Epilepsy

Question 1

Differential diagnosis of epilpesy

Answer 1

• syncope
• transient ischaemic attacks
• REM sleep disorder
• migraine
• hypoglycaemia
• pyschogenic epsiodes

Question 2

Causes of epilepsy

Answer 2

• idiopathic- no obvious pathology/ most common
• brain tumour
• alcohol
• autoimmune condition- can cause localised encephalitis
• brain injury/ trauma- provides an epileptic focus which persists long after the injury has healed
• infections- inflammation provides an epileptic focus

Question 3

Common factors lowering seizure threshold

Answer 3

• sleep deprivation
• alcohol withdrawal
• television flicker
• epileptogenic drugs
• head trauma
• systemic infection
• recreational drugs
• menstruation

Question 4

Occasional factors lowering seizure threshold

Answer 4

• dehydration
• barbiturate withdrawal
• benzodiazepine withdrawal
• hyperventilation
• flashing lights
• diet and missed meals
• stress
• intense exercise

Question 5

Ideal AED

Answer 5

• low risk of interaction
• low protein binding
• long elimination half life
• linear kinetics
• complete absorption

Question 6

Established AED’s

Answer 6

• phenytoin
• phenobarbitone
• primidone
• carbamazepine
• ethosuximide
• clonazepam
• clobazam
• sodium valproate

Question 7

Newer AED’s

Answer 7

• gabapentin
• pregablin
• lacosamide
• topiramate
• lamotrigine

Question 8

Risks of sodium valproate

Answer 8

• high risk of serious developmental disorders

- congenital malformations

Question 9

patient education of sodium valproate

Answer 9

• risks associated
• need to use effective contraception
• need for regular review for treatment
• the need to rapidly consult if she is planning a pregnancy or becomes pregnant

Question 10

what AED’s can worsen absence seizures?

Answer 10

carbamazepine and phenytoin

Question 11

what seizure type does ethosuximide have efficacy against

Answer 11

• absence seizures but not others

Question 12

phenytoin kinetics

Answer 12

• zero order kinetics
• small therapeutic window
• highly protein bound

Question 13

carbamazepine

Answer 13

• induces its own metabolism at initiation
• repeated dosing reduces half life to 1/3
• metabolism is readily induced by drugs that induce hepatic microsomal enzymes
• use of slow release formulations can reduce peak concentrations and improve tolerance