Anti-convulsants

Question 1

Define epilepsy and seizure?

Answer 1

Epilepy: A neurological condition causing frequent seizures
Seizures: sudden changes in behaviour caused by electrical hypersynchronization of neuronal networks in the cerebral cortex

Question 2

What are the to ways epilepsy can be diagnosed?

Answer 2

Electroencephalography (EEG)

Magnetic resonance imaging (MRI)

Question 3

What is the difference between general seizures and partial seizures?

Answer 3

General: Begins simultaneously in both hemispheres of brain
Partial: Begins within a particular area of brain and may spread out

Question 4

What are the 5 types of general seizures?

Answer 4

Tonic-clonic seizures: loss of consciousness leads to muscle stiffening leads to jerking/twitching leads to deep sleep leads to waking up
Absence seizures: brief staring episodes with behavioural arrest
Tonic/atonic seizures: sudden muscle stiffening/sudden loss of muscle control
Myoclonic seizures: sudden, brief muscle contractions
Status epilepticus: greater than 5 min of continuous seizure activity

Question 5

How can you classify partial seizures?

Answer 5

Simple: retained awareness/consciousness
Complex: impaired awareness/consciousness

Question 6

What does SV2A do?

Answer 6

Synaptic vesicle associated (SV2A) protein allows vesicle attachment to presynaptic membrane. Involved in dicking a vesicle containing neurotransmitters

Question 7

What are the 3 post synaptic receptors glutamate activates?

Answer 7

NMDA, AMPA & kainate receptors

Question 8

Describe action and use of Carbemazipine?

Answer 8

Stabilises inactive state of Na+ channel thus reducing neuronal activity and preventing opening of voltage gated Ca channels.

Quick onset of activity and long half life. Indicated in Tonic-clonic seizures and partial seizures
potential severe side-effects (skin problems) in individuals with HLA-B*1502 allele

Question 9

Describe action and use of lamitrogine?

Answer 9

Inactivates Na+ channels thus reducing glutamate neuronal activity
Quick onset of action and long half life
Indicated in Tonic-clonic seizures; absence seizures

Question 10

What are the 2 approaches to treating epilepsy?

Answer 10

Decreasing excitatory transmission or increasing inhibitory transmission

Question 11

Describe action and use of Ethosuximide?

Answer 11

T-type Ca2+ channel antagonist so reduces activity in relay thalamic neurones by prevening vesicle exocytosis
Long half life and used in absence seizures

Question 12

Describe action and use of Levetiracetam?

Answer 12

Binds to synaptic vesicle associated protein (SV2A) thus preventing glutamate release
Quick onset of action, long half life and indicated in Myoclonic seizures.

Question 13

Describe action and use of Topiramate?

Answer 13

Inhibits NMDA & kainate receptors
Also affects VGSCs and GABA receptors
Quick onset of action, long half life and indicated in Myoclonic seizures.

Question 14

What:
Receptor does GABA bind to?
Takes up GBA?
Mettabolises GABA?

Answer 14

GABAa receptors
GAT
GABA transaminase

Question 15

Describe action and use of Diazepam?

Answer 15

Activates GABA receptor once GABA has bound to it Administered as rectal gel and has fast onset of action with long half life and indicated in status epilepticus.

Question 16

Describe the use and action of sodium valporate?

Answer 16

Inhibits GABA transaminase so increases GABA-mediated inhibition.

Fast onset of action with long half life. Indicated in all forms of epiliepsy.