Epilepsy 4

Question 1

What is the mechanism of action of Oxycarbazepine and its main side effect ?

Answer 1

• Inhibits voltage-gated Na+ channels
• May cause sedation

Question 2

Which anti-convulsants induce hepatic enzymes and can ==> affect the efficacy of combined oral contraceptive pill?

Answer 2

Carbamazepine, oxycarbazepine, phenobarbitol, phenytoin, primolone, topiramate

Question 3

For the anti-convulsants which induce hepative enzymes what should be done in terms of contraceptive management ?

Answer 3

• Shouldn’t use the progesterone only pill
• Depot progesterone needs increased frequency of dosing & progesterone implants are not effective
• Morning after pill dose should be increased also as its efficacy is decreased also

Question 4

What is given to someone with epilepsy trying for a baby ?

Answer 4

Folic acid and vit K

Preconceptual counselling is required to get them to try and plan pregnancy so can put them on these things when they are

Question 5

What is status epilepticus ?

Answer 5

This is continuous seizure activity lasting for > 30mins or recurrent (> or equal to 2) seizures spanning this period without full recovery of consciousness between seizures

Question 6

What are the 3 types of status epilepticus ?

Answer 6

1. Generalised convulsive status epilepticus
2. Non-convulsive status - they are conscious but in an altered state
3. Epilepsia partialis continua - continual focal seizure, consciousness preserved

Question 7

What are some of the potential precipitants of status epilepticus ?

Answer 7

• Severe metabolic disorders e.g. hyponatraemia, pyridoxine deficiency
• Infection
• head trauma
• SAH
• Abrupt withdrawal of anti-convulsants
• Treating absence seizures with carbamazepine

Question 8

What can status epilepticus cause ?

Answer 8

• Resp insufficiency & hypoxia
• Hypotension
• Hyperthermia
• Rhabdomyolysis

Question 9

IV What is the management of status epilepticus ?

Answer 9

Stabalise - ABC. Put patient in recovery position + give oxygen.

Identify cause - emergency blood tests +/- CT

Anticonvulsants:

• Start treatment if someone is still seizing after 5 mins.
• 1st line IV lorazepam (2-4mg) or IV diazepam (10mg), if cant get IV access then use buccal midazolam (10mg) or rectal diazepam
• administer a second dose after 10 mins if no response & inform anaesthetist
• If any suggestion of hypoglycaemia then give IV glucose or if suggestion of alcohol abuse or impaired nutritional status give IV thiamine
• 2nd line = IV phenytoin infusion (15-20mg/kg) with ECG monitoring
• 3^rd line = If persists >30mins then give general anaesthetic.