L13 - Epilepsy

Question 1

What causes a seizure?

List 3 symptoms of seizures.

Answer 1

• A seizure is excessive and asynchronous neuronal discharge. It may manifest as:

1 - Behavioural change

2 - Involuntary skeletal muscle contraction

3 - Altered level of awareness

Question 2

Define epilepsy.

Answer 2

Tendency toward recurrent seizures unprovoked by systemic or neurological insults

Question 3

What are the causes and risk factors for developing epilepsy?

Answer 3

1 - Family history

2 - Developmental / acquired CNS abnormalities

3 - Prolonged atypical febrile convulsions (a seizure associated with raised body temperature, usually in the context of infection)

4 - Toxic or metabolic causes

5 - Meningoencephalitis caused by infection

6 - Cardiovascular diseases causing cerebrovascular accidents (NB the cerebrovascular accident often precedes the first seizure by many years)

Question 4

What are the 2 categories of seizures?

Answer 4

1 - Focal seizures

• The seizure begins in one area of the brain and only causes loss of consciousness if it spreads to other areas of the brain rapidly

2 - Bilaterally convulsive seizures

• The seizure begins in both sides of the brain simultaneously, causing loss of consciousness early on in the seizure
• Generalisation is the term for spread of a seizure, and both categories of seizures have potential to generalise. Some seizures also begin as generalised

Question 5

What are the symptoms of focal seizures?

Answer 5

1 - Somatosensory - tingling of the contralateral part of the body

2 - Motor - tonic-clonic movements of the limbs

3 - Autonomic - sweating

4 - Auditory - hearing ringing noises

5 - Visual - seeing flashes of light

Question 6

What are the distinct types of generalised seizures?

Answer 6

1 - Absence

2 - Myoclonic jerks, usually of the arms

3 - Tonic spasms (stiffening of the musculature)

4 - Tonic-clonic spasms (jerking and stiffening of the musculature)

5 - Atonic seizure (loss of tone)

Question 7

Which features are necessary to make a diagnosis of epilepsy?

Answer 7

1 - 2 or more stereotyped attacks

2 - Ictal and post-ictal phases

Question 8

What are the characteristics of frontal lobe seizures?

Answer 8

1 - Bizarre behaviours / motor automatisms

2 - Rapid recovery with minimal post-ictal confusion

Question 9

What is the purpose of an EEG for investigating epilepsy?

Answer 9

It is used to assess the extent of spread of an epileptic seizure

Question 10

What surgical treatments are available for epilepsy?

Answer 10

1 - Resection of the affected area

2 - Vagal nerve stimulation

3 - Deep brain stimulation

Question 11

What is status epilepticus?

Answer 11

A convulsive seizure persisting for >5 minutes without recovery

*This is a medical emergency

Question 12

What anti-epileptic drugs are available?

Answer 12

• Lorazepam
• Focal epilepsy – carbamazepine, lamotrigine, oxcarbazepine
• Generalised epilepsy – sodium valproate, lamotrigine, levetiracetam