Status Epilepticus History, Incidence and Problems

EEG criteria for diagnosing nonconvulsive status epilepticus in comatose - An unsolved puzzle: A narrative review

Introduction

Nonconvulsive status epilepticus (NCSE) is an important and often unrecognized cause of impaired awareness especially in critically ill patients, which can easily be missed. Electroencephalography (EEG) findings in clinically suspected cases are the mainstay of diagnosis.

Review summary

The EEG diagnostic criteria for NCSE have evolved over the past three decades. Furthermore, recent advancements in EEG technologies such as continuous EEG monitoring, and emergency department EEG, along with development of different diagnostic criteria, have increased the detection rate for NCSE in suspected cases. However, treating physicians should have a higher index of clinical suspicion and a lower threshold for recommending this valuable investigation. The introduction of different diagnostic criteria has made it easier for electroencephalographers to report NCSE; nevertheless, diagnosis is not always straightforward. This narrative review aimed to define and discuss the available literature on different EEG diagnostic criteria for NCSE.

Conclusion

There is a need for further prospective research to strengthen the diagnostic accuracy of the available diagnostic criteria, the modified Salzburg Consensus Criteria for NCSE (mSCNC) and updated American Clinical Neurophysiology Society (ACNS) 21 criteria, to verify their accuracy to detect NCSE in comatose patients.

Midazolan nasal no tratamento de crises convulsivas

Pacientes com crises agudas incluindo estado de mal epiléptico, podem apresentar dificuldades no tratamento que geralmente envolve um benzodiazepínico. As drogas mais amplamente utilizadas em pacientes com crises agudas incluem diazepam, lorazepam e midazolam. Nós revisamos a eficácia e a segurança das diversas formas de administração do midazolam. A administração intranasal e bucal do midazolam pode ser uma alternativa a administração retal e intravenosa do diazepam.

The history of status epilepticus and its treatment

Despite the fact that status epilepticus was been recognized since antiquity, its existence was largely ignored until the mid-nineteenth century. In this review we cover the medical literature of status epilepticus from the late nineteenth century until the early 1970s when the modern era of status epilepticus began. We pay particular attention to the impact of the ILAE and its principal members on the understanding and awareness of status epilepticus. We also cover the evolution of treatment regimens advocated for status epilepticus from the late nineteenth century to the early 1970s when the benzodiazepines were established as first line treatments.

Non-convulsive status epilepticus in adults: clinical forms and treatment

Non-convulsive status epilepticus (NCSE) is one of the great diagnostic and therapeutic challenges of modern neurology. Because the clinical features of this disorder may be very discrete and sometimes hard to differentiate from normal behaviour, NCSE is usually overlooked and consequently not treated properly. It is important to be familiar with the clinical subtypes such as absence, simple and complex partial, and subtle status epilepticus because each requires tailored management. In order to improve overall care of patients with NCSE, strict diagnostic criteria are needed that should be based on clinical alterations and ictal electroencephalographic changes. NCSE should be terminated rapidly to prevent patients from serious injuries, particularly if consciousness is impaired.

A diary of epilepsy in the early 1800s

This article describes the diary of a man from 19th-century England (1829-1834) that documents the onset and course of his wife's epilepsy after a stroke. Her stroke produced aphasia and right hemiparesis, but her epilepsy was the diary's focus and caused the greatest concern. The diary documents the history of her epilepsy in detail. In addition to tonic-clonic seizures, she experienced frequent bouts of status epilepticus and complex partial seizures. The diary contains some of the earliest recorded descriptions of status epilepticus and its aftermath of delirium, mood disorder, and hysteria. It also offers some of the earliest and most detailed accounts of complex partial seizures. Bleeding by cupping was the only symptomatic or prophylactic treatment recorded. These aspects of the diary are presented, as are the historical perspectives on epilepsy, including early beliefs and stigmas, therapeutic remedies, and early European views of epilepsy.

Status epilepticus, the grim reaper of the mental health system in early Victoria

In an era when patients with refractory epilepsy were managed in mental asylums in the colonial days of Victoria, Australia, the opinion of the administration was that such patients seemed to have a benign prognosis. However the decision to collect all female epileptics in the colony and manage them in the Ballarat Mental Hospital, effected in 1901, allowed scrutiny of the progress of a cohort of 96 patients over the first seventeen years of the twentieth century, thereby revealing that under asylum conditions no less than a third of their number died as the result of status epilepticus. The results of this survey and the reasons for such an outcome are discussed.

Analysis of clinical characteristics and risk factors for mortality in human status epilepticus

PURPOSE

To analyse clinical data including aetiology, age, antecedents, classification and mortality in human status epilepticus (SE), and to assess prognostic factors for mortality.

METHODS

A prospective study was performed, including detailed analysis of clinical and laboratorial data of SE in individuals of any age, except neonates.

RESULTS

One hundred and eleven SE were included, with patients' age ranging from 3 months to 98 years. SE incidence peaked in the first year of life, and 59.4% of the individuals had previous epilepsy while 40.6% had not. The main underlying causes were noncompliance to treatment in the first group, and CNS infection, stroke and metabolic disturbances in the second group. Overall mortality was 19.8%, and deaths were correlated to aetiology and patient's age. Refractory SE affected 11.7% of the cases. Clinical types included focal, secondarily generalised and generalised SE. Clinical and clinicoelectrographic classifications were convergent, but EEG was essential for the diagnosis in 4.5% of the cases.

CONCLUSIONS

Epileptic patients are at greater risk to develop SE, however, individuals with no prior history of epilepsy and acute neurological problems can also present SE. Aetiology varies with patient's age, and mortality is high and related to age and underlying causes. Clinical and clinicoelectrographic classifications are usually convergent, but in some cases the diagnosis of SE would not be established without the EEG.

[The difficulty of defining and classifying status epilepticus]

Status epilepticus (SE) can theoretically be described using a simple definition based on physiopathological mechanisms: any seizure of epileptic nature, partial or generalized, convulsive or non-convulsive, lasting over a period of more than 30 minutes; or repeated seizures lasting for a period of over 30 minutes without recovery of consciousness. In the context of a historical review of various definitions, the validity of this definition is assessed and questioned. The heterogeneous nature of this condition is evidenced in daily clinical practice and by the results of epidemiologic studies. In the present study, the authors propose a more pragmatic and heuristic classification, taking into account not only clinical but also electroencephalographic data, as well as the particular nature of the epileptic syndrome when this is known.

The epidemiology and management of status epilepticus

Status epilepticus refers to a prolonged seizure state, usually taken as lasting 30 min or longer. This review considers recent studies of the epidemiology of status epilepticus; these have confirmed the high incidence and the high associated mortality and morbidity. Advances in the management of status epilepticus are also reviewed but despite these advances there is still a lack of good comparative studies on which to base treatment regimens.

Determinants of mortality in status epilepticus

Using univariate and multivariate regression analysis, we studied seizure duration, seizure type, age, etiologies, other clinical features, and mortality among 253 adults with status epilepticus (SE) admitted to the Medical College of Virginia. Cerebral vascular disease and discontinuation of antiepileptic drugs (AEDs) were the most prominent causes of SE, each accounting for approximately 22% of all patients in the series. The other principle etiologies were alcohol withdrawal, idiopathic, anoxia, metabolic disorders, hemorrhage, infection, tumor, drug overdose, and trauma. When the patients were divided into two groups, the group with SE lasting < 1 h had a lower mortality as compared with seizure duration > or = 1 h. Low mortality rates were noted in alcohol and AED discontinuation etiologies. Anoxia and increasing age were significantly correlated with higher mortality. The mortality rates of partial and generalized SE were not significantly different. Race and sex did not affect mortality significantly. Our findings represent the first multivariate analysis of predictive indicators of mortality in SE and demonstrate that specific factors influence mortality rate in SE.

Refractory status epilepticus in adults

The management of status epilepticus has improved over the past 20 years, resulting in a substantial decrease in the associated morbidity and mortality. Patients who have seizures that are refractory to initial pharmacologic interventions tend to have significant underlying toxic, metabolic, structural, or infectious disorders, and therefore management of refractory status epilepticus must focus on stabilization and on identification and correction of seizure etiology. Regardless of etiology, the faster the seizures are brought under control, the better the prognosis. Risk of central nervous system injury increases after 30 minutes of seizure activity, and therefore efforts should focus on controlling the abnormal electrical discharges at the earliest time possible, preferably within one hour. Benzodiazepines, phenytoin, and phenobarbital remain the most commonly used first- and second-line anticonvulsants, have proven effective in cases of status epilepticus, and should be administered within the first 45 minutes of management. For refractory status epilepticus, pentobarbital anesthesia is evolving as an effective and recommended treatment modality and should be instituted immediately after phenytoin and phenobarbital loading. The role of other anticonvulsants remains to be investigated in controlled clinical trials.

Generalized convulsive status epilepticus: pathophysiology and treatment

The treatment of generalized convulsive status epilepticus according to a protocol, including a time schedule, prevents unnecessary delay and improves outcome. Based on a literature study and our own clinical experiences a treatment protocol is discussed with special emphasis on medical complications, choice of antiepileptic drugs, route of administration and a proper time schedule.

Generalized convulsive status epilepticus in the adult

Status epilepticus (SE) is defined as recurrent epileptic seizures without full recovery of consciousness before the next seizure begins, or more-or-less continuous clinical and/or electrical seizure activity lasting for more than 30 min whether or not consciousness is impaired. Three presentations of SE are now recognized: recurrent generalized tonic and/or clonic seizures without full recovery of consciousness between attacks, nonconvulsive status where the patient appears to be in a prolonged "epileptic twilight state," and continuous/repetitive focal seizure activity without alteration of consciousness. Generalized convulsive status epilepticus (GCSE) encompasses a broad spectrum of clinical presentations from repeated overt generalized tonic-clonic seizures to subtle convulsive movements in a profoundly comatose patient. Thus, GCSE is a dynamic state that is characterized by paroxysmal or continuous tonic and/or clonic motor activity, which may be symmetrical or asymmetrical and overt or subtle but which is associated with a marked impairment of consciousness and with bilateral (although frequently asymmetrical) ictal discharges on the EEG. Just as there is a progression from overt to increasingly subtle clinical manifestations of GCSE, there is also a predictable sequence of progressive EEG changes during untreated GCSE. A sequence of five patterns of ictal discharges has been observed: discrete electrographic seizures, waxing and waning, continuous, continuous with flat periods, and periodic epileptiform discharges on a relatively flat background. A patient actively having seizures or comatose who exhibits any of these patterns on EEG should be considered to be in GCSE and should be treated aggressively to stop all clinical and electrical seizure activity to prevent further neurological morbidity and mortality.

Status epilepticus in children, adults, and the elderly

Status epilepticus (SE) is a major neurological and medical emergency associated with a high morbidity and mortality. Retrospective and prospective studies from the Medical College of Virginia Epilepsy Research Center have been utilized to investigate several clinical and epidemiological factors associated with SE. Univariate and multivariate logistic regression analysis of predictive indicators in patients with SE indicated that seizure duration, certain specific etiologies, and age were predictors of mortality. Sex, race, and certain other etiologies were not found to be factors that significantly affect mortality. These findings demonstrate that specific indicators are important in predicting mortality in SE. Preliminary prospective epidemiological data from Richmond, Virginia suggested that more than 250,000 cases of SE may occur annually in the United States with a mortality greater than 55,000 individuals. Studies comparing community and university hospitals in Richmond indicate that the mortality and clinical variables associated with SE in these two hospital populations are essentially identical. Further investigations employing prospective population-based studies are essential in evaluating the epidemiology and mortality of SE.

The discovery of anti-epileptic drugs

The general history of epilepsy is well documented, there being detailed accounts from ancient times in Babylonia (Wilson et al., 1990), ancient India (Bharucha & Bharucha, 1989), and China (Lai & Lai, 1991), up until the end of the 19th century (Tempkin, 1971). But relatively little has been written about its medical treatment, (Melville, 1982). The subject of this article is the history of potassium bromide, phenobarbitone and phenytoin, how their use in epilepsy was discovered, and in particular the surprisingly large part played by chance, luck and serendipity, in their introduction to the pharmacopaeia. The advance in this field has been one of sudden leaps forward, followed by periods of apparent inactivity, until the next discovery emerged, a pattern repeated many times, since medical treatment of epilepsy began with potassium bromide in 1857, until the introduction of vigabatrin in 1990.

Phenytoin-loading: pharmacokinetic comparison between an intravenous bolus injection and a diluted standard solution

Phenytoin (PHT) is considered a first or second choice in the treatment of status epilepticus that is refractory to benzodiazepines. The use of an intravenous bolus injection of PHT is hazardous due to the risk of cardiac conduction disturbances, dose-dependent side effects in general, as well as the possibility of severe necrotic lesions in case of extravasation. We compared the number and intensity of side effects and serum level profiles of a highly concentrated, non-dilutable bolus (46 mg/ml) of PHT [Fenytoin, DAK] with a dilutable standard solution (1.5 mg/ml) [Phenhydan] administered intravenously in 500 ml saline. Six healthy volunteers received both regiments (9.1 mg/kg). The diluted solution showed a curvilinear saturation curve with a lower concentration maximum (C-max) than the concentrated solution. Lower toxicity of the diluted solution was indicated by a clinical rating of side effects. Based on a higher incidence and degree of side effects following administration of the more concentrated formulation of PHT, compared with the more diluted preparation, we recommend the use of the less concentrated formulation.

Cerebrospinal fluid lactate levels and prognosis in status epilepticus

Despite recent advances in the treatment of status epilepticus (SE), the mortality and morbidity associated with this condition remains high. Although the reasons for this excessive mortality are not known, several factors are suspected, including cerebral ischemia, cardiovascular collapse, toxic stimulation by neurotransmitters and hormones, or toxic products of intermediary metabolism. Cerebral lactic acidosis can cause cortical injury and has been shown to occur with seizures in experimental animals and in a limited number of human studies. We determined cerebrospinal fluid (CSF) and plasma lactate in 29 patients with generalized SE of diverse etiology. CSF was obtained within 12 h of termination of clinical seizure activity. The mean CSF lactate for all SE patients was elevated (3.74 +/- 0.31 mM) as compared with that of normal controls (1.60 +/- 0.10 mM) from non-neurologic patients undergoing spinal anesthesia. In patients who died or had a poor neurologic recovery, CSF lactate level was 5.36 +/- 0.58 mM (9 patients), whereas in 20 patients who showed good recovery CSF lactate level was 3.01 +/- 0.22 mM (p less than 0.005). The results demonstrate that SE causes a significant increase in CSF lactate and suggest that the magnitude of lactate elevation may serve as a predictive indicator of morbidity and mortality.

Epidemiologic survey of epilepsy among Army draftees in Lombardy, Italy

We conducted an epidemiological survey of epilepsy among males born in 1967 who were called for selection for military service from the Lombardy region in northern Italy. Of 54,520 subjects, 258 had active epilepsy (prevalence, 0.47%). Idiopathic partial epilepsy was most common (29.1%), and generalized idiopathic and/or symptomatic epilepsy was least common (3.8%). In the year preceding the interview, 66.9% of the subjects had been free of generalized tonic-clonic seizures, 57.6% had been free of minor seizures, and 36.9% were seizure-free. Case histories revealed a background of febrile convulsions in 18.9% of subjects, status epilepticus in 11.3%, and a family history of epilepsy in 18.9%. Physical and mental development was normal in 75.5% of the subjects. Education level of subjects was lower than a control group, and the unemployment rate was the same as the local rate.

Status epilepticus in the elderly: etiology, seizure type and outcome

We have studied status epilepticus among 342 patients who had their first seizures after the age of 60 years. One hundred and two patients (30%) had status epilepticus. Cerebrovascular disease (35%) was the leading cause of status, followed by head trauma (21%), multifactorial etiology (11%), metabolic disorders (10%), brain tumors (8%) and CNS infection (2%). The etiology of status remained undetermined in 13 patients (13%). The majority (80%) had partial status or generalized status with focal onset. Overall mortality was 35%.

Rectal diazepam in pediatric status epilepticus

Status epilepticus is a neurologic emergency with an 8% to 12% mortality. Rapid ablation of seizure activity is imperative. Although intravenous administration of diazepam is the preferred immediate treatment, vascular access is often difficult to achieve. Rectal administration of diazepam is easily accomplished during status epilepticus. Five cases in which diazepam administered in the rectal lumen stopped seizure activity are reported. Rectal diazepam appears to be safe and efficacious. It should be considered as an alternate to intravenous therapy when immediate vascular access is delayed. Rectal diazepam may have great benefit in the prehospital setting.

Status epilepticus in children: etiology, clinical features, and outcome

Between August 1984 and September 1986, data were gathered prospectively on 114 episodes of convulsive status epilepticus, defined as seizure duration longer than 30 minutes, affecting 97 children. Status epilepticus was symptomatic in 72% (chronic 59%, acute 13%) and idiopathic or febrile in 28%. We identified precipitating factors in 63% of episodes. The most common factors were inadequate blood levels of anticonvulsants (32 of 60 episodes in children with prior seizures) and febrile illnesses, excluding meningitis or encephalitis (38 of 114 episodes). There was an elevated peripheral white blood cell count in 60%, acidosis with a pH of less than 7.0 in 12.5%, and cerebrospinal fluid pleocytosis not due to meningitis or encephalitis in 8 of 64 episodes. Eight children died, three with severe pre-existing brain damage, two with meningitis, and two with a poorly defined encephalopathy. Eighteen children developed a new neurologic deficit. Outcome was associated with the etiology and duration of status epilepticus, with age at the time of status a minor factor. A permanent deficit occurred in only five children with idiopathic or febrile status epilepticus.

Status epilepticus and alcohol abuse: an analysis of 82 status epilepticus admissions

In 1979-80, 82 cases of grand mal status epilepticus (71 patients, 39 male and 32 female) were admitted to the Casualty Department of Meilahti University Hospital in Helsinki, Finland. The cause of the underlying epilepsy was symptomatic in 43 cases (52.4%) and idiopathic in 19 cases (23.2%). In 6 cases (7.3%), there was a history of alcohol withdrawal seizures, and in 14 cases (17.1%) there was no earlier history of convulsions. Status epilepticus was associated with an acute or progressive cerebral disorder in 14 episodes. These comprised 6 bouts of status with brain tumour, 4 with acute stroke and 4 with brain injury. Alcohol abuse preceded the status in 29 episodes (35.4%), 23 of which occurred in men (53.5% of the male cases). Excessive use of alcohol was the only obvious precipitating factor for status in 16 cases, and in 6 cases the status presented as a prolonged alcohol withdrawal seizure. A change or irregularity of anticonvulsive drug therapy could be documented in 14 cases and an acute infection outside the central nervous system in 7 cases. Intravenous diazepam, used as the only therapy for status epilepticus, was effective in 58 of 78 episodes. In 7 cases of prolonged status, a thiopental sodium anaesthesia proved effective. The total mortality was 4.2%, including 2 deaths from concomitant extracerebral disorders and one late death from brain metastasis.

Status epilepticus. Causes, clinical features and consequences in 98 patients

The etiology, clinical features and outcome of generalized major motor status epilepticus in 98 patients over the age of 14 years have been reviewed. Approximately half of the patients had not had previous seizures. The most common single cause of the status was noncompliance with anticonvulsant drug regimens and this accounted for the status in 53 percent of the patients with previous seizures and in 28 percent of all the patients in our series. The other causes in our series were alcohol-withdrawal, cerebrovascular disease, cerebral tumors or trauma (involving especially the frontal lobe), intracranial infection, metabolic disorders, drug overdose and cardiac arrest. In 15 percent of the patients, however, no specific cause could be found. Status was never the initial manifestation of primary (constitutional) generalized epilepsy in our experience. The etiology of the status was sometime multifactorial, so patients must be screened as fully as possible even when a likely cause is readily apparent. The motor manifestations of the convulsions were frequently restricted in distribution (62 percent of the cases). Focal or lateralized convulsive activity, especially during the course of continued seizure activity, did not necessarily indicate that localized structural pathology was responsible for the status. The seizures were of the tonic variety in a few of our patients and in such circumstances were usually associated with cerebral anoxia. We found that a poor outcome of the status was more likely as its duration increased, and the morbidity rate from the status itself was 12.5 percent among our patients, with a mortality rate of 2.5 percent. The episode of status was usually accompanied by hyperthermia, and often by a brisk peripheral leukocytosis, and in some of our patients a status-induced cerebrospinal fluid pleocytosis also developed. These features may lead to diagnostic confusion if their basis is not recognized. In most of our patients a systemic acidosis developed during the course of the status, but this did not appear to greatly influence the outcome.

Status epilepticus

Status epilepticus may end fatally or may leave serious sequelae. Thus the physician must act quickly and appropriately to stop convulsions using the methods described. Supportive measures--maintenance of airway, protection from harm, maintenance of vital functions--must be accomplished before drug therapy is started. Metabolic abnormalities must be corrected. Striving for levels of antiepileptic drugs in the upper therapeutic range is best, and the physician must be prepared to deal with the side-effects and complications of these medications.

Brain energetics and neurosurgery. A review of recent studies done at Duke University

✓ Consecutive studies of brain energetics undertaken at Duke University during a period of 5 years are described. Various forms of stress such as hypoxia, hyperbaric oxygenation, and selected drugs were used to depict quantitative adverse effects upon the brain's basic energy system, and protectant measures evaluated including hypothermia and appropriate substrates. A systematic survey of substrate protectants was carried out in laboratory animals, and the theory and practice of preserving brain energy levels explored. A foundation for clinical application has been established.

Tratamento do estado de mal epiléptico em crianças pelo Valium

Foi utilizado o Valium no tratamento do estado de mal epiléptico em 40 crianças. Analisando os resultados obtidos, os autores concluem: o medicamento administrado por via endovenosa controlou satisfatoriamente as crises convulsivas nas 40 crianças; o medicamento, aplicado em doses pequenas, sem outra diluição além daquela em que é apresentado, não havendo relação entre a dosagem e a idade dos pacientes, permitiu controlar rapidamente as crises convulsivas; sono superficial foi induzido após o término da injeção; não foram observados sinais e sintomas de intoxicação ou intolerância.