Continuous EEG Monitoring for Status Epilepticus

  • Monica B. Dhakar
  • Lawrence J. Hirsch
Part of the Current Clinical Neurology book series (CCNEU)


There has been a substantial increase in the use of continuous electroencephalography (C-EEG) in critically ill patients, most commonly for detection of nonconvulsive seizures. Studies have found that not only patients with primary brain insults but also those with systemic illness are at high risk of developing nonconvulsive status epilepticus (NCSE). The Neurocrit Care Society and The American Clinical Neurophysiology Society have published consensus statements or guidelines on the indications, duration, and technical aspects of EEG monitoring for status epilepticus (SE). Unified criteria for defining NCSE have also been proposed and published. Nevertheless, critically ill patients can have equivocal patterns, not clearly ictal (“ictal” is used to mean an electrographic seizure pattern in this chapter) or interictal, and have been considered to lie on an ictal-interictal continuum. Diagnostic treatment trials with IV benzodiazepines and non-sedating anti-seizure drugs (ASDs) can be helpful to determine if equivocal patterns are contributing to the patient’s impaired mental status or other neurologic deficits. The labor-intensive and time-consuming process of reviewing 24 h of EEG on many patients can be expedited by using tools such as quantitative EEG (Q-EEG) via commercial software packages. Thus far, there is some evidence to suggest that after strokes and head trauma, NCSE may worsen outcomes. Whether C-EEG monitoring and aggressive treatment of these seizures translates into improved patient outcomes is yet to be proven.


Status epilepticus Continuous EEG Nonconvulsive seizures Intensive care 


  1. 1.
    Hirsch LJ. Continuous EEG monitoring in the intensive care unit: an overview. J Clin Neurophysiol. 2004;21(5):332–40.PubMedGoogle Scholar
  2. 2.
    Herman ST, Abend NS, Bleck TP, Chapman KE, Drislane FW, Emerson RG, et al. Consensus statement on continuous EEG in critically ill adults and children, part I: indications. J Clin Neurophysiol. 2015;32(2):87–95.PubMedPubMedCentralCrossRefGoogle Scholar
  3. 3.
    Brophy GM, Bell R, Claassen J, Alldredge B, Bleck TP, Glauser T, et al. Guidelines for the evaluation and management of status epilepticus. Neurocrit Care. 2012;17(1):3–23.PubMedCrossRefGoogle Scholar
  4. 4.
    Trinka E, Cock H, Hesdorffer D, Rossetti AO, Scheffer IE, Shinnar S, et al. A definition and classification of status epilepticus—report of the ILAE task force on classification of status epilepticus. Epilepsia. 2015;56(10):1515–23.PubMedCrossRefGoogle Scholar
  5. 5.
    Beniczky S, Hirsch LJ, Kaplan PW, Pressler R, Bauer G, Aurlien H, et al. Unified EEG terminology and criteria for nonconvulsive status epilepticus. Epilepsia. 2013;54(Suppl 6):28–9.PubMedCrossRefGoogle Scholar
  6. 6.
    Kaplan PW. EEG criteria for nonconvulsive status epilepticus. Epilepsia. 2007;48(Suppl 8):39–41.PubMedCrossRefGoogle Scholar
  7. 7.
    Leitinger M, Beniczky S, Rohracher A, Gardella E, Kalss G, Qerama E, et al. Salzburg consensus criteria for non-convulsive status epilepticus—approach to clinical application. Epilepsy Behav. 2015;49:158–63.PubMedCrossRefGoogle Scholar
  8. 8.
    Pandian JD, Cascino GD, So EL, Manno E, Fulgham JR. Digital video-electroencephalographic monitoring in the neurological-neurosurgical intensive care unit: clinical features and outcome. Arch Neurol. 2004;61(7):1090–4.PubMedCrossRefGoogle Scholar
  9. 9.
    Sutter R, Fuhr P, Grize L, Marsch S, Ruegg S. Continuous video-EEG monitoring increases detection rate of nonconvulsive status epilepticus in the ICU. Epilepsia. 2011;52(3):453–7.PubMedCrossRefGoogle Scholar
  10. 10.
    McHugh JC, Downey T, Murphy RP, Connolly S. Analysis of routine EEG usage in a general adult ICU. Irish J Med Sci. 2009;178(3):263–6.PubMedCrossRefGoogle Scholar
  11. 11.
    Osman GM, Hirsch LJ. Diagnosing and monitoring seizures in the ICU: the role of continuous EEG for detection and managment of seizures in critically ill patients, including the ictal-interictal continuum. In: Varelas PN, Claassen J, editors. Seizures in critical care: A guide to diagnosis and therapeutics. 3rd ed. New York: Springer (in press).Google Scholar
  12. 12.
    Abend NS, Arndt DH, Carpenter JL, Chapman KE, Cornett KM, Gallentine WB, et al. Electrographic seizures in pediatric ICU patients: cohort study of risk factors and mortality. Neurology. 2013;81(4):383–91.PubMedPubMedCentralCrossRefGoogle Scholar
  13. 13.
    Abend NS, Topjian A, Ichord R, Herman ST, Helfaer M, Donnelly M, et al. Electroencephalographic monitoring during hypothermia after pediatric cardiac arrest. Neurology. 2009;72(22):1931–40.PubMedPubMedCentralCrossRefGoogle Scholar
  14. 14.
    Arndt DH, Lerner JT, Matsumoto JH, Madikians A, Yudovin S, Valino H, et al. Subclinical early posttraumatic seizures detected by continuous EEG monitoring in a consecutive pediatric cohort. Epilepsia. 2013;54(10):1780–8.PubMedPubMedCentralCrossRefGoogle Scholar
  15. 15.
    Carrera E, Claassen J, Oddo M, Emerson RG, Mayer SA, Hirsch LJ. Continuous electroencephalographic monitoring in critically ill patients with central nervous system infections. Arch Neurol. 2008;65(12):1612–8.PubMedCrossRefGoogle Scholar
  16. 16.
    Claassen J, Mayer SA, Kowalski RG, Emerson RG, Hirsch LJ. Detection of electrographic seizures with continuous EEG monitoring in critically ill patients. Neurology. 2004;62(10):1743–8.PubMedCrossRefGoogle Scholar
  17. 17.
    Claassen J, Jette N, Chum F, Green R, Schmidt M, Choi H, et al. Electrographic seizures and periodic discharges after intracerebral hemorrhage. Neurology. 2007;69(13):1356–65.PubMedCrossRefGoogle Scholar
  18. 18.
    Crepeau AZ, Fugate JE, Mandrekar J, White RD, Wijdicks EF, Rabinstein AA, et al. Value analysis of continuous EEG in patients during therapeutic hypothermia after cardiac arrest. Resuscitation. 2014;85(6):785–9.PubMedCrossRefGoogle Scholar
  19. 19.
    Gilmore EJ, Gaspard N, Choi HA, Cohen E, Burkart KM, Chong DH, et al. Acute brain failure in severe sepsis: a prospective study in the medical intensive care unit utilizing continuous EEG monitoring. Intensive Care Med. 2015;41(4):686–94.PubMedCrossRefGoogle Scholar
  20. 20.
    Mani R, Schmitt SE, Mazer M, Putt ME, Gaieski DF. The frequency and timing of epileptiform activity on continuous electroencephalogram in comatose post-cardiac arrest syndrome patients treated with therapeutic hypothermia. Resuscitation. 2012;83(7):840–7.PubMedCrossRefGoogle Scholar
  21. 21.
    O’Connor KL, Westover MB, Phillips MT, Iftimia NA, Buckley DA, Ogilvy CS, et al. High risk for seizures following subarachnoid hemorrhage regardless of referral bias. Neurocrit Care. 2014;21(3):476–82.PubMedPubMedCentralCrossRefGoogle Scholar
  22. 22.
    O’Neill BR, Handler MH, Tong S, Chapman KE. Incidence of seizures on continuous EEG monitoring following traumatic brain injury in children. J Neurosurg Pediatr. 2015;16(2):167–76.PubMedCrossRefGoogle Scholar
  23. 23.
    Oddo M, Carrera E, Claassen J, Mayer SA, Hirsch LJ. Continuous electroencephalography in the medical intensive care unit. Crit Care Med. 2009;37(6):2051–6.PubMedCrossRefGoogle Scholar
  24. 24.
    Payne ET, Zhao XY, Frndova H, McBain K, Sharma R, Hutchison JS, et al. Seizure burden is independently associated with short term outcome in critically ill children. Brain. 2014;137(Pt 5):1429–38.PubMedPubMedCentralCrossRefGoogle Scholar
  25. 25.
    Ronne-Engstrom E, Winkler T. Continuous EEG monitoring in patients with traumatic brain injury reveals a high incidence of epileptiform activity. Acta Neurol Scand. 2006;114(1):47–53.PubMedCrossRefGoogle Scholar
  26. 26.
    Schreiber JM, Zelleke T, Gaillard WD, Kaulas H, Dean N, Carpenter JL. Continuous video EEG for patients with acute encephalopathy in a pediatric intensive care unit. Neurocrit Care. 2012;17(1):31–8.PubMedCrossRefGoogle Scholar
  27. 27.
    Topjian AA, Gutierrez-Colina AM, Sanchez SM, Berg RA, Friess SH, Dlugos DJ, et al. Electrographic status epilepticus is associated with mortality and worse short-term outcome in critically ill children. Crit Care Med. 2013;41(1):215–23.PubMedCrossRefGoogle Scholar
  28. 28.
    Vespa PM, McArthur DL, Xu Y, Eliseo M, Etchepare M, Dinov I, et al. Nonconvulsive seizures after traumatic brain injury are associated with hippocampal atrophy. Neurology. 2010;75(9):792–8.PubMedPubMedCentralCrossRefGoogle Scholar
  29. 29.
    Vespa PM, O’Phelan K, Shah M, Mirabelli J, Starkman S, Kidwell C, et al. Acute seizures after intracerebral hemorrhage: a factor in progressive midline shift and outcome. Neurology. 2003;60(9):1441–6.PubMedCrossRefGoogle Scholar
  30. 30.
    Westover MB, Shafi MM, Bianchi MT, Moura LM, O’Rourke D, Rosenthal ES, et al. The probability of seizures during EEG monitoring in critically ill adults. J Clin Neurophysiol. 2015;126(3):463–71.CrossRefGoogle Scholar
  31. 31.
    Kilbride RD, Costello DJ, Chiappa KH. How seizure detection by continuous electroencephalographic monitoring affects the prescribing of antiepileptic medications. Arch Neurol. 2009;66(6):723–8.PubMedCrossRefGoogle Scholar
  32. 32.
    Privitera M, Hoffman M, Moore JL, Jester D. EEG detection of nontonic-clonic status epilepticus in patients with altered consciousness. Epilepsy Res. 1994;18(2):155–66.PubMedCrossRefGoogle Scholar
  33. 33.
    Towne AR, Waterhouse EJ, Boggs JG, Garnett LK, Brown AJ, Smith JR Jr, et al. Prevalence of nonconvulsive status epilepticus in comatose patients. Neurology. 2000;54(2):340–5.PubMedCrossRefGoogle Scholar
  34. 34.
    Young GB, Doig GS. Continuous EEG monitoring in comatose intensive care patients: epileptiform activity in etiologically distinct groups. Neurocrit Care. 2005;2(1):5–10.PubMedCrossRefGoogle Scholar
  35. 35.
    Young GB, Jordan KG, Doig GS. An assessment of nonconvulsive seizures in the intensive care unit using continuous EEG monitoring: an investigation of variables associated with mortality. Neurology. 1996;47(1):83–9.PubMedCrossRefGoogle Scholar
  36. 36.
    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):189–91.PubMedPubMedCentralCrossRefGoogle Scholar
  37. 37.
    Laccheo I, Sonmezturk H, Bhatt AB, Tomycz L, Shi Y, Ringel M, et al. Non-convulsive status epilepticus and non-convulsive seizures in neurological ICU patients. Neurocrit Care. 2015;22(2):202–11.PubMedCrossRefGoogle Scholar
  38. 38.
    DeLorenzo RJ, Waterhouse EJ, Towne AR, Boggs JG, Ko D, DeLorenzo GA, et al. Persistent nonconvulsive status epilepticus after the control of convulsive status epilepticus. Epilepsia. 1998;39(8):833–40.PubMedCrossRefGoogle Scholar
  39. 39.
    Claassen J, Taccone FS, Horn P, Holtkamp M, Stocchetti N, Oddo M, et al. Recommendations on the use of EEG monitoring in critically ill patients: consensus statement from the neurointensive care section of the ESICM. Intensive Care Med. 2013;39(8):1337–51.PubMedCrossRefGoogle Scholar
  40. 40.
    Jordan KG. Continuous EEG and evoked potential monitoring in the neuroscience intensive care unit. J Clin Neurophysiol. 1993;10(4):445–75.PubMedCrossRefGoogle Scholar
  41. 41.
    Vespa PM, Nuwer MR, Nenov V, Ronne-Engstrom E, Hovda DA, Bergsneider M, et al. Increased incidence and impact of nonconvulsive and convulsive seizures after traumatic brain injury as detected by continuous electroencephalographic monitoring. J Neurosurg. 1999;91(5):750–60.PubMedPubMedCentralCrossRefGoogle Scholar
  42. 42.
    Dennis LJ, Claassen J, Hirsch LJ, Emerson RG, Connolly ES, Mayer SA. Nonconvulsive status epilepticus after subarachnoid hemorrhage. Neurosurgery. 2002;51(5):1136–43; discussion 44.Google Scholar
  43. 43.
    Little AS, Kerrigan JF, McDougall CG, Zabramski JM, Albuquerque FC, Nakaji P, et al. Nonconvulsive status epilepticus in patients suffering spontaneous subarachnoid hemorrhage. J Neurosurg. 2007;106(5):805–11.PubMedCrossRefGoogle Scholar
  44. 44.
    de Greef BT, Schreuder FH, Vlooswijk MC, Schreuder AH, Rooyer FA, van Oostenbrugge RJ, et al. Early seizures after intracerebral hemorrhage predict drug-resistant epilepsy. J Neurol. 2015;262(3):541–6.PubMedCrossRefGoogle Scholar
  45. 45.
    De Herdt V, Dumont F, Henon H, Derambure P, Vonck K, Leys D, et al. Early seizures in intracerebral hemorrhage: incidence, associated factors, and outcome. Neurology. 2011;77(20):1794–800.PubMedCrossRefGoogle Scholar
  46. 46.
    Neshige S, Kuriyama M, Yoshimoto T, Takeshima S, Himeno T, Takamatsu K, et al. Seizures after intracerebral hemorrhage; risk factor, recurrence, efficacy of antiepileptic drug. J Neurol Sci. 2015;359(1–2):318–22.PubMedCrossRefGoogle Scholar
  47. 47.
    Lamy C, Domigo V, Semah F, Arquizan C, Trystram D, Coste J, et al. Early and late seizures after cryptogenic ischemic stroke in young adults. Neurology. 2003;60(3):400–4.PubMedCrossRefGoogle Scholar
  48. 48.
    Mecarelli O, Pro S, Randi F, Dispenza S, Correnti A, Pulitano P, et al. EEG patterns and epileptic seizures in acute phase stroke. Cerebrovasc Dis. 2011;31(2):191–8.PubMedCrossRefGoogle Scholar
  49. 49.
    Carrera E, Michel P, Despland PA, Maeder-Ingvar M, Ruffieux C, Debatisse D, et al. Continuous assessment of electrical epileptic activity in acute stroke. Neurology. 2006;67(1):99–104.PubMedCrossRefGoogle Scholar
  50. 50.
    Singh TD, Fugate JE, Hocker S, Wijdicks EF, Aksamit AJ Jr, Rabinstein AA. Predictors of outcome in HSV encephalitis. J Neurol. 2016;263(2):277–89.PubMedCrossRefGoogle Scholar
  51. 51.
    van de Beek D, de Gans J, Spanjaard L, Weisfelt M, Reitsma JB, Vermeulen M. Clinical features and prognostic factors in adults with bacterial meningitis. N Engl J Med. 2004;351(18):1849–59.PubMedCrossRefGoogle Scholar
  52. 52.
    Blitshteyn S, Jaeckle KA. Nonconvulsive status epilepticus in metastatic CNS disease. Neurology. 2006;66(8):1261–3.PubMedCrossRefGoogle Scholar
  53. 53.
    Chang JW, Chang JH, Park SC, Kim TS, Park YG, Chung SS. Radiologically confirmed de novo glioblastoma multiforme and hippocampal sclerosis associated with the first onset of nonconvulsive simple partial status epilepticus. Acta Neurochir. 2001;143(3):297–300.PubMedCrossRefGoogle Scholar
  54. 54.
    Marcuse LV, Lancman G, Demopoulos A, Fields M. Nonconvulsive status epilepticus in patients with brain tumors. Seizure. 2014;23(7):542–7.PubMedCrossRefGoogle Scholar
  55. 55.
    Kurtz P, Gaspard N, Wahl AS, Bauer RM, Hirsch LJ, Wunsch H, et al. Continuous electroencephalography in a surgical intensive care unit. Intensive Care Med. 2014;40(2):228–34.PubMedCrossRefGoogle Scholar
  56. 56.
    Kamel H, Betjemann JP, Navi BB, Hegde M, Meisel K, Douglas VC, et al. Diagnostic yield of electroencephalography in the medical and surgical intensive care unit. Neurocrit Care. 2013;19(3):336–41.PubMedCrossRefGoogle Scholar
  57. 57.
    Legriel S, Bruneel F, Sediri H, Hilly J, Abbosh N, Lagarrigue MH, et al. Early EEG monitoring for detecting postanoxic status epilepticus during therapeutic hypothermia: a pilot study. Neurocrit Care. 2009;11(3):338–44. 4.Google Scholar
  58. 58.
    Legriel S, Hilly-Ginoux J, Resche-Rigon M, Merceron S, Pinoteau J, Henry-Lagarrigue M, et al. Prognostic value of electrographic postanoxic status epilepticus in comatose cardiac-arrest survivors in the therapeutic hypothermia era. Resuscitation. 2013;84(3):343–50.PubMedCrossRefGoogle Scholar
  59. 59.
    Rittenberger JC, Popescu A, Brenner RP, Guyette FX, Callaway CW. Frequency and timing of nonconvulsive status epilepticus in comatose post-cardiac arrest subjects treated with hypothermia. Neurocrit Care. 2012;16(1):114–22.PubMedPubMedCentralCrossRefGoogle Scholar
  60. 60.
    Akman CI, Abou Khaled KJ, Segal E, Micic V, Riviello JJ. Generalized periodic epileptiform discharges in critically ill children: clinical features, and outcome. Epilepsy Res. 2013;106(3):378–85.PubMedCrossRefGoogle Scholar
  61. 61.
    Foreman B, Claassen J, Abou Khaled K, Jirsch J, Alschuler DM, Wittman J, et al. Generalized periodic discharges in the critically ill: a case-control study of 200 patients. Neurology. 2012;79(19):1951–60.PubMedPubMedCentralCrossRefGoogle Scholar
  62. 62.
    Chatrian GE, Shaw CM, Leffman H. The significance of periodic lateralized epileptiform discharges in eeg: an electrographic, clinical and pathological study. Electroencephalogr Clin Neurophysiol. 1964;17:177–93.PubMedCrossRefGoogle Scholar
  63. 63.
    Gaspard N, Manganas L, Rampal N, Petroff OA, Hirsch LJ. Similarity of lateralized rhythmic delta activity to periodic lateralized epileptiform discharges in critically ill patients. JAMA Neurol. 2013;70(10):1288–95.PubMedGoogle Scholar
  64. 64.
    Snodgrass SM, Tsuburaya K, Ajmone-Marsan C. Clinical significance of periodic lateralized epileptiform discharges: relationship with status epilepticus. J Clin Neurophysiol. 1989;6(2):159–72.PubMedCrossRefGoogle Scholar
  65. 65.
    Benbadis SR, Chen S, Melo M. What’s shaking in the ICU? The differential diagnosis of seizures in the intensive care setting. Epilepsia. 2010;51(11):2338–40.PubMedCrossRefGoogle Scholar
  66. 66.
    Shafi MM, Westover MB, Cole AJ, Kilbride RD, Hoch DB, Cash SS. Absence of early epileptiform abnormalities predicts lack of seizures on continuous EEG. Neurology. 2012;79(17):1796–801.PubMedPubMedCentralCrossRefGoogle Scholar
  67. 67.
    Swisher CB, Shah D, Sinha SR, Husain AM. Baseline EEG pattern on continuous ICU EEG monitoring and incidence of seizures. J Clin Neurophysiol. 2015;32(2):147–51.PubMedCrossRefGoogle Scholar
  68. 68.
    Chong DJ, Hirsch LJ. Which EEG patterns warrant treatment in the critically ill? Reviewing the evidence for treatment of periodic epileptiform discharges and related patterns. J Clin Neurophysiol. 2005;22(2):79–91.PubMedCrossRefGoogle Scholar
  69. 69.
    Sivaraju A, Gilmore EJ. Understanding and managing the ictal-interictal continuum in neurocritical care. Curr Treat Options Neurol. 2016;18(2):8.PubMedCrossRefGoogle Scholar
  70. 70.
    Hopp JL, Sanchez A, Krumholz A, Hart G, Barry E. Nonconvulsive status epilepticus: value of a benzodiazepine trial for predicting outcomes. Neurologist. 2011;17(6):325–9.PubMedCrossRefGoogle Scholar
  71. 71.
    O’Rourke D, Chen PM, Gaspard N, Foreman B, McClain L, Karakis I, et al. Response rates to anticonvulsant trials in patients with triphasic-wave eeg patterns of uncertain significance. Neurocrit Care. 2016;24(2):233–9.PubMedPubMedCentralCrossRefGoogle Scholar
  72. 72.
    Hirsch LJ, Gaspard N. Status epilepticus. Continuum. 2013;19(3 Epilepsy):767–94.Google Scholar
  73. 73.
    Stewart CP, Otsubo H, Ochi A, Sharma R, Hutchison JS, Hahn CD. Seizure identification in the ICU using quantitative EEG displays. Neurology. 2010;75(17):1501–8.PubMedPubMedCentralCrossRefGoogle Scholar
  74. 74.
    Williamson CA, Wahlster S, Shafi MM, Westover MB. Sensitivity of compressed spectral arrays for detecting seizures in acutely ill adults. Neurocrit Care. 2014;20(1):32–9.PubMedCrossRefGoogle Scholar
  75. 75.
    Swisher CB, White CR, Mace BE, Dombrowski KE, Husain AM, Kolls BJ, et al. Diagnostic accuracy of electrographic seizure detection by neurophysiologists and non-neurophysiologists in the adult ICU using a panel of quantitative EEG trends. J Clin Neurophysiol. 2015;32(4):324–30.PubMedCrossRefGoogle Scholar
  76. 76.
    Dericioglu N, Yetim E, Bas DF, Bilgen N, Caglar G, Arsava EM, et al. Non-expert use of quantitative EEG displays for seizure identification in the adult neuro-intensive care unit. Epilepsy Res. 2015;109:48–56.PubMedCrossRefGoogle Scholar
  77. 77.
    Friedman DE, Schevon C, Emerson RG, Hirsch LJ. Cyclic electrographic seizures in critically ill patients. Epilepsia. 2008;49(2):281–7.PubMedCrossRefGoogle Scholar
  78. 78.
    Moura LM, Shafi MM, Ng M, Pati S, Cash SS, Cole AJ, et al. Spectrogram screening of adult EEGs is sensitive and efficient. Neurology. 2014;83(1):56–64.PubMedPubMedCentralCrossRefGoogle Scholar
  79. 79.
    Abend NS, Topjian AA, Gutierrez-Colina AM, Donnelly M, Clancy RR, Dlugos DJ. Impact of continuous EEG monitoring on clinical management in critically ill children. Neurocrit Care. 2011;15(1):70–5.PubMedPubMedCentralCrossRefGoogle Scholar
  80. 80.
    Ney JP, van der Goes DN, Nuwer MR, Nelson L, Eccher MA. Continuous and routine EEG in intensive care: utilization and outcomes, United States 2005–2009. Neurology. 2013;81(23):2002–8.PubMedPubMedCentralCrossRefGoogle Scholar
  81. 81.
    Vespa P, Tubi M, Claassen J, Blanco M, McArthur D, Velazquez AG, et al. Metabolic crisis occurs with seizures and periodic discharges after brain trauma. Ann Neurol. 2016;79(4):579–90.PubMedCrossRefGoogle Scholar

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© Springer Science+Business Media LLC 2018

Authors and Affiliations

  1. 1.Department of NeurologyYale University School of MedicineNew HavenUSA

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