Epilepsy Flashcards
What is epilepsy?
A neurological disorder which represents a brain state that supports recurrent, unprovoked seizures
What are seizures?
Abnormal, paroxysmal changes in the electrical activity f the brain, reflecting large scale synchronous discharges of neuronal networks
What is status epilipticus?
A form of life-threatening epilepsy with seizures which last more than 5 minutes
What are the general features of a tonic-clonic seizure?
Tonic contraction of axial muscles and face muscles, clonic contractions is then where there are jerks of increasing amplitude followed by relaxation phase
What structural changes occur in the brain of those with epilepsy?
Prominent loss of cells in the CA2 and CA3 region of the hippocampus, loss of chandelier cells
What are chandelier cells and how are they implicated in epilepsy?
They are a specifically population of GABAergic interneurones which control the activity of the cortical pyramidal cells, loss of these (as seen in epilepsy) can lead to an increased risk of abnormal excitatory activity
What cellular mechanisms are involved in epilepsy?
Decreased inhibition from GABAergic neurones and increased glutamatergic excitation and ion channel disruption leading to increased influx of Na+
What sodium channel blockers may be used in the treatment of epilepsy?
Phenytoin, carbamazepine, sodium valproate, lamotrigine and topiramate
What type of seizure can ethosuximide or sodium valproate be used to treat?
Absence seizures
How is gabapentin/pregabalin used in the treatment of epilepsy?
Binds to the a2delta subunit of calcium channels to prevent depolarisation
How is tiagibine used in the treatment of epilepsy?
Inhibits GABA reuptake by working on GAT-1
How is vigabatrin used in the treatment of epilepsy?
Inhibits GABA transaminase to inhibit GABA metabolism so more is available
What type of seizures can sodium valproate be used for?
All seizures
What is the treatment of status epilepticus?
Intravenous diazepam
