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Detailed information of LENNOX-GASTAUT SYNDROME
LENNOX-GASTAUT SYNDROME
DEFINITION:
An epileptic syndrome characterized by the triad of multiple
seizure types (generalized and partial), diffuse spike-slow waves
(<3 Hz), and slow mental development.
EPIDEMIOLOGY:
- incidence: 0.1/100,000
- accounts for 3.2% of children (5-15 years) with epilepsy
- age of onset:
- 1 to 8 years with peak at 3-5 years
- risk factors:
- M > F (3:2)
- infantile spasms
- family history of Lennox-Gastaut Syndrome (LGS) in 3-40% of
cases
PATHOGENESIS:
- defined by the International Classification of Epilepsy as a
cryptogenic or symptomatic generalized epileptic syndrome
- symptomatic with etiology known or unknown
- generalized origin of seizure
- other terms for LGS: static seizures, akinetic epilepsy,
minor motor epilepsy, propulsive petit mal, akinetic petit mal,
severe myokinetic epilepsy of early childhood with
slow-spike-and-wave
- in 60% of cases, LGS occurs in children suffering from a
previous encephalopathy
- specific etiology found in 50-90% of cases
2. Types of LGS
- generalized myoclonic and atypical absence seizures are
most common
- unknown etiology
2. Symptomatic (62%)
- tonic seizures are most common
- known etiologies:
- hypoxic ischemic encephalopathy (HIE) with PVL
- intrauterine infections (CMV, rubella, toxoplasmosis)
- cerebral dysgenesis (tuberous sclerosis)
- migration disorders (lissencephaly)
2. Postnatal
- head trauma
- meningoencephalitis
- brain malformations
- frontal lobe tumors
- inborn errors of metabolism (lipid storage disease,
aminoacidopathies)
CLINICAL FEATURES:
- seizures very frequent (average number of seizures/day: 25)
- 31% occur during drowsiness
- 54% occur during inactive wakefulness
- status epilepticus common
INVESTIGATIONS:
- background is abnormally slow
- interictal trace shows diffuse slow spike-waves at <3 Hz on
waking and/or burst of fast rhythms (10 Hz) during sleep
2. Imaging Studies
- abnormalities observed
- increased frequency of cerebral atrophy particularly
subcorticol
MANAGEMENT:
- monotherapy best
- valproic acid, carbamazepine, phenytoin, phenobarbital,
clonazepam
- acetazolamide for atypical absence seizures
- ketogenic diet and steroids
2. Prognosis
- complete control rarely achieved for more than 6 months
- partial control (> 50% reduction in seizure activity) is the
ideal therapeutic goal
- only 15-26% have seizure remission for more than 5 years
- mental retardation is present in 60-95% after 5 years
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Pediatric Database - LENNOX-GASTAUT SYNDROME
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