Epidemiology and outcomes of status epilepticus in the elderly

A longitudinal MRI and TSPO PET-based investigation of brain region-specific neuroprotection by diazepam versus midazolam following organophosphate-induced seizures

Acute poisoning with organophosphorus cholinesterase inhibitors (OPs), such as OP nerve agents and pesticides, can cause life threatening cholinergic crisis and status epilepticus (SE). Survivors often experience significant morbidity, including brain injury, acquired epilepsy, and cognitive deficits. Current medical countermeasures for acute OP poisoning include a benzodiazepine to mitigate seizures. Diazepam was long the benzodiazepine included in autoinjectors used to treat OP-induced seizures, but it is now being replaced in many guidelines by midazolam, which terminates seizures more quickly, particularly when administered intramuscularly. While a direct correlation between seizure duration and the extent of brain injury has been widely reported, there are limited data comparing the neuroprotective efficacy of diazepam versus midazolam following acute OP intoxication. To address this data gap, we used non-invasive imaging techniques to longitudinally quantify neuropathology in a rat model of acute intoxication with the OP diisopropylfluorophosphate (DFP) with and without post-exposure intervention with diazepam or midazolam. Magnetic resonance imaging (MRI) was used to monitor neuropathology and brain atrophy, while positron emission tomography (PET) with a radiotracer targeting translocator protein (TSPO) was utilized to assess neuroinflammation. Animals were scanned at 3, 7, 28, 65, 91, and 168 days post-DFP and imaging metrics were quantitated for the hippocampus, amygdala, piriform cortex, thalamus, cerebral cortex and lateral ventricles. In the DFP-intoxicated rat, neuroinflammation persisted for the duration of the study coincident with progressive atrophy and ongoing tissue remodeling. Benzodiazepines attenuated neuropathology in a region-dependent manner, but neither benzodiazepine was effective in attenuating long-term neuroinflammation as detected by TSPO PET. Diffusion MRI and TSPO PET metrics were highly correlated with seizure severity, and early MRI and PET metrics were positively correlated with long-term brain atrophy. Collectively, these results suggest that anti-seizure therapy alone is insufficient to prevent long-lasting neuroinflammation and tissue remodeling.

Elderly patients with nonconvulsive status epilepticus: Clinical-EEG data, hospital mortality, STESS and EMSE

Purpose To assess the clinical-EEG aspects, characterization of subtypes, relationships with prognostic scales and the occurrence of death in elderly patients in the acute phase of nonconvulsive status epilepticus (NCSE). Methodology Clinical variables, EEG data, Status epilepticus severity score (STESS), and the Epidemiology-based mortality score in status epilepticus (EMSE) were related to the death of 96 patients who were over 60 years old, with NCSE. Results NCSE with coma was observed in 31 patients (19 non-subtle and 12 "subtle" SE) and focal NCSE with impairment of consciousness in 65 cases. There were no significant EEG differences according to the type of NCSE. Higher STESS scores occurred in the comatose NCSE patients when compared to those with focal NCSE and impairment of consciousness (4.8 ± 1.2 vs 3.7 ± 1.2; T-Test; p<0.001). It was observed that 25 (26%) elderly died, with a mean survival time of 19.3 days. Elderly people with a higher risk of death are those diagnosed with NCSE with coma (HR 2.76; 95% CI 1.15-6.65; p = 0.023), with STESS≥3 (HR 16.0; CI 1.77-45.08; p = 0.014), with EMSE≥64 (HR 3.67; CI 1.54-8.72; p = 0.003), and those with no history of recurrent SE (HR 6.80; CI 1.42-32.64; p = 0.017), in Cox regression. Conclusion The ictal EEG patterns did not distinguish the subtypes of NCSE. Thirty-day mortality rate was high in elderly patients with NCSE. The clinical variables are related to prognosis. Mortality in the elderly was associated with comatose NCSE patients, with STESS≥3, with EMSE≥64, and no history of recurrent SE.

Treating Status Epilepticus: Phenytoin Versus Levetiracetam

For decades, phenytoin has been the drug of choice for the treatment of epilepsy but also the second-line treatment for status epilepticus (SE). However, newer antiepileptic drugs (AEDs) have emerged as safer alternatives for the suppression of seizures. Consequently, phenytoin has recently fallen under scrutiny in the research world, prompting many studies to compare its efficacy to these other drugs, most notably levetiracetam. Levetiracetam is a second-generation AED, which is gaining wide clinical use as the second-line agent in treating SE patients. This review focuses on several clinical studies that have directly compared the effectiveness of phenytoin and levetiracetam in suppressing SE seizure activity. Additionally, this review highlights several advantages of using levetiracetam over phenytoin in this clinical context.

Early Neurologic Recovery, Practice Pattern Variation, and the Risk of Endotracheal Intubation Following Established Status Epilepticus

OBJECTIVE

To quantify the association between early neurologic recovery, practice pattern variation, and endotracheal intubation during established status epilepticus, we performed a secondary analysis within the cohort of patients enrolled in the Established Status Epilepticus Treatment Trial (ESETT).

METHODS

We evaluated factors associated with the endpoint of endotracheal intubation occurring within 120 minutes of ESETT study drug initiation. We defined a blocked, stepwise multivariate regression, examining 4 phases during status epilepticus management: (1) baseline characteristics, (2) acute treatment, (3) 20-minute neurologic recovery, and (4) 60-minute recovery, including seizure cessation and improving responsiveness.

RESULTS

Of 478 patients, 117 (24.5%) were intubated within 120 minutes. Among high-enrolling sites, intubation rates ranged from 4% to 32% at pediatric sites and 19% to 39% at adult sites. Baseline characteristics, including seizure precipitant, benzodiazepine dosing, and admission vital signs, provided limited discrimination for predicting intubation (area under the curve [AUC] 0.63). However, treatment at sites with an intubation rate in the highest (vs lowest) quartile strongly predicted endotracheal intubation independently of other treatment variables (adjusted odds ratio [aOR] 8.12, 95% confidence interval [CI] 3.08-21.4, model AUC 0.70). Site-specific variation was the factor most strongly associated with endotracheal intubation after adjustment for 20-minute (aOR 23.4, 95% CI 6.99-78.3, model AUC 0.88) and 60-minute (aOR 14.7, 95% CI 3.20-67.5, model AUC 0.98) neurologic recovery.

CONCLUSIONS

Endotracheal intubation after established status epilepticus is strongly associated with site-specific practice pattern variation, independently of baseline characteristics, and early neurologic recovery and should not alone serve as a clinical trial endpoint in established status epilepticus.

TRIAL REGISTRATION INFORMATION

ClinicalTrials.gov Identifier: NCT01960075.

Efficacy of levetiracetam, fosphenytoin, and valproate for established status epilepticus by age group (ESETT): a double-blind, responsive-adaptive, randomised controlled trial

BACKGROUND

Benzodiazepine-refractory, or established, status epilepticus is thought to be of similar pathophysiology in children and adults, but differences in underlying aetiology and pharmacodynamics might differentially affect response to therapy. In the Established Status Epilepticus Treatment Trial (ESETT) we compared the efficacy and safety of levetiracetam, fosphenytoin, and valproate in established status epilepticus, and here we describe our results after extending enrolment in children to compare outcomes in three age groups.

METHODS

In this multicentre, double-blind, response-adaptive, randomised controlled trial, we recruited patients from 58 hospital emergency departments across the USA. Patients were eligible for inclusion if they were aged 2 years or older, had been treated for a generalised convulsive seizure of longer than 5 min duration with adequate doses of benzodiazepines, and continued to have persistent or recurrent convulsions in the emergency department for at least 5 min and no more than 30 min after the last dose of benzodiazepine. Patients were randomly assigned in a response-adaptive manner, using Bayesian methods and stratified by age group (<18 years, 18-65 years, and >65 years), to levetiracetam, fosphenytoin, or valproate. All patients, investigators, study staff, and pharmacists were masked to treatment allocation. The primary outcome was absence of clinically apparent seizures with improved consciousness and without additional antiseizure medication at 1 h from start of drug infusion. The primary safety outcome was life-threatening hypotension or cardiac arrhythmia. The efficacy and safety outcomes were analysed by intention to treat. This study is registered in ClinicalTrials.gov, NCT01960075.

FINDINGS

Between Nov 3, 2015, and Dec 29, 2018, we enrolled 478 patients and 462 unique patients were included: 225 children (aged <18 years), 186 adults (18-65 years), and 51 older adults (>65 years). 175 (38%) patients were randomly assigned to levetiracetam, 142 (31%) to fosphenyltoin, and 145 (31%) were to valproate. Baseline characteristics were balanced across treatments within age groups. The primary efficacy outcome was met in those treated with levetiracetam for 52% (95% credible interval 41-62) of children, 44% (33-55) of adults, and 37% (19-59) of older adults; with fosphenytoin in 49% (38-61) of children, 46% (34-59) of adults, and 35% (17-59) of older adults; and with valproate in 52% (41-63) of children, 46% (34-58) of adults, and 47% (25-70) of older adults. No differences were detected in efficacy or primary safety outcome by drug within each age group. With the exception of endotracheal intubation in children, secondary safety outcomes did not significantly differ by drug within each age group.

INTERPRETATION

Children, adults, and older adults with established status epilepticus respond similarly to levetiracetam, fosphenytoin, and valproate, with treatment success in approximately half of patients. Any of the three drugs can be considered as a potential first-choice, second-line drug for benzodiazepine-refractory status epilepticus.

FUNDING

National Institute of Neurological Disorders and Stroke, National Institutes of Health.

Status epilepticus in Auckland, New Zealand: Incidence, etiology, and outcomes

OBJECTIVE

To determine the incidence, etiology, and outcome of status epilepticus (SE) in Auckland, New Zealand, using the latest International League Against Epilepsy (ILAE) SE semiological classification.

METHODS

We prospectively identified patients presenting to the public or major private hospitals in Auckland (population = 1.61 million) between April 6, 2015 and April 5, 2016 with a seizure lasting 10 minutes or longer, with retrospective review to confirm completeness of data capture. Information was recorded in the EpiNet database.

RESULTS

A total of 477 episodes of SE occurred in 367 patients. Fifty-one percent of patients were aged <15 years. SE with prominent motor symptoms comprised 81% of episodes (387/477). Eighty-four episodes (18%) were nonconvulsive SE. Four hundred fifty episodes occurred in 345 patients who were resident in Auckland. The age-adjusted incidence of 10-minute SE episodes and patients was 29.25 (95% confidence interval [CI] = 27.34-31.27) and 22.22 (95% CI = 20.57-23.99)/100 000/year, respectively. SE lasted 30 minutes or longer in 250 (56%) episodes; age-adjusted incidence was 15.95 (95% CI = 14.56-17.45) SE episodes/100 000/year and 12.92 (95% CI = 11.67-14.27) patients/100 000/year. Age-adjusted incidence (10-minute SE) was 25.54 (95% CI = 23.06-28.24) patients/100 000/year for males and 19.07 (95% CI = 16.91-21.46) patients/100 000/year for females. The age-adjusted incidence of 10-minute SE was higher in Māori (29.31 [95% CI = 23.52-37.14]/100 000/year) and Pacific Islanders (26.55 [95% CI = 22.05-31.99]/100 000/year) than in patients of European (19.13 [95% CI = 17.09-21.37]/100 000/year) or Asian/other descent (17.76 [95% CI = 14.73-21.38]/100 000/year). Seventeen of 367 patients in the study died within 30 days of the episode of SE; 30-day mortality was 4.6%.

SIGNIFICANCE

In this population-based study, incidence and mortality of SE in Auckland lie in the lower range when compared to North America and Europe. For pragmatic reasons, we only included convulsive SE if episodes lasted 10 minutes or longer, although the 2015 ILAE SE classification was otherwise practical and easy to use.

Age-Related Susceptibility to Epileptogenesis and Neuronal Loss in Male Fischer Rats Exposed to Soman and Treated With Medical Countermeasures

Elderly individuals compose a large percentage of the world population; however, few studies have addressed the efficacy of current medical countermeasures (MCMs) against the effects of chemical warfare nerve agent exposure in aged populations. We evaluated the efficacy of the anticonvulsant diazepam in an old adult rat model of soman (GD) poisoning and compared the toxic effects to those observed in young adult rats when anticonvulsant treatment is delayed. After determining their respective median lethal dose (LD50) of GD, we exposed young adult and old adult rats to an equitoxic 1.2 LD50 dose of GD followed by treatment with atropine sulfate and the oxime HI-6 at 1 min after exposure, and diazepam at 30 min after seizure onset. Old adult rats that presented with status epilepticus were more susceptible to developing spontaneous recurrent seizures (SRSs). Neuropathological analysis revealed that in rats of both age groups that developed SRS, there was a significant reduction in the density of mature neurons in the piriform cortex, thalamus, and amygdala, with more pronounced neuronal loss in the thalamus of old adult rats compared with young adult rats. Furthermore, old adult rats displayed a reduced density of cells expressing glutamic acid decarboxylase 67, a marker of GABAergic interneurons, in the basolateral amygdala and piriform cortex, and a reduction of astrocyte activation in the piriform cortex. Our observations demonstrate the reduced effectiveness of current MCM in an old adult animal model of GD exposure and strongly suggest the need for countermeasures that are more tailored to the vulnerabilities of an aging population.

Duration of therapeutic coma and outcome of refractory status epilepticus

OBJECTIVE

Examine the association of duration of therapeutic coma (TC) with seizure recurrence, morbidity, and mortality in refractory status epilepticus (RSE). Define an optimal window for TC that provides sustained seizure control and minimizes complications.

METHODS

Retrospective, observational cohort study involving patients who presented with RSE to the University of Alabama at Birmingham or the University of California at San Francisco from 2010 to 2016. Relationship of duration of TC with primary and secondary outcomes was evaluated using two-sample t tests, simple linear regression, and chi-square tests. Multivariable linear and logistic regression models were used to identify independent predictors. Predictive ability of TC for seizure recurrence was quantified using a receiver-operating characteristic curve. Youden index was used to determine an optimal cutoff value.

RESULTS

Multivariable analysis of clinical and treatment characteristics of 182 patients who were treated predominantly with propofol as anesthetic agent showed that longer duration of the first trial of TC (27.2 vs 15.6 hours) was independently associated with a higher chance of seizure recurrence following the first weaning attempt (P = 0.038) but not with poor functional neurologic outcome upon discharge, in-hospital complications, or mortality. Furthermore, higher doses of anesthetic utilized during the first trial of TC were independently associated with fewer in-hospital complications (P = 0.003) and associated with a shorter duration of mechanical ventilation and total length of stay. Duration of TC was identified as an independent predictor of seizure recurrence with an optimal cutoff point at 35 hours.

SIGNIFICANCE

This study suggests that a shorter duration yet deeper TC as treatment for RSE may be more effective and safer than the currently recommended TC duration of 24-48 hours. Prospective and randomized trials should be conducted to validate these assertions.

Targeting the glutamatergic system to counteract organophosphate poisoning: A novel therapeutic strategy

One of the devastating effects of acute exposure to organophosphates, like nerve agents, is the induction of severe and prolonged status epilepticus (SE), which can cause death, or brain damage if death is prevented. Seizures after exposure are initiated by muscarinic receptor hyperstimulation-after inhibition of acetylcholinesterase by the organophosphorus agent and subsequent elevation of acetylcholine-but they are reinforced and sustained by glutamatergic hyperexcitation, which is the primary cause of brain damage. Diazepam is the FDA-approved anticonvulsant for the treatment of nerve agent-induced SE, and its replacement by midazolam is currently under consideration. However, clinical data derived from the treatment of SE of any etiology, as well as studies on the control of nerve agent-induced SE in animal models, have indicated that diazepam and midazolam control seizures only temporarily, their antiseizure efficacy is reduced as the latency of treatment from the onset of SE increases, and their neuroprotective efficacy is limited or absent. Here, we review data on the discovery of a novel anticonvulsant and neuroprotectant, LY293558, an AMPA/GluK1 receptor antagonist. Treatment of soman-exposed immature, young-adult, and aged rats with LY293558, terminates SE with limited recurrence of seizures, significantly protects from brain damage, and prevents long-term behavioral deficits, even when LY293558 is administered 1 h post-exposure. More beneficial effects and complete neuroprotection is obtained when LY293558 administration is combined with caramiphen, which antagonizes NMDA receptors. Further efficacy studies may bring the LY293558 + caramiphen combination therapy on the pathway to approval for human use.

Long-Term Effects of Early Life Seizures on Endogenous Local Network Activity of the Mouse Neocortex

Understanding the long term impact of early life seizures (ELS) is of vital importance both for researchers and clinicians. Most experimental studies of how seizures affect the developing brain have drawn their conclusions based on changes detected at the cellular or behavioral level, rather than on intermediate levels of analysis, such as the physiology of neuronal networks. Neurons work as part of networks and network dynamics integrate the function of molecules, cells and synapses in the emergent properties of brain circuits that reflect the balance of excitation and inhibition in the brain. Therefore, studying network dynamics could help bridge the cell-to-behavior gap in our understanding of the neurobiological effects of seizures. To this end we investigated the long-term effects of ELS on local network dynamics in mouse neocortex. By using the pentylenetetrazole (PTZ)-induced animal model of generalized seizures, single or multiple seizures were induced at two different developmental stages (P9-15 or P19-23) in order to examine how seizure severity and brain maturational status interact to affect the brain's vulnerability to ELS. Cortical physiology was assessed by comparing spontaneous network activity (in the form of recurring Up states) in brain slices of adult (>5 mo) mice. In these experiments we examined two distinct cortical regions, the primary motor (M1) and somatosensory (S1) cortex in order to investigate regional differences in vulnerability to ELS. We find that the effects of ELSs vary depending on (i) the severity of the seizures (e.g., single intermittent ELS at P19-23 had no effect on Up state activity, but multiple seizures induced during the same period caused a significant change in the spectral content of spontaneous Up states), (ii) the cortical area examined, and (iii) the developmental stage at which the seizures are administered. These results reveal that even moderate experiences of ELS can have long lasting age- and region-specific effects in local cortical network dynamics.

Prognosis of status epilepticus in elderly patients

PURPOSE

To evaluate the clinical features and prognosis of status epilepticus (SE) in patients above 70 years old.

METHODS

Retrospective analysis of all patients ≥70 years old with SE registered prospectively during 4 years. Follow-up after discharge was performed.

RESULTS

Ninety patients were evaluated. Acute symptomatic etiology was the most prevalent. The mean number of antiepileptic drugs (AEDs) used was 2.7 ± 1.2, and 21% of the patients required sedation. A poor outcome was considered when death (31.1%) or developing of new neurological impairment at discharge (32.2%) occurred. After multivariate analysis, four variables predicted a poor outcome: acute symptomatic etiology (OR: 6.320; 95% CI: 1.976-20.217; P = .002), focal motor SE type (OR: 9.089; 95% CI: 2.482-33.283; P = .001), level of consciousness (OR: 4.596; 95% CI: 1.903-11.098; P = .001), and SE duration >12 hours (OR: 3.763; 95% CI: 1.130-12.530; P = .031). Independent predictive factors of mortality were SE duration >12 hours (OR: 4.306; 95% CI: 1.044-17.757; P = .043), modified Status Epilepticus Severity Score (mSTESS) (OR: 2.216; 95% CI: 1.313-3.740; P = .003), and development of complications (OR: 3.334; 95% CI: 1.004-11.070, P = .049). Considering long-term mortality, age (HR 1.036; 95% CI 1.001-1.071; P = .044), a potentially fatal underlying cause (HR 2.609; 95% CI 1.497- 4.548; P = .001), and mSTESS score >4 (HR 1.485; 95% CI 1.158-1.903; P = .002) remained as predictive factors. There was no association between sedation and the number of AEDs used with outcome at discharge or long-term mortality (P > .05).

CONCLUSIONS

SE above 70 years old has a high morbimortality. Prognosis is not related to treatment aggressiveness.

The electroclinical spectrum, etiologies, treatment and outcome of nonconvulsive status epilepticus in the elderly

BACKGROUND

Nonconvulsive status epilepticus (NCSE) in the elderly is particularly difficult to diagnose, mainly due to subtle clinical manifestations and associated comorbidities. The recently validated electroencephalography (EEG) diagnostic criteria for NCSE and the proposed operational classification of status epilepticus provide tools that can allow an earlier diagnosis and better management of NCSE in this age group, possibly contributing to reduce its high mortality.

MATERIAL AND METHODS

we used these tools to identify and characterize a cohort of elderly (>60year-old) patients admitted at our institution in a 3-year period; the video-EEG and clinical files of the patients fulfilling EEG diagnostic criteria for NCSE were reviewed, being in this study described their electroclinical spectrum, etiologies, treatment, inhospital mortality, and status epilepticus severity score (STESS).

RESULTS

Fourty patients (23 women; mean age 76.6years) were identified. Although dyscognitive NCSE associated with >2.5Hz of epileptiform discharges (ED) was the most frequent electroclinical phenotype, this was quite heterogeneous, ranging from patients with aura continua to patients in coma, associated with frequent ED or rhythmic slow activities. Acute symptomatic (45%) and multifactorial (27.5%) etiologies were the most common, and associated with the worst prognosis. There was a trend to use newer antiepileptic drugs in the early steps of NCSE treatment. The inhospital mortality was high (22.5%) and predicted by STESS scores ≥3.

CONCLUSION

In the elderly, NCSE has heterogeneous electroclinical phenotypes and etiologies. In spite of the treatment limitations conditioned by the comorbidities, more aggressive treatments could be justified to reduce mortality in patients with high STESS scores.

Flupirtine and diazepam combination terminates established status epilepticus: results in three rodent models

Objective

Status epilepticus (SE) is a neurological emergency requiring rapid termination of seizures. New treatment choices are needed for benzodiazepine-refractory SE or established SE (ESE). Previous studies have demonstrated that the potassium-channel opener flupirtine terminates seizures in neonatal animals. However, its effectiveness in adult ESE has not been tested. We tested whether flupirtine alone or in combination with the benzodiazepine diazepam would terminate ESE in three animal models.

Methods

SE was induced by administration of lithium followed by pilocarpine, by electrical stimulation of the hippocampus or by diisopropylfluorophosphate (DFP) administration. Seizures were assessed by EEG recorded from the hippocampus and cortex.

Results

Flupirtine alone did not terminate ESE within 60 min of administration in any of the three models of ESE. A combination of flupirtine and diazepam terminated ESE within 60 min in all the three models. The drug combination shortened the duration of ESE in all three models. Drug responsiveness was distinct between each model.

Conclusion

A combination of the potassium channel opener flupirtine and diazepam is a potential therapy for ESE.

New onset status epilepticus in older patients: Clinical characteristics and outcome

PURPOSE

We here evaluated (1) the differential characteristics of status epilepticus (SE) in older (≥60 years) compared to younger adults (18-59 years). In particular, we were interested in (2) the proportion and characteristics of new onset SE in patients with no history of epilepsy (NOSE) in older compared to younger adults, and (3) predictive parameters for clinical outcome in older subjects with NOSE.

METHODS

We performed a monocentric retrospective analysis of all adult patients (≥18years) admitted with SE to our tertiary care centre over a period of 10 years (2006-2015) to evaluate clinical characteristics and short-time outcome at discharge.

RESULTS

One-hundred-thirty-five patients with SE were included in the study. Mean age at onset was 64 years (range 21-90), eighty-seven of the patients (64%) were older than 60 years. In 76 patients (56%), SE occurred as NOSE, sixty-seven percent of them were aged ≥60 years. There was no age-dependent predominance for NOSE. NOSE was not a relevant outcome predictor, especially regarding age-related subgroups. Older patients with NOSE had less frequently general tonic clonic SE (GTCSE; p=0.001) and were more often female (p=0.01). Regarding outcome parameters and risk factors in older patients with NOSE, unfavourable outcome was associated with infections during in-hospital treatment (0.04), extended stay in ICU (p=0.001), and generally in hospital (p<0.001).

CONCLUSION

In our cohort, older patients represented the predominant subgroup in patients with SE. Older patients suffered more often from non-convulsive semiology and had a less favourable short-time outcome. NOSE was not a predictive outcome parameter in older patients. Data suggest that avoiding infections should have a priority because higher infection rates were associated with unfavourable outcome.

The Prehospital Predictors of Tracheal Intubation for in Patients who Experience Convulsive Seizures in the Emergency Department

Objective To identify the prehospital factors predicting the performance of tracheal intubation (TI) at the emergency department (ED) in patients with convulsive seizure or epilepsy. Methods We performed a retrospective analysis of seizure patients who underwent TI at the ED soon after arrival. The clinical variables obtained in the prehospital setting were reviewed. Patients The study population included consecutive adult patients who were transported to an urban tertiary care ED due to convulsive seizure between August 2010 and September 2015. Results Among the 822 eligible patients, 59 patients (7.2%) underwent TI at the ED. Four independent prehospital predictors were identified using multivariate analysis: age ≥50 years (+1 point), meeting the definition of convulsive status epilepticus (+4 points), and an on-scene heart rate of ≥120 bpm (+1 point) led to a higher likelihood of TI, while a higher on-scene (alert or confused) level of consciousness (-3 points) led to a lower likelihood of TI. The derived prediction rule (the sum of all points) had good predictive performance with an area under the curve of 0.88 (95% confidence interval: 0.79-0.97), a sensitivity of 0.62, a specificity of 0.91, and a positive likelihood ratio of 10.6, when the cut-off value was set to 5 points. Conclusion We constructed a simple prehospital prediction rule to help predict the need for TI in seizure patients, even in the prehospital phase. This may possibly lead to the more effective management of seizure patients in the ED.

Susceptibility to Soman Toxicity and Efficacy of LY293558 Against Soman-Induced Seizures and Neuropathology in 10-Month-Old Male Rats

Acute nerve agent exposure causes prolonged status epilepticus (SE), leading to death or long-term brain damage. We have previously demonstrated that LY293558, an AMPA/GluK1 kainate receptor antagonist, terminates SE induced by the nerve agent soman and protects from long-term brain damage, in immature rats and young-adult rats, even if administered with a relatively long latency from the time of exposure. However, susceptibility to the lethal consequences of SE increases with age, and mortality by SE induced by soman is substantially greater in older animals. Therefore, in the present study, we compared the susceptibility to soman toxicity of 10-month-old male rats with that of young-adult male rats (42 to 50 days old) and examined the protective efficacy of LY293558 in the older group. A lower percentage of the 10-month-old rats developed SE after injection of 1.2 × LD₅₀ soman, compared to the young adults, the latency to seizure onset was longer in the older rats, and seizure intensity did not differ between the two age groups. However, mortality rate in the older rats who developed SE was higher than in the young adults. Acetylcholinesterase activity in the amygdala, hippocampus, and piriform cortex did not differ between the two age groups. Administration of LY293558 at 20 or 60 min post-exposure suppressed SE, increased 24-h survival rate, decreased the long-term risk of death, reduced neuronal degeneration in the amygdala, hippocampus, piriform, and entorhinal cortices, and facilitated recovery from body weight loss. Thus, LY293558 is an effective countermeasure against soman toxicity also in older animals.

Predictors of hospital and one-year mortality in intensive care patients with refractory status epilepticus: a population-based study

Background

The aim was to determine predictors of hospital and 1-year mortality in patients with intensive care unit (ICU)-treated refractory status epilepticus (RSE) in a population-based study.

Methods

This was a retrospective study of the Finnish Intensive Care Consortium (FICC) database of adult patients (16 years of age or older) with ICU-treated RSE in Finland during a 3-year period (2010–2012). The database consists of admissions to all 20 Finnish hospitals treating RSE in the ICU. All five university hospitals and 11 out of 15 central hospitals participated in the present study. The total adult referral population in the study hospitals was 3.92 million, representing 91% of the adult population of Finland. Patients whose condition had a post-anoxic aetiological basis were excluded.

Results

We identified 395 patients with ICU-treated RSE, corresponding to an annual incidence of 3.4/100,000 (95% confidence interval (CI) 3.04–3.71). Hospital mortality was 7.4% (95% CI 0–16.9%), and 1-year mortality was 25.4% (95% CI 21.2–29.8%). Mortality at hospital discharge was associated with severity of organ dysfunction. Mortality at 1 year was associated with older age (adjusted odds ratio (aOR) 1.033, 95% CI 1.104–1.051, p = 0.001), sequential organ failure assessment (SOFA) score (aOR 1.156, CI 1.051–1.271, p = 0.003), super-refractory status epilepticus (SRSE) (aOR 2.215, 95% CI 1.20–3.84, p = 0.010) and dependence in activities of daily living (ADL) (aOR 2.553, 95% CI 1.537–4.243, p < 0.0001).

Conclusions

Despite low hospital mortality, 25% of ICU-treated RSE patients die within a year. Super-refractoriness, dependence in ADL functions, severity of organ dysfunction at ICU admission and older age predict long-term mortality.

Trial registration

Retrospective registry study; no interventions on human participants.

Status epilepticus in the elderly patients: A national data study in Thailand

There are limited data in terms of incidence, clinical features, and outcomes in elderly patients with status epilepticus (SE) in national level. We retrospectively explored national data in Thailand for reimbursement of all SE in elderly patients admitted in the fiscal year 2004-2012. SE in elderly patients (age>60years old) were diagnosed and searched based on ICD 10 (G41) from the national database of from the National Health and Security Office. There were 3326 SE in elderly patients. The national incidence of SE was highest at 8.78patients/100,000/year in 2012. The average age was 72.02years and most were males (1379 patients; 58.8%). At discharge, 66% of patients had improved and in-hospital mortality rate was 14.5%. Predictors of poor outcomes were older age≥80years, being female, hospital levels, chronic renal failure, central nervous system infection, respiratory failure, pneumonia, septicemia, shock, acute renal failure, and hyperkalemia. In conclusion, the number of cases of SE in elderly patients in Thailand has been increasing annually. Increasing age was associated with poor outcome in admitted elderly SE patients.

Status epilepticus in the elderly-A retrospective study on 120 patients

PURPOSE

Status epilepticus (SE) is one of the most common neurological emergencies with a high incidence in the elderly. Major determinants of prognosis are patients' age, duration of SE and underlying etiology. We aimed identifying differences in clinical presentation of SE, etiologies and outcome between patients (pts.) sixty years or older (≥60) and younger than sixty (<60) years (yrs).

METHODS

We retrospectively analyzed 120 patients (48 women) with SE admitted to the Neurological Intensive Care Unit (NICU), Department of Neurology, Paracelsus Medical University Salzburg, Austria between 1/2011 and 01/2013.

KEY FINDINGS

Median age was 69 years (range 14-90) (63% ≥60yrs). Generalized tonic clonic SE was the most common SE type, whereas non convulsive SE with and without coma tended to occur more frequently in the elderly (33% ≥60 yrs. vs. 20%<60 yrs, Chi2=3.511, p=0.061). Preexisting history of epilepsy was more common in the younger age group (64% vs 41% p=0.014). An acute symptomatic cause of SE was identified in 25% (31/120), with cerebrovascular diseases being more frequent in the elderly (47% vs. 11%; p<0.01). Duration of SE did not differ between the age groups (p=0.63). Mortality was higher in elderly patients (31% vs. 7%, p=0.028, Chi Square=5.18) and moderate disability in younger patients (42% vs 17%; p=0.005, Chi Square=7.83). After Bonferroni correction only the higher rate of cerebrovascular etiologies in the elderly was statistically significant.

SIGNIFICANCE

In the elder population, SE occurs more often in patients without preexisting epilepsy and is most frequently caused by cerebrovascular diseases. NCSE tends to be more frequent in the elderly and diagnosis is complicated by subtle clinical presentation. Even though comorbidities represent treatment limitations, in our sample no differences in choice of AED as well as dosage were observed between the age groups, reflecting a trend toward AEDs with more favorable adverse event profile in all patients. SE in older patients is associated with poorer outcome and higher mortality.

Managing Status Epilepticus in the Older Adult

The aim of this systematic review was to describe particularities in epidemiology, outcome, and management modalities in the older adult population with status epilepticus. There is a higher incidence of status epilepticus in the older adult population, and it commonly has a nonconvulsive presentation. Diagnosis in this population may be difficult and requires an unrestricted use of EEG. Short and long term associated-mortality are high, and age over 60 years is an independent factor associated with poor outcome. Stroke (acute or remote symptomatic), miscellaneous metabolic causes, dementia, infections hypoxemia, and brain injury are among the main causes of status epilepticus occurrence in this age category. The use of anticonvulsive agents can be problematic as well. Thus, it is important to take into account the specific aspects related to the pharmacokinetic and pharmacodynamic changes in older critically-ill adults. Beyond these precautions, the management may be identical to that of the younger adult, including prompt initiation of symptomatic and anticonvulsant therapies, and a broad and thorough etiological investigation. Such management strategies may improve the vital and functional prognosis of these patients, while maintaining a high overall quality of care.

Mortality predictors of epilepsy and epileptic seizures among hospitalized elderly

Epilepsy and epileptic seizures are common brain disorders in the elderly and are associated with increased mortality that may be ascribed to the underlying disease or epilepsy-related causes.

OBJECTIVE

To describe mortality predictors of epilepsy and epileptic seizures in elderly inpatients.

METHOD

Retrospective analysis was performed on hospitalized elderly who had epilepsy or epileptic seizures, from January 2009 to December 2010. One hundred and twenty patients were enrolled.

RESULTS

The most common etiology was ischemic stroke (37%), followed by neoplasias (13%), hemorrhagic stroke (12%), dementias (11.4%) and metabolic disturbances (5.5%). In a univariate analysis, disease duration (p = 0.04), status epilepticus (p < 0.001) and metabolic etiology (p = 0.005) were associated with mortality. However after adjustment by logistic regression, only status epilepticus remained an independent predictor of death (odds ratio = 13; 95%CI = 2.3 to 72; p = 0.004).

CONCLUSION

In this study status epilepticus was an independent risk factor for death during hospitalization.

Pharmacotherapy for Status Epilepticus

Status epilepticus (SE) represents the most severe form of epilepsy. It is one of the most common neurologic emergencies, with an incidence of up to 61 per 100,000 per year and an estimated mortality of 20 %. Clinically, tonic-clonic convulsive SE is divided into four subsequent stages: early, established, refractory, and super-refractory. Pharmacotherapy of status epilepticus, especially of its later stages, represents an "evidence-free zone," due to a lack of high-quality, controlled trials to inform clinical decisions. This comprehensive narrative review focuses on the pharmacotherapy of SE, presented according to the four-staged approach outlined above, and providing pharmacological properties and efficacy/safety data for each antiepileptic drug according to the strength of scientific evidence from the available literature. Data sources included MEDLINE and back-tracking of references in pertinent studies. Intravenous lorazepam or intramuscular midazolam effectively control early SE in approximately 63-73 % of patients. Despite a suboptimal safety profile, intravenous phenytoin or phenobarbital are widely used treatments for established SE; alternatives include valproate, levetiracetam, and lacosamide. Anesthetics are widely used in refractory and super-refractory SE, despite the current lack of trials in this field. Data on alternative treatments in the later stages are limited. Valproate and levetiracetam represent safe and effective alternatives to phenobarbital and phenytoin for treatment of established SE persisting despite first-line treatment with benzodiazepines. To date there are no class I data to support recommendations for most antiepileptic drugs for established, refractory, and super-refractory SE. Limiting the methodologic heterogeneity across studies is required and high-class randomized, controlled trials to inform clinicians about the best treatment in established and refractory status are needed.

Incidence and mortality of super-refractory status epilepticus in adults

OBJECTIVES

Super-refractory status epilepticus (SRSE) is defined as status epilepticus (SE) that continues or recurs 24h or more after the onset of anesthetic therapy. We defined the incidence and outcome of SRSE in adults in Finland.

METHODS

We analyzed retrospectively the Finnish Intensive Care Consortium database in order to identify adult patients with SRSE treated in ICUs in Finland during a three-year period (2010-2012). The database consists of admissions to all 20 Finnish hospitals treating refractory SE (RSE) with general anesthesia in the intensive care unit (ICU). We included consecutive adult (16 years or older) patients with RSE and identified those who had SRSE. Patients with postanoxic etiologies were excluded.

RESULTS

All five university hospitals and 10/15 of the central hospitals participated. The adult referral population of the study hospitals is 3.9 million, representing 91% of the total adult population of Finland. We identified 395 patients with ICU-treated RSE, 87 (22%) of whom were classified as having SRSE. This corresponds to an annual incidence of SRSE of 0.7/100,000 (95% confidence interval [CI]: 0.6-0.9). The one-year mortality rates were 36% (95% CI: 26-46%) for patients with SRSE and 22% (95% CI: 17-27%) for patients with RSE. Mortality was highest (63%) in patients with SRSE aged over 75 years.

CONCLUSIONS

Approximately 20% of patients with RSE treated in Finnish ICUs progressed to having SRSE. The incidence of SRSE, 0.7/100,000, is about 5-10% of the incidence of SE. The mortality of patients with SRSE, 36%, was comparable to earlier studies and twofold higher than the mortality of patients with RSE. This article is part of a Special Issue entitled "Status Epilepticus".

Can anesthetic treatment worsen outcome in status epilepticus?

Status epilepticus refractory to first-line and second-line antiepileptic treatments challenges neurologists and intensivists as mortality increases with treatment refractoriness and seizure duration. International guidelines advocate anesthetic drugs, such as continuously administered high-dose midazolam, propofol, and barbiturates, for the induction of therapeutic coma in patients with treatment-refractory status epilepticus. The seizure-suppressing effect of anesthetic drugs is believed to be so strong that some experts recommend using them after benzodiazepines have failed. Although the rationale for the use of anesthetic drugs in patients with treatment-refractory status epilepticus seems clear, the recommendation of their use in treating status epilepticus is based on expert opinions rather than on strong evidence. Randomized trials in this context are lacking, and recent studies provide disturbing results, as the administration of anesthetics was associated with poor outcome independent of possible confounders. This calls for caution in the straightforward use of anesthetics in treating status epilepticus. However, there are still more questions than answers, and current evidence for the adverse effects of anesthetic drugs in patients with status epilepticus remains too limited to advocate a change of treatment algorithms. In this overview, the rationale and the conflicting clinical implications of anesthetic drugs in patients with treatment-refractory status epilepticus are discussed, and remaining questions are elaborated. This article is part of a Special Issue entitled "Status Epilepticus".

Aetiology and outcome of generalized convulsive status epilepticus in elderly

PURPOSE

Convulsive status epilepticus (CSE) is a common neurologic emergency in elderly people. The current study elaborates the clinical characteristics and outcome of CSE in elderly patients.

METHODS

Analysis of data of generalized CSE patients, aged 60 years and above admitted at the neurointensive care unit (NICU) was performed. The primary outcome for analysis was in-hospital mortality. The study population was divided into groups based on progression of CSE and mortality to analyze difference in study variables. Mortality of the group was analyzed using life tables.

RESULTS

A total of 33 patients satisfied the inclusion criteria from medical records of 212 patients with CSE. Mean age of the study population was 67.0 ± 6.8 years; 69.7% were men. Acute symptomatic aetiology was the commonest cause of CSE (60.6%); nine (27.3%) patients progressed to refractory status epilepticus (RSE) of which five patients had prolonged RSE. The overall mortality was 18.2%. Complications of mechanical ventilation and mean age were higher in patients who died. Though vascular aetiology was the leading cause of CSE (39.3%), it was not associated with progression to RSE or mortality. Acute symptomatic aetiology accounted for five out of the six deaths in the entire cohort.

CONCLUSION

Less than one-third of elderly patients with CSE progressed to RSE. Vascular aetiology, the leading cause of generalized CSE in elderly, was not associated with progression to RSE and mortality. Acute symptomatic aetiology was associated with high mortality.

Altered Expression of Intersectin1-L in Patients with Refractory Epilepsy and in Experimental Epileptic Rats

Epilepsy is a common neurological disorder. Because its underlying mechanisms remain incompletely understood, current treatments are not adequate for all epilepsy patients, and some patients progress to refractory epilepsy. Under physiological conditions, excitatory and inhibitory neurons function in a dynamic balance. Epilepsy develops when this balance is disrupted. Intersectin1-L is a major scaffold protein in the central nervous system that contains multiple functional domains, and it is the long form of intersectin1. Recent studies have shown that intersectin1-L plays an important role in the process of neurotransmitter release. In this study, we investigated the expression pattern and distribution of intersectin1-L in patients with refractory epilepsy, in a rat model of pilocarpine-induced epilepsy, and in a rat model of amygdala-kindled epilepsy by immunohistochemistry, immunofluorescence, and Western blotting. The purpose of this study was to explore the relationship between epilepsy and intersectin1-L. The results showed that the intersectin1-L protein was primarily expressed in neurons in brain tissue. Its expression was remarkably increased in patients with refractory epilepsy and in epilepsy model rats. These results suggest that the abnormal expression of the intersectin1-L protein in epileptic brain tissue may play an important role in epilepsy, especially refractory epilepsy.

Tonic glutamate in CA1 of aging rats correlates with phasic glutamate dysregulation during seizure

OBJECTIVE

Characterize glutamate neurotransmission in the hippocampus of awake-behaving rodents during focal seizures in a model of aging.

METHODS

We used enzyme-based ceramic microelectrode array technology to measure in vivo extracellular tonic glutamate levels and real-time phasic glutamate release and clearance events in the hippocampus of awake Fischer 344 rats. Local application of 4-aminopyridine (4-AP) into the CA1 region was used to induce focal motor seizures in different animal age groups representing young, late-middle aged and elderly humans.

RESULTS

Rats with the highest preseizure tonic glutamate levels (all in late-middle aged or elderly groups) experienced the most persistent 4-AP-induced focal seizure motor activity (wet dog shakes) and greatest degree of acute seizure-associated disruption of glutamate neurotransmission measured as rapid transient changes in extracellular glutamate levels.

SIGNIFICANCE

Increased seizure susceptibility was demonstrated in the rats with the highest baseline hippocampal extracellular glutamate levels, all of which were late-middle aged or aged animals. The manifestation of seizures behaviorally was associated with dynamic changes in glutamate neurotransmission. To our knowledge, this is the first report of a relationship between seizure susceptibility and alterations in both baseline tonic and phasic glutamate neurotransmission.

Early predictors of refractory status epilepticus: an international two-center study

BACKGROUND AND PURPOSE

Status epilepticus (SE) refractory to first- and second-line antiepileptic drugs carries high mortality. Little is known on early prediction of refractory SE (RSE)—an essential tool for planning appropriate therapy. Our aim was to identify and validate independent early RSE predictors in adults.

METHODS

Clinical and laboratory data on consecutive intensive care unit patients with SE from two academic care centers (a derivation data set from a Swiss center and a validation data set from a US center) were assessed. Multivariable analysis was performed with the derivation set to identify RSE predictors at SE onset. Their external validity was evaluated with an independent validation set. Measures of calibration and discrimination were assessed.

RESULTS

In all, 302 patients were analyzed (138 with and 164 without RSE), 171 in the derivation data set and 131 in the validation data set. Acute SE etiology, coma/stupor and serum albumin <35 g/l at SE onset were independent predictors for RSE in the derivation data set [odds ratio (OR) 2.02, 95% confidence interval (CI) 1.01-4.07; OR 4.83, 95% CI 2.42-9.68; OR 2.45, 95% CI 1.16-5.16]. The prediction model showed good measures of calibration (Hosmer-Lemesow goodness-of-fit test P = 0.99) and discrimination (area under the receiver operating characteristic curve 0.8) on the derivation data set—results that were similar in the validation data set (Hosmer-Lemeshow P = 0.24; area under the receiver operating characteristic curve 0.73).

CONCLUSIONS

This study confirms the independent prognostic value of readily available parameters for early RSE prediction. Prospective studies are needed to identify additional robust predictors, which could be added to the proposed model for further optimization towards a reliable prediction scoring system.

The established status epilepticus trial 2013

Benzodiazepine-refractory status epilepticus (established status epilepticus, ESE) is a relatively common emergency condition with several widely used treatments. There are no controlled, randomized, blinded clinical trials to compare the efficacy and tolerability of currently available treatments for ESE. The ESE treatment trial is designed to determine the most effective and/or the least effective treatment of ESE among patients older than 2 years by comparing three arms: fosphenytoin (fPHT) levetiracetam (LVT), and valproic acid (VPA). This is a multicenter, randomized, double-blind, Bayesian adaptive, phase III comparative effectiveness trial. Up to 795 patients will be randomized initially 1:1:1, and response-adaptive randomization will occur after 300 patients have been recruited. Randomization will be stratified by three age groups, 2-18, 19-65, and 66 and older. The primary outcome measure is cessation of clinical seizure activity and improving mental status, without serious adverse effects or further intervention at 60 min after administration of study drug. Each subject will be followed until discharge or 30 days from enrollment. This trial will include interim analyses for early success and futility. This trial will be considered a success if the probability that a treatment is the most effective is >0.975 or the probability that a treatment is the least effective is >0.975 for any treatment. Proposed total sample size is 795, which provides 90% power to identify the most effective and/or the least effective treatment when one treatment arm has a true response rate of 65% and the true response rate is 50% in the other two arms.

Outcome predictors for status epilepticus--what really counts

In adult patients with status epilepticus (SE)-a life-threatening state of ongoing or repetitive seizures--the current evidence regarding outcome prediction is based on clinical, biochemical and EEG determinants. These predictors of outcome involve clinical features such as age, history of prior seizures or epilepsy, SE aetiology, level of consciousness, and seizure type at SE onset. The clinical risk-benefit calculation between the danger of undertreated persistent seizure activity and, conversely, the potential damage from unwarranted aggressive treatments remains a constant challenge. Improved knowledge of outcome determinants, as well as increased availability of reliable outcome prediction models early in the course of SE, is paramount for optimization of treatment of patients who develop this disorder. In this Review, we discuss the major prognostic determinants of outcome in SE. Through consideration of studies that provide measures of association between predictors of SE outcome and death, we propose a detailed--but as yet unvalidated--paradigm for assessment of these predictors during the course of SE. Such an algorithm could guide the organization of results from existing trials and provide direction with regard to the parameters that should be monitored in future studies of SE.

Episodes of status epilepticus in young adults: etiologic factors, subtypes, and outcomes

The aim of this study was to evaluate the type, duration, etiology, treatment, and outcome of status epilepticus (SE) episodes, among patients aged 16-50 years. A total of 101 SE episodes in 88 young adult patients fulfilled our criteria. The mean age was 32 years. Status epilepticus episodes were most frequently observed in patients 21-30 years of age. A total of 53% of the patients were male, and 57% had pre-existing epilepsy. Seventy of the 101 episodes were convulsive SE. The most common etiology was withdrawal of or change in antiepileptic drugs (AEDs), seen in 31% of the SE episodes. This study included treatment of SE with traditional AEDs. Sixty-six episodes were treated successfully with intravenous infusion of 18-mg/kg phenytoin, and six episodes were treated with 10-mg/kg phenytoin. A total of 28% of the SE episodes remained refractory to first-line treatment, which was related to the duration of SE and mortality. The outcome was death in 14% of the patients due to underlying etiologies in the hospital.

Safety and efficacy of intravenous lacosamide for adjunctive treatment of refractory status epilepticus: a comparative cohort study

BACKGROUND

Refractory status epilepticus (RSE) is an emergency with high mortality requiring neurointensive care. Treatment paradigms include first-generation antiepileptic drugs (AEDs) and anesthetics. Lacosamide (LCM) is a new AED, holding promise as a potent treatment option for RSE. High-level evidence regarding safety and efficacy in the treatment of RSE is lacking.

OBJECTIVE

The objective of the study was to evaluate the safety profile and efficacy of intravenous (i.v.) LCM as an add-on treatment in adult RSE patients.

METHODS

All consecutive RSE patients treated in the intensive care units (ICUs) of an academic tertiary care center between 2005 and 2011 were included. Severity of status epilepticus (SE) was graded by the SE Severity Scale (STESS), and SE etiology was categorized according to the guidelines of the International League Against Epilepsy (ILAE). Outcomes were seizure control, RSE duration, and death.

RESULTS

Of 111 RSE patients, 53 % were treated with LCM. Twenty-five patients with hypoxic-ischemic encephalopathy were excluded. Mortality was 30 %. Mean number of AEDs, duration, severity, and etiology of SE, as well as critical medical conditions did not differ between patients with and without LCM. While age tended to be higher, critical interventions, such as the use of anesthetics and mechanical ventilation, tended to be less frequent in patients with LCM. Seizure control tended to be achieved more frequently in patients with LCM (odds ratio, OR 2.34, 95 % CI 0.5-10.1, p = 0.252). Among patients with LCM, 51 % received LCM as the last AED (including hypoxic-ischemic encephalopathy), allowing the reasonable assumption that LCM was responsible for seizure control, which was achieved in 91 %. Multivariable analysis revealed a decreased mortality in patients with LCM (OR 0.34, 95 % CI 0.1-0.9, p = 0.035). A possible confounder in this context was the implementation of continuous video-electroencephalography (EEG) monitoring 6 months prior to the first use of i.v. LCM. There were no serious LCM-related adverse events.

CONCLUSION

LCM had a favorable safety profile as adjunctive treatment for RSE. Its use was associated with decreased mortality of RSE-a finding that might have been confounded by the implementation of continuous video-EEG monitoring in the ICU prior to the use of i.v. LCM, leading to heightened awareness as well as earlier diagnosis and treatment of SE. Randomized trials are warranted to further strengthen the evidence of efficacy of LCM for RSE treatment.

The brain, seizures and epilepsy throughout life: understanding a moving target

The human brain is a tremendously complex and still enigmatic three-dimensional structure, composed of countless interconnected neurons and glia. The temporal evolution of the brain throughout life provides a fourth dimension, one that influences every element of the brain's function in health and disease. This temporal evolution contributes to the probability of seizure generation and to the type and the nature of these seizures. The age-specific properties of the brain also influence the consequences of seizures on neuronal structure and behavior. These, in turn, govern epileptic activity and cognitive and emotional functions, contributing to the diverse consequences of seizures and epilepsy throughout life.

Seizures and epilepsy in elderly patients of an urban area of Iran: clinical manifestation, differential diagnosis, etiology, and epilepsy subtypes

The incidences of seizures and epilepsy in the population show a peak after 60 years of age. Due to the lack of reported clinical aspects of seizure and epilepsy in the older patients in our region in Iran, this study was conducted to describe the clinical manifestation, etiology, differential diagnosis, and epilepsy subtypes of epilepsy and seizure. A cross-sectional retrospective study was performed on all consecutively elderly seizure and epilepsy patients, referred to the Epilepsy Association in the city of Qom, Iran over a 10-year period. A total of 466 patients aged >60 years were admitted. 31 % of the patients had epilepsy or seizure and 69 % of them had non-epileptic events. The most prevalent differential diagnoses in the beginning were syncope and cardiovascular disorders. The most frequent clinical symptom of epilepsy was generalized tonic-clonic seizures (75 %). The most common cause of seizure was systemic metabolic disorder (27 %). In epileptic elderly patients, no cause was ascertained for 38 % and the most frequently observed pathological factors were cerebrovascular diseases, which accounted for 24 %. The most common type of epileptic seizure was generalized epileptic seizures (75 %). 10 % of elderly epileptic patients suffered from status epilepticus, which was primarily caused by anoxia. Despite the rising rate and potentially profound physical and psychosocial effects of seizures and epilepsy, these disorders have received surprisingly little research focus and attention in Iran. Referring older patients to a specialist or a specialist epilepsy center allows speedy assessment, appropriate investigation and treatment, and less likely to miss the diagnosis.

Status epilepticus in the elderly: epidemiology, clinical aspects and treatment

The aim of the study was to review the epidemiology, clinical profile and discuss the etiology, prognosis and treatment options in patients aged 60 years or older presenting with status epilepticus. We performed a systematic review involving studies published from 1996 to 2010, in Medline/PubMed, Scientific Electronic Library on line (Scielo), Latin-American and Caribbean Center of Health Sciences Information (Lilacs) databases and textbooks. Related articles published before 1996, when relevant for discussing epilepsy in older people, were also included. Several population studies had shown an increased incidence of status epilepticus after the age of 60 years. Status epilepticus is a medical and neurological emergency that is associated with high morbidity and mortality, and is a major concern in the elderly compared to the general population. Prompt diagnosis and effective treatment of convulsive status epilepticus are crucial to avoid brain injury and reduce the fatality rate in this age group.

High prevalence of nonconvulsive and subtle status epilepticus in an ICU of a tertiary care center: a three-year observational cohort study

BACKGROUND

Status epilepticus is one of the most important neurological emergencies and requires immediate therapy and admission to the intensive care unit. We hypothesized that nonconvulsive and subtle status epilepticus are more frequent than reported.

METHODS

This observational cohort study describes types, courses, duration, length of hospital stay, outcome and case fatality rate of status epilepticus in adults in relation to demographic and clinical variables. It was conducted in an intensive care unit of a tertiary care center over three years.

RESULTS

111 status epilepticus episodes had a median duration of 48h. Hospitalization length was 18±15.3 days. 81% of the status epilepticus episodes were nonconvulsive and subtle. Case fatality rate was 17%. Age over 70 years had independent positive influence on status epilepticus course (OR: 5.135; p=0.0029). Hospital stay increased by 1.13h with each additional hour of status epilepticus (p=0.02). Subtle status epilepticus was a risk factor for refractoriness (p=0.0065).

CONCLUSIONS

Prevalence of nonconvulsive and subtle status epilepticus was higher than reported, emphasising the importance of clinical awareness. Older age was associated with more favorable course. This unexpected and contradictory result has to be taken into account during therapeutic interventions in the elderly and should warn from early resignation regarding treatment.

Midazolam versus diazepam for the treatment of status epilepticus in children and young adults: a meta-analysis

BACKGROUND

Rapid treatment of status epilepticus (SE) is associated with better outcomes. Diazepam and midazolam are commonly used, but the optimal agent and administration route is unclear.

OBJECTIVES

The objective was to determine by systematic review if nonintravenous (non-IV) midazolam is as effective as diazepam, by any route, in terminating SE seizures in children and adults. Time to seizure cessation and respiratory complications was examined.

METHODS

We performed a search of PubMed, Web of Knowledge, Embase, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, American College of Physicians Journal Club, Cochrane Central Register of Controlled Trials, the Cumulative Index to Nursing and Allied Health Literature, and International Pharmaceutical Abstracts for studies published January 1, 1950, through July 4, 2009. English language quasi-experimental or randomized controlled trials comparing midazolam and diazepam as first-line treatment for SE, and meeting the Consolidated Standards of Reporting Trials (CONSORT)-based quality measures, were eligible. Two reviewers independently screened studies for inclusion and extracted outcomes data. Administration routes were stratified as non-IV (buccal, intranasal, intramuscular, rectal) or IV. Fixed-effects models generated pooled statistics.

RESULTS

Six studies with 774 subjects were included. For seizure cessation, midazolam, by any route, was superior to diazepam, by any route (relative risk [RR] = 1.52; 95% confidence interval [CI] = 1.27 to 1.82). Non-IV midazolam is as effective as IV diazepam (RR = 0.79; 95% CI = 0.19 to 3.36), and buccal midazolam is superior to rectal diazepam in achieving seizure control (RR = 1.54; 95% CI = 1.29 to 1.85). Midazolam was administered faster than diazepam (mean difference = 2.46 minutes; 95% CI = 1.52 to 3.39 minutes) and had similar times between drug administration and seizure cessation. Respiratory complications requiring intervention were similar, regardless of administration route (RR = 1.49; 95% CI = 0.25 to 8.72).

CONCLUSIONS

Non-IV midazolam, compared to non-IV or IV diazepam, is safe and effective in treating SE. Comparison to lorazepam, evaluation in adults, and prospective confirmation of safety and efficacy is needed.

A clinical, radiological and outcome study of status epilepticus from India

The objective of this study is to evaluate the clinical and radiological characteristics and the outcome of status epilepticus (SE). 117 consecutive patients with SE were evaluated including their demographics, history of epilepsy, antiepileptic drug (AED) default, comorbidities, SE type and duration. The study included 22 children, 77 adults and 18 elderly patients with SE. Blood counts, serum chemistry, ECG, cranial MRI, cerebrospinal fluid and EEG were done. Patients were treated with IV phenytoin, valproate, lorazepam or diazepam as per a fixed protocol and responses to first and second drugs were noted. Death during hospital was recorded. The etiology of SE was infection in 53.8%, drug default in 7.9%, metabolic in 14.5%, stroke in 12.8% and miscellaneous in 11% of patients. 92.3% of patients had convulsive and 7.7% nonconvulsive SE. Cranial MRI was abnormal in 62%. Infection as an etiology was more common in children, drug default and metabolic causes in adults and stroke in adults and elderly. Following first AED, SE was controlled in 50%. 30% of patients remained refractory to second AED which was related to duration of SE and mortality. 29% patients died and death was higher in elderly (44%) compared to children (14%). Acute symptomatic SE is more common in developing countries. Refractory SE is associated with SE duration and mortality.

Comparisons of the mortality and clinical presentations of status epilepticus in private practice community and university hospital settings in Richmond, Virginia

We prospectively compared the clinical course of 119 patients treated for status epilepticus (SE) in private practice community hospitals and 344 SE patients treated in the VCU university hospitals in Richmond, Virginia USA over a 2-year period to test the hypothesis that SE presents with the same mortality and clinical patterns in both clinical settings. Of the patients reviewed, the major etiologies for SE were cerebrovascular disease, decreased anti-epileptic drug levels in epileptic patients, anoxia-hypoxia, and remote symptomatic. The other etiologies included were alcohol related, trauma, central nervous system infections, tumors, systemic infection, metabolic disorders, idiopathic, and hemorrhage. These observations provide the first direct prospective comparison of SE present in university and private practice community hospital settings in the same geographic area. Mortality was the highest in the elderly population while the pediatric population had low mortality in both clinical settings. Etiology risk factors for outcome were similar for both the populations. The data also suggest that the higher degree of illness severity in university hospitals may be associated with a higher incidence of SE, but not with mortality or a different clinical presentation of the condition. The results of this study demonstrate that SE has the same mortality and is present in an essentially identical manner in university and private practice community hospitals and underscores the fact that mortality in SE is not just associated with tertiary care hospitals and the importance of recognizing the severity of SE in the private practice setting.

Age-dependent mortality in the pilocarpine model of status epilepticus

Status epilepticus (SE) is an acute neurological emergency associated with significant morbidity and mortality. Age has been shown to be a critical factor in determining outcome after SE. Understanding the causes of this increased mortality with aging by developing an animal model to study this condition would play a major role in studying mechanisms to limit the mortality due to SE. Here we employed pilocarpine to induce SE in rats aged between 5 and 28 weeks. Similar to clinical studies in man, we observed that age was a significant predictor of mortality following SE. While no deaths were observed in 5-week-old animals, mortality due to SE increased progressively with age and reached 90% in 28-week-old animals. There was no correlation between the age of animals and severity of SE. With increasing age mortality occurred earlier after the onset of SE. These results indicate that pilocarpine-induced SE in the rat provides a useful model to study age-dependent SE-induced mortality and indicates the importance of using animal models to elucidate the mechanisms contributing to SE-induced mortality and the development of novel therapeutic interventions to prevent SE-induced death.

Status epilepticus during old age is not associated with enhanced hippocampal neurogenesis

Increased production of new neurons in the adult dentate gyrus (DG) by neural stem/progenitor cells (NSCs) following acute seizures or status epilepticus (SE) is a well known phenomenon. However, it is unknown whether NSCs in the aged DG have similar ability to upregulate neurogenesis in response to SE. We examined DG neurogenesis after the induction of continuous stages III-V seizures (SE) for over 4 h in both young adult (5-months old) and aged (24-months old) F344 rats. The seizures were induced through 2-4 graded intraperitoneal injections of the excitotoxin kainic acid (KA). Newly born cells in the DG were labeled via daily intraperitoneal injections of the 5'-bromodeoxyuridine (BrdU) for 12 days, which commenced shortly after the induction of SE in KA-treated rats. New cells and neurons in the subgranular zone (SGZ) and the granule cell layer (GCL) were analyzed at 24 h after the last BrdU injection using BrdU and doublecortin (DCX) immunostaining, BrdU-DCX and BrdU-NeuN dual immunofluorescence and confocal microscopy, and stereological cell counting. Status epilepticus enhanced the numbers of newly born cells (BrdU(+) cells) and neurons (DCX(+) neurons) in young adult rats. In contrast, similar seizures in aged rats, though greatly increased the number of newly born cells in the SGZ/GCL, failed to increase neurogenesis due to a greatly declined neuronal fate-choice decision of newly born cells. Only 9% of newly born cells in the SGZ/GCL differentiated into neurons in aged rats that underwent SE, in comparison to the 76% neuronal differentiation observed in age-matched control rats. Moreover, the number of newly born cells that migrate abnormally into the dentate hilus (i.e., ectopic granule cells) after SE in the aged hippocampus is 92% less than that observed in the young adult hippocampus after similar SE. Thus, SE fails to increase the addition of new granule cells to the GCL in the aged DG, despite a considerable upregulation in the production of new cells, and SE during old age leads to much fewer ectopic granule cells. These results have clinical relevance because earlier studies have implied that both increased and abnormal neurogenesis occurring after SE in young animals contributes to chronic epilepsy development.