Nonconvulsive seizures are more prevalent than physicians realize.
Trained to care for high-risk patients, emergency physicians are used to monitoring all of the critical vital signs, especially those of patients with unclear presentation. But even emergency physicians at state-of-the-art hospitals have had to forgo one crucial element of the workup of a neurologic patient: electrographic monitoring of brain activity and function.
The problem is a matter of time. Because conventional EEG (electroencephalography) reports take between several hours to a day or more to obtain — and are simply unavailable in some EDs — emergency physicians seldom order them, knowing that the results will come back too late to intervene effectively in invisible disease states like nonconvulsive status epilepticus (NCSE).
This gap in testing has helped conceal the prevalence of NCSE. Nonconvulsive seizures may be present in up to one-third of all critically ill patients,[[1] and have been shown to co-exist at startling rates with several conditions seen frequently in the ED (see figure 1).
Clinically, the problem of NCSE is also a matter of time to cessation. In the same way we now understand that time is brain in cases of stroke, nonconvulsive seizures cause increasing neuronal damage the longer they go untreated.[[2]] Effective seizure control becomes more challenging over time, as drug efficacy diminishes after two hours of seizure.[[3]
Delays in treatment put the patient at greater risk for intubation and unnecessary transfer to the ICU. These facts prompted the American Heart Association to add to its 2020 Emergency Cardiovascular Care guidelines. The AHA now recommends EEG administration for cardiac arrest patients following ROSC (return of spontaneous circulation).[4]
The practical difficulties of diagnosing a prevalent brain condition associated with higher morbidity and mortality[5] have led emergency physicians to defer its investigation or treat without confirmation. A new tool, applied and interpreted by the emergency physician at the patient’s bedside, removes these obstacles.
Equipped with rapid response electroencephalography or “Rapid-EEG” technology, a new point-of-care brain monitoring device (Ceribell, Sunnyvale, CA) was the subject of a recent observational study conducted across five U.S. academic hospitals. The study concluded that Rapid-EEG accurately indicated the presence of nonconvulsive seizures,[6] allowing for the timely administration of anti-seizure medication. Because the device has demonstrated 100% sensitivity for seizures (and 93% specificity), it also allows physicians to rule out NCSE with confidence, saving patients from the effects of powerful — and unnecessary — medication.[7]
Designed for emergency use, these brain sensors can be used by any clinician at the bedside after a brief training; the AI-enabled results are definitive and relatively quick (approximately five minutes).[8] Rapid-EEG is not a replacement for conventional EEG, of course, but the ability to monitor for non-convulsive seizures and get immediate, clear results at the point of care meets the specific needs of the ED and its patient population. Point-of-care brain monitoring may also be conducted continuously, answering growing calls for the continuous monitoring of high-risk patients.[[9, 10]
As a specialty, we have not previously had the tools to adequately address nonconvulsive seizures in the ED. Now that we do, we need to become more attuned to the likelihood of NCSE and more proactive in protecting our patients from it.
A Brain on Fire
In these and many other common ED scenarios, the missing piece of the ED workup — the ability to quickly assess brain activity and identify nonconvulsive seizures or NCSE — can create significant downstream impacts. Foremost among these are the impacts to the patient, such as the potential for long-term cognitive damage and a higher likelihood of the disease developing into something more serious (e.g., refractory status epilepticus or super-refractory status epilepticus).[2]
But there are impacts to the hospital as well: the incorrect or suboptimal use of the hospital’s resources, including avoidable intubation and ventilator use and, in some cases, admitting the patient to the wrong service. In addition to their financial and quality implications, these missteps also undermine patient trust and physician confidence.
Beyond the Impasse
NCSE has gone “overlooked and undertreated” for far too many critically ill patients.[3] With point-of-care brain monitoring, emergency physicians can finally obtain the accurate and timely diagnosis of non-convulsive seizures that allows us to provide proper treatment and escalation to patients who need it—and avoid unnecessary treatments and transfers for those who don’t. And while the adoption of new technologies is always a story of uneven developments, a brain sensor with Rapid-EEG is one of a very few technologies whose ease of use, reliability, and clarity moves us beyond the impasse, effectively closing a major testing gap in our specialty.
[1]. Herman, S., Abend, N.S., Bleck, T.S. et al. (2015) Consensus statement on continuous EEG in critically ill adults and children. J Clin Neurophysiol., 32(2):87-108, https://doi.org/10.1097/WNP.0000000000000166
[2]. Young, G.B., Jordan, K.G. and Doig, G.S. (1996) An assessment of nonconvulsive seizures in the intensive care unit using continuous EEG monitoring: an investigation of variables associated with mortality. Neurology, 47(1):83-89, https://doi.org/10.1212/wnl.47.1.83
[3]. Lowenstein, D.H. and Alldredge, B.K. (1993) Status Epilepticus at an Urban Public Hospital in the 1980s. Neurology 43(3 part 1):483-488. https://doi.org/10.1212/wnl.43.3_part_1.483.
[4]. Merchant, Raina M., Alexis A. Topjian, et al. Part 1: Executive Summary: 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation 2020;142(16):S337–S357. https://doi.org/10.1161/CIR.0000000000000918.
[5]. Herman, S., Abend, N.S., Bleck, T.S. et al. (2015) Consensus statement on continuous EEG in critically ill adults and children. J Clin Neurophysiol., 32(2):87-108, https://doi.org/10.1097/WNP.0000000000000166
[6]. Vespa, P. et al (2020). Evaluating the Clinical Impact of Rapid Response Electroencephalography: A Multicenter Prospective Observational Clinical Trial. Critical Care Medicine. Published online: https://doi.org/10.1097/CCM.0000000000004428.
[7]. Kamousi, B. et al (2020) Neurocrit Care. Published online: https://doi.org/10.1007/s12028-020-01120-0
[8]. Vespa, P. et al (2020). Evaluating the Clinical Impact of Rapid Response Electroencephalography: A Multicenter Prospective Observational Clinical Trial. Critical Care Medicine. Published online: https://doi.org/10.1097/CCM.0000000000004428.
[9]. Friedman, D., Claassen, J. and Hirsch, L.J. (2009) Continuous electroencephalogram monitoring in the intensive care unit. Anesth. & Analg., 109(2):506-23, https://doi.org/10.1213/ane.0b013e3181a9d8b5
[10]. Herman, S., Abend, N.S., Bleck, T.S., et al. (2015) Consensus statement on continuous EEG in critically ill adults and children.
1 Comment
We desperately need an EM RCT on this device. Hospitalists use it to stall admissions, it is NOT fast–takes an hour plus to use, it is significantly contributing to crowding / boarding and holding up transfers,
This is biotech gone wild–profit focused company trying to pitch an AI neurologist to small community hospitals.