Convulsive status epilepticus is defined as a convulsive seizure which continues for a prolonged period (longer than five minutes), or when convulsive seizures occur one after the other with no recovery between. Convulsive status epilepticus is an emergency and requires immediate medical attention. Non-convulsive status epilepticus is uncommon and management is usually less urgent.
- Estimated incidence is between 3.5 and 50 cases per 100,000 person/years. The incidence is higher in poorer populations. It recurs in about a third of patients.
- Risk factors include age under 5 years or elderly age, genetic predisposition, intellectual disability and structural brain pathology.
- Potential precipitants include drug withdrawal, intercurrent illness, metabolic disturbance (eg, hypoglycaemia), cerebrovascular event and alcohol intoxication or withdrawal.
This would be the same as any convulsion but unremitting. The diagnosis of tonic-clonic status is usually clear, although it needs to be distinguished from pseudo-status epilepticus which is non-epileptic attacks with a psychological basis.
Non-epileptic status should be considered. See the separate Non-epileptic Seizures article.
- Give immediate emergency care and treatment for prolonged (lasting five minutes or more) or repeated (three or more in an hour) convulsive seizures in the community.
- Treatment should be administered by trained clinical personnel or, if specified by an individually agreed protocol drawn up with the specialist, by family members or carers with appropriate training.
First-line treatment in the community
- General protective measures - eg, ensuring the head is protected, releasing any constricting neck wear, moving away from a dangerous position.
- Resuscitation as required: secure the airway and assess respiratory and cardiac function.
- Use buccal midazolam as first-line treatment for prolonged or repeated seizures in the community. Administer rectal diazepam if preferred or if buccal midazolam is not available.
- If intravenous (IV) access is established and resuscitation facilities are available, administer IV lorazepam.
- Depending on response to treatment, the person's situation and any personalised care plan, call an ambulance, particularly if:
- The seizure is continuing five minutes after the emergency medication has been administered.
- The person has a history of frequent episodes of serial seizures or has convulsive status epilepticus.
- This is the first episode requiring emergency treatment.
- There are concerns or difficulties monitoring the person's airway, breathing, circulation or other vital signs.
Treatment in hospital
- Secure airway, give high-concentration oxygen.
- Assess cardiac and respiratory function, check blood glucose levels and secure IV access in a large vein.
- Administer IV lorazepam as first-line treatment. Administer IV diazepam if IV lorazepam is unavailable, or buccal midazolam if unable to secure immediate IV access. Administer a maximum of two doses of the first-line treatment (including pre-hospital treatment).
- If seizures continue, administer IV phenobarbital or phenytoin as second-line treatment. Fosphenytoin (a prodrug of phenytoin) can be given more rapidly and, when given intravenously, causes fewer injection-site reactions than phenytoin.
- Refractory convulsive status epilepticus:
- Administer IV midazolam, propofol or thiopental sodium to treat adults with refractory convulsive status epilepticus. Administer IV midazolam or thiopental sodium to treat children and young people with refractory convulsive status epilepticus.
- Adequate monitoring, including blood levels of anti-epileptic drugs (AEDs), and critical life systems support are required.
Emergency investigations in hospital
- Pulse oximetry; blood gases.
- Blood for glucose, renal function, electrolytes, liver function, calcium and magnesium; FBC and clotting; AED levels.
- 5 ml of serum and 50 ml of urine samples should be saved for future analysis, including toxicology, especially if the cause of the status epilepticus is uncertain.
- Correct hypoglycaemia if present.
- Parenteral thiamine should be considered if alcohol abuse is suspected.
- Pyridoxine (vitamin B6) should be given if the status epilepticus is caused by pyridoxine deficiency.
- Identify and treat any underlying cause. Status is associated with community-acquired bacterial meningitis and seizures. Seizures occurring in the acute phase of the illness are predictors of poor outcome.
- Identify and treat medical complications - eg, CXR to evaluate the possibility of aspiration.
- Regular AEDs should be continued at optimal doses and the reasons for status epilepticus should be investigated.
- An individual treatment pathway should be formulated for children, young people and adults who have recurrent convulsive status epilepticus.
- Only prescribe buccal midazolam or rectal diazepam for use in the community if there has been a previous episode of prolonged or serial convulsive seizures.
This is less common than tonic-clonic status epilepticus. Treatment for non-convulsive status epilepticus is less urgent than for convulsive status epilepticus. Non-convulsive status (eg, absence status or continuous focal seizures with preservation of consciousness) may be difficult to diagnose. In non-comatose patients it may present as confusion, personality change or psychosis. Treatment should be considered as follows:
- Maintenance or reinstatement of usual oral anti-epileptic therapy.
- Consider benzodiazepine treatment (midazolam 10 mg buccally or intranasally, lorazepam 4 mg IV, or diazepam 10 mg IV).
- Use of IV benzodiazepines under electroencephalographic (EEG) control, particularly if the diagnosis is not established.
- Referral for specialist advice and/or EEG monitoring.
The true morbidity and mortality of status epilepticus is unclear. Short-term mortality has ranged from 0.5-20% with age over 65 frequently identified as the most significant risk factor. The Status Epilepticus Severity Score (STESS), consisting of the variables level of consciousness, seizure type, age above or below 65, and history of prior seizure, older age, lower levels of consciousness, generalised convulsive/nonconvulsive morphologies, and absence of prior seizures, were all indicative of a worse prognosis.
Good seizure control in pre-existing epilepsy.
Further reading and references
Epilepsy; NICE CKS, July 2019 (UK access only)
Epilepsies: diagnosis and management; NICE Clinical Guideline (October 2019)
Billington M, Kandalaft OR, Aisiku IP; Adult Status Epilepticus: A Review of the Prehospital and Emergency Department Management. J Clin Med. 2016 Aug 235(9). pii: jcm5090074. doi: 10.3390/jcm5090074.
Hesdorffer DC, Logroscino G, Cascino GD, et al; Recurrence of afebrile status epilepticus in a population-based study in Rochester, Minnesota. Neurology. 2007 Jul 369(1):73-8.
British National Formulary (BNF); NICE Evidence Services (UK access only)
Wang KW, Chang WN, Chang HW, et al; The significance of seizures and other predictive factors during the acute illness for the long-term outcome after bacterial meningitis. Seizure. 2005 Dec14(8):586-92. Epub 2005 Oct 25.
Diagnosis and management of epilepsy in adults; Scottish Intercollegiate Guidelines Network - SIGN (2015 updated 2018)