Epilepsy Flashcards
What is a seizure?
Sudden, excessive high frequency neuronal discharge
Not random but highly synchronous
A disorder of the cerebral cortex
May be loss of consciousness
Behavioural changes related to site of discharge - focus
What is the prevelance of epilepsy?
0.5 - 1% of population
children and elderly susceptible
2 % - one seizure
30,000 new cases p.a.
30 % drug-refractory
20 - 30 % refractory to surgery
1000 deaths per year 50% SUDEP
60-90 % undiagnosed or untreated in developing countries
What are the causes of epilepsy?
70% idiopathic/cryptogenic
genetic - rare familial disorders
congenital - structural abnormalities -dysplasia
birth trauma - ischaemia
neurological/neurodegenerative - elderly
head trauma - penetrating or non-penetrating
metabolic - glucose/electrolyte imbalance
disease - meningitis, tumour, abcess
2 or more unprovoked seizures
linked to deprived areas
25% also have learning disability
What are the ways of recording epilepsy?
EEG
MEG
How is imaging done in epilepsy?
PET – monitors local metabolism
MRI – structure and volume
fMRI – relates activity to structure
How is epilepsy diagnosed?
EEG
MRI
video telemetry
clinical description
What is a simple focal/partial seizure?
a general strange feeling that’s hard to describe
a “rising” feeling in your tummy – like the sensation in your stomach when on a fairground ride
a feeling that events have happened before (déjà vu)
unusual smells or tastes
tingling in your arms and legs
an intense feeling of fear or joy
stiffness or twitching in part of your body, such as an arm or hand
You remain awake and aware while this happens.
These seizures are sometimes known as “warnings” or “auras” because they can be a sign that another type of seizure is about to happen.
What is a complex partial/focal seizure?
During a complex partial seizure, you lose your sense of awareness and make random body movements, such as:
smacking your lips
rubbing your hands
making random noises
moving your arms around
picking at clothes or fiddling with objects
chewing or swallowing
You will not be able to respond to anyone else during the seizure and you will not have any memory of it.
What is a tonic-clonic seizure?
A tonic-clonic seizure, previously known as a “grand mal”, is what most people think of as a typical epileptic fit.
They happen in 2 stages – an initial “tonic” stage, shortly followed by a second “clonic” stage:
tonic stage – you lose consciousness, your body goes stiff, and you may fall to the floor
clonic stage – your limbs jerk about, you may lose control of your bladder or bowel, you may bite your tongue or the inside of your cheek, and you might have difficulty breathing
The seizure normally stops after a few minutes, but some last longer. Afterwards, you may have a headache or difficulty remembering what happened and feel tired or confused.
What is an absent seizure?
An absence seizure, which used to be called a “petit mal”, is where you lose awareness of your surroundings for a short time. They mainly affect children, but can happen at any age.
During an absence seizure, a person may:
stare blankly into space
look like they’re “daydreaming”
flutter their eyes
make slight jerking movements of their body or limbs
The seizures usually only last up to 15 seconds and you will not be able to remember them. They can happen several times a day.
What are myoclonic seizures?
A myoclonic seizure is where some or all of your body suddenly twitches or jerks, like you’ve had an electric shock. They often happen soon after waking up.
Myoclonic seizures usually only last a fraction of a second, but several can sometimes occur in a short space of time. You normally remain awake during them.
What are clonic seizures?
Clonic seizures cause the body to shake and jerk like a tonic-clonic seizure, but you do not go stiff at the start.
They typically last a few minutes and you might lose consciousness.
What are tonic seizures?
Tonic seizures cause all your muscles to suddenly become stiff, like the first stage of a tonic-clonic seizure.
This might mean you lose balance and fall over.
What are atonic seizures?
Atonic seizures cause all your muscles to suddenly relax, so you may fall to the ground.
They tend to be very brief and you’ll usually be able to get up again straight away.
Where do seizures arise?
Anywhere
subcortical rare
mostly cortical
frontal, parietal, occipital, temporal
Temporal most prevalent - 30-40%
Hippocampus, entorhinal cortex, amygdala
drug refractory
surgical resection
