PEDBASE.org - The Pediatric Database - Detailed information of CHILDHOOD ABSENCE EPILEPSY

CHILDHOOD ABSENCE EPILEPSY

DEFINITION:

An epileptic syndrome characterized by generalized seizures (absence and tonic-clonic) and typical EEG findings.

EPIDEMIOLOGY:

incidence: 1/100,000
- occurs in 8% of children (5-14 years) with epilepsy
age of onset:
- 3 to 13 years
risk factors:
- F > M (females = 60-76%)
- family history of epilepsy in 15-44% of cases
- multifactorial type of inheritence

PATHOGENESIS:

1. Background

defined by the International Classification of Epilepsy as an idiopathic generalized epileptic syndrome
- no known underlying cause
- generalized origin of seizure
also known as pyknolepsy, petit mal

2. Seizure Characteristics

most common clinical presentation
- in school a 6-7 year old girl has episodic staring spells of sudden onset which are typically characterized by a statue-like facial expression, cessation of ongoing activity, un-responsiveness, and eye-blinking or lip-smacking; the spell stops abruptly and the child has no memory of the event
not associated with an aura
no period of post-ictal impairment
lasts <15 seconds
triggered by hyperventilation
normal neurologic examination and intelligence

CLINICAL FEATURES:

1. Seizure Types

1. Typical Absence Seizures

simple or complex

2. Generalized Tonic-Clonic Seizures

in children 7 years and older, 40% will develop tonic-clonic seizures after having absence seizures

INVESTIGATIONS:

1. EEG

interictal trace and background normal
ictal - bilateral synchronous symmetrical spike-waves usually at 3 Hz spontaneously and/or activated by hyperventilation - easy to differentiate from PCS EEG

2. Imaging Studies

1. CT

usually not necessary

MANAGEMENT:

1. Antiepileptic Medications

1. Ethosuximide (Zarantin)

drug of choice for children age 6 years and less
initial dose is 20 mg/kg/day po bid with progressive increase until seizure control or side effects
control in 72% of patients without side effects
SE: nausea, vomiting, cramps, pain, weight loss, diarrhea drowsiness, headaches, dizziness, euphoria, hiccups

2. Valproic Acid

drug of choice for children older than 6 yrs or ethosuximide failure
used in children older than 6 as tonic-clonic seizures more prevelent in this age group