Epilepsy

Question 1

What is the definition of an epileptic seizure?

Answer 1

an intermittent stereotyped disturbance of consciousness, behaviour, emotion, motor function or sensation which, on clinical grounds, is believed to result from abnormal neuronal discharges
- nature of the seizure depends on which part of the brain is malfunctioning

Question 2

Describe ILAE classification of epileptic seizures

Answer 2

Generalised seizures

• myoclonic
• clonic
• absence (typical/atypical)
• tonic
• tonic-clonic
• atonic

Focal seizures (aka partial seizures)

• simple
• complex

Question 3

What features are suggestive of a generalised seizure?

Answer 3

History of myoclonic jerks, particularly first thing in the morning
Absences or feeling strange with flickering lights

Question 4

What features are generally suggestive of a focal seizure?

Answer 4

History of deja vu
A rising sensation from the abdomen
Episodes where patient looks blank with lip-smacking and/or fiddling with clothes

Question 5

What features can be used to characterise focal seizures?

Answer 5

Aura
Motor features
Autonomic features
Degree of awareness
Degree of responsiveness

Question 6

What investigations would be carried out to test for epilepsy?

Answer 6

EEG (for primary generalised epilepsies)

• including hyperventilation and photic stimulation
• may include sleep deprivation

MRI for patients under age 50 with possible focal onset seizures (to exclude other serious causes)
CT for patients over age 50 with possible focal onset seizures (to exclude other serious causes)

Video-telemetry if uncertain about diagnosis

Question 7

Which drugs are used to treat primary generalised seizures?

Answer 7

Sodium valproate
Lamotrigine
Levetir acetam

Question 8

Which drugs are used to treat partial, or secondary generalised seizures?

Answer 8

Lamotrigine

Carbamaz epine

Question 9

Which drug is used to treat absence seizures?

Answer 9

Ethosuximide

Question 10

What is status epilepticus?

Answer 10

Prolonged or recurrent tonic-clonic seizures persisting for more than 30 minutes with no recovery period between seizures
Usually occurs in patients with no previous history of epilepsy

Question 11

Why is status epilepticus so dangerous?

Answer 11

Can be fatal, although death is usually a result of the underlying cause and not the seizure itself
Uses a huge amount of oxygen and glucose so can cause brain damage

Question 12

What can cause status epilepticus?

Answer 12

Stroke
Tumour
Alcohol

Question 13

Which drugs are used in the first line treatment of status epilepticus?

Answer 13

Benzodiazepines:

• Midazolam (buccal/intranasal)
• Lorazepam (bolus)
• Diazepam (IV/rectal)

Question 14

Which drugs are used in the second line treatment of status epilepticus?

Answer 14

Phenytoin

Valproate

Question 15

Which drugs are used in the third line treatment of status epilepticus (last resort)?

Answer 15

Anaesthesic drugs + propofol or thiopentone

Question 16

Describe the nature of non-epileptic attacks?

Answer 16

Often look bizaare and are generally motor
May resemble a swoon
May superficially look tonic-clonic but movements may be alternating (in epileptic seizures movements do not alternate)
Can be either prolonged or brief
Patient may have a history of other medically unexplained symtoms

Question 17

What are non-epileptic attacks and what causes them?

Answer 17

“Functional seizures” that are not caused by abnormal electrical activity in the brain
Are psychogenic; are caused by subconscious thoughts, emotions or stresses
History may indicate possible causes, e.g. abuse or PTSD

Question 18

What investigations might be conducted when a patient presents with a possible first seizure?

Answer 18

Blood sugar (hypoglycaemia can cause seizures)
ECG
Consider alcohol or drugs (may need a tox screen)
CT head

Question 19

List some causes of blackout

Answer 19

Epileptic seizure
Syncope
Hypoxic seizure
Concussive seizure
Cardiac arrhythmia
Non-epileptic attack
Other (narcolepsy, movement disorder, migraine)

Question 20

How do benzodiazepines work?

Answer 20

Enhance synaptic inhibition by increasing GABA activity

Question 21

Name the major excitatory and inhibitory neurotransmitters

Answer 21

Excitatory - Glutamate

Inhibitory - GABA

Question 22

Describe the side-effects and potential complications of sodium valproate

Answer 22

Very teratogenic
Tremor
Weight gain
Nausea
Drowsiness
Transient hair loss
Hepatitis
Pancreatitis 
Ataxia

Question 23

Describe the side-effects of lamotrigine

Answer 23

Skin rash

Difficulty sleeping

Question 24

Describe the side-effects of carbamazepine

Answer 24

Ataxia
Drowsiness
Nystagmus
Blurred vision
Low serum sodium (inhibits Na+ channels)
Skin rash

Question 25

Describe the investigations that should be carried out for suspected first seizures (aside from standard epilepsy investigations)

Answer 25

Blood sugar test (hypoglycaemia can cause seizures)
ECG
Consider alcohol and drugs
CT head