Prolonged postictal stupor: nonconvulsive status epilepticus, medication effect, or postictal state?

Frequency and Implications of Complications in the ICU After Status Epilepticus: No Calm After the Storm

OBJECTIVES

To investigate the frequency, types, and implications of complications during intensive care in patients after status epilepticus has been successfully terminated.

DESIGN

Retrospective study.

SETTING

ICUs at a Swiss tertiary academic medical care center.

PATIENTS

Data were collected from the digital patient records of all adult patients with status epilepticus from 2012 to 2018.

INTERVENTIONS

None.

METHODS

Primary outcomes were defined as frequency of complications following status epilepticus termination and return to premorbid functional baseline. Univariable analyses regarding the relative risks of complications occurring after status epilepticus termination for no return to premorbid neurologic function were estimated by Poisson regression with robust error variance.

RESULTS

Of 311 patients with status epilepticus, 224 patients (72%) were treated on the ICU for more than 24 hours following status epilepticus termination. Ninety-six percent of patients remained in a prolonged state of altered consciousness for a median of 2 days (interquartile range, 1-3 d) and 80% had complications during their ICU treatment. Fifty-five percent had new-onset delirium with a median duration of 2 days (interquartile range, 1-3 d). Forty-two percent had mechanical ventilation for a median of 4 days (interquartile range, 2-11 d) and 21% had nosocomial infections diagnosed after status epilepticus. Multivariable analyses revealed that mechanical ventilation for more than 24 hours after status epilepticus, and arterial hypotension requiring vasopressors were independently associated with increased risk of no return to premorbid function (RRfor each additional day = 1.01; 95% CI, 1.02-1.03 and RRfor each additional day = 1.03; 95% CI, 1.01-1.05) and death (RRfor each additional day = 1.11; 95% CI, 1.04-1.19 and RRfor each additional day = 1.15; 95% CI, 1.03-1.28). Delirium was independently associated with a decreased relative risk of death (RRfor each additional day = 0.55; 95% CI, 0.37-0.80), but prolonged ICU- and hospital stays.

CONCLUSIONS

Complications after status epilepticus termination are frequent and associated with no return to premorbid function, death, and prolonged ICU- and hospital stays. These results call for heightened awareness and further studies mainly regarding prediction and preventive strategies in this context.

Non-convulsive status epilepticus: mimics and chameleons

Non-convulsive status epilepticus (NCSE) is an enigmatic condition with protean manifestations. It often goes unrecognised, leading to delays in its diagnosis and treatment. The principal reason for such delay is the failure to consider and request an electroencephalogram (EEG), although occasional presentations have no scalp or surface electroencephalographic correlate. In certain settings with limited EEG availability, particularly out-of-hours, clinicians should consider treating without an EEG. Patients need a careful risk–benefit analysis to assess the risks of neuronal damage and harm versus the risks of adverse effects from various intensities of therapeutic intervention. Specialists in EEG, intensive care or epilepsy are invaluable in the management of patients with possible NCSE.

Ictal cerebral positron emission tomography (PET) in focal status epilepticus

The diagnosis of focal status epilepticus (SE) can be challenging, particularly when clinical manifestations leave doubts about its nature, and electroencephalography (EEG) is not conclusive. This work addresses the utility of ictal (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET) in focal SE, which was performed in eight patients in whom SE was finally diagnosed. Clinical, MRI and EEG data were reviewed. (18)F-FDG-PET proved useful: (1) to establish the diagnosis of focal SE, when clinical elements were equivocal or the EEG did not show clear-cut epileptiform abnormalities; (2) to delineate the epileptogenic area in view of possible resective surgery; and (3) when clinical features, MRI and EEG were incongruent regarding the origin of SE. We suggest that ictal (18)F-FDG-PET may represent a valuable diagnostic tool in selected patients with focal SE or frequent focal seizures.

Electroencephalographic criteria for nonconvulsive status epilepticus: synopsis and comprehensive survey

There have been many attempts at defining the electroencephalography (EEG) characteristics of nonconvulsive status epilepticus (NCSE) without a universally accepted definition. This lack of consensus arises because the EEG expression of NCSE does not exist in isolation, but reflects status epilepticus under the variety of pathologic conditions that occur with age, cerebral development, encephalopathy, and epilepsy syndrome. Current NCSE definitions include "boundary conditions," in which electroencephalographic seizure activity occurs without apparent clinical seizures. Furthermore, what appears to one interpreter as status epilepticus, is not to another reader, reflecting the "art" of EEG interpretation. Seizures and epilepsy syndromes have undergone an evolution that has moved beyond a classification of focal or generalized conditions into a syndromic approach. It seems appropriate to make similar changes in the EEG analysis of the syndromes of NCSE. In effect, the literature on epilepsy classification has progressed to incorporate the different NCSE types with clinical descriptions, but the specific EEG evidence for these types is found largely in individual reports, and often by description only. NCSE classification of EEG patterns should derive from the aggregate of published EEG patterns in the respective clinical subtype, supported by an analysis of these EEG studies. The analysis that follows presents clinical descriptions and EEG patterns of NCSE in the neonatal period, infancy, childhood, adulthood, and late adulthood from a syndromic perspective based on age, encephalopathy, cerebral development, etiology, and syndrome. Proceeding from the proposed classification of status epilepticus syndromes in "Status epilepticus: its clinical features and treatment in children and adults" (published in 1994 by Cambridge University Press, New York), we have performed a systematic search for reports presenting EEG patterns of NCSE using the online medical search engine PubMed for 22 different search strategies. EEG patterns were reviewed by two board-certified epileptologists who reached consensus regarding presence of NCSE. From a total of 4,328 search results, 123 cases with corresponding EEG patterns could be allocated to underlying epilepsy syndromes. Typical characteristic, prominent electrographic patterns, and sequential arrangements are elucidated for the different NCSE syndromes. This compendium of patterns by NCSE syndrome classification with illustration of EEGs, and delineation of electroencephalographic features helps define the characteristics and semiologic borderlines among the types of NCSE.

Acute confusion or altered mental state: consider nonconvulsive status epilepticus

BACKGROUND

The diagnosis of nonconvulsive status epilepticus (NCSE) is particularly challenging in elderly patients. Confusion, personality change, dysphasia, subtle motor activity and nystagmus may be the only presenting signs.

OBJECTIVE

To review current knowledge about NCSE with special focus on older people.

METHODS

Systematic review of the current literature via Medline search.

CONCLUSION

Although prospective studies are still lacking, NCSE may be one of the most frequently missed diagnoses in patients presenting with altered mental status. Elderly patients are at particular risk of diagnostic errors because of the broad range of presentations of NCSE, significant comorbidities (especially cerebrovascular disease), limited awareness of this particular seizure emergency or difficulties with access to electroencephalography. Although diagnostic criteria and treatment remain controversial, the diagnosis of NCSE is important because it is potentially reversible.