Seizure and Epilepsy Flashcards
What is epilepsy?
Recurring and spontaneous seizures affecting 1 in 100-200 people
What are primary generalizes onset seizures?
Electrical discharges appear to start over the whole brain at the same time without a warning
What are secondary generalized seizures?
Electrical discharges start in one area and then either remain localised or spread over the whole brain. There is a warning
What are idiopathic generalized seizures?
Onset is in childhood or adolescence
Usually no focal symptoms/signs
Polygenic cause
Provoked by sleep deprivation
What is Juvenile myoclonic Epilepsy (JME)?
The most common form of generalised epilepsy
It has juvenile onset
Can be with or without absences
Photosensitive and triggered by sleep deprivation
What are generalised tonic clonic seizures?
Sudden onset, without warning in primary generalised epilepsy
What are the stages in a tonic, clonic seizure?
Tonic phase: continuous muscles spasm, fall, cyanosis, tongue biting, incontinence
Clonic phase: Rhythmic jerking slows and gets larger in amplitude as attack ends (lasts 1-3 minutes)
Post-ictal stage: Coma, drowsiness, confusion, headache, muscle aching, memory loss
What is a grand mal seizure also known as?
A generalised tonic clonic seizure
What is a petite mal?
An absence lasting 5-20 seconds
It happens multiple times a day
Tone is preserved
Person is unresponsive and looses memory for that interval
What is a simple partial seizure?
The patient is aware because there is an aura
Now called a focal seizure with awareness
What is a complex partial seizure?
An aura with a level of reduced awareness
Now called a focal seizure with reduced awareness
Where do partial seizures most commonly occur?
In the temporal lobe (70%) and frontal (25%)`
Why are deep sited seizures often missed?
Because the EEG measures extracellular activity and it’s hard with a deep seizure
What are some causes of temporal lobe seizures?
Hippocampal sclerosis (50%) Tumour (18%) Birth hypoxia (10%) Post traumatic (8%)
What are some signs and symptoms of temporal lobe epilepsy?
- Hallucinations of taste, speech and smell
- Pallor, flushing, heart rate changes
- Automatisms likes semi-purposeful limb movements and lip smacking
What are some signs and symptoms of a frontal lobe seizure?
Forced head
Eye deviation to the contralateral side
Jacksonian spread with Todd’s paresis
What is a Jacksonian March?
A type of focal partial seizure
What is Todd’s paresis
A paralysis that follows a seizure
What are some symptoms of parietal lobe seizures?
Positive sensory symptoms
Tingling/pain
Distortion of body shape/image
Jacksonian march
What are some symptoms of occipital lobe seizures?
- Typically simple visual hallucination like calls of coloured or flashing lights
- Amaurosis (blackout or whiteout) at onset
What is the difference between a blackout and a whiteout?
Blackout- loss of memory
Whiteout- fainting
What is the definition of epileptogenesis?
The process by which parts of a normal brain are converted into hyperexcitable brain
Which channelopathies are associated with epilepsy?
- Na+ channel inactivation is too slow in excitatory neurones. Caused by a Na+ channel mutation and causes impaired action potential repolarization
- Reduced number of functional Na+ channels in inhibitory neurones. Causes impaired action potential generation
- Reduced number of K+ channels in excitatory neurones. Causes impaired action potential repolarisation
What do anti-epileptic drugs (AED’s) do?
They prevent the spread of a seizure of epileptic discharges so that the seizure is more controlled
They don’t prevent seizures
