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Seizure Disorder - Description

Other Names

epilepsy

ICD-9

780, Seizures

ICD-9-CM uses two general classifications for seizure disorders. Those in the 780 series are for convulsions, which may or may not be epileptic seizures, certain kinds of seizures (e.g, febrile seizures), or seizures not otherwise specified, whereas epilepsy and epileptic syndromes are coded for in the 345 group. Most require fourth and even fifth digits (see Seizures ICD9(PDF Document 64 KB)).

Description

Seizure: A sudden, involuntary, time-limited alteration in behavior, motor activity, autonomic function, consciousness, or sensation, accompanied by an abnormal electrical discharge in the brain. Seizures can be provoked by acute medical conditions (e.g., trauma, electrolyte disturbances, meningitis) or they can occur without provocation.

Epilepsy: A condition in which an individual has recurrent, unprovoked seizures.

Status epilepticus
: Traditionally, status epilepticus has been defined as more than thirty minutes of continuous seizure activity or recurrent seizures without intercurrent recovery of consciousness. Most seizures will stop on their own within five minutes of onset. A child with a seizure lasting 5 minutes or more will likely require medical intervention to stop it. [Jenssen: 2006] (See Status epilepticus).

See Related Issues below for information regarding assessment and treatment of specific seizure types and Infantile Spasms - old.

Genetics

Although seizures may run in families, inheritance patterns are hard to predict. Epilepsy is probably a polygenic disorder, and may require a combination of genetic and environmental susceptibilities to be expressed in an individual. Sometimes the clinical presentation suggests a particular epilepsy syndrome; clinical testing is available for some of these. See Genetic testing for specific epilepsy syndromes (Gene Reviews) and [Deprez: 2009] for more information.

Prognosis

The primary elements of prognosis include: seizure recurrence risk, likelihood for seizures to be controlled by medication, and the likelihood for normal neuro-cognitive development. In general, prognosis will depend on the underlying etiology and the type of seizure. Prognosis for a child with seizures may vary from excellent to devastating.
  • Seizure recurrence risk after a first afebrile, generalized, tonic-clonic seizure in a typically developing child is 25-50%:
    • Age of the child and duration of the event do not affect the risk of recurrence.
    • Half of recurrences will occur in the first 6 months following a first seizure, two thirds will occur within one year, and 90% or more within 2 years.
    • The EEG is an important predictor of recurrence. If the EEG is normal, the 5-year recurrence risk is 25%.
  • Seizure recurrence risk for children with an epilepsy syndrome:
    • Depends on the epilepsy syndrome
    • In general, idiopathic or genetically-determined epilepsy has the best prognosis.
    • Up to 75% of children will experience a prolonged remission from seizures; this is not affected by the use of anti-epileptic drugs (AEDs).
  • Likelihood for seizures to be controlled by medication:
    • 50% of children with epilepsy will respond to the first medication
    • 20-30 % of children will not respond completely, will require two medications for control, or will change medication before control is reached.
    • 20-30% of patients will have intractable epilepsy that doesn't respond completely to multiple medications and/or other treatments such as the ketogenic diet, surgery, and the vagal nerve stimulator. Demographic information - seizures (Epilepsy Foundation of America)
  • Likelihood for normal neuro-cognitive development depends on the epilepsy syndrome - see discussion of individual syndromes in the Seizure Disorder, Related Issues.

Prevalence

Pediatric epilepsy incidence in Singapore was 24 per 100000 person-years, and was highest in early childhood. Focal epilepsy was found to be more common than generalized epilepsy. [Chan: 2010] Looking at different parameters, a study of pediatric epilepsy in Brazil found an incidence rate of 7/100000 children with a prevalence of 65.2/10000 children. [Nunes: 2011] Demographic information - seizures (Epilepsy Foundation of America) presents information from the Epilepsy Foundation of America, but it is unclear from this information how those numbers were derived.

Impact

Estimates of annual direct and indirect costs of care in the U.S. for individuals with epilepsy (for all ages) are $15.5 billion. See Demographic information - seizures (Epilepsy Foundation of America) for more information.

Helpful Articles

PubMed search for practice guidelines for seizures or epilepsy in children

Neville BG, Chin RF, Scott RC.
Childhood convulsive status epilepticus: epidemiology, management and outcome.
Acta Neurol Scand Suppl. 2007;186:21-4. PubMed abstract

Hauser WA, Beghi E.
First seizure definitions and worldwide incidence and mortality.
Epilepsia. 2008;49 Suppl 1:8-12. PubMed abstract

Subcommittee on febrile seizures.
Neurodiagnostic evaluation of the child with a simple febrile seizure.
Pediatrics. 2011;127(2):389-94. PubMed abstract

Seizure Disorder Module Authors

Authors: Denise Morita, MD - 12/2011
Lynne M Kerr, MD, PhD - 5/2011
Content Last Updated: 6/2011

The authors listed above are responsible for the overall Seizure Disorder Module. Authors contributing to individual pages in the module are listed on those pages.

Page Bibliography

Chan D, Phuah HK, Ng YL, Choong CT, Lim KW, Goh WH.
Pediatric epilepsy and first afebrile seizure in singapore: epidemiology and investigation yield at presentation.
J Child Neurol. 2010;25(10):1216-22. PubMed abstract

Deprez L, Jansen A, De Jonghe P.
Genetics of epilepsy syndromes starting in the first year of life.
Neurology. 2009;72(3):273-81. PubMed abstract

Jenssen S, Gracely EJ, Sperling MR.
How long do most seizures last? A systematic comparison of seizures recorded in the epilepsy monitoring unit.
Epilepsia. 2006;47(9):1499-503. PubMed abstract

Nunes ML, Geib LT.
Incidence of epilepsy and seizure disorders in childhood and association with social determinants: a birth cohort study.
J Pediatr (Rio J). 2011;87(1):50-6. PubMed abstract