Epilepsy

Question 1

What are tonic-clonic convulsions?

Answer 1

Previously known as grand Mal
Often without warning
Involves loss of consciousness with a full fit

Question 2

What is an absence seizure?

Answer 2

Previously known as petit Mal
Often in children
Often patient goes blank, staring for 10 seconds

Question 3

What are myoclonic seizures?

Answer 3

Abrupt, shock-like jerks

May affect whole body, arms or legs

Question 4

Which other pathologies/causes which may present as seizures need to be excluded?

Answer 4

Cerebral tumour
Cerebrovascular accident
Alcohol withdrawal
Hyper/hypoglycaemia
Syphilis
Drugs (antidepressants may reduce seizure threshold)

Question 5

What is the management for generalised seizures?

Answer 5

1st line valproate or carbamazepine or lamotrigine (in females of child bearing age)
2nd line levetiracetam

Question 6

What is the management for absence seizures?

Answer 6

1st line ethosuximide

2nd line valproate/lamotrigine

Question 7

What is valproate?

Answer 7

Potentiates GABA
Causes Na-channel blocker
Side effects: sedation, weight gain, tremor 
Causes birth defects
Causes liver damage

Question 8

What is carbamazepine?

Answer 8

Use dependent blockade of Na channels
Side effects: rashes, dizziness, double vision
Many interactions: induction leads to accelerated metabolism of interacting drugs
Causes birth defects

Question 9

What is phenytoin?

Answer 9

Less commonly used
Side effects: increased gum growth, nystagmus (toxic effect)
Causes birth defects

Question 10

What is the zero order kinetics of phenytoin?

Answer 10

Metabolism saturates and so get disproportionate increases in plasma concentration of increasing dose
Rates of metabolism varies between patients
Requires plasma concentration monitoring

Question 11

What is lamotrigine?

Answer 11

Use dependent blockade of Na-channels, reduces release of glutamate
Not particularly sedating
Withdraw if the patient develops rash/flu-like illness- risk of bone marrow toxicity

Question 12

What are the haematological effects of anti-epileptic drugs?

Answer 12

Can cause leucopenia (fever, sore throat, rash, mouth ulcers)
Withdraw if severe leucopenia
Lamotrigine0 aplastic anaemia
Valproate- thrombocytopenia

Question 13

How do anti-epileptic drugs affect the liver?

Answer 13

Carbamazepine and valproate affect hepatic function

LFT (essential with valproate) and INR monitoring

Question 14

How do anti-epileptic drugs affect the skin?

Answer 14

May cause rashes

Stevens-johnson syndrome, toxic epidermal necrolysis (carbamazepine, lamotrigine, phenytoin, valproate)

Question 15

How do you treat epilepsy in pregnancy?

Answer 15

Withdraw if possible before conception
Treatment is preferable to hypoxic seizures
Reduced control of epilepsy (due to enzyme induction and increased volume of distribution)

Question 16

Which anti-epileptic are teratogenic?

Answer 16

Carbamazepine, valproate, phenytoin
Neural tube defect
Carbamazepine has been favoured, lower rate of birth defect

Question 17

How is a neural tube defect prevented?

Answer 17

5mg folic acid daily in trimester 1, counselling and screening

Question 18

Why can neonatal bleeding tendency be increased?

Answer 18

Carbamazepine and phenytoin (enzyme induction)

Vitamin K1 given for third trimester

Question 19

What can lead to failure of oral contraceptives?

Answer 19

Enzyme induction with phenytoin, carbamazepine and phenobarbitone

Question 20

What is considered first line is pregnancy?

Answer 20

Lamotrigine for generalised seizures

Question 21

What is status epileptics?

Answer 21

Continuous seizure for 30 mins or 2 fits without recovery between them

Question 22

What is used to treat status epilepticus?

Answer 22

Lorazempam i.v
Diazepam i.v or rectal solution 
Clonazepam 
Phenytoin slow i.v
Failing above general anaesthetic like propofol

Question 23

When are epileptic patients allowed to drive?

Answer 23

Seizure free for 1 year
Or if attacks occur while asleep over a 3 year period
some drugs cause drowsiness, avoid driving

Question 24

When is withdrawal considered in epilepsy?

Answer 24

Patient is seizure free for 2-4 years
Withdrawal gradually as this can precipitate epilepsy
Reduce dose every 4 weeks
Stop driving during withdrawal