week 5 Flashcards
Differentiate between a seizure and epilepsy
a seziure is an episode of inappropriate electrical discharge within the brain leading to disordered brain activity
epilepsy is a diagnosed condition of recurrent seizures (often without a reparent cause) - repetitive and largely unpredicatable seizures
Explain what is meant by the phrase ‘epileptic focus’
epileptic focal (focus) is the site of the brain where the seizure originated.
describe the electrical changes that contribute to a neuorone’s hyperexcitable state
start by drawing neuron action potential draft and explain hyperexcitability
Causes of hyperexcitable state:
- problems with glutamate (Na+ in) or gaba receptors (chloride in -)
> sensitivity, quanitity, or dysfunction
- sodium potassium pump failing
> insufficient ATP - glucose and o2
> cell cannot reach resting membrane potential
- trauma and toxins
> phospholipid membrane is broken
> Na+ freely enters causing hyperexcitability
define and describe the typical presentatation of the most common types of seizures - focal and generalised
focal seizure - effects only one hemisphere of the brain (initially only effects one)
> can be isolated jerking movements - can present as many different things
Generalised seizure - both hemispheres of the brain
> effects RAS - most commonly unconcious
> Motor: E.g. tonic clonic (stiff muslces and shaking)
Tonic - muscle stiffness
Clonic - jerking movements
Tonic clonic - muscle stiffness and jerking movements
catatonic - unconcious or disasociation
Absent - severe disociation
atonic - flacid muscles
myoclonic - isolated jerking movements (e.g. single arm)j
dicuss the challenges associated with a diagnosis of temporal lobe epilepsy
these are behavioural seziures - focal impaired awareness seizure
in that there are changes in behaviour
they can see hallucinations
they can go into autopilot without knowing (e.g. driving)
often staring into space or blank stare
The symptoms are not what people consider ‘seizures’ and people can experience one of these seizures without knowing something is wrong
Outline the current consensus on the prehospital management of seizures, including the treatment of status epilepticus
follow their seizure management plan if they have known epilepsy
high flow oxygen - OPA insitu if no trismus
ensuring the pt is a safe environment (place something soft under their head)
attempt to keep maintain clear airway
take BGL and treat if inadequate
if seizure occurs longer than 5 mins or more than 1 seizure before returning to normal GCS - IM midaz 0.1mg per kg up to 10mg
- provide second dose PRN after 5 mins - call ICP so they can give IV midaz and kepra
or if TBI give midaz immeditatly
transport with notification = time = tissue
Status epilepticus = a seizure that lasts longer than 5 minutes or multiple seizures where full GCS wasn’t returned postictal before another seizure
describe the role of various pharmacological therapies for the acute seizure patient, and their mechanism of action at the synapse
midazolam:
activates gaba receptors (gaba agonist), and chloride enters the cell decreasing RMP - cell needs a larger stimulus to depolarise.
glutamate vesciles have a protein bound to it called SV2A (which causes exocytosis when activated) - kepra prevents this exocystosis of glutamate to the following neuron. Therefore, the next neuron is not as excitable.
explain the dangers of status epilepticus and why it constitues a medical emergency
excessive electrical discharges are taking place in the brain that may cause permannent brain damage or death- accosiated with high morbidity
excessive use of o2 and glucose - if person is not breathing for themselves - they are not breathing they aren’t producing
