Sunday, 17 October 2010

MRCP revision battle 32.4: Epilepsy

Epilepsy is defined as a recurrent tendency to spontaneous, intermittent, abnormal electrical activity in part of the brain, manifest as seizures (OHCM definition)

Epileptic seizures are subdivided into:
  • partial seizures = features come from one part of the brain
    • simple partial = consciousness not impaired
    • complex partial = consciousness impaired - usually temporal lobe, aura may preceed and automatisms may feature
  • generalised seizures = features not localisable to one part of the brain
    • absence = petit mal = brief <10 second pauses - 3Hz spikes
    • atonic = becomes flaccid
    • tonic-clonic - classic stiffening and jerking
    • myoclonic

Treatment is usually started after the second seizure.   It would be started after the first if any of the following conditions apply:
  • neurological deficit
  • structural abnormality
  • EEG unequivocal
  • pt/family/carers keen for treatment

First line treatment depends on the seizure type:
  • generalised
    • 1st line: sodium valproate
    • 2nd line: lamotrigine
  • partial
    • 1st line: carbamezepine
    • 2nd line: sodium valproate
  • absence
    • sodium valproate or ethosuximide
    • note that carbamazepine may worsen absence seizures

Remember that both sodium valproate and lamotrigine are associated with Steven Johnson syndrome.

Cannot drive until seizure-free for 1 yr, or 3 yrs of night time only seizures.
HGV drivers need to be off meds and seizure-free for 10 yrs.

If a pt has no seizures for 2 yrs, you may consider stopping meds over 2-3 months.

On to battle 32.5...