Epilepsy

Question 1

What is epilepsy?

Answer 1

The tendency to recurrent, unprovoked seizures

Question 2

What is a seizure?

Answer 2

An abnormal, excessive, synchronised discharge of cerebral neurons

Question 3

Why must an individual have more than one epileptic-type seizure to be diagnosed with epilepsy?

Answer 3

Only 50% of individuals who present with a seizure will go on to have a second within 2 years - to this prevents overtreatment

Question 4

What is the UK prevalence of epilepsy?

Answer 4

0.5%

Question 5

Name the three more prevalent neurological conditions

Answer 5

Migraine, stroke, dementia

Question 6

What percentage of people will have developed epilepsy by the time they are 90?

Answer 6

5%

Question 7

Describe the appearance of SUDEP on EEG

Answer 7

A tonic-clonic seizure pattern followed by the permanent cessation of brainwave activity

Question 8

How much more likely to die are epileptics than the general population?

Answer 8

3-4x

Question 9

State at least 3 acquired causes of epilepsy

Answer 9

Tumours, stroke, infection, TBI

Question 10

State 3 inherited causes of epilepsy

Answer 10

Vascular malformations, metabolic disorders, malformations of cortical development (MCDs)

Question 11

Name the compound released by neural cells in chronic epilepsy which perpetuates seizures via positive feedback

Answer 11

High-mobility group box 1 (HMGB1)

Question 12

Name the receptor which HMGB1 acts on

Answer 12

Toll-like receptor 4 (TLR4)

Question 13

Name 2 inflammatory mediators released by HMGB1 binding to its receptor

Answer 13

IL-1beta and NF-kappaB

Question 14

How do IL-1beta and NK-kappaB lead to chronic seizures?

Answer 14

They bind to NMDA receptors, leading to a calcium influx and hyperexcitability of neurons, leading to chronic seizures and epilepsy

Question 15

How do EEGs measure brain activity?

Answer 15

By recording the potential change in an area of the brain relative to the areas around it. This detects neuron firing as it is associated with a flow of sodium ions

Question 16

How does blinking cause an EEG artefact?

Answer 16

The eyeball is positive compared to the vitreous. When someone blinks, the eyeball moves up and this generates an artefact

Question 17

What is the standard discharge on an EEG recording of an absence seizure?

Answer 17

3Hz

Question 18

Describe a tonic-clonic seizure

Answer 18

The patient’s muscles all become stiff at once - accompanied by cessation of breathing - followed by uncontrolled muscle jerking. This is followed by deep unconsciousness with deep breathing to repay the oxygen debt

Question 19

Describe a tonic seizure

Answer 19

Sudden onset muscle stiffness followed by deep unconsciousness

Question 20

Describe an atonic seizure

Answer 20

Sudden onset of complete loss of muscle tone

Question 21

Describe the consequence of a focal seizure at the occipital pole

Answer 21

Simple visual hallucinations, e.g. balls of light

Question 22

Describe the 3 components of a typical focal temporal lobe seizure

Answer 22

An aura - typically a disturbance in memory - followed by a period of unresponsiveness with awareness, followed by automatisms and involuntary movements

Question 23

Name at least 2 anti-epileptic drugs which enhance GABA inhibition

Answer 23

Benzodiazepines, phenobarbital, topiramate, sodium valproate

Question 24

Name an anti-epileptic drug which reduces glutamate-mediated excitation at the pre-synapse

Answer 24

Topiramate, levetiracetam

Question 25

Name an anti-epileptic drug which reduces glutamate-mediated excitation at the post-synapse

Answer 25

Topiramate, parampanel

Question 26

Name an anti-epileptic drug which blocks the action potential via sodium channel depolarisation

Answer 26

Phenytoin, carbamazepine, sodium valproate, lamotrigine, topiramate

Question 27

Name an anti-epileptic drug which acts on calcium T channels

Answer 27

Ethosuximide