Dravet syndrome

 

Presentation

Infants with recurrent febrile seizures, often with febrile status or atypical febrile seizures.

 

Multiple seizure types often in clusters in a preschool child; with GTCs, focal seizures and severe myoclonic seizures often triggered by hyperthermia (fever or hot bath).

 

Epileptic encephalopathy results in disordered development with language and cognitive impairment, low muscle tone with poor balance; or behavioural and sleep difficulties.

 

About a quarter have f/h/o febrile seizures.

 

Investigations

EEG has diffuse background slowing with generalized or multifocal abnormalities.

 

SCN1A sodium channel mutation found in most cases, but also other gene mutations identified. Consider gene test in infants with recurrent prolonged / atypical seizures (with or without fever).

 

Management

Initial treatment offered with Valproate, Clobazam or Topiramate.

Avoid sodium channel blockers such as Lamotrigine, Carbamazepine or Rufinamide as these can worsen myoclonus.

Increased risk of SUDEP.

Resistant seizures may require polytherapy, Cannabidiol, Vagal Nerve Stimulator or Ketogenic diet under tertiary neurologist.

Development severely affected by poor seizure control.

 

Related disorder of Generalised epilepsy with febrile seizures plus has less seizure burden and normal developmental outcome; often needing no medications or rescue therapy, with remission before puberty.