- Myoclonic-atonic seizures are the defining feature.
- Frequent tonic seizures as the main seizure type is not usual in this syndrome.
- The syndrome is considered an epileptic encephalopathy.
- The EEG usually has a normal background particularly at onset of syndrome, with frequent generalised discharges of 2 to 3 Hz spike/polyspike waves.
- Non-convulsive status epilepticus is a frequent feature.
- Up to half of patients have a good outcome despite early refractory symptomatology.
- Treatment usually involves high dose valproate in combination with other anticonvulsants.
- Consider early referral to Paediatric Neurology.
According to the NICE Guideline: The Epilepsies:
- The seizure type(s) and epilepsy syndrome, aetiology, and co-morbidity, should be determined.
- If there is diagnostic uncertainty, individuals should be referred to tertiary services soon (within 4 weeks) for further assessment.
- ~1% to 2% of all childhood epilepsies.
Age at onset
- 6 months to 6 years, peak 2-4 years.
- There is often a strong family history of epilepsy including other epilepsy syndromes.
- A proportion of these patients are SCN1a positive.
- SLC2A1 has also been found (Glucose Transporter gene)
Signs | Symptoms
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 events.
- Atonic and absence seizures are frequent and sometimes many occur each day.
- Tonic seizures are not a major feature.
- Non-convulsive status epilepticus for hours or days affects 1/3 of patients.
- In 2/3's of patients, febrile and non-febrile generalised tonic clonic seizures appear first, several months prior to myoclonic astatic seizures.
- The seizure frequency can become very severe and sometimes refractory to treatment. However, despite this, the outcome for most is favourable.
Neurological and mental state
- Normal prior to the onset of seizures.
- Lennox Gastaut Syndrome.
- Atypical childhood epilepsy with centrotemporal spikes
- Dravet syndrome
- Usually normal background particularly at onset of syndrome, with frequent generalised discharges of 2 to 3 Hz spike/polyspike wave. With time background may show generalised slowing.
- Epileptogenic activity increases in sleep.
- Photic stimulation may trigger generalised spike/wave or myoclonic astatic seizures.
- Non-convulsive status leads to continuous or discontinuous and repetitive 2 to 3 Hz spike/ wave.
- Symptomatic causes need to be excluded.
- 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 behavioural abnormalities.
- Ataxia and motor linguistic disturbances may emerge.
- Early referral to paediatric neurology
- Sodium valproate
- Refractory cases may respond to the Ketogenic diet.
Discussion with family
- Epilepsy Medical Record
- Drug Handout
- Potential of performing baseline educational assessment (through school counsellor)
Epilepsy Action (UK) have information for Parents on Epilepsy with Myoclonic Astatic Seizures (Doose Syndrome)
- Panayiotopoulos CP. The epilepsies: Seizures, syndromes and management: Based on the ILAE classifications and practice parameter guidelines. Chipping Norton, Oxfordshire: Bladen Medical Publishing; 2005.
- Roger J, Bureau M, Dravet C, Genton P, Tassinari CA, Wolf P, editors. Epileptic syndromes in infancy, childhood and adolescence (4th ed). Montrouge, France: John Libbey Eurotext Ltd ; 2005.