Generalized Convulsive Status Epilepticus (GCSE) is defined as two or more episodes of seizures without return to baseline neurologic functioning or any seizure lasting more than 5 minutes.1 Compared to the previous description of GCSE as any seizure activity lasting for more than 30 minutes, this updated definition reflects a new recognition of the increased morbidity and mortality associated with prolonged seizure activity. While many GCSE cases are related to nonadherence to antiepileptic medications, up to 50% of patients with GCSE have no prior seizure history.2 Clinicians must consider the reversible causes of GCSE.
Fever and infection have been cited as the most common causes of seizures in children. In the febrile and seizing patient, meningitis and encephalitis should be included in the differential diagnoses. Computed tomography (CT) and lumbar puncture (LP), once the seizure is controlled, are necessary to rule out a CNS infection. Clinicians should start antibiotic therapy and/or antiviral agents empirically while other diagnostic testings are underway.
Editor’s Commentary: Of note, a simple febrile seizure is almost never the sole manifestation of bacterial meningitis in children.3 Unless there are other signs of “badness” (e.g. nuchal rigidity, comatose state, petechial rashes, or prolonged, focal, or multiple seizures), there is often no further workup necessary in an otherwise well-appearing child. In a study by Green et al., no child who presented with only a simple febrile seizure was found to have bacterial meningitis.4
Most emergency and prehospital clinicians are good at considering hypoglycemia as one of the most common causes of GCSE. If not already tested by EMS, point-of-care glucose of <45 mg/dL in a seizing patient should prompt correction with 50 mL of D50 in adults. Children and infants should receive 2mL/kg of D25 and 5 mL/kg of D10, respectively (remember the Rule of 50s). In the malnourished or alcoholic patient, consider adding 100mg of IV thiamine.
Both hyponatremia (Na<120 mEq/L), or hypernatremia (Na>160 mEq/L) can lead to GCSE. If the patient is actively seizing, treat hyponatremia with hypertonic saline by giving 100 mL 3% NaCl IV over 10 minutes. Acute hypernatremia, which is defined as hypernatremia that has been present for less than 48 hours, is uncommon and occurs primarily in patients with diabetes insipidus who acutely lose their ability to replace water losses due to surgery or acute illness. It can also occur in patients with severe dehydration or salt poisoning. Treat these patients with IV D5W at 3-6 ml/kg/hour with the goal of replacing the entire water deficit within 24 hours.
Other metabolic derangements that should be corrected simultaneously include hypocalcemia, hypokalemia, and hypomagnesemia.
The list of drugs that can contribute to GCSE is too extensive to be fully addressed here. Major culprits include isoniazid (INH), antidepressants (specifically, tricyclic antidepressants), and lithium. Isoniazid toxicity can be treated with Pyridoxine (1g per gram of INH or 5g IV). Treat TCA toxicity with sodium bicarbonate. Consider hemodialysis in your poisoned patient with severe lithium toxicity after consulting with the local poison control center.
Women and GCSE
Lastly, when managing young (and possibly pregnant) women with seizures, eclampsia should be high on the differential. It is important to remember that a significant number of cases of eclampsia can occur weeks after delivery in the postpartum period. Loading doses of 4-6g of IV magnesium are commonly used in these patients.
- When managing patients with GCSE, we need to consider a wide range of possible causes beyond medication nonadherence.
- Many of the etiologies are rapidly reversible when correctly identified and treated, which ultimately results in reducing morbidity and mortality.
- Millikan D, Rice B, Silbergleit R. Emergency treatment of status epilepticus: current thinking. Emerg Med Clin North Am. 2009 Feb;27(1):101-13, ix. doi: 10.1016/j.emc.2008.12.001. PMID: 19218022.
- Huff JS, Fountain NB. Pathophysiology and definitions of seizures and status epilepticus. Emerg Med Clin North Am. 2011 Feb;29(1):1-13. doi: 10.1016/j.emc.2010.08.001. PMID: 21109098.
- Santillanes G, Luc Q. Emergency Department Management of Seizures in Pediatric Patients. Pediatric Emergency Medicine Practice. 2015 Mar;12(3).
- Green SM, Rothrock SG, Clem KJ, Zurcher RF, Mellick L. Can seizures be the sole manifestation of meningitis in febrile children? Pediatrics. 1993 Oct;92(4):527-34. PMID: 8414822.