Epilepsy

Question 1

What is a seizure?

Answer 1

a sustained and synchronised electrical discharge in the brain causing symptoms and signs

Question 2

Describe the epileptic activity in a generalised seizure

Answer 2

• large, prolonged recurrent electrical discharges (Na+ influx) in the neutron which the brain cannot compensate for resulting in a tonic phase (stiffening of the muscles) followed by a general clonic phase (when inhibition is reinitiated)
• in epilepsy, this can lead to increased and accelerated synchronised spread of action potentials in the brain

Question 3

List the excitatory components to neurons

Answer 3

• EAA (eg. glutamate)
• action on NMDA/ AMPA/ kainate receptors
• Na+ and Ca2+ influx

Question 4

List the inhibitory components to neurons

Answer 4

• GABA/glycine
• action on GABA receptor
• Cl- influx

Question 5

Define epilepsy

Answer 5

a tendency to have recurrent unprovoked seizures

Question 6

Describe the drug management of epilepsy

Answer 6

• lamotrigine can be used in pregnancy
• lamotrigine, levetiracetam and valproate can be used for all seizure types
• carbamazepine, gabapentin and phenytoin are better for focalised seizures
• ethosuximide is for absence seizures
• carbamazepine can worsen myoclonic seizures

Question 7

Describe the treatment for status epilepticus

Answer 7

• give buccal midazolam/IV lorazepam
• treat underlying cause if known (eg. hypoglycaemia)
• give another dose of benzodiazepine if seizing has not stopped after 5-10 mins after first administration
• if still no improvement give levetiracetam or phenytoin