Background
Status epilepticus is defined as recurrent or continuous seizure activity lasting longer than 30 minutes in which the patient does not regain baseline mental status.[1]
Pathophysiology
Seizures result from rapid abnormal electrical discharges from cerebral neurons. This presents clinically as involuntary alterations of consciousness or motor activity. Consumption of oxygen, glucose, and energy substrates (eg, ATP, phosphocreatine) is significantly increased in cerebral tissue during seizures. Optimal delivery of these metabolic substrates to cerebral tissue requires adequate cardiac output and intravascular fluid volume.
Prolonged seizures are associated with cerebral hypoxia, hypoglycemia, and hypercarbia and with concurrent and progressive lactic and respiratory acidosis. When cerebral metabolic needs exceed available oxygen, glucose, and metabolic substrates (especially during status epilepticus), neuronal destruction can occur and may be irreversible. Hypoxia, hypercarbia, hyperthermia, tachycardia, hypertension, hyperglycemia, hyperkalemia, and lactic acidosis result from massive sympathetic discharge.
Epidemiology
Frequency
United States
Seventy percent of children younger than 1 year who are subsequently diagnosed with epilepsy present with status epilepticus as the initial symptom of their illness. In children with epilepsy, 20% have status epilepticus within 5 years of diagnosis. Five percent of children with febrile seizures present with status epilepticus.
International
Rates are similar to those in the United States.
Mortality/Morbidity
In the United States, the overall mortality is 10-15%.
Sex
No sexual predilection is recognized.
Age
Status epilepticus is common at any age. Certain etiologies are more prevalent in selected age groups (see Causes).
Mitchell WG. Status epilepticus and acute serial seizures in children. J Child Neurol. Jan 2002;17 Suppl 1:S36-43. [Medline].
Brevoord JC, Joosten KF, Arts WF, van Rooij RW, de Hoog M. Status epilepticus: clinical analysis of a treatment protocol based on midazolam and phenytoin. J Child Neurol. Jun 2005;20(6):476-81. [Medline].
Papavasiliou AS, Kotsalis C, Paraskevoulakos E, Karagounis P, Rizou C, Bazigou H. Intravenous midazolam in convulsive status epilepticus in children with pharmacoresistant epilepsy. Epilepsy Behav. Apr 2009;14(4):661-4. [Medline].
Holsti M, Dudley N, Schunk J, Adelgais K, Greenberg R, Olsen C, et al. Intranasal midazolam vs rectal diazepam for the home treatment of acute seizures in pediatric patients with epilepsy. Arch Pediatr Adolesc Med. Aug 2010;164(8):747-53. [Medline].
Appleton R, Choonara I, Martland T,et al. The treatment of convulsive status epilepticus in children. The Status Epilepticus Working Party, Members of the Status Epilepticus Working Party. Arch Dis Child. Nov 2000;83(5):415-9. [Medline].
Arzimanoglou A. Outcome of status epilepticus in children. Epilepsia. 2007;48 Suppl 8:91-3. [Medline].
Bassin S, Smith TL, Bleck TP. Clinical review: status epilepticus. Crit Care. Apr 2002;6(2):137-42. [Medline].
Chin RF, Neville BG, Peckham C, et al. Incidence, cause, and short-term outcome of convulsive status epilepticus in childhood: prospective population-based study. Lancet. Jul 15 2006;368(9531):222-9. [Medline].
Choudhery V, Townend W. Best evidence topic reports. Lorazepam or diazepam in paediatric status epilepticus. Emerg Med J. Jun 2006;23(6):472-3. [Medline].
Epilepsy Foundation of America's Working Group on Status Epilepticus. Treatment of convulsive status epilepticus. JAMA. Aug 18 1993;270(7):854-9. [Medline].
Hanhan UA, Fiallos MR, Orlowski JP. Status epilepticus. Pediatr Clin North Am. Jun 2001;48(3):683-94. [Medline].
Kalviainen R, Eriksson K, Parviainen I. Refractory generalised convulsive status epilepticus: a guide to treatment. CNS Drugs. 2005;19(9):759-68. [Medline].
Korff CM, Nordli DR Jr. Diagnosis and management of nonconvulsive status epilepticus in children. Nat Clin Pract Neurol. Sep 2007;3(9):505-16. [Medline].
Lang ES, Andruchow JE. Evidence-based emergency medicine. What is the preferred first-line therapy for status epilepticus?. Ann Emerg Med. Jul 2006;48(1):98-100. [Medline].
Manno EM. New management strategies in the treatment of status epilepticus. Mayo Clin Proc. Apr 2003;78(4):508-18. [Medline].
Meierkord H. The risk of epilepsy after status epilepticus in children and adults. Epilepsia. 2007;48 Suppl 8:94-5. [Medline].
Neville BG, Chin RF, Scott RC. Childhood convulsive status epilepticus: epidemiology, management and outcome. Acta Neurol Scand Suppl. 2007;186:21-4. [Medline].
Novorol CL, Chin RF, Scott RC. Outcome of convulsive status epilepticus: a review. Arch Dis Child. Nov 2007;92(11):948-51. [Medline].
Pellock JM. Overview: definitions and classifications of seizure emergencies. J Child Neurol. May 2007;22(5 Suppl):9S-13S. [Medline].
Prasad AN, Seshia SS. Status epilepticus in pediatric practice: neonate to adolescent. Adv Neurol. 2006;97:229-43. [Medline].
[Best Evidence] Prasad K, Al-Roomi K, Krishnan PR, Sequeira R. Anticonvulsant therapy for status epilepticus. Cochrane Database Syst Rev. 2005;CD003723. [Medline].
Raspall-Chaure M, Chin RF, Neville BG, Bedford H, Scott RC. The epidemiology of convulsive status epilepticus in children: a critical review. Epilepsia. Sep 2007;48(9):1652-63. [Medline].
Riviello JJ Jr, Ashwal S, Hirtz D, et al. Practice parameter: diagnostic assessment of the child with status epilepticus (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology and the Practice Committee of the Child Neurology Society. Neurology. Nov 14 2006;67(9):1542-50. [Medline].
Rosenow F, Hamer HM, Knake S. The epidemiology of convulsive and nonconvulsive status epilepticus. Epilepsia. 2007;48 Suppl 8:82-4. [Medline].
Saz EU, Karapinar B, Ozcetin M, et al. Convulsive status epilepticus in children: Etiology, treatment protocol and outcome. Seizure. Dec 30 2010;[Medline].
Scott RC, Kirkham FJ. Clinical update: childhood convulsive status epilepticus. Lancet. Sep 1 2007;370(9589):724-6. [Medline].
Stephenson JB. Childhood convulsive status epilepticus. Lancet. Oct 14 2006;368(9544):1327-8; author reply 1328. [Medline].
Sugai K. Treatment of convulsive status epilepticus in infants and young children in Japan. Acta Neurol Scand Suppl. 2007;186:62-70. [Medline].
Sugai K. Treatment of convulsive status epilepticus in infants and young children in Japan. Acta Neurol Scand. Apr 2007;115(4 Suppl):62-70. [Medline].
Treiman DM. Treatment of convulsive status epilepticus. Int Rev Neurobiol. 2007;81:273-85. [Medline].
Yoshikawa H, Yamazaki S, Abe T, Oda Y. Midazolam as a first-line agent for status epilepticus in children. Brain Dev. Jun 2000;22(4):239-42. [Medline].

