DRAVET SYNDROME
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ALTERNATE NAMES
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Severe Myoclonic Epilepsy Of/In Infancy; SMEI Syndrome; Epilepsy with Polymorphic
Seizures; Polymorphic Epilepsy in Infancy; PMEI
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DESCRIPTION
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Dravet syndrome (DS) is a rare, genetic epileptic encephalopathy (dysfunction of the
brain) with onset during the first year of life. Mutations of the SCN1A gene cause
up to 80% of diagnosed cases of DS. Frequently referred to as a sodium channelopathy,
this intractable epilepsy is characterized by unilateral (one-sided) clonic or tonic
clonic (grand mal) seizures that are prolonged (> 5 minutes) or progress to status
epilepticus (>30 minutes) and require emergency management. Myoclonic seizures, often
called myoclonic jerks, are common. Over time seizures occur more frequently without
obvious triggers, and resistant to treatment.
Between one and four years of age, children develop other seizure types including
atypical absence, eyelid myoclonia and non-convulsive seizures. All seizure types
may be prolonged or lead to status epilepticus--a state of continuous seizure requiring
emergency medical care. Children with DS typically experience poor development of
language and motor skills, hyperactivity, and difficulty relating to others.
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DIAGNOSTIC TESTING, PHYSICAL FINDINGS, AND
ICD-9-CM/ICD-10-CM
CODING
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Diagnostic testing: Genetic testing for mutations within the SCN1A gene; EEGs.
Physical
findings:
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-
-
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•
Abnormal eye movement disorder.
ICD-9: 345.1
ICD-10:
G40
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PROGRESSION
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Infants with Dravet syndrome appear normal at birth with most children showing signs
and symptoms of this disorder during the first year of life. As children with Dravet
syndrome get older, the degree of intellectual impairment appears to correlate with
the frequency of seizures. The decline in cognitive function tends to stabilize after
age 4. Children surviving into adolescence and adulthood are dependent on caregivers.
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TREATMENT
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Seizures in Dravet syndrome are difficult to manage, but can be reduced by anticonvulsant
drugs. Some medications may aggravate seizures necessitating close monitoring of medication
use by the claimant’s medical source(s). Treatment with a ketogenic diet high in fats
and low in carbohydrates has been of benefit in some cases.
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SUGGESTED PROGRAMMATIC
ASSESSMENT*
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Suggested MER for Evaluation:
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•
Clinical history and examination that describes the diagnostic features of the impairment,
and physical and cognitive findings;
-
•
Imaging studies such as CT, MRI, or PET scans documenting structural changes in the
brain;
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•
EEG reports measuring abnormalities in electrical activity in the brain; and
-
•
Laboratory testing to rule out other causes (such as low or high blood sugar, low
sodium, low magnesium or thyroid disorder) for seizures and for mutations in the SCN1A
gene.
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Suggested Listings for Evaluation:
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DETERMINATION
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LISTING
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REMARKS
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Meets
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11.02
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Listing level severity must be documented.
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111.02 |
Listing level severity must be documented.
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Equals |
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* Adjudicators may, at their discretion, use the Medical Evidence of Record or the
listings suggested to evaluate the claim. However, the decision to allow or deny the
claim rests with the adjudicator.
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