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Childhood Absence Epilepsy

Description

Other Names

Petit mal epilepsy, generalized nonconvulsive epilepsy

ICD-9

345.0, Generalized non-convulsive epilepsy

Description

Childhood absence epilepsy (CAE) is a form of idiopathic, genetically-determined, generalized epilepsy that is characterized by absence seizures and in 10% of cases, generalized tonic-clonic seizures. CAE accounts for 10-15% of childhood epilepsy cases. Absence seizures start between the ages of 4 and 10 years of age with the peak age of occurrence 6 to 7 years. Seizures occur many times a day. [Bergqvist: 2007] Absence seizures may also occur in juvenile absence epilepsy, which occurs after age 10, and in juvenile myoclonic epilepsy; thus the presence of absence seizures does not automatically mean the child has childhood absence epilepsy.

Characteristics of an absence seizure (and see Absence seizures (Youtube.com; idriveavan)):
  • The child stares, sometimes blinks, eyes may begin to roll back;
  • The seizure lasts 2-20 seconds, but usually less than 10 seconds;
  • The seizure INTERRUPTS ACTIVITY (such as drinking from cup, playing);
  • The child isn't aware of surroundings, such as being called by name;
  • The child experiences many a day, sometimes up to 100/day;
  • The child has no warning, seizure begins and ends suddenly;
  • The child not usually aware of having had a seizure; and
  • Absence seizures increase with hyperventilation; this is a good provocative test in the clinic.
Although absence seizures occur in typical children, these children have higher rates of behavioral, social, and educational problems. Morbidity in educational/social/behavioral situations may be related to the amount of time with abnormal brain activity due to seizures. There is no mortality unless patient is in a situation where a period of unresponsiveness might be dangerous (e.g., swimming, bathing).

Prevalence

5-50 cases per 100,000 of the population; some studies suggest it is more common in females than males. [Jallon: 2005]

Genetics

The etiology of CAE is genetic with complex multifactorial inheritance. 15-45% of children with CAE have a positive family history and monozygotic twins have a 75% concordance rate. Affected family members may have other forms of idiopathic or generalized epilepsy, such as febrile convulsions and generalized tonic clonic seizures. Absence epilepsy is linked to the GABA receptor gamma 2 subunit and the voltage gated calcium channel alpha 1A subunit. See [Weber: 2008] for more information.

Prognosis

The majority (65-70%) of children with CAE have remission of seizures in adolescence; good prognostic signs are earlier age at onset and absences as the only seizure type (no generalized tonic clonic seizures). [Wirrell: 1996] [Verrotti: 2011] The recurrence risks after antiepileptic treatment withdrawal in children who have been seizure free for two years is 16%. [Ramos-Lizana: 2010] The prognosis for juvenile absence epilepsy for becoming seizure free is not as favorable. [Loiseau: 2002]

Roles Of The Medical Home

The Medical Home provider should initiate diagnostic evaluation (EEG) and manage seizures including writing prescriptions for seizure medications and monitoring educational achievement and mood problems. If a referral to a pediatric neurologist to consider tapering medication is being considered, an EEG with that visit is helpful.

Practice Guidelines

Wheless JW, Clarke DF, Carpenter D.
Treatment of pediatric epilepsy: expert opinion, 2005.
J Child Neurol. 2005;20 Suppl 1:S1-56; quiz S59-60. PubMed abstract

Glauser T, Ben-Menachem E, Bourgeois B, Cnaan A, Chadwick D, Guerreiro C, Kalviainen R, Mattson R, Perucca E, Tomson T.
ILAE treatment guidelines: evidence-based analysis of antiepileptic drug efficacy and effectiveness as initial monotherapy for epileptic seizures and syndromes.
Epilepsia. 2006;47(7):1094-120. PubMed abstract

Helpful Articles

PubMed search for articles on Absence Epilepsy in children for the last 5 years

Benbadis SR.
Practical management issues for idiopathic generalized epilepsies.
Epilepsia. 2005;46 Suppl 9:125-32. PubMed abstract

Caraballo RH, Dalla Bernardina B.
Idiopathic generalized epilepsies.
Handb Clin Neurol. 2013;111:579-89. PubMed abstract

Clinical Assessment

Screening

None needed. Families should be instructed to observe siblings for the presence of similar events. As learning problems are very common in children with CAE, consider screening for these at periodic intervals.

Diagnostic Criteria

2005 ILAE Task Force for Classification and Terminology [Loiseau: 2002]
Inclusion Criteria:
  1. Age at onset between 4 and 10 years and a peak at 5 years to 7 years
  2. Normal neurologic state and development
  3. Brief (4 s to 20 s, exceptionally longer) and frequent (tens per day) absence seizures with abrupt and severe impairment (loss) of consciousness Automatisms are frequent but have no significance in the diagnosis.
  4. EEG ictal discharges of generalized high-amplitude spike and double (maximum occasional three spikes are allowed) spike- and slow-wave complexes. They are rhythmic at around 3 Hz with a gradual and regular slowdown from the initial to the terminal phase of the discharge. Their duration varies from 4 s to 20 s.
Exclusion criteria:
  1. Other than typical absence seizures such as GTCS, or myoclonic jerks prior to or during the active stage of absences
  2. Eyelid myoclonia, perioral myoclonia, rhythmic massive limb jerking, and single or arrhythmic myoclonic jerks of the head, trunk, or limbs. However, mild myoclonic elements of the eyes, eyebrows, and eyelids may be featured, particularly in the first 3 s of the absence seizure.
  3. Mild or no impairment of consciousness during the 3-Hz to 4-Hz discharges.
  4. Brief EEG 3-Hz to 4-Hz spike-wave paroxysms of less than 4 s, multiple spikes (more than 3) or ictal discharge fragmentations.
  5. Visual (photic) and other sensory precipitation of clinical seizures.
There has been much discussion about criteria for childhood absence epilepsy over the years. These criteria are stricter than previous criteria and there are many children who almost meet these criteria, or who meet these criteria but have one of the exclusion criteria. They are treated in the same way as those meeting the criteria, but have a more guarded prognosis for being seizure free. [Valentin: 2007]

Differential Diagnosis

It can be difficult to differentiate between absence seizures, partial complex seizures and daydreaming. Daydreaming has no clear start or stop, can be interrupted, and occurs less frequently and in predictable situations (e.g., the classroom). Partial complex seizures will often end with the child feeling confused, and these usually occur infrequently (a few times a week or a day compared to many a day). Partial complex seizures are often longer than 20 seconds, and may be accompanied by automatisms (lip smacking, teeth grinding, finger movements).

Atypical absence seizures may be seen in children with developmental delays/intellectual deficits. The EEG shows 1.5-2.5 Hz sharp-slow complexes; these represent a different type of symptomatic seizure.

Pearls & Alerts

Daydreaming and absence seizures

Daydreaming and absence seizures can be very difficult to distinguish. As a diagnosis of absence epilepsy is associated with two years of treatment with an antiepileptic medication, it is important to have the correct diagnosis before initiating treatment. Families and teachers of children with absence epilepsy almost always note an interruption of activity during the events, and children with absence epilepsy don't usually respond to the triad of touch, voice, and eye contact when someone tries to stop the seizure.

Children who don't respond to the medication

Children who don't respond to the medication should be seen by a pediatric neurologist because they may have a different epilepsy syndrome and might need changes in treatment.

Learning problems and attention problems

Children with absence epilepsy have more learning and attention problems and information about school progress should be sought during well child and chronic care exams. [Cerminara: 2013]

Depression

Depression and other mood disorders are more common in children with CAE than in the general population. Consider using a screening tool when these children visit the Medical Home. See Screening tools for mood disorders (MassGeneral.org)

Declining school performance

Declining school performance may signal a need for increased medication in a child already being treated for absence seizures, side effects of medications, mood disorders, and/or learning problems.

History & Examination

Family History

Family history should be closely questioned. It is not surprising to find a family history of seizures that went away by the teen years when the family inquires of other family members.

Pregnancy Or Perinatal History

Usually normal

Current & Past Medical History

Usually normal on presentation. Ongoing assessment will include seizure control, atypical features that might make the provider rethink the diagnosis, and looking for side effects of the prescribed medication.

Developmental & Educational Progress

The provider should inquire about school performance and whether the spells have been noted at school. Since absence seizures may occur many - hundreds of times - a day, it is not uncommon for development, particularly in speech and language, or educational achievement, to be mildly impaired. After the child has been diagnosed, developmental and educational progress should be monitored closely. Seizures may affect school performance and medication may also cause difficulty concentrating.

Social & Family Functioning

Mood disorders are more prevalent in children with seizures.

Physical Exam

General

The physical exam is usually completely normal in children with absence epilepsy. Hyperventilation for 2-3 minutes almost always induces an absence seizure. Children on medications require a full general exam.

Testing

Laboratory Testing

Baseline laboratory testing if the child is to be started on valproic acid or ethosuximide includes LFTs and CBC with differential.

Imaging

MRI brain - In a child with typical absence epilepsy, including a characteristic EEG, clinical history, and normal development and exam, neuro-imaging is not usually necessary. [Gaillard: 2009]

Other Testing

EEG - shows typical (frontally predominant) 3-Hz spike and wave complexes that occur in trains with hyperventilation and have an abrupt beginning and ending. Background activity is normal in children with CAE. Examples of absence seizures on EEG (Epilepsy.com)
An EEG may be helpful after the child has been seizure free on medication for two years to decide about medication tapering.

Subspecialist Collaborations & Other Resources

Pediatric Neurology (see Services below for relevant providers)

Depending on the comfort of the Medical Home provider and family, a referral to pediatric neurology may be helpful to confirm the diagnosis and suggest management or to make a decision about tapering medicine. Otherwise, the child with typical CAE can usually be managed within the Medical Home.

Electroencephalography (EEG) (see Services below for relevant providers)

A characteristic EEG is part of the diagnostic criteria for childhood absence epilepsy. Examples of absence seizures on EEG (Epilepsy.com)

Treatment & Management

Overview

Depending on factors such as distance from the subspecialist and comfort of the Medical Home provider, management of the child with clear absence seizures who is typically developing and has a normal neurologic exam may be accomplished in the Medical Home with an optional consultation with a pediatric neurologist near the beginning of management and/or after the patient has been seizure free for 2 years and a medication taper is being considered..

Pearls & Alerts

Ethosuximide doesn't treat generalized tonic-clonic seizures

Ethosuximide doesn't treat generalized tonic-clonic seizures that sometimes accompany the absence seizures (10 % of cases). [Bergqvist: 2007] This should be discussed when medication choice is made with the family.

Systems

Neurology

Ethosuximide treats absence seizures, but not concurrent generalized tonic-clonic seizures; absence seizures are the only indication for its use. It is still regarded as a first line medication by some experts [Somerville: 2009] as it may be associated with fewer adverse attentional effects and other side effects. Many neurologists use valproic acid for CAE, as it treats absence, generalized tonic-clonic, and myoclonic seizures, but may have significant side effects in some children and serum drug level and other blood tests are required on a regular basis. [Gianoli: 1990] Lamotrigine is also considered to be a first line medication by some experts, [Wheless: 2005] although a Cochrane study didn't find enough evidence to distinguish one medication from another. [Posner: 2005] Also see [Glauser: 2013]. Clinical trials to determine the best initial treatment of CAE are currently underway (see the Clinical Trials section below). Zonisamide and levetiracetam may also be helpful, but aren't included below as they are generally regarded as second line medications. See [Krick: 1992] for more information regarding treatment options.

Absence seizures may be exacerbated by carbamazepine and gabapentin. [Somerville: 2009]
Specific medications:
Ethosuximide (Zarontin): Start at approximately 10 mg/kg/day divided BID, and increase weekly to a dose approximately 30 mg/kg depending on response. Check LFTs, CBC with differential before starting. Comes as 250 mg capsules and as 250mg/5ml syrup.
Valproic acid (Depakote or Depakene): Start approximately 10 mg/kg/day divided BID and increase weekly to approximately 30 mg/kg depending on response. Check LFTs, CBC before starting. Optimize calcium and vitamin D intake. Obtain trough level and repeat labs 3- 6 months after beginning and until patient is stabilized. Comes in liquid, sprinkles, and capsules, regular and extended release forms.
Lamotrigine (Lamictal): This medication needs to be increased slowly due to the risk of allergic skin reactions. (It also needs to be started at a lower dose with a longer time between medications if the child is already on valproic acid. This should be done only with the recommendation of a pediatric neurologist.) Lamotrigine is started at approximately 5 mg/kg/day and increased every 2 weeks to about 50-400 mg/day. It comes in tablets and chewable dispersible tablets.
Tapering medications: A seizure free interval of 1 to 2 years is recommended before tapering medication. Some providers choose to do an EEG and will taper if it is normal and keep the child on medication for another year if abnormal.

Learning/Education/Schools

Children with absence epilepsy may have educational difficulties for many reasons including:
  • abnormalities in the brain reflected in the fact that the child has absence epilepsy
  • neurocognitive defects ([Kernan: 2012])
  • loss of learning time due to frequent seizures before treatment
  • poor seizure control with medication
  • side effects of the medication
  • mood disorders
Children should be monitored closely; this is easiest to do if the PCP requests testing results and IEPs from the school. Input from the Medical Home provider regarding progress and IEP goals may be helpful for the child and school. A description of attention and executive function in 15 children with absence epilepsy compared to age-matched controls can be found in [D'Agati: 2012].

Frequently Asked Questions

My son really wants to go to sleepovers with his friends, but we've noticed that when he doesn't get a good night of sleep he has more absence seizures the next day, despite his medication. Is this common?

Yes, a lot of families have noticed this. You might want to discuss sleep hygiene with your Medical Home provider to optimize sleep when he isn't on sleepovers, and then work with your son and the family he would visit for the sleepover to see if you could work out a sleepover with sufficient sleep.

My daughter has been seizure free (petit mal or absence seizures) for more than year but then had a generalized tonic-clonic seizure out of the blue. She is on ethosuximide and I was told her blood level was good just a week or two before the seizure. Why did this happen?

Although ethosuximide is an excellent medication for absence seizures, it doesn't prevent generalized tonic clonic seizures which can happen in children with absence epilepsy. You should let your Medical Home provider or neurologist, depending on your child's seizure plan, know about the new seizure type and he/she might wish to begin another medication.

Every time my child gets a fever she seems to have more seizures. Why?

Fevers, and illness in general, seems to lower seizure threshold in children with epilepsy. Breakthrough seizures should be discussed with your Medical Home provider who may wish to increase the medication dose to a level that will protect your child even during illness.

Issues Related to Childhood Absence Epilepsy

Resources

Information for Clinicians

Childhood absence epilepsy (Epilepsy Foundation)

Genetics in Primary Care Institute (GPCI)
A collaboration among the Health Resources & Services Administration, the Maternal & Child Health Bureau, and the American Academy of Pediatrics aimed at increasing collaboration in the care of children with known or suspected genetic disorders. Includes health supervision and management guidelines, and other useful resources.

Helpful Articles

PubMed search for articles on Absence Epilepsy in children for the last 5 years

Benbadis SR.
Practical management issues for idiopathic generalized epilepsies.
Epilepsia. 2005;46 Suppl 9:125-32. PubMed abstract

Caraballo RH, Dalla Bernardina B.
Idiopathic generalized epilepsies.
Handb Clin Neurol. 2013;111:579-89. PubMed abstract

Clinical Tools

Patient Education & Instructions

Let's Talk about...EEG(PDF Document 107 KB)
Brief, 3-page fact sheet about electroencephalographs that measure brain activity, from Primary Children's Medical Center.

Information & Support for Families

Family Diagnosis Page

Support National & Local

Epilepsy Association of Utah
For individuals with epilepsy, families, and friends, this site offers newsletters, events, links, local and youth support groups, stuff for kids, first aid for seizures, and more.

Services for Patients & Families

Educational Advocacy

See all Educational Advocacy services providers (38) in our database.

Electroencephalography (EEG)

See all Electroencephalography (EEG) services providers (2) in our database.

Pediatric Neurology

See all Pediatric Neurology services providers (4) in our database.

Services for People with Disabilities

See all Services for People with Disabilities services providers (76) in our database.

For other services related to this condition, browse our Services categories or search our database.

Authors

Authors: Lynne M Kerr, MD, PhD - 6/2013
Denise Morita, MD - 6/2013

Bibliography

Benbadis SR.
Practical management issues for idiopathic generalized epilepsies.
Epilepsia. 2005;46 Suppl 9:125-32. PubMed abstract

Bergqvist, A G Christina.
Idiopathic Pediatric Epilepsy Syndromes.
Continuum. 2007;13(4):106-120.
An excellent review article from the lifelong learning curriculum of the American Board of Psychiatry and Neurology

Caraballo RH, Dalla Bernardina B.
Idiopathic generalized epilepsies.
Handb Clin Neurol. 2013;111:579-89. PubMed abstract

Cerminara C, D'Agati E, Casarelli L, Kaunzinger I, Lange KW, Pitzianti M, Parisi P, Tucha O, Curatolo P.
Attention impairment in childhood absence epilepsy: an impulsivity problem?.
Epilepsy Behav. 2013;27(2):337-41. PubMed abstract

D'Agati E, Cerminara C, Casarelli L, Pitzianti M, Curatolo P.
Attention and executive functions profile in childhood absence epilepsy.
Brain Dev. 2012;34(10):812-7. PubMed abstract

Gaillard WD, Chiron C, Helen Cross J, Simon Harvey A, Kuzniecky R, Hertz-Pannier L, Gilbert Vezina L.
Guidelines for imaging infants and children with recent-onset epilepsy.
Epilepsia. 2009;. PubMed abstract

Gianoli GJ, Miller RH, Guarisco JL.
Tracheotomy in the first year of life.
Ann Otol Rhinol Laryngol. 1990;99(11):896-901. PubMed abstract

Glauser T, Ben-Menachem E, Bourgeois B, Cnaan A, Chadwick D, Guerreiro C, Kalviainen R, Mattson R, Perucca E, Tomson T.
ILAE treatment guidelines: evidence-based analysis of antiepileptic drug efficacy and effectiveness as initial monotherapy for epileptic seizures and syndromes.
Epilepsia. 2006;47(7):1094-120. PubMed abstract

Glauser TA, Cnaan A, Shinnar S, Hirtz DG, Dlugos D, Masur D, Clark PO, Adamson PC.
Ethosuximide, valproic acid, and lamotrigine in childhood absence epilepsy: initial monotherapy outcomes at 12 months.
Epilepsia. 2013;54(1):141-55. PubMed abstract / Full Text

Jallon P, Latour P.
Epidemiology of idiopathic generalized epilepsies.
Epilepsia. 2005;46 Suppl 9:10-4. PubMed abstract

Kernan CL, Asarnow R, Siddarth P, Gurbani S, Lanphier EK, Sankar R, Caplan R.
Neurocognitive profiles in children with epilepsy.
Epilepsia. 2012;53(12):2156-63. PubMed abstract

Krick J, Murphy PE, Markham JF, Shapiro BK.
A proposed formula for calculating energy needs of children with cerebral palsy.
Dev Med Child Neurol. 1992;34(6):481-7. PubMed abstract

Loiseau, P and Panayiotopoulos, CP.
Childhood Absence Epilepsy.
International League Against Epilepsy; (2002) http://www.ilae-epilepsy.org/ctf/childhood_absence.html.

Posner EB, Mohamed K, Marson AG.
Ethosuximide, sodium valproate or lamotrigine for absence seizures in children and adolescents.
Cochrane Database Syst Rev. 2005;(4):CD003032. PubMed abstract

Ramos-Lizana J, Aguirre-Rodríguez J, Aguilera-López P, Cassinello-García E.
Recurrence risk after withdrawal of antiepileptic drugs in children with epilepsy: a prospective study.
Eur J Paediatr Neurol. 2010;14(2):116-24. PubMed abstract

Somerville ER.
Some treatments cause seizure aggravation in idiopathic epilepsies (especially absence epilepsy).
Epilepsia. 2009;50 Suppl 8:31-6. PubMed abstract

Valentin A, Hindocha N, Osei-Lah A, Fisniku L, McCormick D, Asherson P, Moran N, Makoff A, Nashef L.
Idiopathic generalized epilepsy with absences: syndrome classification.
Epilepsia. 2007;48(11):2187-90. PubMed abstract

Verrotti A, Olivieri C, Agostinelli S, Coppola G, Parisi P, Grosso S, Spalice A, Zamponi N, Franzoni E, Iannetti P, Chiarelli F, Curatolo P.
Long term outcome in children affected by absence epilepsy with onset before the age of three years.
Epilepsy Behav. 2011;20(2):366-9. PubMed abstract

Weber YG, Lerche H.
Genetic mechanisms in idiopathic epilepsies.
Dev Med Child Neurol. 2008;50(9):648-54. PubMed abstract

Wheless JW, Clarke DF, Carpenter D.
Treatment of pediatric epilepsy: expert opinion, 2005.
J Child Neurol. 2005;20 Suppl 1:S1-56; quiz S59-60. PubMed abstract

Wirrell EC, Camfield CS, Camfield PR, Gordon KE, Dooley JM.
Long-term prognosis of typical childhood absence epilepsy: remission or progression to juvenile myoclonic epilepsy.
Neurology. 1996;47(4):912-8. PubMed abstract