Treatment of acute seizures and status epilepticus

Acute symptomatic seizures and status epilepticus in older adults: A narrative review focusing on management and outcomes

A clear narrative of acute symptomatic seizures (ASyS) in older adults is lacking. Older adults (≥60 years) have the highest incidence of seizures of all age groups and necessitate a tailored approach. ASyS has a bimodal peak in infancy and old age (82.3–123.2/100,000/year after 65 years of age). ASyS can represent half of the new-onset seizures in older adults and can progress to acute symptomatic status epilepticus (ASySE) in 52–72% of the patients. Common etiologies for ASyS in older adults include acute stroke and metabolic disturbances. For ASySE, common etiologies are acute stroke and anoxic brain injury (ABI). Initial testing for ASyS should be consistent with the most common and urgent etiologies. A 20-min electroencephalogram (EEG) is less sensitive in older adults than in younger adults and might not help predict chronic epilepsy. The prolonged postictal phase is an additional challenge for acute management. Studies note that 30% of older adults with ASyS subsequently develop epilepsy. The risk of wrongly equating ASyS as the first seizure of epilepsy is higher in older adults due to the increased long-term challenges with chronic anti-seizure medication (ASM) treatment. Specific challenges to managing ASyS in older adults are related to their chronic comorbidities and polypharmacy. It is unclear if the prognosis of ASyS is dependent on the underlying etiology. Short-term mortality is 1.6 to 3.6 times higher than younger adults. ASySE has high short-term mortality, especially when it is secondary to acute stroke. An acute symptomatic etiology of ASySE had five times increased risk of short-term mortality compared to other types of etiology.

Specific characteristics and current diagnostic and treatment modalities performance of super refractory status epilepticus in children: A comparative study

OBJECTIVE

Super-refractory status epilepticus (SRSE) is associated with significant morbidity and mortality in children. We explored the clinical spectrum, specific characteristics, and outcome in SRSE patients admitted in a pediatric intensive care unit (PICU) and investigated how well current diagnostic or treatment modalities perform compared to Status Epilepticus (SE) and Refractory SE (RSE) patients.

METHODS

Retrospective analysis of PICU patients admitted with convulsive SE during 2009-2019. Eighty-six patients were classified as SE, RSE, and SRSE. New-onset RSE (NORSE) and febrile infection-related epilepsy syndrome (FIRES) were also identified. Functional outcome was evaluated by the modified Rankin scale.

RESULTS

Patients with SRSE (n = 20) had longer weaning off anesthetics (p = 0.014), length of stay, mechanical ventilation duration, higher illness severity scores, and poorer outcome compared to SE (n = 13) or RSE (n = 53) patients (all p < 0.001). Diagnosis, mainly expressed by high prevalence of NORSE (n = 13) and FIRES (n = 9), was independently associated with SRSE (p = 0.024). Abnormal MRI findings (p = 0.005), and epilepsy-related pathogenic variants identified by whole-exome sequencing (WES) were mostly found in SRSE patients. Compared to intravenous immunoglobulins and steroid pulses, plasmapheresis and ketogenic diet, more often used in SRSE (p < 0.01), contributed better to seizure control. Only SRSE (AUROC > 0.80, 95% CI = 0.68-0.94, p < 0.001) and diagnosis (AUROC > 0.70, 95% CI = 0.55-0.83, p = 0.02) could predict a poor outcome.

CONCLUSION

The majority of SRSE patients are characterized by considerable functional decline and morbidity. WES analysis may reveal epilepsy-related pathogenic variants while early aggressive immunotherapy and/or ketogenic diet might prove beneficial. Multicenter studies for prediction models of outcome are needed.

Risk factors associated with short-term mortality and recurrence of status epilepticus in dogs

Background

Status epilepticus (SE) is an emergency associated with serious consequences for both patient and owner. Data regarding risk factors for short‐term mortality or recurrence in dogs with SE is limited.

Objective

Identify risk factors associated with short‐term mortality (euthanasia or spontaneous death) and recurrence of SE in dogs.

Animals

One hundred twenty‐four client‐owned dogs that sustained an episode of SE.

Methods

Retrospective multicenter study using data collected from medical records of dogs presented in SE to the contributing institutions. Multivariable logistic regression analysis was performed using a manual backwards stepwise approach to identify risk factors associated with short‐term mortality and recurrence of SE after discharge.

Results

Short‐term mortality for affected dogs was 29.8%. Factors significantly associated with short‐term mortality included increased patient age, shorter duration of hospitalization, development of SE before arrival, and SE caused by a potentially fatal etiology. Status epilepticus recurred in 27% of dogs that survived to discharge. Factors significantly associated with recurrence of SE included prior history of pharmacoresistant epilepsy and predominance of a focal seizure phenotype.

Conclusions and Clinical Importance

Our results may be used to inform clinicians and dog owners regarding risk factors for both short‐term mortality and recurrence in dogs with SE.

Antiepileptic drugs in critically ill patients

BACKGROUND

The incidence of seizures in intensive care units ranges from 3.3% to 34%. It is therefore often necessary to initiate or continue anticonvulsant drugs in this setting. When a new anticonvulsant is initiated, drug factors, such as onset of action and side effects, and patient factors, such as age, renal, and hepatic function, should be taken into account. It is important to note that the altered physiology of critically ill patients as well as pharmacological and nonpharmacological interventions such as renal replacement therapy, extracorporeal membrane oxygenation, and target temperature management may lead to therapeutic failure or toxicity. This may be even more challenging with the availability of newer antiepileptics where the evidence for their use in critically ill patients is limited.

MAIN BODY

This article reviews the pharmacokinetics and pharmacodynamics of antiepileptics as well as application of these principles when dosing antiepileptics and monitoring serum levels in critically ill patients. The selection of the most appropriate anticonvulsant to treat seizure and status epileptics as well as the prophylactic use of these agents in this setting are also discussed. Drug-drug interactions and the effect of nonpharmacological interventions such as renal replacement therapy, plasma exchange, and extracorporeal membrane oxygenation on anticonvulsant removal are also included.

CONCLUSION

Optimal management of antiepileptic drugs in the intensive care unit is challenging given altered physiology, polypharmacy, and nonpharmacological interventions, and requires a multidisciplinary approach where appropriate and timely assessment, diagnosis, treatment, and monitoring plans are in place.

Clinical profile and neurodevelopmental outcome of new-onset acute symptomatic seizures in children

PURPOSE

To study clinical profile, neurodevelopmental outcome and its predictors in children with acute symptomatic seizures (ASS).

METHODS

Short-term neurodevelopmental outcome and predictors of poor outcomes were prospectively assessed in 105 consecutive children with ASS aged 3 months-12 years RESULTS: Mean age was 51.2+42.2months (3-144 months); 67.2% were males. Central nervous system (CNS) infection in 82%, status epilepticus in 15.2%, abnormal neuroimaging in 62.8% and abnormal electroencephalography in 22.3% were noted. At discharge, 27.6% had poor outcome including death (13%); CNS infections were significantly associated with poor outcome compared to ASS of other aetiologies (32.6% vs 5.2%, p=0.02). Low GCS (OR 4.9, 95%CI 1.2-20.7), abnormal electroencephalograph (OR 4.3, 95%CI 1-16.9) and neuroimaging (OR 12.1, 95%CI 1.4-105.2) were independent predictors of poor outcome. After 6 months, 16% children had delayed neurodevelopment and cognition; 6% had seizure recurrences. Abnormal electroencephalograph (p=0.002; OR 6.8, 95%CI 2.0-23.1), abnormal neuroimaging (p=0.015; OR 9.47, 95%CI 1.18-75.8),>1 anti-epileptic (p=0.00; OR 9.9, 95%CI 2.88-33.9), intubation (p=0.004; OR 6.25, 95%CI 1.79-21.7) and poor outcome at discharge (p=0.02; OR 4.44, 95%CI1.38-14.2) predicted abnormal neurodevelopment.

CONCLUSIONS

CNS infections are the most common cause of ASS in children from developing countries. Abnormal neurodevelopment and seizure recurrences on short-term follow-up are seen in a minority of children.

Status epilepticus in dogs and cats, part 1: etiopathogenesis, epidemiology, and diagnosis

OBJECTIVE

To review current knowledge of the etiopathogenesis, diagnosis, and consequences of status epilepticus (SE) in veterinary patients.

DATA SOURCES

Human and veterinary literature, including clinical and laboratory research and reviews.

ETIOPATHOGENESIS

Status epilepticus is a common emergency in dogs and cats, and may be the first manifestation of a seizure disorder. It results from the failure of termination of an isolated seizure. Multiple factors are involved in SE, including initiation and maintenance of neuronal excitability, neuronal network synchronization, and brain microenvironmental contributions to ictogenesis. Underlying etiologies of epilepsy and SE in dogs and cats are generally classified as genetic (idiopathic), structural-metabolic, or unknown.

DIAGNOSIS

Diagnosis of convulsive SE is usually made based on historical information and the nature of the seizures. Patient specific variables, such as the history, age of seizure onset, and physical and interictal neurological examination findings can help hone the rule out list, and are used to guide selection and prioritization of diagnostic tests. Electroencephalographic monitoring is routinely used in people to diagnose SE and guide patient care decisions, but is infrequently performed in veterinary medicine. Nonconvulsive status epilepticus has been recognized in veterinary patients; routine electroencephalography would aid in the diagnosis of this phenomenon in dogs and cats.

CLINICAL SEQUELAE

Status epilepticus is a medical emergency that can result in life-threatening complications involving the brain and systemic organs. Status epilepticus often requires comprehensive diagnostic testing, treatment with multiple anticonvulsant agents, and intensive supportive care.

High-Dose Benzodiazepine Dependence: A Qualitative Study of Patients' Perceptions on Initiation, Reasons for Use, and Obtainment

Background

High-dose benzodiazepine (BZD) dependence is associated with a wide variety of negative health consequences. Affected individuals are reported to suffer from severe mental disorders and are often unable to achieve long-term abstinence via recommended discontinuation strategies. Although it is increasingly understood that treatment interventions should take subjective experiences and beliefs into account, the perceptions of this group of individuals remain under-investigated.

Methods

We conducted an exploratory qualitative study with 41 adult subjects meeting criteria for (high-dose) BZD-dependence, as defined by ICD-10. One-on-one in-depth interviews allowed for an exploration of this group’s views on the reasons behind their initial and then continued use of BZDs, as well as their procurement strategies. Mayring’s qualitative content analysis was used to evaluate our data.

Results

In this sample, all participants had developed explanatory models for why they began using BZDs. We identified a multitude of reasons that we grouped into four broad categories, as explaining continued BZD use: (1) to cope with symptoms of psychological distress or mental disorder other than substance use, (2) to manage symptoms of physical or psychological discomfort associated with somatic disorder, (3) to alleviate symptoms of substance-related disorders, and (4) for recreational purposes, that is, sensation-seeking and other social reasons. Subjects often considered BZDs less dangerous than other substances and associated their use more often with harm reduction than as recreational. Specific obtainment strategies varied widely: the majority of participants oscillated between legal and illegal methods, often relying on the black market when faced with treatment termination.

Conclusions

Irrespective of comorbidity, participants expressed a clear preference for medically related explanatory models for their BZD use. We therefore suggest that clinicians consider patients’ motives for long-term, high-dose BZD use when formulating treatment plans for this patient group, especially since it is known that individuals are more compliant with approaches they perceive to be manageable, tolerable, and effective.

Comparison of short-term effects of midazolam and lorazepam in the intra-amygdala kainic acid model of status epilepticus in mice

Benzodiazepines remain as the first-line treatment for status epilepticus (SE), but debate continues as to the choice and delivery route of pharmacotherapy. Lorazepam is currently the preferred anticonvulsant for clinical use, but midazolam has become a popular alternative, particularly as it can be given by nonintravenous routes. Anticonvulsants are also commonly used to terminate SE in animal models. Here, we aimed to compare the efficacy of midazolam with that of lorazepam in an experimental model of focal-onset SE. Status epilepticus was induced by intra-amygdala microinjection of kainic acid in 8week old C57Bl/6 mice. Forty minutes later, mice were treated with an intraperitoneal injection of either lorazepam or midazolam (8mg/kg). Electroencephalogram (EEG) activity, histology, and behavioral tests assessing recovery of function were evaluated and compared between groups. Intraperitoneal injection of either lorazepam or midazolam resulted in similar patterns of reduced EEG epileptiform activity during 1-hour recordings. Damage to the hippocampus and presentation of postinsult anxiety-related behavior did not significantly differ between treatment groups at 72h. However, return of normal behaviors such as grooming, levels of activity, and the evaluation of overall recovery of SE mice were all superior at 24h in animals given midazolam compared with lorazepam. Our results indicate that midazolam is as effective as lorazepam as an anticonvulsant in this model while also providing improved animal recovery after SE. These data suggest that midazolam might be considered by researchers as an anticonvulsant in animal models of SE, particularly as it appears to satisfy the requirements of refining procedures involving experimental animals at early time-points after SE.

Etiology, clinical course and response to the treatment of status epilepticus in children: A 16-year single-center experience based on 602 episodes of status epilepticus

OBJECTIVE

evaluation of etiology, clinical course and response to the treatment of status epilepticus (SE) in children, with particular investigation of superrefractory SE.

MATERIALS AND METHODS

The retrospective study included children with convulsive SE aged 0.2-18 years, treated from 1995 to 2011. Status epilepticus is defined as a continuous seizure or intermittent seizures without full recovery of consciousness between seizures for at least 30 min. Refractory SE is diagnosed if SE lasts for more than 60 min, while superrefractory SE if SE continues or recurs 24 h or more after the onset of an anesthesia therapy, including those cases that recur after reduction or withdrawal of an anesthesia. The etiology was summarized in five categories: idiopathic/cryptogenic, remote symptomatic, febrile SE, acute symptomatic and progressive encephalopathy. The patients were treated according to the same hospital protocol. Midazolam iv and diazepam rectally were given as the first line drugs, phenobarbital/phenytoin iv as the second line drugs. If they failed, third line drugs, midazolam and thiopental were given in continuous intravenous infusion. The medication was defined as effective if seizure clinically stopped within 20 min, without recurrence within the next 6 h. Midazolam was assessed as effective even if it failed as the first line, but was effective in intravenous infusion as the third line drug.

RESULTS

The study consisted of 602 SE in 395 children. There were 305 (50.7%) refractory SE episodes, and 43 (7.1%) of superrefractory SE. Idiopathic/cryptogenic and febrile SE was the most common etiology in the first SE, while progressive encephalopathy and remote symptomatic was in recurrent and superrefractory SE. The most effective drugs were: midazolam (306/339) given in mean dose of 0.4 mg/kg (range 0.1-1.2 mg/kg), thiopental (47/57) in mean dose of 4 mg/kg (range 3-5 mg/kg), phenobarbital (91/135) in dose of 20 mg/kg. Midazolam successfully stopped 306/339 SE episodes (90.3%), 67 SE (21.9%) by equal or lower dose than 0.2 mg/kg as the first line drug, while all other 239 episodes (78.9%) were stopped by intravenous infusion in range 0.2-1.2 mg/kg/h (mean 0.4 mg/kg/h) as the third line drug. Adverse effects were frequent in superrefractory SE (60.5%). In 15 patients, corticosteroids contributed to the reduction of seizure recurrence after anesthetic withdrawal and cessation of epilepsia partialis continua. Case fatality rate was 5.1% in all patients, while 21.3% in patients with superrefractory SE.

CONCLUSION

Status epilepticus in children was characterized by heterogeneous etiology, prolonged duration and commonly good response to midazolam only given in high doses. Superrefractory SE was not so rare in children, especially among the patients with progressive encephalopathy.

Robust control of burst suppression for medical coma

OBJECTIVE

Medical coma is an anesthetic-induced state of brain inactivation, manifest in the electroencephalogram by burst suppression. Feedback control can be used to regulate burst suppression, however, previous designs have not been robust. Robust control design is critical under real-world operating conditions, subject to substantial pharmacokinetic and pharmacodynamic parameter uncertainty and unpredictable external disturbances. We sought to develop a robust closed-loop anesthesia delivery (CLAD) system to control medical coma.

APPROACH

We developed a robust CLAD system to control the burst suppression probability (BSP). We developed a novel BSP tracking algorithm based on realistic models of propofol pharmacokinetics and pharmacodynamics. We also developed a practical method for estimating patient-specific pharmacodynamics parameters. Finally, we synthesized a robust proportional integral controller. Using a factorial design spanning patient age, mass, height, and gender, we tested whether the system performed within clinically acceptable limits. Throughout all experiments we subjected the system to disturbances, simulating treatment of refractory status epilepticus in a real-world intensive care unit environment.

MAIN RESULTS

In 5400 simulations, CLAD behavior remained within specifications. Transient behavior after a step in target BSP from 0.2 to 0.8 exhibited a rise time (the median (min, max)) of 1.4 [1.1, 1.9] min; settling time, 7.8 [4.2, 9.0] min; and percent overshoot of 9.6 [2.3, 10.8]%. Under steady state conditions the CLAD system exhibited a median error of 0.1 [-0.5, 0.9]%; inaccuracy of 1.8 [0.9, 3.4]%; oscillation index of 1.8 [0.9, 3.4]%; and maximum instantaneous propofol dose of 4.3 [2.1, 10.5] mg kg(-1). The maximum hourly propofol dose was 4.3 [2.1, 10.3] mg kg(-1) h(-1). Performance fell within clinically acceptable limits for all measures.

SIGNIFICANCE

A CLAD system designed using robust control theory achieves clinically acceptable performance in the presence of realistic unmodeled disturbances and in spite of realistic model uncertainty, while maintaining infusion rates within acceptable safety limits.

Should we treat patients with impaired consciousness and periodic patterns on EEG?

PURPOSE

The significance of periodic EEG patterns in patients with impaired consciousness is controversial. We aimed to determine if treating these patterns influences clinical outcome.

METHOD

We studied all patients who had periodic discharges on their EEG recordings from January 2007 to December 2009. Patients with clinical seizures within the preceding 24h, or with unequivocal electrographical seizure activity were excluded. Logistic regression was performed to analyze for factors associated with (a) mortality (b) functional status (c) resolution of EEG pattern.

RESULTS

Of the 4246 patients who had EEG, 111 (2.6%) had periodic EEG patterns. 64 met inclusion criteria. In adjusted analysis, higher mortality was associated with acute symptomatic etiology (OR 17.74, 95% CI 1.61-196.07, p=0.019), and presence of clinical seizures (OR 4.73, 95% CI 1.10-20.34, p=0.037). For each unit decrement of GCS, the odds of inpatient mortality and a poorer functional state on discharge increased by 23% (95% CI 7-37%, p=0.009) and 33% (95% CI 9-51%, p=0.011) respectively. Administration of abortive therapy was an independent risk factor for poorer functional status on discharge (adjusted OR 41.39, 95% CI 2.88-594.42, p=0.006), while patients with history of pre-existing cerebral disease appeared more likely to return to baseline functional status on discharge (unadjusted OR 5.00, 95% CI 1.40-17.86, p=0.013).

CONCLUSION

Treatment of periodic EEG patterns does not independently improve clinical outcome of patients with impaired conscious levels. Occurrence of seizures remote to the time of EEG and lower GCS scores independently predict poor prognoses.

Pediatric seizures

On the basis of strong evidence, treatment is highly dependent on the seizure semiology results, electroencephalography (EEG) findings, and origin. • On the basis of moderate evidence and consensus, vigorous use of video EEG recordings and home video cameras should be used to delineate the epileptic syndromes. • On the basis of strong evidence, pediatric epilepsy syndromes have common comorbidities. As a consensus, some pediatric epilepsy centers consider referral to a neuropsychologist to be first-line care in these patients. • On the basis of strong evidence and consensus, antiepileptic drug therapy has its own complications and should be discontinued after an appropriate treatment course. • On the basis of moderate evidence and consensus, uncontrolled seizures put patients at risk for significant morbidity and mortality.

Review article: Convulsive and non-convulsive status epilepticus: an emergency medicine perspective

Status epilepticus (SE) is divided into convulsive and non-convulsive types; both are associated with significant morbidity and mortality. Although convulsive SE is easily recognized, non-convulsive SE remains an elusive diagnosis as physical signs are varied and subtle. Successful management depends on a comprehensive approach that involves diagnostic testing and pharmacological interventions while ensuring cerebral oxygenation and perfusion at all times. There are a limited number of well-designed studies to support the development of evidence-based recommendations for the management of SE, especially for the management of non-convulsive status. Benzodiazepines, specifically lorazepam, continue to be the most commonly recommended first-line therapy; best treatment for refractory status cases depends on resources available and must be tailored to the individual institution. In order to facilitate care, it is recommended that each institution develop a management protocol for these patients.

Predicting seizures: a behavioral approach

This article reviews the epilepsy cycle, distinguishing the interictal, preictal, ictal, and postictal phases. Evidence suggesting that the preictal phase can sometimes be identified based on neurophysiologic signals, premonitory features, the presence of trigger factors, or self-report is also reviewed. Diary studies have shown that seizures are not randomly distributed in time and that a subgroup of persons with epilepsy can predict an impending seizure. Paper diary data and preliminary analysis of electronic diary data suggest that seizure prediction is feasible. Whereas all of this evidence sets the stage for seizure prediction and preemptive therapy, several questions remain unanswered. First, what proportion of persons with epilepsy can predict their seizures? Second, within and among individuals, how accurate is prediction? Third, can prediction be improved through education about group level or individual predictors? And finally, in a group that can make robust predictions what are the most effective interventions for reducing seizure probability at times of high risk? The answers to these questions could reduce the burden of epilepsy by making seizures predictable and setting the stage for preemptive therapy. This work could improve the understanding of epilepsy by providing a context for studying the transitions from the interictal to preictal and ictal states. More prospective studies are needed; challenges certainly exist, but as the studies discussed here demonstrate, the field is rich with promise for improving the lives of patients with epilepsy.