Status Epilepticus

1. Definition

Conventional definition: >30 min of continuous seizure or convulsions or of intermittent seizures without full recovery.

There is evidence that seizures of 30 minutes or longer duration cause neuronal damage, and this is the basis for the definition. However, do not wait for brain damage to occur--treat for status epilepticus if the seizure has lasted more than 5 to 10 minutes.

2. Classification of status

Generalized motor status is a true medical emergency

3. Stages of status epilepticus

  1. Discrete seizures
  2. Merging seizures
  3. Continuous ictal activity
  4. Continuous ictal activity, punctuated by low voltage flat activity
  5. Periodic epileptiform discharges on a quiet background
(Treiman et al. 1990)

4. Systemic complications of status

5. Mortality of status epilepticus

6. Mortality of status epilepticus

A comparison of survival by duration in status epilepticus shows a marked increase in mortiality for patients in prolonged status epilepticus. 

(Towne et al. 1994)

7. Neuronal death

8. Epilepsy

9.  Important!!

    Eliminate the electrical seizure to prevent neuronal injury in status epilepticus

10. Steps in treatment

  1. ABC's
  2. Quick assessment
  3. Stop the seizure
  4. Find the cause

11. Quick assessment



head trauma?
medical noncompliance?
alcohol or barbiturate use?
theophylline use?


elevated blood pressure?
focal seizure onset?
focal neurologic exam?

12. Causes of status

Medication withdrawal
Alcohol withdrawal
Metabolic disorder
CNS infection 
Congenital brain injury

Some patients have more than one etiology.
(Towne et al. 1994)

13. Laboratory studies often useful

14. Simple procedures always recommended

15. Initial Rx for seizures

If hypoglycemic, then:
  1. IV glucose (50 cc D50)
  2. Thiamine (10 mg IV + 90 mg IM)

16. Anticonvulsants

17. Benzodiazepines

18. Diazepam has a short duration of action

Diazepam has only a short duration of action. This is primarily because it quickly redistributes from brain to fat. Note that plasma diazepam concentration is less than half its peak ten minutes after an IV infusion. 

(Ramsay et al. 1979)

19. Phenytoin

20. Fosphenytoin

  • Prodrug of phenytoin for parenteral administration
  • Rapidly and completely converted to phenytoin by nonspecific tissue phosphatases
  • Water soluble, pH 8.6 - 9
  • Can be given IM
  • No sterile necrosis or tissue abscesses
  • Molecular weight 1.5 times that of phenytoin

21. IV loading of fosphenytoin

Fosphenytoin is rapidly converted to phenytoin. Plasma concentrations of phenytoin are essentially identical whether phenytoin or fosphenytoin is infused.

22. Phenobarbital

23. Intravenous valproic acid

24. Serial seizures

25. Refractory status: midazolam

26. Refractory status: pentobarbital

27. EEG burst suppression

A quiet EEG background is frequently interrupted by bursts of high voltage activity. The high voltage activity often contains epileptiform spikes or spike-wave discharges.

28. Other types of status epilepticus

29. Controversies in status epilepticus

30. Periodic discharges

This patient had right frontal periodic discharges and encephalopathy. Treatment with fosphenytoin and valproate improved the discharges, but the patient was clinically unimproved. 

31. Time table for treatment of status

a. 0-10 min, do ABC's:

b. 10-20 min, administer a benzodiazepine drug:

Lorazepam (0.1 mg/kg at 2 mg/min IV) or diazepam (0.2 mg/kg at 5 mg/min IV). Lorazepam is the drug of choice. Both drugs act quickly, diazepam slightly faster, but it redistributes to fat quickly, and its effective duration of action may be only 5-10 min. With diazepam, repeated doses are often necessary. If diazepam is used, phenytoin (or fosphenytoin) should next be given to prevent recurrence of seizures. The effective duration of action of lorazepam is 8-10 hours, and is recommended for initial treatment of status epilepticus.

c. 20-60 min, administer fosphenytoin or phenytoin

Fosphenytoin  is a water-soluble phosphate pro-drug of phenytoin. It replaces IV phenytoin, which is highly alkaline (pH 12) and dissolved in 40% propylene glycol/10% ethanol. It can be dosed using "phenytoin equivalents". (Its molecular weight is 1.5 times that of phenytoin.) Can be used IM. Can be given at a rate of 150 mg/min IV. Hypotension and cardiac arrhythmias are less common than with phenytoin.

Phenytoin  In adults give 18 mg/kg no faster than 50 mg/min IV. Monitor ECG and BP during infusion. Do not use glucose-containing IV solution. Purge IV line with normal saline before infusion. Do not give phenytoin IM because it may cause sterile abscesses. Ensure adequate IV access because local infiltration of phenytoin can cause skin necrosis.

d. >60 min

e. If seizures persist:


  1. Barry E, Hauser WA (1992) Status epilepticus: the interaction of epilepsy and acute brain disease. Neurology 43: 1473-1478. PubMed
  2. Hesdorffer DC, Logroscino G, Cascino G, Annegers JF, Hauser WA (1998) Risk of unprovoked seizure after acute symptomatic seizure: effect of status epilepticus. Ann Neurol. 44: 908-12.
  3. Parent JM, Lowenstein DH (1994) Treatment of refractory generalized status epilepticus with continuous infusion of midazolam. Neurology 44: 1837-1840. PubMed
  4. Ramsay RE, Hammond EJ, Perchalski RJ, Wilder BJ (1979) Brain uptake of phenytoin, phenobarbital, and diazepam. Arch Neurol. 36: 535-9. PubMed
  5. Towne AR, Pellock JM, Ko D, DeLorenzo RJ (1994) Determinants of mortality in status epilepticus. Epilepsia 35: 27-34. PubMed
  6. Treiman DM, Meyers PD, Walton NY, Collins JF, Colling C, Rowan AJ, Handforth A, Faught E, Calabrese VP, Uthman BM, Ramsay RE, Mamdani MB (1998) A comparison of four treatments for generalized convulsive status epilepticus. Veterans Affairs Status Epilepticus Cooperative Study Group. N Engl J Med. 339: 792-8.
  7. Treiman DM, Walton NY, Kendrick C (1990) A progressive sequence of electroencephalographic changes during generalized convulsive status epilepticus. Epilepsy Res. 5: 49-60. PubMed
  8. Wilder BJ (ed.) (1993) The use of parenteral antiepileptic drugs & the role for fosphenytoin. Neurology 46 suppl. 1. PubMed
  9. Working Group on Status Epilepticus (1993) Treatment of status epilepticus: recommendations of the Epilepsy Foundation of America's Working Group on Status Epilepticus. JAMA 270: 854-859.  PubMed

Last revised 07/25/2003
M. Steven Evans [ mail | epilepsy page ]