Epilepsy

Question 1

What are the 3 phases of an epileptic seizure?

Answer 1

1. Prodromal (aura)
2. Ictal (seizure)
3. Post-ictal (recovery)

Question 2

What are the types of epileptic seizures?

Answer 2

1. Generalized
   - primary
   - secondary
2. Focal
   - complex partial

Question 3

What are generalized seizures caused by?

Answer 3

Abnormal oscillations in thalamocortical loops

Question 4

What is a secondary generalized seizure?

Answer 4

Where a partial seizure spreads to involve both cerebral hemispheres

Question 5

Complex partial seizures commonly originate in which lobe?

Answer 5

Temporal lobe

Question 6

Which type of seizure is frequently preceded by an aura?

Answer 6

Complex partial seizure

Question 7

On an EEG, what type of waves would be seen if someone was awake + alert?

Answer 7

Beta waves

Question 8

On an EEG, what type of waves would be seen if someone was awake + relaxed?

Answer 8

Alpha waves

Question 9

On an EEG, what type of waves would be seen if someone was in a coma?

Answer 9

Delta waves

Question 10

Focal seizures originating in the temporal lobe often cause which automatisms?

Answer 10

Chewing, lip-smacking

Question 11

What are the 2 types of Jacksonian seizures?

Answer 11

Focal aware motor

Focal aware sensory

Question 12

In what direction do Jacksonian seizures travel?

Answer 12

Distal to proximal

Question 13

In a primary generalized tonic-clonic seizure, how long does the tonic stage last?

Answer 13

10 - 40 seconds

Question 14

In a primary generalized tonic-clonic seizure, how long does the clonic stage last?

Answer 14

2 - 3 minutes

Question 15

In relation to seizures, what is meant by ‘tonic’?

Answer 15

Muscle rigidity

Question 16

In relation to seizures, what is meant by ‘clonic’?

Answer 16

Repetitive muscle contractions

Question 17

Absence seizures generally occur in what age group?

Answer 17

Childhood

Question 18

What will the EEG pattern be for an absence seizure?

Answer 18

Spike-and-wave patterns

Question 19

Which epileptic situation is a medical emergency?

Answer 19

Status epilepticus

Question 20

For how long does a seizure need to last to be considered status epilepticus?

Answer 20

> 5 minutes

Question 21

What is the mortality rate of status epilepticus?

Answer 21

10 - 15%

Question 22

What 3 things can status epilepticus result in?

Answer 22

Brain hypoxia

Brain acidosis

Excitotoxicity

Question 23

What is excitotoxicity?

Answer 23

Cell death caused by the excessive release of glutamate

Question 24

What is the electrical basis for the initiation of a focal seizure?

Answer 24

Paroxysmal depolarising shift (PDS)

Question 25

Which 2 ion channels and receptors are involved in the depolarisation phase of a paroxysmal depolarising shift (PDS)?

Answer 25

Na channels Ca channels AMPA glutamate receptors NMDA glutamate receptors

Question 26

What prevents a paroxysmal depolarising shift (PDS) / focal seizure from spreading?

Answer 26

Inhibitory interneurons around the focus providing a surround inhibition via GABA synapses

Question 27

What is the most common pathological finding in focal epilepsy?

Answer 27

Hippocampal sclerosis

Question 28

Hippocampal sclerosis involves neuronal loss in which area of the hippocampus?

Answer 28

CA1 subfield

Question 29

What is the most common type of hippocampal sclerosis?

Answer 29

Mesial temporal sclerosis

Question 30

Mesial temporal sclerosis involves the loss of which type of cells?

Answer 30

Hilar cells

Question 31

Loss of hilar cells in mesial temporal sclerosis can lead to what? Why does this increase seizure activity?

Answer 31

Mossy fibre sprouting New mossy fibre connections are not inhibited by the normal inhibitory connections. New connections may be self-excitatory and promote seizure activity

Question 32

Which condition that affects the cortex can cause epilepsy?

Answer 32

Focal cortical dysplasia

Question 33

Which 3 types of cell are found in focal cortical dysplasia?

Answer 33

Balloon cells Dysplastic neurons Giant neurons

Question 34

Spike-and-wave patterns on an EEG are a sign of which type of seizure?

Answer 34

Absence seizure

Question 35

Which cells have been implicated in the initiation of PDS's?

Answer 35

Astrocytes

Question 36

What are 3 non-pharmacological treatments of epilepsy?

Answer 36

Surgery Nerve stimulation Ketogenic diet

Question 37

In nerve stimulation for the treatment of epilepsy, which nerve is stimulated and by how much does it reduce seizure frequency?

Answer 37

Vagus nerve - reduces seizure frequency by 50%

Question 38

The effects of which type of seizure travel distal to proximal?

Answer 38

Jacksonian