- Status epilepticus (SE) is defined as a continuous seizure lasting >30 minutes or recurrent seizures without return to baseline in between. After 30 minutes, ischemic injury to the brain is more likely to occur. Seizures lasting >5 minutes are unlikely to resolve without anticonvulsant therapy and are likely to progress to SE without intervention.
- SE presents in several forms:
- Generalized SE: continuous or repeated generalized convulsion(s) with persistent loss of consciousness and neurologic function
- Nonconvulsive SE, myoclonic SE, or absence SE: persistent encephalopathy, often with variable subtle motor signs such as myoclonus or nystagmus
- Repeated partial seizures with alteration of consciousness (focal SE) or preserved consciousness (epilepsia partialis continua)
- Systemic complications of SE:
- Hyperthermia, rhabdomyolysis
- Tachycardia, hypertension early → hypotension late
- Hypoxia, hypercapnia, aspiration pneumonia
- Impaired cerebral autoregulation
- Rare: cardiac arrhythmias, neurogenic pulmonary edema, bone fractures
- Neuromuscular blockers used in intubation may obscure ongoing seizures. EEG monitoring is mandatory for all patients who have had any pharmacologic paralysis during SE.
- Continued encephalopathy after convulsions have stopped may indicate ongoing electrographic seizures (nonconvulsive SE), found in up to 30% of children after treated SE.
- Nonepileptic seizures can be mistaken for SE. EEG establishes the diagnosis.
- Incidence in pediatric patients is 17 to 23/100,000. In children <1 year old, incidence is 135 to 156/100,000.
- ~40–70% of children have no history of seizures.
- Known epilepsy
- Remote or acute central nervous system (CNS) insult
- History of previous SE
- Low anticonvulsant drug levels
- Younger age
- Adherence to the anticonvulsant medication regimen and clinical follow-up in patients with epilepsy
- Avoid rapid changes in anticonvulsants unless urgently needed.
- Prompt treatment of convulsive seizures
SE may be related to acute or chronic factors or frequently of unknown etiology.
- Common acute factors:
- Infectious meningoencephalitis
- Metabolic: electrolyte abnormalities, hypoglycemia
- Trauma or hemorrhage
- Ischemic stroke, hypoxic-ischemic injury
- Medications: low anticonvulsant drug levels or abrupt withdrawal of anticonvulsants, inappropriate anticonvulsants (e.g., absence SE with phenytoin or carbamazepine use in generalized epilepsy or with tiagabine in focal epilepsy)
- Subacute or chronic factors:
- Epilepsy of any cause
- Brain tumors
- Brain malformations (e.g., lissencephaly, polymicrogyria, hemimegalencephaly, neurocutaneous syndromes)
- Other structural brain abnormalities such as strokes hypoxic-ischemic encephalopathy (HIE) or periventricular leukomalacia (PVL)
- Genetic epilepsies: Dravet syndrome (febrile SE), Angelman syndrome (myoclonic SE), progressive myoclonic epilepsy syndromes
- Inflammatory disorders (e.g., Rasmussen encephalitis, N-methyl-D-aspartate [NMDA] receptor antibody syndrome)
- Acute malfunction of ventriculoperitoneal (VP) shunt
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