ROLE OF CONTINUOUS
EEG IN SRSE

Timely initiation of continuous electroencephalography (cEEG) is critical3

The immediate goal of super-refractory status epilepticus (SRSE) treatment is to control the seizure1

Most experts agree that aborting electrographic seizures is the primary goal in managing super-refractory status epilepticus (SRSE).1,2 Patients with SRSE are treated in the intensive care unit (ICU) with coma-inducing anesthetic agents after receiving previous treatment of benzodiazepines and antiepileptic drugs.1,2 Upon treatment with anesthetics, the depth of coma induction is carefully monitored by continuous electroencephalogram (cEEG) with the goal of terminating all electrographic seizures.2,11

cEEG monitoring is critical for patient care3,10

The use of cEEG is critical for accurate and early diagnosis, timely treatment, and monitoring of SE3,10 and RSE.3 Additionally, cEEG is used to monitor SRSE.2

cEEG can be especially helpful in the detection of nonconvulsive patients,3,10 in whom clinical symptoms of seizure activity are less obvious.3,4,10 Whereas convulsive SE may present with an overt pattern of muscle contraction and relaxation,5 nonconvulsive SE is characterized by changes in a patient’s level of consciousness (stupor, staring, unresponsiveness) without large-scale motor symptoms.3

The Neurocritical Care Society Guidelines for the Evaluation and Management of Status Epilepticus provide the following recommendations* for cEEG use3:

1. The use of cEEG is usually required for the treatment of SE (strong recommendation, very low quality)

2. cEEG should be initiated within 1 hour of SE onset if ongoing seizures are expected (strong recommendation, low quality)

3. The duration of cEEG monitoring should be at least 48 hours in comatose patients to evaluate for nonconvulsive seizures (strong recommendation, low quality)

4. The person reading the EEG in the ICU setting should have specialized training in cEEG interpretation, including the ability to analyze raw EEG as well as quantitative EEG tracings (strong recommendation, low quality)

*Recommendations were graded according to the quantity of available evidence in the literature.
Ongoing monitoring of patients with cEEG

Seizures may still occur during a burst-suppression pattern so it is critical to maintain ongoing monitoring of patients with cEEG.2

Using cEEG to monitor patient response to treatment

cEEG is also used to direct treatment and gauge efficacy in patients with SRSE.2 Inadequate changes in cEEG patterns may inform healthcare providers to change the dosage and/or treatment approach.1,3,6 Conversely, satisfactory cEEG changes would inform the providers of successful treatment wean attempts.6 cEEG can also be used to monitor the effectiveness of first-line (benzodiazepines), second-line (antiepileptic), and third-line (coma-inducing anesthetic) treatments to determine the progression of SE to RSE3 and SRSE.2

Delays in initiating cEEG should be minimized as cumulative duration of seizure activity affects mortality and neurologic outcome.7,8 For patients with SRSE, access to facilities in which appropriate monitoring and interpretation of cEEG can be performed is usually required for patient care.3 Specialized cEEG interpretation training is needed in ICU settings.9,10

Prior to progression to SRSE, transfer to facilities with access to cEEG should be considered for patients experiencing uncontrolled, recurring seizures.3

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Use of Continuous EEG in SRSE

Hear more about the use of cEEG in SRSE management from Stephan Mayer, MD, FCCM.

References:
  1. Shorvon S, Ferlisi M. The treatment of super-refractory status epilepticus: a critical review of available therapies and a clinical treatment protocol. Brain. 2011;134(10):2802-2818.
  2. Hocker S, Tatum WO, LaRoche S, Freeman WD. Refractory and super-refractory status epilepticus–an update. Curr Neurol Neurosci Rep. 2014;14:452.
  3. Brophy GM, Bell R, Claassen J, et al. Guidelines for the evaluation and management of status epilepticus. Neurocrit Care. 2012;17(1):3-23.
  4. Trinka E. Brigo F, Shorvon S. Recent advances in status epilepticus. Curr Opin Neurol. 2016;29(2):189-198.
  5. Lowenstein DH, Alldredge BK. Status epilepticus. N Engl J Med. 1998;338:970-976.
  6. Friedman D, Claassen J, Hirsch LJ. Continuous electroencephalogram monitoring in the intensive care unit. Anesth Analg. 2009;109(2):506-523.
  7. Young B, Jordan K, Doig G. An assessment of nonconvulsive seizures in the intensive care unit using continuous EEG monitoring: an investigation of variables associated with mortality.Neurology. 1996;47:83-89.
  8. Scholtes FB, Renier WO, Meinardi H. Generalized convulsive status epilepticus: causes, therapy, and outcome in 346 patients. Epilepsia. 1994;35(5):1104-1112.
  9. Privitera MD, Strawsburg RH. Electroencephalographic monitoring in the emergency department. Emerg Med Clin North Am. 1994;12(4):1089-1100.
  10. Herman ST, Abend NS, Bleck TP, et al; Critical Care Continuous EEG Task Force of the American Clinical Neurophysiology Society. Consensus statement on continuous EEG in critically ill adults and children, part I: indications. J Clin Neurophysiol. 2015;32(2):87-95.
  11. 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):453-457.