Epilepsy Flashcards
What are seizures?
Abnormally large and hyper synchronous activity of neutrons
Describe activity within generalised seizures?
Both hemispheres involved
Describe hemispheric activation in focal seizures?
Originates I;one hemisphere
Describe hemispheric activation in focal to bilateral seizures?
Originates in one hemisphere and spreads to both
What determines the symptoms of a focal seizure ?
The cortical region
Describe a focal seizure
Consciousness remains
Unable to speak or talk
Describe a focal impaired awareness seizure
Any degree of impairment during seizure
Types of focal seizures
Focal aware
Focal impaired awareness
Awareness unknown
Name of focal seizure where unable to determine if Individual is conscious:
Awareness unknown is
Describe the firing in a generalised seizure:
Synchronised and wide spread
Early sign of focal impaired seizure:
Amnesia
Which circuit is implicated in early stage of generalised seizures?
Thalamocortical
Originating in thalamocortical regions, where does a generalised seizure spread to?
All areas of the cortex simultaneously
Describe hemispheric activation in a generalised seizure ?
Bilateral symmetrical
Impact of consciousness within generalised seizure:
Presumed to be impacted
Focal seizures can result in what other kind of seizure …
Secondary generalised seizure
During a focal seizure, what circuit is recruited to trigger a generalised seizure ?
Thalamocortical
Degree of thalamocortical involvement determines whether what arises during a secondary generalised seizure ?
Tonic clonic convulsions
Persistent seizures if the brain is termed as:
Status epilepticus
Criteria for status epilepticus:
Persists for more than 30 minute
OR
2 seizures with no intermediate full recovery in 30 minutes
Which disorder is a risk factor for future unprovoked seizures:
Status epilepticus
What happens during an EEG?
Electrical activity Amplified and summated into spike wave discharge
Which ions and NT are associated with too much excitation ?
Sodium
Calcium
Glutamate
Aspartate
Describe the direction of currents associated with too little inhibition ?
Outward potassium
Inward chloride
Which NT implicated in too little inhibition ?
GABBA
Why is increased excitation not always associated with seizures ?
Inhibitory neurons may be over excited
Which neurons concentrate brain activity within small regions ?
Inhibitory interneurons (10-20% of all neurons)
Interneurons maintain excitability flowing …
In one direction : not sideways
Risk of recurrence seizures after 1st seizure:
30 to 35%
Seizure recurrence risk after second seizure:
60%
Epilepsy criteria:
2 or more unprovoked seizures
3 classifications Of epilepsy:
Idiopathic
Symptomatic
Cryptogenic
