Definiton: Paroxysmal abnormal discharges
of neurons in the CNS.
Attacks are typically stereotyped and unpredictable.
Epilepsy is a symptom not a disease, although the cause is
5% of people will have at least one seizure in their life.
0.5% of people have recurrent seizures.
Other causes of syncope; hysteria.
Usually Hx only. EEG may be helpful.
Refer to neurologist.
Use only one drug. Raise dose until maximum
before switching to another drug.
At 20y: 50% fit free, off treatment;
20% fit free, on treatment;
30% fits despite treatment.
Consider weaning off treatment after 3y.
Many antiepileptic drugs (AEDs) are toxic. Monitoring drug levels
may be useful in:
- NOT valproate
Difficult to control epilepsy
- Review diagnosis (exclude structural lesion)
- Check compliance
- Drug interactions?
- Consider surgery (temporal lobectomy for hippocampal sclerosis)
- Liver enzyme induction
- NOT valproate
- with other AEDs
- Protein binding (bay be affected in liver failure, nephrosis)
MRC withdrawal study 1991
41% relapse within 2 years vs.
22% of those still on AEDs.
Risk of relapse:
- long history of seizures before remission
- multiple seizure types
- structural lesion
- abnormal neurological signs
- learning disability
- Withdrawal of AEDs
- Structural lesions
- Metabolic disturbance (esp. ↓Na+ or ↓glucose)
- drug levels
- EEG (exclude pseudoseizures)
- imaging (exclude structural lesion)
- IV diazepam 10mg (once only)/IV lorazepam (max twice only)
- (PR paraldehyde 5 ml in equal volume of arachis oil)
- IM fosphenytoin/IV infusion phenytoin/phenobarbitone
- Admit to ITU, ventilate, IV infusion thiopentone
Risk of teratogenesis vs. risk of epilepsy on pregnancy
Remember physiological changes of pregnancy:
↑vol of distr., Δ protein binding.
- background risk 3%
- risk on one AED 7% (i.e., 4% excess risk)
- risk on >1 AED 15% (i.e., 12% excess risk)
Single seizure: 1 year ban.
Withdrawing treatment: while withdrawing + 6/12 after.
HGV licence: 10 year ban.