Brain Rhythms: 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 to recurrent and stereotyped seizures.

Question 3

What is the prevalence of epilepsy in the UK?

Answer 3

1%.

Question 4

List 6 causes and risk factors for developing epilepsy.

Answer 4

1 - Family history.

2 - Other underlying CNS abnormalities.

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

4 - Tumours.

5 - Meningoencephalitis caused by infection.

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

Question 5

List the 2 broad categories of seizures.

Answer 5

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 6

List 5 symptoms of focal seizures.

Answer 6

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 7

List 5 symptoms of bilaterally convulsive seizures.

Answer 7

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 8

Define ictal and postictal.

Answer 8

• The ictal phase is the seizure itself.

- The postictal phase is the altered state of consciousness after a seizure.

Question 9

List the features that would be necessary to make a diagnosis of epilepsy.

Answer 9

1 - 2 or more stereotyped attacks.

2 - Ictal and postictal phases.

Question 10

List 2 characteristics of frontal lobe seizures.

Answer 10

1 - Bizarre behaviours / motor automatisms.

2 - Rapid recovery with minimal postictal confusion.

Question 11

Give an example of a structural lesion that can cause some forms of epilepsy.

In which area of the brain do seizures begin due to this lesion?

Answer 11

• Hippocampal sclerosis.

- This causes temporal lobe seizures.

Question 12

What is the purpose of an EEG for investigating epilepsy?

Answer 12

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

Question 13

List 3 surgical treatments of epilepsy.

Answer 13

1 - Resection of the affected area.

2 - Vagal nerve stimulation.

3 - Deep brain stimulation.

Question 14

Why might an ECG be used to monitor epileptic seizures?

How does vagal nerve stimulation work?

Answer 14

• Because epileptic seizures are characterised by ictal tachycardia.
• Vagal nerve stimulation works by stimulating the CNS when tachycardia is detected.

Question 15

What is status epilepticus?

Answer 15

A convulsive seizure persisting for >5 minutes without recovery.

*This is a medical emergency.

Question 16

List 4 antiepileptic drugs.

Answer 16

1 - Lorazepam.

2 - Levetiracetam.

3 - Phenytoin.

4 - Valproate.

Question 17

What is non-epileptic attack disorder?

Answer 17

A disorder in which events resembling epileptic seizures occur, but without the characteristic electrical discharges associated with epilepsy.