Management approaches to prolonged seizures and status epilepticus

Seizures - just the tip of the iceberg: Critical care management of super-refractory status epilepticus

Super-refractory status epilepticus (SRSE) is defined as status epilepticus (SE) that continues or recurs 24 h or more after the onset of anesthetic therapy, including those cases where SE recurs on the reduction or withdrawal of anesthesia. Although SRSE is a rare clinical problem, it is associated with high mortality and morbidity rates. This article reviews the treatment approaches and the systemic complications commonly encountered in patients with SRSE. As evident in our search of literature, therapy for SRSE and its complications have been based on clinical reports and expert opinions since there is a lack of controlled and randomized trials. Even though this complex condition starts as a neurological disorder, because of the associated systemic complications, it can be considered as a multisystem disorder requiring scrupulous attention and deliberate efforts to prevent, detect, and treat these systemic effects. We have critically reviewed the intensive care management for SRSE per se as well as its associated systemic complications. We believe that a good recovery can occur even after prolonged and severe SRSE as long as the systemic complications are detected early and managed appropriately.

Changes over Time in Intracranial Air in Patients with Cerebral Air Embolism: Radiological Study in Two Cases

Cerebral air embolism can be easily identified on computed tomography (CT) scans. However, changes in the distribution and amount of intracranial air are not well known. We report two patients with cerebral air embolism and present imaging findings on the serial changes in the intracranial air. We thought that the embolic source was venous in one patient because CT showed air inflow in cortical veins in the bilateral frontal areas, reflecting air buoyancy. In the other patient, CT showed air inflow into not only the cortical veins but also the bilateral cerebral hemispheres and we thought this to be a paradoxical cerebral air embolism. We found that intracranial air can be promptly absorbed and while cerebral infarcts due to air are clearly visualized on diffusion-weighted images (DWI), the air may rapidly disappear from images. In patients with suspected cerebral air embolism whose CT findings show no intracranial air, DWI should be performed because it may reveal cerebral infarction due to cerebral air embolism.

Management of refractory status epilepticus in an actively dying patient

No consensus guidelines exist for the treatment of refractory myoclonic status epilepticus or refractory myoclonus in the palliative care setting. Evidence-based guidelines for the general medical population are often neither practical nor applicable at the end of life. Many challenges, including medication availability, route of administration, monitoring, and work-up are all unique to the palliative care setting. Two patients with refractory myoclonus versus refractory myoclonic status epilepticus are described here, illustrating the challenges involved in treatment as well the need for further research for therapy in the palliative care setting.

Status epilepticus: current treatment strategies

Status epilepticus is a neurological emergency that is commonly encountered by the neurohospitalist. Successful treatment depends upon the recognition of prolonged seizure activity and the acute mobilization of available resources. Pharmacologic treatment regimens have been shown to decrease the time needed for successful control of seizures and have provided for the rapid administration of anticonvulsant medications. Treatment strategies have evolved so that clinicians can administer effective doses of medication by whatever routes of administration are immediately available. Traditional algorithms for the treatment of status epilepticus have used a stepwise approach to the administration of first-, second-, and third-order medications. More recent options have included aggressive anesthetic doses of medications while second-line medications are being titrated.

Propofol infusion syndrome in refractory status epilepticus

BACKGROUND AND PURPOSE

Propofol is used for treating refractory status epilepticus, which has high rate of mortality. Propofol infusion syndrome is a rare but often fatal syndrome, characterized by lactic acidosis, lipidemia, and cardiac failure, associated with propofol infusion over prolonged periods of time. We investigated the clinical factors that characterize propofol infusion syndrome to know the risk of them in refractory status epilepticus.

METHODS

This retrospective observation study was conducted in Samsung medical center from Jan. 2005 to Dec. 2009. Thirty two patients (19 males, 13 females, aged between 16 and 64 years), with refractory status epilepsy were included. Their clinical findings and treatment outcomes were evaluated retrospectively. We divided our patients into established status epilepticus (ESE) and refractory status epilepticus (RSE). And then the patients with RSE was further subdivided into propofol treatment group (RSE-P) and the other anesthetics treatment group (RSE-O). We analyzed the clinical characteristics by comparison of the groups.

RESULTS

There were significant differences of hypotension and lipid change between ESE and RSE (p<0.05). However, there was no significant difference between RSE-P and RSE-O groups. The hospital days were longer in RSE than in ESE (p=0.012) and treatment outcome was also worse in RSE than in ESE (p=0.007) but there were no significant differences of hospital stays and treatment outcome between RSE-P and RSE-O.

CONCLUSIONS

RSE is very critical disease with high mortality, which may show as many clinical changes as propofol infusion syndrome. Therefore propofol infusion syndrome might be considered as one of the clinical manifestations of RSE.

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.

Pharmacokinetics of intravenous lorazepam in pediatric patients with and without status epilepticus

OBJECTIVE

To evaluate the single dose pharmacokinetics of an intravenous dose of lorazepam in pediatric patients treated for status epilepticus (SE) or with a history of SE.

STUDY DESIGN

Ten hospitals in the Pediatric Emergency Care Applied Research Network enlisted patients 3 months to 17 years with convulsive SE (status cohort) or for a traditional pharmacokinetics study (elective cohort). Sparse sampling was used for the status cohort, and intensive sampling was used for the elective cohort. Non-compartmental analyses were performed on the elective cohort, and served to nest compartmental population pharmacokinetics analysis for both cohorts.

RESULTS

A total of 48 patients in the status cohort and 15 patients in the elective cohort were enrolled. Median age was 7 years, 2 months. The population pharmacokinetics parameters were: clearance, 1.2 mL/min/kg; half-life, 16.8 hours; and volume of distribution, 1.5 L/kg. On the basis of the pharmacokinetics model, a 0.1 mg/kg dose is expected to achieve concentrations of approximately 100 ng/mL and maintain concentrations >30 to 50 ng/mL for 6 to 12 hours. A second dose of 0.05 mg/kg would achieve desired therapeutic serum levels for approximately 12 hours without excessive sedation. Age-dependent dosing is not necessary beyond using a maximum initial dose of 4 mg.

CONCLUSIONS

Lorazepam pharmacokinetics in convulsive SE is similar to earlier pharmacokinetics measured in pediatric patients with cancer, except for longer half-life, and similar to adult pharmacokinetics parameters except for increased clearance.

Status epilepticus

Status epilepticus (SE) is a medical emergency associated with significant morbidity and mortality. SE is defined as a continuous seizure lasting more than 30 min, or two or more seizures without full recovery of consciousness between any of them. Based on recent understanding of the pathophysiology, it is now considered that any seizure that lasts more than 5 min probably needs to be treated as SE. GABAergic mechanisms play a crucial role in terminating seizures. When the seizure persists, GABA-mediated mechanisms become ineffective and several other putative mechanisms of seizure suppression have been recognized. Early treatment of SE with benzodiazepines, followed if necessary by fosphenytoin administration, is the most widely followed strategy. About a third of patients with SE may have persistent seizures refractory to the first-line medications. They require aggressive management with second-line medications such as barbiturates, propofol, or other agents. In developing countries where facilities for assisted ventilation are not readily available, it may be helpful to use nonsedating antiepileptic drugs (such as sodium valproate, levetiracetam, or topiramate) at this stage. It is important to recognize SE and institute treatment as early as possible in order to avoid a refractory state. It is equally important to attend to the general condition of the patient and to ensure that the patient is hemodynamically stable. This article reviews current knowledge regarding the management of convulsive SE in adults.

Efficacy and usability of buccal midazolam in controlling acute prolonged convulsive seizures in children

A Prolonged convulsive seizure is the most common neurological medical emergency with poor outcome. An ideal anticonvulsant should be easy-to-use, effective, and safe, and it should also have a long-lasting effect. Benzodiazepines, give via the intravenous or rectal route have generally been used as first-line drugs. In small children, IV access can be difficult and time consuming. Midazolam is a potent anticonvulsant and is rapidly absorbed from the rectal, nasal, and buccal mucosa. Our aim was to evaluate the efficacy and usability of buccal midazolam in controlling seizures in children with acute prolonged seizures, by comparing it with rectal diazepam. Ninety-eight patients were enrolled, with 49 patients in each treatment group. In the buccal midazolam group, 42 (88%) patients were controlled in less than 4 min of drug administration, and all of the patients were controlled within 5 min of drug administration. In the rectal diazepam group, 24 (49%) patients were controlled in less than 4 min and 40 (82%) patients were controlled within 5 min of drug administration. The time for drug administration and drug effect was significantly less with buccal midazolam than with rectal diazepam (p value<0.001). In the buccal midazolam group, 46 (94%) parents were satisfied with their child's treatment and route of drug administration while in the rectal diazepam group, 7 (14%) parents were satisfied. Buccal midazolam was significantly more acceptable than rectal diazepam (p value<0.001). In conclusion, buccal midazolam may be as effective as rectal diazepam but more convenient to use in the controlling acute prolonged seizures in children, especially in situations in which there is a difficulty in gaining IV access, for example, in infants.

Diazepam administration after prolonged status epilepticus reduces neurodegeneration in the amygdala but not in the hippocampus during epileptogenesis

An episode of status epilepticus (SE), if left untreated, can lead to death, or brain damage with long-term neurological consequences, including the development of epilepsy. The most common first-line treatment of SE is administration of benzodiazepines (BZs). However, the efficacy of BZs in terminating seizures is reduced with time after the onset of SE; this is accompanied by a reduced efficacy in protecting the hippocampus against neuronal damage, and is associated with impaired function and internalization of hippocampal GABA(A) receptors. In the present study, using Fluoro-Jade C staining, we found that administration of diazepam to rats at 3 h after the onset of kainic acid-induced SE, at a dose sufficient to terminate SE, had no protective effect on the hippocampus, but produced a significant reduction in neuronal degeneration in the amygdala, piriform cortex, and endopiriform nucleus, examined on days 7-9 after SE. Thus, in contrast to the hippocampus, the amygdala and other limbic structures are responsive to neuroprotection by BZs after prolonged SE, suggesting that GABA(A) receptors are not significantly altered in these structures during SE.

Postoperative nonconvulsive encephalopathic status: identification of a syndrome responsible for delayed progressive deterioration of neurological status after skull base surgery

Object

Over a 10-year period, the authors have observed a rare but recurring syndrome manifested by a delayed, postoperative, progressive decline in the level of consciousness to deep coma that is time-limited to several days with abrupt awakening. Extensive evaluation and workup demonstrated an abnormality on continuous electroencephalographic monitoring that implied nonconvulsive status epilepticus after the exclusion of structural, perfusion, infectious, or metabolic causes. This state has been very refractory to treatment with antiepileptic medication. In this article, the authors raise the awareness of this syndrome and its diagnosis, management, and outcome.

Methods

The authors reviewed the medical records of a cohort of 7 patients who exemplified this syndrome who were treated during the last 5 years.

Results

All 7 patients were women with a mean (± SD) age of 55 ± 15 years. The mean duration of surgery was 8.9 ± 1.8 hours. All patients had a stereotypical course of delayed progressive decline in their level of consciousness after surgery (average 3.3 ± 4.3 days) leading to deep coma. The unconscious state was time-limited, lasting on average 17.3 ± 13.7 days. Continuous electroencephalographic monitoring demonstrated a generalized abnormality with periodic discharges and abundant slow delta activity. A rather abrupt awakening occurred a few days after cessation of electrographic seizure activity. Structural, vascular, infectious, or metabolic causes were excluded based on an extensive workup.

Conclusions

In this study, the authors delineate and raise the awareness of an unusual syndrome. Recognition of this syndrome is important as a cause for delayed coma after surgery. The authors stress the need for respiratory, hemodynamic, and nutritional support for these patients until recovery. The origin of this syndrome remains enigmatic and is likely to be multifactorial with a prominent pharmacological role related to anesthetic agent or medication in a setting of craniotomy that is associated with alteration of the blood-brain barrier.

Cortical regional hyperperfusion in nonconvulsive status epilepticus measured by dynamic brain perfusion CT

BACKGROUND AND PURPOSE

Nonconvulsive status epilepticus (NCSE) is associated with a mortality rate of up to 18%, therefore requiring prompt diagnosis and treatment. Our aim was to evaluate the diagnostic value of perfusion CT (PCT) in the differential diagnosis of NCSE versus postictal states in patients presenting with persistent altered mental states after a preceding epileptic seizure. We hypothesized that regional cortical hyperperfusion can be measured by PCT in patients with NCSE, whereas it is not present in postictal states.

MATERIALS AND METHODS

Nineteen patients with persistent altered mental status after a preceding epileptic seizure underwent PCT and electroencephalography (EEG). Patients were stratified as presenting with NCSE (n = 9) or a postictal state (n = 10) on the basis of clinical history and EEG data. Quantitative and visual analysis of the perfusion maps was performed.

RESULTS

Patients during NCSE had significantly increased regional cerebral blood flow (P > .0001), increased regional cerebral blood volume (P > .001), and decreased (P > .001) mean transit time compared with the postictal state. Regional cortical hyperperfusion was depicted in 7/9 of patients with NCSE by ad hoc analysis of parametric perfusion maps during emergency conditions but was not a feature of postictal states. The areas of hyperperfusion were concordant with transient clinical symptoms and EEG topography in all cases.

CONCLUSIONS

Visual analysis of perfusion maps detected regional hyperperfusion in NCSE with a sensitivity of 78%. The broad availability and short processing time of PCT in an emergency situation is a benefit compared with EEG. Consequently, the use of PCT in epilepsy may accelerate the diagnosis of NCSE. PCT may qualify as a complementary diagnostic tool to EEG in patients with persistent altered mental state after a preceding seizure.

Generalised convulsive status epilepticus in Singapore: clinical outcomes and potential prognostic markers

PURPOSE

To study the characteristics, outcomes and prognostic markers of convulsive status epilepticus (SE) in Singapore.

METHODS

62 adult admissions to the National University Hospital Singapore from 2002 to 2005 were studied. Ethnicity, history of epilepsy, educational subnormality, neuroimaging, seizure duration, length of stay, Modified Rankin Scale (MRS) pre and post discharge, blood glucose, creatine kinase, potassium, white cell and platelet count were recorded. An MRS> or =3 at discharge was defined as a poor outcome. ROCs of significant variables were plotted to identify the best test cut-offs.

RESULTS

Mean age was 59.2 years (range 20-94). 75.9% patients had epilepsy. Mean length of stay was 14 days (range 1-75). Univariate analyses revealed age (p=0.01, OR 1.075, 95% CI 1.030-1.122), length of stay in ICU (p=0.03, OR 1.299, 95% CI 1.014-1.665) and hospital (p=0.014, OR 1.203, 95% CI 1.038-1.393) and hyperglycemia (p=0.045, OR 1.327, 95% CI 1.007-1.750) associated with poor outcome. Test cut-off values for prognostic markers were established: age> or =55 years (ROC 0.790, sensitivity 72.3, specificity 85.7, PPV9 4.4%, NPV 48.8%) and serum glucose> or =7 mmol/L (ROC 0.737, sensitivity 72.3, specificity 80.0, PPV 93.5%, NPV 36.4%). A discriminant model using these variables was then constructed with probability scores for poor outcome.

DISCUSSION

Age, hyperglycemia and length of stay in hospital influenced outcome from convulsive SE in the local population with hyperglycemia being a novel prognostic marker. Some prognostic markers cited in the literature differed, highlighting the possibility that these indicators may vary across population groups.

Propofol and barbiturates for the anesthesia of refractory convulsive status epilepticus: pros and cons

OBJECTIVE

To discuss mainly the use of propofol and barbiturates in the anesthesia of refractory status epilepticus (RSE).

METHODS

Review of literature.

RESULTS

There are no prospective, randomized works comparing the effects of anesthetics in the treatment of RSE. Recently, the use of propofol has increased in the treatment of RSE. Propofol terminates both clinical and electric seizures quickly, but the maintenance of burst-suppression EEG pattern requires repetitive titration of doses. Relapses of seizures have occurred in 19-33% of patients, especially when tapering of dose. The advantages of barbiturates are lower frequency of short-term treatment failures, breakthrough seizures and changes to a different anesthetic agent. On the other hand, prolonged recovery leads to prolonged duration of mechanical ventilation, intensive care and hospital stay.

DISCUSSION

The use of propofol, barbiturates or midazolam in the anesthesia of RSE can be justified. When using propofol, the duration of high doses should be limited to 48 hours and the risk of propofol infusion syndrome should be kept in mind. High doses of barbiturates terminate effectively seizures but recovery from anesthesia prolongs ventilator treatment and intensive care.

Comparison of buccal midazolam with rectal diazepam in the treatment of prolonged seizures in Ugandan children: a randomized clinical trial

OBJECTIVE

Our goal was to compare the efficacy and safety of buccal midazolam with rectal diazepam in the treatment of prolonged seizures in Ugandan children.

METHODS

This was a single-blind, randomized clinical trial in which 330 patients were randomly assigned to receive buccal midazolam or rectal diazepam. The trial was conducted in the pediatric emergency unit of the national referral hospital of Uganda. Consecutive patients who were aged 3 months to 12 years and presented while convulsing or who experienced a seizure that lasted >5 minutes were randomly assigned to receive buccal midazolam plus rectal placebo or rectal diazepam plus buccal placebo. The primary outcome of this study was cessation of visible seizure activity within 10 minutes without recurrence in the subsequent hour.

RESULTS

Treatment failures occurred in 71 (43.0%) of 165 patients who received rectal diazepam compared with 50 (30.3%) of 165 patients who received buccal midazolam. Malaria was the most common underlying diagnosis (67.3%), although the risk for failure of treatment for malaria-related seizures was similar: 35.8% for rectal diazepam compared with 31.8% for buccal midazolam. For children without malaria, buccal midazolam was superior (55.9% vs 26.5%). Respiratory depression occurred uncommonly in both of the treatment arms.

CONCLUSION

Buccal midazolam was as safe as and more effective than rectal diazepam for the treatment of seizures in Ugandan children, although benefits were limited to children without malaria.

Convulsive status epilepticus: clinical profile in a developing country

PURPOSE

In developing countries optimal care of status epilepticus (SE) is associated with major barriers, particularly transportation.

METHODS

A prospective study of SE was performed between 1994 and 1996 to determine the clinical profile, response to treatment and outcome, Glasgow Outcome Scale (GOS).

RESULTS

Of the 85 patients admitted, the mean age was 33 years (8-75 years), 16% <16 years of age. The mean duration of SE before admission was 18.02 h (1-72 h). Only 23 (28%) patients, all locals, presented within <3 h of onset. Etiology included acute symptomatic (54%), remote symptomatic (7%), cryptogenic (19%), and established epilepsy (20%). Central nervous system infections accounted for 24 (28%) of the etiologies. Seventy-five (88%) patients responded to first-line drugs and 10 (12%) required second-line drugs. The mean duration of SE was significantly long in nonresponders (Mean +/- SD: 32.6 +/- 20.11 vs. 15.2 +/- 18.32, p < 0.006). Duration (p < 0.01; OR 1.04, 95% CI 1.01-1.07) and acute symptomatic etiology (p < 0.038; OR 10.38, 95% CI 1.13-95.09) were the independent predictors of no-response to first-line drugs. Of the nine deaths (10.5%), eight were in acute symptomatic group. Predictors of mortality included female sex (p < 0.017, OR 13.41, 95% CI 1.59-115.38) and lack of response to first-line drugs (p < 0.0001, OR 230.27, 95% CI 8.78-6037.19). Longer duration was associated with poor GOS 1-4 (p = 0.001). Of the 37 patients with <6 h, 81% had GOC5 outcome.

CONCLUSION

This study suggests that longer duration of SE and acute symptomatic etiology are independent predictors of lack of response to first-line drugs. Failure to respond to first-line drugs and duration predict the outcome.

Advances in the management of seizures and status epilepticus in critically ill patients

Seizures and status epilepticus are common in critically ill patients. They can be difficult to recognize because most are non-convulsive and require electroencephalogram monitoring to detect; hence, they are currently underdiagnosed. Early recognition and treatment are essential to obtain maximal response to first-line treatment and to prevent neurologic and systemic sequelae. Anti-seizure medication should be combined with management of the underlying cause and reversal of factors that can lower the seizure threshold, including many medications, fever, hypoxia, and metabolic imbalances. This article discusses specific treatments and specific situations, such as hepatic and renal failure patients and organ transplant patients.

Comparative Efficacy and Safety of Antiepileptic Drugs for the Treatment of Status Epilepticus

Status epilepticus (SE) is a medical emergency with high mortality rate. Common causes of SE include noncompliance with antiepileptic medications, drug- and alcohol-related etiologies, and central nervous system (CNS) infections. Because prolonged seizures can cause neuronal damage, treatment should be initiated promptly to avoid potential complications. Previous studies support intravenous (IV) lorazepam as first-line therapy and IV phenytoin or fosphenytoin as a second-line medication. If first-and second-line medications fail to control SE, further treatment with propofol, pentobarbital, midazolam, or other medications should be considered. Many of the drugs currently used to control SE are associated with sedation, respiratory suppression, hypotension, cardiac dysrhythmia, and anaphylactic reactions. Therefore, IV valproate or other newer antiepileptic drugs may be considered as an alternative third-line therapy for those who cannot tolerate the hypotensive effects of other anticonvulsants. This paper reviews comparative effectiveness and safety concerns among frequently used medications for SE.

Epidemiology and outcomes of status epilepticus in the elderly

Status epilepticus (SE) is a serious condition of prolonged or repetitive seizures. The annual incidence (86/100,000) of SE in the elderly who are aged 60 and greater is almost twice that of the general population and is even higher in those who are 70 years and older. Either acute or remote symptomatic stroke causes approximately 60% of SE seen in the elderly. SE is associated with a high mortality in the elderly (38%), with a rate approaching 50% in patients older than 80 years of age. Etiology is a strong determinant of mortality in the elderly: mortality approaches 100% in patients with anoxia and 30% in patients with either metabolic disorders, hemorrhages, tumors, or systemic infections. Mortality is almost three times higher in SE associated with acute ischemic stroke than in stroke alone, indicating synergistic effects. Duration of SE is also a factor in mortality. Treatment should be initiated for any convulsive seizure that lasts at least 10 min or is repetitive. An electroencephalogram (EEG) should be promptly obtained so that a diagnosis can be made without delay. Because older patients have a greater likelihood of nondiagnostic findings on routine EEGs, prolonged EEG recordings and inpatient video-EEG monitoring significantly increase the rate of establishing a definitive diagnosis. Nonconvulsive status epilepticus in the elderly is especially difficult to diagnose and should be evaluated with an EEG. Treatment of SE is complicated by altered pharmacokinetics in the elderly. Initial treatments, usually the administration of an intravenous benzodiazepine, have overall success rates of 55% for overt convulsive SE and 14.9% for subtle SE. For refractory SE, little is gained by using additional standard drugs, and general anesthesia with continuous EEG monitoring is recommended.

A comparison of buccal midazolam and rectal diazepam for the acute treatment of seizures

In this study, the authors aimed to evaluate buccal midazolam as a practical and safe alternative medication for children who suffer from seizures in the emergency setting and in home practice or anywhere. The effects and side effects of buccal midazolam and rectal diazepam were compared in the treatment of acute convulsions in 43 children, ranging in age from 2 months to 12 years who were seen at the emergency service of the children hospital. Midazolam was given on the even days of the month and diazepam was given on the odd days. In the midazolam group, the seizures of 18/23 (78%) patients terminated in 10 minutes; however 5/23 (22%) patients did not respond. In the diazepam group 17/20 (85%) patients responded in 10 minutes, but 3/20 (15%) did not respond. Midazolam was found to be as effective as diazepam and the difference was not statistically significant (p<0.05). Response periods of the 2 drugs showed no significant difference (p>0.05). The need for a second drug for seizures that did not stop with the first drug was equal, and the difference was not statistically significant (p>0.05). They did not observe any serious complications. In conclusion, buccal midazolam is safe and as effective as rectal diazepam for the treatment of seizures.

Refractory status epilepticus

PURPOSE OF REVIEW

Although conventional anticonvulsant agents can terminate status epilepticus in most cases, a substantial minority of patients develops medically refractory status and requires more aggressive care. This review explores the options available.

RECENT FINDINGS

Increasing numbers of previously unexpected etiologies for refractory status epilepticus continue to be reported. There are also some promising new therapies on the horizon, both for the short and the longer terms.

SUMMARY

Refractory status epilepticus, while a challenge to the intensivist, can be treated with drugs that are commonly used by intensivists. The cooperation of an interested electroencephalographer is vital.

Status epilepticus: clinical analysis of a treatment protocol based on midazolam and phenytoin

The efficacy of a combination of midazolam and phenytoin in treating generalized convulsive status epilepticus in children was studied retrospectively. The patient group comprised all patients admitted for generalized convulsive status epilepticus to the pediatric intensive care unit over 7 years. Patients treated according to the protocol were included (N = 122). These patients were treated with the following regimen; each subsequent step was taken if clinical evidence of epileptic activity persisted: midazolam 0.5 mg/kg rectally or 0.1 mg/kg intravenously. After 10 minutes: midazolam 0.1 mg/kg intravenously. After 10 minutes: phenytoin 20 mg/kg intravenously in 20 minutes. After phenytoin load: midazolam 0.2 mg/kg intravenously followed by midazolam 0.1 mg/kg/hour continuously, increased by 0.1 mg/kg/hour every 10 minutes to maximum 1 mg/kg/hour. Phenobarbital 20 mg/kg intravenously or pentobarbital 2 to 5 mg/kg intravenous load, 1 to 2 mg/kg/hour continuously intravenously. Patients who received initial rectal diazepam were included. Patients were categorized according to the cause of generalized convulsive status epilepticus. These categories were then related to the level of antiepileptic therapy needed. Patients' ages ranged from 0.5 to 197.4 months. The cause of generalized convulsive status epilepticus was idiopathic or febrile convulsions in two thirds of cases. Most (89%) patients were managed on midazolam and phenytoin. Generalized convulsive status epilepticus was terminated with midazolam alone in 58 patients, with the addition of phenytoin in 19 patients and with continuous midazolam in 32 patients. Thirteen patients needed additional barbiturates. The relationship between the level of antiepileptic therapy and etiology was not significant. Fifty-two patients needed artificial ventilation. Seven patients died; no deaths were directly attributable to generalized convulsive status epilepticus itself. With the use of the proposed protocol, combining midazolam and phenytoin, 89% of the cases of generalized convulsive status epilepticus could be successfully managed.

Refractory status epilepticus following self-poisoning with the organochlorine pesticide endosulfan

We describe a case of refractory status epilepticus presenting to a rural general hospital in Sri Lanka. This patient's condition was precipitated by intentional self-poisoning with the organochlorine insecticide endosulfan. Although rarely seen in developed countries, pesticide poisoning particularly with endosulfan is an important cause of difficult-to-manage seizures in Asian countries. In this case report, we discuss the management of status epilepticus and refractory status epilepticus. Further, we specifically discuss the clinical pharmacology and toxicology of endosulfan.

Propofol treatment of refractory status epilepticus: a study of 31 episodes

PURPOSE

Refractory status epilepticus (RSE) is a critical medical condition with high mortality. Although propofol (PRO) is considered an alternative treatment to barbiturates for the management of RSE, only limited data are available. The aim of this study was to assess PRO effectiveness in patients with RSE.

METHODS

We retrospectively considered all consecutive patients with RSE admitted to the medical intensive care unit (ICU) between 1997 and 2002 treated with PRO for induction of EEG-monitored burst suppression. Subjects with anoxic encephalopathy showing pathological N20 on somatosensory evoked potentials were excluded.

RESULTS

We studied 31 RSE episodes in 27 adults (16 men, 11 women; median age, 41.5 years). All patients received PRO, and six also subsequently thiopental (THP). Clonazepam (CZP) was administered with PRO, and other antiepileptic drugs (AEDs) concomitant with PRO and THP. RSE was successfully treated with PRO in 21 (67%) episodes and with THP after PRO in three (10%). Median PRO injection rate was 4.8 mg/kg/h (range, 2.1-13), median duration of PRO treatment was 3 days (range, 1-9), and median duration of ICU stay was 7 days (range, 2-42). In 24 episodes in which the patient survived, shivering after general anesthesia was seen in 10 episodes, transient dystonia and hyperlipemia in one each, and mild neuropsychological impairment in five. The seven deaths were not directly related to PRO use.

CONCLUSIONS

PRO administered with CZP was effective in controlling most of RSE episodes, without major adverse effects. In this setting, PRO may therefore represent a valuable alternative to barbiturates. A randomized trial with these drug classes could definitively assess their respective role in RSE treatment.

The Management of Status Epilepticus

Status epilepticus is a major medical emergency associated with significant morbidity and mortality. Status epilepticus is best defined as a continuous, generalized, convulsive seizure lasting > 5 min, or two or more seizures during which the patient does not return to baseline consciousness. Lorazepam in a dose of 0.1 mg/kg is the drug of first choice for terminating status epilepticus. Patients who continue to have clinical or EEG evidence of seizure activity after treatment with lorazepam should be considered to have refractory status epileptics and should be treated with a continuous infusion of propofol or midazolam. This article reviews current information regarding the management of status epilepticus in adults.

The treatment of status epilepticus

Status epilepticus (SE) is a life-threatening emergency that requires prompt treatment, including basic neuroresuscitation principles (the ABCs), antiepileptic drugs to stop the seizure, and identification of etiology. Symptomatic SE is more common in younger children. Treating the precipitating cause may prevent ongoing neurologic injury and facilitates seizure control. A systematic treatment regimen, planned in advance, is needed, including one for refractory status epilepticus (RSE). Here we emphasize definitions, clinical and electroencephalography stages, early treatment, special circumstances that may require immediate seizure control, and treatment of RSE. Because much clinical research in SE has been done in adults, we indicate the patient population studied.

Clinical policy: Critical issues in the evaluation and management of adult patients presenting to the emergency department with seizures

This clinical policy focuses on critical issues in the evaluation and management of adult patients with seizures. The medical literature was reviewed for articles that pertained to the critical questions posed. Subcommittee members and expert peer reviewers also supplied articles with direct bearing on this policy. This clinical policy focuses on 6 critical questions: What laboratory tests are indicated in the otherwise healthy adult patient with a new-onset seizure who has returned to a baseline normal neurologic status?Which new-onset seizure patients who have returned to a normal baseline require a head computed tomography (CT) scan in the emergency department (ED)?Which new-onset seizure patients who have returned to normal baseline need to be admitted to the hospital and/or started on an antiepileptic drug?What are effective phenytoin or fosphenytoin dosing strategies for preventing seizure recurrence in patients who present to the ED after having had a seizure with a subtherapeutic serum phenytoin level?What agent(s) should be administered to a patient in status epilepticus who continues to seize after having received benzodiazepine and phenytoin?When should electroencephalographic (EEG) testing be performed in the ED? Recommendations for patient management are provided for each 1 of these topics on the basis of strength of evidence (Level A, B, or C). Level A recommendations represent patient management principles that reflect a high degree of clinical certainty; Level B recommendations represent patient management principles that reflect moderate clinical certainty; and Level C recommendations represent other patient management strategies based on preliminary, inconclusive, or conflicting evidence, or based on consensus of the members of the Clinical Policies Committee. This clinical policy is intended for physicians working in hospital-based EDs.

Time to treatment in prolonged seizure episodes

Prompt intervention in seizure emergencies is critical to reducing morbidity and mortality risks associated with status epilepticus. To determine the need for wider education about the benefits of at-home treatment, we examined the time from seizure onset to initial treatment in a cohort of patients with epileptic seizures. The seizure database of patients admitted in the greater Richmond, Virginia, area during a 5-year period (1989-1994) was queried to extract time to seizure treatment. Records were available for 889 patients. Patients were divided into two subgroups: children (age < 16 years, 29.7% of the cohort) and adults. Time to seizure treatment varied broadly; only 41.5% of all patients received their first antiepilepsy drug within 30 minutes. Time to treatment did not significantly differ between age groups. This baseline study supports the need for patient education regarding seizure emergencies and wider availability of at-home treatment options to shorten time to seizure treatment.

Severe rhabdomyolysis and acute renal failure in a kidney transplant patient treated with tacrolimus and chimaeric CD25 monoclonal antibody

Recently observations of rhabdomyolysis in patients treated with tacrolimus have been reported. The authors present a kidney transplant patient who had an epileptic seizures, severe rhabdomyolysis, and acute renal failure. The patient was initially immunosuppressed with tacrolimus and chimeric CD25 monoclonal antibody. After intensive therapy with plasmapheresis, CVVH, and dialysis, the patient completely recovered at 11/2 year his serum creatinine is 1.2 mg/dL.

Development of a model of seizure-induced hippocampal injury with features of programmed cell death in the BALB/c mouse

Although mice are amenable to gene knockout, they have not been exploited in the setting of seizure-induced neurodegeneration due to the resistance to injury of key mouse strains. We refined and developed models of seizure-induced neuronal death in the C57BL/6 and BALB/c strains by focally evoking seizures using intra-amygdala kainic acid. Seizures in adult male BALB/c mice, or C57BL/6 mice as reference, caused ipsilateral death of CA1 and CA3 neurons within the hippocampus. Termination of seizures by lorazepam was more effective than diazepam in both strains, largely restricting neuronal loss to the CA3 sector. Electroencephalography (EEG) recordings defined injurious and non-injurious seizure patterns, which could not be separated adequately by behavioral observation alone. Degenerating neurons in the hippocampus were positive for DNA fragmentation and approximately a third of these exhibited morphologic features of programmed cell death. Western blot analysis revealed the cleavage of caspase-8 after seizures in both strains. These data refine our C57BL/6 model and establish a companion model of focally evoked limbic seizures in the BALB/c mouse that provides further evidence for activation of programmed cell death after seizures.

Comparing the Bispectral Index and Suppression Ratio with Burst Suppression of the Electroencephalogram During Pentobarbital Infusions in Adult Intensive Care Patients

OBJECTIVE

The bispectral index (BIS), a processed variable derived from the raw electroencephalogram (EEG) used to guide sedation in the intensive care unit (ICU), has not been tested during barbiturate therapy for elevated intracranial pressure. We determined the BIS and suppression ratio (SR) values during traditional burst monitoring of the raw EEG during pentobarbital infusions.

DESIGN

Prospective, observational cohort study.

SETTING

A 42-bed multidisciplinary ICU in a tertiary care medical center.

PATIENTS

Twelve consecutive patients with elevated intracranial pressure treated with pentobarbital infusions.

INTERVENTION

All patients were monitored continuously with the Aspect Medical Systems A-1050 bedside EEG monitor using a bilateral referential montage. Pentobarbital doses were titrated based on the raw EEG to attain a burst-suppression pattern with a goal of 3-5 bursts/minute. Drug dosage, intracranial pressure, cerebral perfusion pressure values, EEG bursts/minute, BIS version 3.2, and SR were recorded daily.

MEASUREMENTS AND MAIN RESULTS

The 12 patients were monitored for 62 patient-days. Mean +/- SD age was 32 +/- 15 years, seven (58%) patients were male, mean Acute Physiology and Chronic Heath Evaluation II score was 17.0 +/- 5.0, and hospital mortality was 42%. The mean pentobarbital infusion rate was 124 +/- 49 mg/hour or 2.3 +/- 1.3 mg/kg/hour, and mean pentobarbital serum concentration was 29.7 +/- 13 microg/ml. The mean BIS value was 18 +/- 14, mean SR 56% +/- 36%; BIS correlated well with SR (r=-0.99, p<0.001). For patient-days with a burst-suppression pattern, BIS 3.2 (r=0.90, p<0.001) and SR (r=-0.89, p<0.001) strongly correlated with the number of bursts/minute. The mean BIS value corresponding to 3-5 bursts/minute was 15 (95% confidence interval [CI] 10-20); SR value was 71 (95% CI 61-80).

CONCLUSION

The Aspect A-1050 applied to patients and monitored by nurses and physicians works well as a bedside EEG monitor, providing a raw EEG signal to titrate barbiturate therapy. The continuous data trend and real-time digital output for the BIS and SR quantify the degree of EEG suppression well and may prove helpful in facilitating titration of barbiturate infusions.

Treatment of status epilepticus: a survey of neurologists

BACKGROUND

New antiepileptic drugs (AEDs) have provided alternatives to traditional treatment paradigms for status epilepticus (SE).

METHODS

To determine current treatment preferences for generalized convulsive status epilepticus (GCSE), we surveyed 106 members of the Critical Care or Epilepsy sections of the American Academy of Neurology.

RESULTS

Most respondents initially treat patients with intravenous (IV) lorazepam (76%), followed by phenytoin or fosphenytoin (95%) if first-line therapy fails. Preferences for GCSE refractory to two AEDs (RSE) varied: 43% would give phenobarbital, 19% would give one of three continuous-infusion (cIV) AEDs (pentobarbital, midazolam, propofol), and 16% would give IV valproic acid. About half indicated "burst suppression" (56%) and half indicated "elimination of seizures" (41%) as the titration goal for cIV-AED therapy. About half (42%) would add a new cIV-AED, and the other half (41%) would not add another agent to treat electrographic SE refractory to four AEDs.

DISCUSSION

In accordance with published trials and general guidelines, neurologists most often use lorazepam followed by phenytoin or fosphenytoin as first-line and second-line therapies for GCSE. There is no consensus for third-line or fourth-line treatment for RSE. The treatment of RSE needs to be studied in a large, prospective, randomized, multicenter trial.

New management strategies in the treatment of status epilepticus

Status epilepticus is a neurologic emergency associated with high mortality and long-term disability. Recent advances in our understanding of the pathophysiological mechanisms involved in the initiation and perpetuation of seizure activity have revealed that status epilepticus is a dynamic and evolving process. Alterations at the cellular level parallel physiological, physical, and electrical changes at the bedside. Loss of cerebral autoregulation and neuronal damage begin after 30 minutes of continuous seizure activity. This understanding has led to changes in treatments of status epilepticus, which must be multidisciplinary and occur simultaneously in many different areas. The goals of pharmacological therapy are to terminate seizures early and prevent recurrence. Two recent large clinical studies have shown the benefit of early administration of benzodiazepines to control status epilepticus. Pharmacological algorithms designed to focus medical management have trended toward earlier and more aggressive treatment. The hope is that continued exploration into the basic mechanisms involved in status epilepticus and future controlled clinical trials defining optimal medical management will produce further advances.

Use of an anesthesia cerebral monitor bispectral index to assess burst-suppression in pentobarbital coma

A seven-year-old child with generalized status epilepticus who was placed in a barbiturate coma was monitored with the bispectral index monitor in addition to the standard full channel electroencephalogram. This child had a low bispectral index number and high suppression ratio on the bispectral index monitor when the desired level of pentobarbital coma was induced. There was excellent correlation of the bispectral index monitor to the suppression ratio. The burst rate also correlated well to the bispectral index number and to the suppression ratio. Therefore the bispectral index monitor could allow the patient in barbiturate coma to leave the intensive care unit for diagnostic or therapeutic procedures and may one day replace the full-channel electroencephalogram in the management of patients in barbiturate coma.

Status epilepticus: a review of different syndromes, their current evaluation, and treatment

BACKGROUND

Status epilepticus (SE) encompasses a wide range of seizure types with different clinical presentations, pathophysiologies, treatment imperatives, and outcomes. The most dramatic and life-threatening form, generalized convulsive status epilepticus, has been reviewed in all of these aspects, but other less common types of SE have been described less extensively.

REVIEW SUMMARY

Definitions of generalized convulsive SE and its pathophysiology are reviewed briefly. Defining SE by a specific duration of seizures is controversial and has implications for studies and for clinical management. Several types of SE are different in their causes, presentations, and outcomes. Many are underdiagnosed. This article focuses on the pharmacology and clinical studies of several anticonvulsant medications used to treat SE. A protocol approach is not detailed. Rather, the clinical evaluation begins with meticulous diagnosis of the type of SE. Establishing the SE syndrome diagnosis and use of anticonvulsants with demonstrated effectiveness facilitate an appropriate treatment plan for individual patients. Recent developments in the basic science of SE raise the possibility of better treatments in the future.

CONCLUSIONS

As there are many types of seizures, there are also many types of SE. Each has unique presentations and treatment considerations. Review of actual clinical data from SE treatment studies should be helpful in devising the best treatment for an individual patient.

Progress in clinical neurosciences: Status epilepticus: a critical review of management options

Although generalized tonic-clonic status epilepticus (SE) is frequently seen, an evidence-based approach to management is limited by a lack of randomized clinical studies. Clinical practice, therefore, relies on a combination of expert recommendations, local hospital guidelines and dogma based on individual preference and past successes. This review explores selected and controversial aspects of SE in adults and provides a critical appraisal of currently recommended management strategies.

Status Epilepticus

Status epilepticus (SE) is a common neurologic emergency with a high mortality. Immediate recognition and rapid treatment are essential. After initial stabilization of airway and circulation, the patient should be treated as soon as possible with an intravenous (IV) benzodiazepine, followed immediately by IV fosphenytoin. If SE persists, general anesthesia should be initiated, with intubation and cardiac monitoring. Electroencephalogram must also be monitored to ensure suppression of all seizures. Etiology of SE should be assessed through history, examination, blood tests, and brain imaging.

Strategies for optimizing antiepileptic drug therapy in elderly people

The elderly take more antiepileptic drugs (AEDs) than all other adults. This extensive use directly correlates with an increased prevalence of epilepsy in a growing population of older people, as well as other neuropsychiatric conditions such as neuropathic pain and behavioral disorders associated with dementia and for which AEDs are administered. The agents account for nearly 10% of all adverse drug reactions in the elderly and are the fourth leading cause of adverse drug reactions in nursing home residents. Numerous factors associated with advanced age contribute to the high frequency of untoward drug effects in this population; however, strategies are available to ensure optimal outcomes.