Epilepsy Flashcards
What is a seizure?
Sustained and synchronised electrical discharge in the brain which causes symptoms or signs
Which neurotransmitters/ions can excite a neuron?
EAA
Action of NMDA/AMPA kainate channels
Sodium / calcium influx
Which neurotransmitters/ions can inhibit a neuron?
GABA/glycine
action on GABA receptors
Chloride influx
What is the other name for a generalised tonic-clonic seizure?
Bilaterally convulsive
What is epilepsy?
A tendency to have recurrent unprovoked seizures
What percentage of the population are affected by epilepsy?
0.5%
List the common causes of epilepsy?
Vacular Hippocampal sclerosis Infection Trauma Tumour Degenerative Unknown
What is the cause of faints in epilepsy?
Lack of blood to the brain
What. is the cause of fits in epilepsy?
Electrical discharge
Compare and contrast syncope and seizures
Syncope - common trigger, almost always has prodrome, gradual onset, 1-30second. duration, brief convulsions, incontinence uncommon, post-octal confusion is rare, recovery is rapid
Seizure rarely has a trigger, commonly has prodrome, lasts 1-3. mins, prolonged convulsive jerks, incontinence common, post-octal confusion common, recovery is slow
Localised epilepsy can cause a generalised tonic-clonic seizure. T/F?
True
There will be a positive neurological symptom at the onset of a localised seizure. t/f?
tRUE
What investigations are used for possible epilepsy?
MRI
CT
What investigation can be used to help classify epilepsy as generalised or localised in young people?
EEG
Describe the mechanism of action of the anti-epileptic drugs pregabalin and gabapentin
Inhibit voltage gated calcium channels which drive neurotransmitter release
Describe the mechanism of action of the anti-epileptic drugs carbamexapine, lamotrigine and oxcarbazepine?
Inhibit voltage gated sodium channels which increase nerve excitability and drive action potentials
Describe the mechanism of action of the anti-epileptic drug retigabine
Increases activity of voltage gated potassium channels which reduce neuronal excitability
Describe the mechanism of action of the anti-epileptic drug levetiracetam
Inhibits SV2A which is required for the release of neurotransmitters from vesicles
Describe the mechanism of action of the anti-epileptic drugs vigabatrin and valproate
Inhibit degradation fo GABA
Describe the mechanism of action of the anti-epileptic drug tiagabine
Inhibit removal of GABA from the synapse by the GABA transporter
Describe the mechanism of action of the anti-epileptic drugs benzodiazepines, barbiturates, falbamate and topiramate
Increase GABA receptor activity to reduce neuronal activity
Which anti-epileptic drug blocks AMPA receptors?
Parampanel
Which anti-epileptics are used for epilepsy with a localised onset?
Lamotrigine
Carbamazepine
Levetiracetam
Which anti-epileptics are used for epilepsy with a generalised onset?
Valproate
Levetiracetam
Lamotrigine
Anti-epileptic drugs are affected in all patients. T/F?
False
