Week 5 Seizure

Question 1

Differentiate a seizure vs epilepsy

Answer 1

Seizure = episode of inappropriate electrical discharge resulting in disordered brain activity
Epilepsy = a condition where there are repetitive but largely unpredictable episodes of seizure activity

Question 2

Explain what is meant by the phrase epileptic focus

Answer 2

An epileptic focus is a group of cells within the cortex that are hyperexcitable and are the cause for the seizure activity.
Not everyone with Epilepsy has a definable focus but those whose can be located might be given the opportunity for surgical removal

Question 3

Describe the electrical changes that contribute to a neurons hyperexcitable state

Answer 3

Hyperexcitable because:
Membrane potential is less negative then most cells - closer to threshold and more easily excited

Question 4

Epidemiology of Epilepsy

Answer 4

~50mil world wide
4-10 per 1000in developed countries
Second only to stroke for most common serious Neurological disorder

Question 5

Describe the typical presentations of the most common types of seizures

Answer 5

The 5 most common seizure types
Absence seizures
Short loss of awareness and cessation of all activity, commonly with a blank stare, may include eyelid flutter or eye roll

clonic seizures
Brief, shock like jerks of a muscle or a group of muscles

Tonic and atonic
Sudden stiffness or tension in the muscles of the arms, legs or trunk
Atonic =muscles in the body relax

Tonic clonic
First Tonic where muscles stiffen, then clonic phase where they are jerking

Question 6

Focal and generalised seizures

Answer 6

Focal/partial: - localised area of the brain
Can start in one part of the brain and spread to other parts - as it spreads more symptoms occur
They can notice minor symptoms first (aura)
When it evolves to entire brain it causes Tonic clonic

Generalised - both hemispheres
Surges of abnormal nerve discharges throughout the cortex ofthe brain.

Question 7

Challenges associated with diagnosis of temporal lobe Epilepsy

Answer 7

They are behavioural seizures
They can go into an autopilot state and have a seizure without knowing
Changes in behaviour
Can see hallucinations

These Epilepsy are often misdiagnosed or missed as people don’t accosiate their behaviour with Epilepsy.

Question 8

Prehospital management of seizures

Answer 8

Oxygenation
Check bgl
Ensure safe enviornment
Midaz if they seize for more than 5 minute, or don’t return to their baseline before seizing, or are a danger to themselves
Need to gather a thorough history, and identify potential causes
2 doses Midaz, need Icp for 3rd (they can do iv), then they use kepra
Transport

Question 9

Describe the role of various pharmalogical therapies for acute seizure patients, and describe their Mechanism of action at the synapse

Answer 9

Levetiracetem (keppra)
Icp drug given after 3rd dose of midaz
It works by binding to vesicle protein 2a which is involved in vesicle fusion and neurotransmission exocytosis
Inhibits ca+ from binding to the vesicles preventing exocytosis. Therefore, the neurotransmitters cannot be released into the synaptic cleft to bind to the dendrite for nerve impulse to continue

Midazolam:
Binds to gaba to neural membranes in cns (gaba a )
Receptor is a chloride ion channel
Enhances inhibitorybp effect of gaba through hyperpolarisation
Increases frequency of chloride channel opening
Negatively charged ions enter into the cell, therefore making it more negative and requiring a larger stimulus for depolarisation,

Question 10

Dangers of status epilepticus and why it constitutes as a medical emergency

Answer 10

Status epilepticus is a seizure with 5 minutes or more of continuous clinical and/or electrographic seizure activity or recurrent seizure activity without recovery between seizures
Because it can lead to permanent brain damage or death due to Hypoxia