Prevalence
~1% to 2% of all childhood epilepsies.

Age at onset
7 months to 6 years; peak at 2 to 4 years.

Sex
Males (2/3) predominate.

Neurological and mental state
Normal prior to the onset of seizures.

Etiology
The idiopathic form is genetically determined and probably linked with GEFS+. Cryptogenic and symptomatic myoclonic-astatic seizures are common but they are not part of Doose syndrome.

Clinical manifestations
Myoclonic-astatic seizures are the defining symptoms (100%), manifesting with symmetrical myoclonic jerks immediately followed by loss of muscle tone (atonic component). They cause lightning-like falls, head nodding, or bending of the knees. More than half of patients have brief absence seizures often together with myoclonic jerks, facial myoclonias, and atonic manifestations. Atonic and absence seizures are frequent and sometimes many occur each day.

Tonic seizures are an exclusion criterion.

Non-convulsive status epilepticus for hours or days affects 1/3 of patients.

In 2/3 of patients, febrile and non-febrile generalized tonic-clonic seizures (GTCS) appear first, several months prior to myoclonic astatic seizures.

Inter-ictal EEG
Usually normal background, with frequent generalized discharges of 2 to 3 Hz spike/polyspike waves.

Ictal EEG
Myoclonic and atonic seizures = discharges of irregular spike-waves or polyspike-waves at 2.5 to 3 Hz or more. Atonia coincides with the slow wave of a single or multiple spike-wave complex and diffuse electromyography (EMG) paucity. Non-convulsive status = continuous or discontinuous and repetitive 2 to 3 Hz spikes and waves.

Prognosis
Unclear, probably because of different selection criteria.

Half of patients (probably with the idiopathic form) achieve seizure freedom and normal development. The others, probably symptomatic cases, continue with seizures, severe impairment of cognitive functions, and behavioral abnormalities. Ataxia and motor and linguistic disturbances may emerge.

Differential diagnosis
Myoclonic-astatic seizures occur in many childhood epilepsies, particularly epileptic encephalopathies. Application of inclusion and exclusion criteria would differentiate it from benign or progressive myoclonic epilepsies, Dravet syndrome, Lennox-Gastaut syndrome, atypical benign focal epilepsy of childhood, atypical progressive forms of Rolandic epilepsy and Panayiotopoulos syndrome.

Management options*
High doses of valproate could be combined with levetiracetam, ethosuximide, clonazepam, or sulthiame#. Intravenous benzodiazepines are used for non-convulsive status epilepticus.

*Expert opinion, please check FDA-approved indications and prescribing information
#Not approved by the FDA

See also: http://professionals.epilepsy.com/page/syndromes_astatic.html

This page was adapted from:

The educational kit on epilepsies
The epileptic syndromes
By C. P. Panayiotopoulos

Originally published by MEDICINAE
21 Cave Street, Oxford OX4 1BA
First published 2006 and reprinted in 2007