Seizures

Question 1

Seizures:

Causes for seizures?

Answer 1

Hypoxia
Cerebellar surgery
Toxins
Head injury
Metabolic disturbance
Medication/Substance withdrawal
Meningitis
CNS lesions
Degenerative disease
Sleep deprivation

Question 2

Seizures:

Investigations required for a seizure?

Answer 2

• CBE, EUC, CMP, syphillis serology
• EEG (may include sleep deprived study **normal EEG or brain scan does not exclude epilesy)
• ECG, possibly echocardiogram
• CXR
• MRI or CT brain

Question 3

Seizures:

Management pearls?

Answer 3

When to treat = if likely underlying epilepsy (focal, brain abnormality, EEG abnormality, neurological signs) then treat to avoid further seizures

Moderate evidence suggesting immediate treatment is likely to reduce seizure recurrence in the first 2 years when compared to delayed treatment initiation.

Of uncontrolled epilepsy - 30% ultimately are diagnosed with Non epileptiform seizures

Relapse post treatment rate of 40% and most commonly within 1 year; 10% will be treatment resistant.

Do not wean anti-epileptics until 2 years since last seizure.

Seizure risk increases by 30% in pregnancy.

Drug levels are not required unless phenytoin being used in elderly.

Advice to give:

• keep seizure diary
• do not stop medication suddenly
• motor vehicles registration do need to know
• No driving until deemed fit
• Avoid triggers (fatigue, lack of sleep, stress, alcohol excess, flashing lights if sensitive)
• No high risk sports/activities where a seizure could result in death/serious injury of patient or others

Question 4

Seizures:

Medications and how to use them?

Answer 4

Focal seizures:
1) Carbamazepine CR
100mg daily for 2 weeks then increase by 100mg per day to max 200mg BD
2) Multiple options

Generalised seizures:

1)
a) Male or Fertile with reliable contraception = sodium valproate 500mg daily for 1 week then increase to 500mg BD
b) Fertile with unreliable contraception = Levetiracetam 250mg BD for 1 week then increase to 500mg BD
2) Multiple options

**Carbamazepine and phenytoin can precipitate absence seizures

Question 5

Seizures:

Medication side effects?

Answer 5

General
-Rash, SJS, nausea, dizziness, ataxia, fatigue, visual disturbance

Carbamazepine - agranulocytosis

Valproate - Hair loss, hepatotoxicity (highest risk in first 2years of treatment so LFTs every 2 months for 6months), teratogenic

Phenytoin - hirsutism, gingival hyperplasia

Question 6

Seizures:

What type of seizures are associated with reduced driving crash risk?

Answer 6

If one of the following is NOT the cause/type then needs 1 year non-driving period

• childhood
• first
• acute symptomatic (secondary to medical condition)
• ‘safe seizure’ (consciousness maintained)
• epilepsy treated for the first time
• sleep only seizures
• previously well controlled

Question 7

Seizures:

Common driving considerations?

Answer 7

Private license non driving period if seizure occurs in the first 6 months of starting epilepsy treatment = 6 months (If commercial license = 10years)

If initial treatment results in no seizures 6 months after treatment initiation = conditional license with Annual review

If weaning medication = no driving until 3 months after last dose reduction

Question 8

Seizures:

KISS classification of seizures and history required to classify them?

Answer 8

• Focal or Generalised
• Motor AND/OR Non motor symptoms
• Onset pattern
• Awareness
• Other symptoms

Question 9

Seizures:

What defines treatment resistant epilepsy?

Answer 9

ongoing seizures despite 2 anti-epileptics at adequate doses = specialist referral

Question 10

Seizures:

Risk of congenital malformations on anti epileptic drugs?

Answer 10

6% versus 3% if not on them

valproate is the most teratogenic at 17% increased risk

Question 11

Seizures:

What key preventative health areas are impacted by anti-epileptic drugs?

Answer 11

• Contraception with implanon, nuva ring or COCP (increased metabolism of hormones = failure)
• osteopenia/osteoporosis (bone health affected by medication in long term)

Question 12

Seizures:

Is there a special population to consider when treating seizures?

Answer 12

Yes - Non Japanese Asian ethnicity should have HLA-B*1502 testing as it predicts higher incidence of SJS with carbamazepine

Question 13

Seizures:

Seizure risk if positive EEG?

Answer 13

90% risk of further seizures

Question 14

Seizures:

If generalised epileptic discharges are on EEG is an MRI required?

Answer 14

No, as there is no association with brain lesions

Question 15

Seizures:

Risk of MRI in first unprovoked seizure?

Answer 15

20 - 37% of the time a lesion is found which may or may not be epileptogenic or require intervention