered mental status. Ann Emerg Med. 1999;33(2):251-281. (Clinical policy)
  56. Krumholz A, Wiebe S, Gronseth G, et al. Practice parameter: evaluating an apparent unprovoked first seizure in adults (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology and the American Epilepsy Society. Neurology. 2007;69(21):1996-2007. (Practice parameter)
  57. Practice parameter: neuroimaging in the emergency patient presenting with seizure (summary statement). American College of Emergency Physicians, American Academy of Neurology, American Association of Neurological Surgeons, American Society of Neuroradiology. Ann Emerg Med. 1996;28(1):114-118. (Practice parameter)
  58. Devinsky O, Nadi S, Theodore WH, et al. Cerebrospinal fluid pleocytosis following simple, complex partial, and generalized tonic-clonic seizures. Ann Neurol. 1988;23(4):402-403. (Retrospective chart review; 27 patients, 62 specimens)
  59. Prokesch RC, Rimland D, Petrini JL Jr, et al. Cerebrospinal fluid pleocytosis after seizures. South Med J. 1983;76(3):322-327. (Case series; 102 patients)
  60. Rider LG, Thapa PB, Del Beccaro MA, et al. Cerebrospinal fluid analysis in children with seizures. Pediatr Emerg Care. 1995;11(4):226-229. (Retrospective chart review; 212 children)
  61. Barry E HW. Pleocytosis after status epilepticus. Arch. Neurol. 1994;51:190-193. (Retrospective chart review; 138 patients)
  62. Jaitly R, Sgro JA, Towne AR, et al. Prognostic value of EEG monitoring after status epilepticus: a prospective adult study. J Clin Neurophysiol. 1997;14(4):326-334. (Case series; 180 patients)
  63. Nei M, Lee JM, Shanker VL, et al. The EEG and prognosis in status epilepticus. Epilepsia. 1999;40(2):157-163. (Case series; 50 patients)
  64. Leitinger M, Beniczky S, Rohracher A, et al. Salzburg consensus criteria for non-convulsive status epilepticus--approach to clinical application. Epilepsy Behav. 2015;49:158-163. (Retrospective case control study; 100 patients)
  65. Chari G, Yadav K, Nishijima D, et al. Improving the ability of ED physicians to identify subclinical/electrographic seizures on EEG after a brief training module. Intl J Emerg Med. 2019;12(1):11. (Randomized controlled trial; 30 emergency physicians at 3 institutions)
  66. Shah AM, Vashi A, Jagoda A. Review article: convulsive and non-convulsive status epilepticus: an emergency medicine perspective. Emerg Med Australas. 2009;21(5):352-366. (Review)
  67. Sutter R, Ruegg S, Kaplan PW. Epidemiology, diagnosis, and management of nonconvulsive status epilepticus: opening Pandora’s box. Neurol Clin Pract. 2012;2(4):275-286. (Review)
  68. Fernandez-Torre JL, Kaplan PW, Hernandez-Hernandez MA. New understanding of nonconvulsive status epilepticus in adults: treatments and challenges. Expert Rev Neurother. 2015;15(12):1455-1473. (Review)
  69. Lawson T, Yeager S. Status epilepticus in adults: a review of diagnosis and treatment. Crit Care Nurse. 2016;36(2):62-73. (Review)
  70. Silbergleit R, Durkalski V, Lowenstein D, et al. Intramuscular versus intravenous therapy for prehospital status epilepticus. N Engl J Med. 2012;366(7):591-600. (Randomized control trial; 893 patients)
  71. Alldredge BK, Gelb AM, Isaacs SM, et al. A comparison of lorazepam, diazepam, and placebo for the treatment of out-of-hospital status epilepticus. N Engl J Med. 2001;345(9):631-637. (Randomized, double-blind clinical trial; 205 patients)
  72. Leppik IE, Derivan AT, Homan RW, et al. Double-blind study of lorazepam and diazepam in status epilepticus. JAMA. 1983;249(11):1452-1454. (Randomized controlled trial; 78 patients)
  73. Gilad R, Izkovitz N, Dabby R, et al. Treatment of status epilepticus and acute repetitive seizures with I.V. valproic acid vs phenytoin. Acta Neurol Scand. 2008;118(5):296-300. (Prospective clinical trial; 74 patients)
  74. Misra UK, Kalita J, Patel R. Sodium valproate vs phenytoin in status epilepticus: a pilot study. Neurology. 2006;67(2):340-342. (Randomized controlled trial; 82 patients)
  75. Remy C, Jourdil N, Villemain D, et al. Intrarectal diazepam in epileptic adults. Epilepsia. 1992;33(2):353-358. (Prospective randomized study; 39 patients)
  76. Shaner DM, McCurdy SA, Herring MO, et al. Treatment of status epilepticus: a prospective comparison of diazepam and phenytoin versus phenobarbital and optional phenytoin. Neurology. 1988;38(2):202-207. (Randomized clinical trial; 36 patients)
  77. Misra UK, Kalita J, Maurya PK. Levetiracetam versus lorazepam in status epilepticus: a randomized, open labeled pilot study. J Neurol. 2012;259(4):645-648. (Randomized open-label pilot study; 79 patients)
  78.  Prasad M, Krishnan PR, Sequeira R, et al. Anticonvulsant therapy for status epilepticus. Cochrane Database Syst Rev. 2014;10(9):CD003723. (Cochrane review; 18 studies, 2755 participants)
  79. Kaplan PW. Intravenous valproate treatment of generalised nonconvulsive status epilepticus. Clin Eectroencephalogr. 1999;30(1):1-4. (Case report)
  80. Berkovic SF, Andermann F, Guberman A, et al. Valproate prevents the recurrence of absence status. Neurology. 1989;39(10):1294-1297. (Clinical trial; 25 patients)
  81. Thomas P, Valton L, Genton P. Absence and myoclonic status epilepticus precipitated by antiepileptic drugs in idiopathic generalized epilepsy. Brain. 2006;129(Pt 5):1281-1292. (Case series; 14 patients)
  82. Osorio I, Reed RC, Peltzer JN. Refractory idiopathic absence status epilepticus: a probable paradoxical effect of phenytoin and carbamazepine. Epilepsia 2000;41(7): 887-894. (Retrospective chart review)
  83. Eue S, Grumbt M, Muller M, et al. Two years of experience in the treatment of status epilepticus with intravenous levetiracetam. Epilepsy Behav. 2009;15(4):467-469. (Retrospective review; 43 patients)
  84. Rupprecht S, Franke K, Fitzek S, et al. Levetiracetam as a treatment option in non-convulsive status epilepticus. Epilepsy Res. 2007;73(3):238-244. (Retrospective chart review; 8 patients)
  85. Navarro V, Dagron C, Elie C, et al. Prehospital treatment with levetiracetam plus clonazepam or placebo plus clonazepam in status epilepticus (SAMUKeppra): a randomised, double-blind, phase 3 trial. Lancet Neurol. 2016;15(1):47-55. (Randomized clinical trial; 107 patients)
  86. Albers JM, Moddel G, Dittrich R, et al. Intravenous lacosamide--an effective add-on treatment of refractory status epilepticus. Seizure. 2011;20(5):428-430. (Case series; 7 patients)
  87. Lang N, Lange M, Schmitt FC, et al. Intravenous lacosamide in clinical practice-Results from an independent registry. Seizure. 2016;39:5-9. (Prospective observational study; 119 patients)
  88. Hottinger A, Sutter R, Marsch S, et al. Topiramate as an adjunctive treatment in patients with refractory status epilepticus: an observational cohort study. CNS Drugs. 2012;26(9):761-772. (Observational cohort study; 268 patients)
  89. Hofler J, Trinka E. Lacosamide as a new treatment option in status epilepticus. Epilepsia. 2013;54(3):393-404. (Review)
  90. Wasim M, Husain AM. Nonconvulsive seizure control in the intensive care unit. Curr Treat Options Neurol. 2015;17(3):340. (Review)
  91. Bleck T, Cock H, Chamberlain J, et al. The established status epilepticus trial 2013. Epilepsia. 2013;54 Suppl 6:89-92. (Multicenter randomized double-blind clinical trial; proposed sample size, 795 patients)
  92. Rossetti AO, Lowenstein DH. Management of refractory status epilepticus in adults: still more questions than answers. Lancet Neurol. 2011;10(10):922-930. (Review)
  93. Rossetti AO. Which anesthetic should be used in the treatment of refractory status epilepticus? Epilepsia. 2007;48 Suppl 8:52-55. (Review)
  94. Claassen J, Hirsch LJ, Emerson RG, et al. Treatment of refractory status epilepticus with pentobarbital, propofol, or midazolam: a systematic review. Epilepsia. 2002;43(2):146-153. (Systematic review)
  95. Roberts RJ, Barletta JF, Fong JJ, et al. Incidence of propofol-related infusion syndrome in critically ill adults: a prospective, multicenter study. Crit Care. 2009;13(5):R169. (Prospective review; 1017 patients)
  96. Teran F, Harper-Kirksey K, Jagoda A. Clinical decision making in seizures and status epilepticus. Emerg Med Pract. 2015;17(1):1-24. (Review)
  97. McMicken D, Liss JL. Alcohol-related seizures. Emerg Med Clin North Am. 2011;29(1):117-124. (Review)
  98. Earnest MP, Feldman H , Marx JA, et al, Intracranial lesions shown by CT scans in 259 cases of first alcohol-related seizures. Neurology. 1988;38(10):1561-1565. (Retrospective review; 259 patients)
  99. Fernandez-Torre JL, Martinez-Martinez M. Non-convulsive status epilepticus as an unrecognized cause of acute confusion in alcoholics. Eur J Neurol. 2007;14(8):e14-e15. (Case report)
  100. Niedermeyer E, Freund G, Krumholz A. Subacute encephalopathy with seizures in alcoholics: a clinical-electroencephalographic study. Clin Electroencephalogr. 1981;12(3):113-129. (Case series)
  101. Sechi G, Serra A. Wernicke’s encephalopathy: new clinical settings and recent advances in diagnosis and management. Lancet Neurol. 2007;6(5):442-455. (Review)
  102. Sheth RD, Drazkowski JF, Sirven JI, et al. Protracted ictal confusion in elderly patients. Arch Neurol. 2006;63(4):529-532. (Case series; 22 patients)
  103. Rosenow F, Hamer HM, Knake S. The epidemiology of convulsive and nonconvulsive status epilepticus. Epilepsia. 2007;48 Suppl 8:82-84. (Review)
  104. Rohracher A, Reiter DP, Brigo F, et al. Status epilepticus in the elderly-a retrospective study on 120 patients. Epilepsy Res. 2016;127:317-323. (Retrospective case series; 120 patients)
  105. Cheng S. Non-convulsive status epilepticus in the elderly. Epileptic Disord. 2014;16(4):385-394. (Review)
  106. Veran O, Kahane P, Thomas P, et al. De novo epileptic confusion in the elderly: a 1-year prospective study. Epilepsia. 2010;51(6):1030-1035. (Prospective case series; 44 patients)
  107. Dunne JW, Summers QA, Stewart-Wynne EG. Non-convulsive status epilepticus: a prospective study in an adult general hospital. Q J Med. 1987;62(238):117-126. (Prospective case series; 113 patients)
  108. Scholtes FB, Renier WO, Meinardi H. Simple partial status epilepticus: causes, treatment, and outcome in 47 patients. J Neurol Neurosurg Psychiatry. 1996;61(1):90-92. (Retrospective case series; 47 patients)
  109. Stephen LJ, Brodie MJ. Epilepsy in elderly people. Lancet. 2000;355(9213):1441-1446. (Review)
  110. Korn-Lubetzki I, Steiner-Birmanns B, Galperin I, et al. Nonconvulsive status epilepticus in older people: a diagnostic challenge and a treatable condition. J Am Geriatr Soc. 2007;55(9):1475-1476. (Review)
  111. Bottaro FJ, Martinez OA, Pardal MM, et al. Nonconvulsive status epilepticus in the elderly: a case-control study. Epilepsia. 2007;48(5):966-972. (Retrospective case-control study; 53 patients)
  112. Kaplan PW. Assessing the outcomes in patients with nonconvulsive status epilepticus: nonconvulsive status epilepticus is underdiagnosed, potentially overtreated, and confounded by comorbidity. J Clin Neurophysiol. 1999;16(4):341-352. (Review)
  113. Shavit L, Grenader T, Galperin I. Nonconvulsive status epilepticus in elderly a possible diagnostic pitfall. Eur J Intern Med. 2012;23(8):701-704. (Prospective case series; 14 patients)
  114.  Sutter R, Fuhr P, Grize L, et al. Continuous video-EEG monitoring increases detection rate of nonconvulsive status epilepticus in the ICU. Epilepsia. 2011;52(3):453-457. (Review)
  115. Bleck TP. Management approaches to prolonged seizures and status epilepticus. Epilepsia. 1999;40 Suppl 1:S59-S63. (Review)
  116. Sutter R. Are we prepared to detect subtle and nonconvulsive status epilepticus in critically ill patients? J Clin Neurophysiol. 2016;33(1):25-31. (Review)
  117. Herman ST, Abend NS, Bleck TP, et al. Consensus statement on continuous EEG in critically ill adults and children, part I: indications. J Clin Neurophysiol. 2015;32(2):87-95. (Consensus statement)
  118. Kuroda Y. Neurocritical care update. J Intensive Care. 2016;4:36. (Review)
  119. Abdel Baki SG, Omurtag A, Fenton AA, et al. The new wave: time to bring EEG to the emergency department. Int J Emerg Med. 2011;4:36. (Review)
  120. Roodsari GS, Chari G, Mera B, et al. Can patients with non-convulsive seizure be identified in the emergency department? World J Emerg Med. 2017;8(3):190-194. (Restrospective study; 332 patients)
  121. Sergot P, Chari, G., Omurtag, A. Utility of a brief training module on improving emergency physicians’ ability to identify non-convulsive seizure on emergent electroencephalography performed in patients with altered mental status. Ann Emerg Med. 2015;66(4):S111-S112. (Prospective study; in progress)
  122. Zeiler FA. Early use of the NMDA receptor antagonist ketamine in refractory and superrefractory status epilepticus. Crit Care Res Pract. 2015;2015:831260. (Literature review)
  123. Fung EL, Fung BB, Subcommittee on the Consensus Statement of the Hong Kong Epilepsy Society. Review and update of the Hong Kong Epilepsy Guideline on status epilepticus. Hong Kong Med J. 2017;23(1):67-73. (Consensus statement)
  124. Sabharwal V, Ramsay E, Martinez R, et al. Propofol-ketamine combination therapy for effective control of super-refractory status epilepticus. Epilepsy Behav. 2015;52(Pt A):264-266. (Retrospective review; 67 patients)
  125. Niquet J, Baldwin R, Suchomelova L, et al. Treatment of experimental status epilepticus with synergistic drug combinations. Epilepsia. 2017;58(4):e49-e53. (Animal study)
  126. Gaspard N, Foreman B, Judd LM, et al. Intravenous ketamine for the treatment of refractory status epilepticus: a retrospective multicenter study. Epilepsia. 2013;54(8):1498-1503. (Retrospective review; 60 patients)
  127. Hofler J, Rohracher A, Kalss G, et al. (S)-ketamine in refractory and super-refractory status epilepticus: a retrospective study. CNS Drugs. 2016;30(9):869-876. (Retrospective review; 42 patients)
  128. Jones RM, Butler JA, Thomas VA, et al. Adherence to treatment in patients with epilepsy: associations with seizure control and illness beliefs. Seizure. 2006;15(7):504-508. (Cross-sectional study; 54 patients)
Publication Information
Authors

Annalee Morgan Baker, MD, FACEP; Matthew Amir Yasavolian, MD; Navid Reza Arandi, MD

Peer Reviewed By

Cappi Lay, MD; Elaine Rabin, MD; Felipe Teran, MD, MSCE; Kyle B. Walsh, MD, MS

Publication Date

October 1, 2019

  
Pub Med ID: 31557430

Get Permission

Content you might be interested in
Already purchased this course?
Log in to read.
Purchase a subscription

Price: $449/year

140+ Credits!

Money-back Guarantee
Get A Sample Issue Of Emergency Medicine Practice
Enter your email to get your copy today! Plus receive updates on EB Medicine every month.
Please provide a valid email address.