status epilepticus
(medicine) Occurrence of prolonged, generalized epileptic seizures in rapid succession with brief intervals of coma.
|
Results for status epilepticus
|
On this page:
|
(medicine) Occurrence of prolonged, generalized epileptic seizures in rapid succession with brief intervals of coma.
Status epilepticus
Definition
Status epilepticus is a term describing a state of continuous seizure activity. In the past, 30 minutes of continuing seizure or frequent attacks that prevent recovery was required for the definition of status to be met. However, since most seizures last less than four to five minutes, it is now understood that any seizure that continues five minutes or longer should be potentially considered as status epilepticus, and managed accordingly.
Description
Nearly all types of seizures have the potential of occurring in a continuous or repeated fashion. There are two general categories: generalized status and focal status, depending on the clinical features of the situation. Generalized status can preferentially manifest with tonic, clonic, absence, and/or myoclonic seizures. Hence, status can be merely a prolongation of commonly observed individual seizure types. Non-convulsive status epilepticus can manifest with sustained or repeating complex partial seizures with a change in mental status, or simply as a focal seizure with limited physical signs but without alteration of consciousness. Status can occur in individuals who have epilepsy already. However, in some cases, the first seizure that a person experiences can be status epilepticus.
Demographics
The epidemiology of status epilepticus varies depending on the study. However, in the United States the incidence is approximately up to 40 per 100,000 individuals. Therefore more than 100,000 cases of status occur annually. Up to 10% of all first-time seizures are situations of status epilepticus. The mortality of status epilepticus is roughly 20%. Those most at risk are the very young or the elderly. The causes of death vary depending on the age of the patient, presence of medical complications, duration of the uncontrollable seizures, and the underlying cause of the status epilepticus.
Causes and symptoms
The exact pathophysiology of why a seizure evolves into status is complex and not fully understood. However, status epilepticus has many causes, some of which are the same as causes of seizures in general. In infants, status can occur in the setting of perinatal hypoxia or anoxia (low oxygen or lack of oxygen) that injures the brain. Also, illness such as meningitis that can cause seizures can also be severe enough to cause status epilepticus. Metabolic disorders of infancy and childhood that can be causes of epilepsy can also produce status epilepticus. In adults, infections of the brain, strokes, brain tumors, and severe head trauma can cause seizures and hence status epilepticus.
Clinically, status epilepticus is basically a prolonged seizure situation. Individual seizures occurring frequently enough to impair full recovery to baseline function can be a manifestation of status epilepticus as well. A limited seizure such as an arm jerking without alteration of consciousness is called a simple or focal seizure. If it occurs continuously, the term epilepsy partialis continua is used. This is the least serious of the different types of status epilepticus. The more dangerous type is, of course, generalized tonic/clonic status. This is because cardiac arrhythmias or blood pressure changes can be life threatening. Also, breathing and oxygenation can be compromised, and patients may require ventilator assistance. Complex partial seizures and absence seizures are manifested with an alteration of consciousness. When these particular seizures become status, patients may simply appear confused or agitated. Since they are not having convulsions, they may be misdiagnosed as having a psychiatric symptom. Nevertheless, prompt and accurate diagnosis is important for proper management.
Diagnosis
When convulsions are occurring, status is typically easily recognized. However, subtle status, as in complex partial or absence status, may necessitate an electroencephalogram (EEG) for diagnosis. The EEG is not only used for initial diagnosis, but is often left running for longer periods to monitor response to treatment. The recognition of seizure activity is only one of the urgent tasks in the care of the patient. The other major issue is to rapidly identify the cause of seizures and the status epilepticus. This involves testing blood for at least glucose, electrolytes, liver function, and illicit substances. Very low blood glucose or extreme changes in sodium, for example, can cause seizures. Infections such as meningitis can cause status. Rapidly assessed levels of older, commonly used seizure medications such as phenytoin, Phenobarbital, carbamazepine, and valproic acid are sometimes sought in cases where there is no available history from the patient. Indeed, one of the most frequent causes of status is low anticonvulsant levels in a patient with a history of epilepsy.
Treatment team
Patients in status epilepticus will often necessitate a neurologist to guide the management from the emergency department through the rest of the hospital stay. Social workers are important for discharge plans because many patients who survive status epilepticus may need skilled nursing or rehabilitation to fully recover prior to being discharged home.
Treatment
The treatment of status depends on identifying quickly the underlying cause, if any. In cases of hypoglycemia, thiamine must be administered just prior to glucose supplementation. This is because some individuals, alcoholics for example, may be deficient in thiamine and a correction of glucose levels without thiamine supplementation can cause a condition known as Wernicke's encephalopathy. Sodium must be corrected slowly or a condition called central pontine myelinolysis can occur. A computed tomography (CT) scan of the brain is often ordered to evaluate for any brain trauma. A lumbar puncture may be performed to determine if there is meningitis so appropriate antibiotics can be used. Overall, in cases that an identifiable cause of status can be found, the key to successful treatment is the management of the underlying cause itself. There are published guidelines for the treatment of seizures themselves. Initially, a sedative such as lorazepam or diazepam is given, which can stop many seizures at least temporarily while a longer-acting anticonvulsant such as phenytoin takes effect. If seizures persist, then the addition of Phenobarbital is typically added. Since this particular medication, when fully loaded, causes respiratory depression, an anesthesiologist is consulted to manage ventilator assistance. Status epilepticus is managed and treated in an intensive care unit with EEG monitoring to continually assess the response to seizure medications. When Phenobarbital fails to stop the ongoing seizures, a number of other medications are considered, such as a midazolam drip or propofol. Anesthetic dosages of these particular medications are usually effective in suppressing seizure activity. Approximately every 24 hours, the dosage is reduced to determine if seizures recur or not. The severity of status can vary widely. Sometimes, it is effectively treated within one to two hours and other times the status is severe and extremely resistant to treatment and lasts for weeks. In such cases, the mortality rate is significant because of risk of medical complications such as pneumonia and blood clots.
Recovery and rehabilitation
The recovery from status epilepticus will depend on its duration. If status can be effectively stopped in a relatively short period of time, complete neurological recovery is possible. The longer the seizures persist, the greater the chance of cerebral injury. Also, the longer the status epilepticus, the more difficult it is to stop. A complication of status epilepticus can actually be the development of epilepsy in a percentage of cases.
Prognosis
The prognosis with status epilepticus will depend on the duration of status and co-existing medical problems. The prognosis is good for recovery if status can be stopped in a relatively short period of time (hours) and there are no complications such as infection, active cardiac problems, or other active medical issues. However, prognosis for complete recovery is less favorable as status persists for long periods of time. Co-existing medical problems will complicate management and chance for a negative outcome.
Special concerns
It is important to be on the lookout for subtle status situations that may go unrecognized. An EEG is a relatively easy way to rule in or rule out presence of active seizures. It is crucial to respond urgently to status epilepticus because the longer the seizures continue the more difficult they are to stop.
Resources
BOOKS
Browne, T. R., and G. L. Holmes. Handbook of Epilepsy, 2nd edition. Philadelphia: Lippinocott Williams & Wilkins, 2000.
Engel, Jr., J., and T. A. Pedley. Epilepsy: A Comprehensive Textbook. Philadelphia: Lippincott-Raven, 1998.
Hauser, W. A., and D. Hesdorffer. Epilepsy: Frequency, Causes, and Consequences. New York: Demos Publications, 1990.
Wyllie, E. The Treatment of Epilepsy: Principles and Practice, 3rd edition. Philadelphia: Lippincott Williams & Wilkins. 2001.
PERIODICALS
Epilepsy Foundation of America's Working Group on Status Epilepticus. "Treatment of Convulsive Status Epilepticus: Recommendations of the JAMA." Journal of the American Medical Association 270 (1993): 854–859.
Hesdorffer, D. C., G. Logroscino, G. Cascino, J. F. Annegers, and W. A. Hauser. "Risk of Unprovoked Seizure after Acute Symptomatic Seizure: Effect of Status Epilepticus." Annals of Neurology 44 (1998): 908–912.
ORGANIZATIONS
American Epilepsy Society. 342 North Main Street, West Hartford, CT 06117-2507. (860) 586-7505. http://www.aesnet.org.
Epilepsy Foundation of America. 4351 Garden City Drive, Landover, MD 20785-7223. (800) 332-1000. http://www.epilepsyfoundation.org.
Internation League Against Epilepsy. Avenue Marcel Thiry 204, B-1200, Brussels, Belgium. + 32 (0) 2 774 9547; Fax: + 32 (0) 2 774 9690. http://www.epilepsy.org.
Roy Sucholeiki, MD
A seizure lasting more than 30 minutes, or a series of seizures without pause between them. Patient often does not respond to medication.
| ICD-10 | G41. |
|---|---|
| ICD-9 | 345.3 |
| eMedicine | emerg/554 |
| MeSH | D013226 |
Status epilepticus (SE) refers to a life threatening condition in which the brain is in a state of persistent seizure. Definitions vary, but traditionally it is defined as one continuous seizure or recurrent seizures without regaining consciousness between seizures for greater than 30 minutes. Many doctors, however, believe that 5 minutes is sufficient to damage neurons and that seizures are unlikely to self-terminate by that time.
In known epileptics, this condition is associated with poor compliance (adherence to medication regimen), alcohol withdrawal, and metabolic disturbances. As a primary presentation it normally indicates a tumour or abscess.
It can also be induced by nerve agents such as soman.[1]
Status epilepticus can be divided into two categories—convulsive and nonconvulsive, the latter of which is underdiagnosed.
Epilepsia partialis continua is a variant involving hour, day, or even week-long jerking. It is a consequence of vascular disease, tumours, or encephalitis, and is drug-resistant.
Generalized myoclonus is commonly seen in comatose patients following CPR and is seen by some as an indication of catastrophic damage to the neocortex.[2]
Complex partial status epilepticus, or CPSE, and absence status epilepticus are rare forms of the condition which are marked by nonconvulsive seizures. In the case of CPSE, the seizure is confined to a small area of the brain, normally the temporal lobe. But the latter, absence status epilepticus, is marked by a generalised seizure affecting the whole brain, and an EEG is needed to differentiate between the two conditions. This results in episodes characterized by a long-lasting stupor, staring and unresponsiveness.
Shortly after it was introduced in 1963, diazepam became the first choice for SE. Even though other benzodiazepines such as clonazepam were useful, diazepam was relied upon almost exclusively. This began to change in 1975 with a preliminary study on lorazepam conducted by Waltregny and Dargent, who found that its pharmacological effects were longer lasting than those of an equal dose of diazepam.[3] This meant it did not have to be repeatedly injected like diazepam,[4] the effects of which would wear off 5–15 minutes later in spite of its 30-hour half-life (due to extensive redistribution of diazepam outside the vascular compartment as diazepam is highly lipid soluble). It has also been found that patients who were first tried on diazepam were much more likely to require endotracheal tubing than patients who were first tried on phenobarbital, phenytoin,[5] or lorazepam.[6]
Today, the benzodiazepine of choice is lorazepam for initial treatment due to its long (2–8 hour) duration of action and rapid onset of action, thought to be due to its high affinity for GABA receptors and to its low lipid solubility which causes it to remain in the vascular compartment. If lorazepam is not available, then diazepam should be given.[7] Sometimes, the failure of lorazepam alone is considered to be enough to classify a case of SE as refractory.
Phenytoin was once another first-line therapy, although the prodrug fosphenytoin can be administered three times as fast and with far fewer injection site reactions. If these or any other hydantoin derivatives are used, then cardiac monitoring is a must if they are administered intravenously. Because the hydantoins take 15–30 minutes to work, a benzodiazepine or barbiturate is often co-administered. Because of diazepam's short duration of action, they were often administered together anyway.
Before the benzodiazepines were invented, there were the barbiturates, which are still used today if benzodiazepines or the hydantoins are not an option. These are used to induce a barbituric coma. The barbiturate most commonly used for this is phenobarbital. Thiopental or pentobarbital may also be used for that purpose if the seizures have to be stopped immediately or if the patient has already been compromised by the underlying illness or toxic/metabolic-induced seizures; however, in those situations, thiopental is the agent of choice.
The failure of phenobarbital therapy does not preclude the success of a lengthy comatose state induced by a stronger barbiturate such as secobarbital. Such was the case for Ohori, Fujioka, and Ohta ca. 1998, when they induced a 10-month long coma (or "anesthesia" as they called it) in a 26-year-old woman suffering from refractory status epilepticus secondary to viral encephalitis and then tapered her off the secobarbital very slowly while using zonisamide at the same time.[8]
If this proves ineffective or if barbiturates cannot be used for some reason, then a general anesthetic such as propofol[9] is tried; sometimes it is used second after the failure of lorazepam.[10] This also means putting the patient on artificial respiration. Propofol has been shown to be effective in suppressing the jerks seen in myoclonus status epilepticus, but as of 2002, there have been no cases of anyone going into myoclonus status epilepticus, undergoing propofol treatment, and then not dying anyway.[11]
The use of lidocaine in status epilepticus was first reported in 1955 by Bernhard, Boem and Hojeberg.[12] Since then, it has been used in cases refractory to phenobarbital, diazepam, and phenytoin, and has been studied as an alternative to barbiturates and general anesthetics.[13][14] Lidocaine is a sodium channel blocker and has been used where sodium channel dysfunction was suspected.[15] However, in some studies, it was either ineffective or even harmful for most patients.[16] The last is not so surprising in light of the fact that lidocaine has been known to cause seizures in humans and laboratory animals at doses greater than 15 µg/mL[17] or 2–3 mg/kg.[18]
This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)
Join the WikiAnswers Q&A community. Post a question or answer questions about "status epilepticus" at WikiAnswers.
Copyrights:
![]() | Sci-Tech Dictionary. McGraw-Hill Dictionary of Scientific and Technical Terms. Copyright © 2003, 1994, 1989, 1984, 1978, 1976, 1974 by McGraw-Hill Companies, Inc. All rights reserved. Read more | |
![]() | Neurological Disorder. Gale Encyclopedia of Neurological Disorders. Copyright © 2005 by The Gale Group, Inc. All rights reserved. Read more | |
![]() | Dental Dictionary. Mosby's Dental Dictionary. Copyright © 2004 by Elsevier, Inc. All rights reserved. Read more | |
![]() | Wikipedia. This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Status epilepticus". Read more |