Epilepsy Flashcards
What is the difference between a seizure and epilepsy?
Seizure
- episode of neuronal hyperactivity
Epilepsy
- at least two unprovoked episodes of seizures
At what age are you most likely to suffer from epilepsy?
Highest chance under the age of 10 and over the age of 70
What are the two classifications of seizures?
Generalised
Focal
What is partial epilepsy?
The area of neuronal hyperactivity occurs in a focal part of the brain.
The effect on the patient depends on the part of the brain that is affected
- e.g. a seizure in the motor part of the brain can cause twitching of certain limbs
What are some common causes of a partial seizure?
Fissure Abscess Bleed Epilepsy Stroke Hypertension Brain infection
What is a generalised seizure?
The discharge of electrical activity distorts the whole brain
What causes generalised epilepsy?
It is a primary seizure, meaning the epilepsy is the diagnosed condition, and it is not a symptom of a different problem
What should you do if you see someone having a seizure?
Keep them out of harms way
Put them in the recovery position
If movements stop, and they have no impairments of their ABCs, they do not need hospitalisation
What is meant by a tonic clonic seizure?
Generalised seizure Tonic phase - lose conscisouness - tensing of the skeletal muscles - only lasts a few seconds Clonic - muscles contract and relax rapidly, causing convulsions - eyes roll back - strong jaw contractions causes damage to the tongue/cheek Usually followed by a deep sleep
Name some features of partial epilepsy?
History of trauma Focal aura (including gustatory/sensory/motor features) - associated with neurological discharge in the affected area of the brain Confusion after the attck Drowsiness Automatisms Nocturnal events Focal neurological symptoms at the start
Name some features of generalised seizures?
Photosensitivity (flashing lights set it off) Age of onset (8-26) Alcohol or sleep deprivation Myoclonus (especially in the morning) Lack of aura Seizures within 2 hours of awakening Family history of idiopathic generalised epilepsy Abnormal EEG
What investigations are needed if someone has had a seizure?
Brain imaging
EEG
ECG
Systemic provocations
What is an EEG, and what is it used for?
A brainwave test
Not very reliable as brainwaves change depending on tiredness, hunger and stress levels
- hard to reproduce
5% of young people have ‘epileptic abnormalities’ when they are actually fine
Good at classifying epilepsy and risk of recurrence
Describe how an EEG is used.
The test takes one hour and consists of electrodes being placed on the head to observe brain wave activity.
This should be done lying at rest.
Hyperventilation and drowsiness are possible activating features of seizures and should be induced during the test
Photic stimulation should also be tested in order to detect whether the patient is photosensitive
What is an ambulatory EEG?
An EEG worn by the patient over a 24 hour period
- for classification of any seizure had in this time
- increases likelihood of picking up a seizure
What is a video telemetry EEG?
An ambulatory EEG, where a patient’s movements are also recorded by a video camera
- patient remains in hospital
Why would a patient need a video telemetry EEG?
It isn’t clear what kind of seizures the patient is having
Epilepsy medication isn’t working
Seizures might not be epileptic in cause
What are some causes of seizures that aren’t epileptic?
Migraine Narcolepsy Transient global amnesia Panic attack One seizure - syncope Multiple seizures - syncope or non-epileptic attack disorder
What is non-epileptic attack disorder?
These are attacks that look like seizures, but are coupled with no abnormal electrical activity in the brain
What is status epileptius?
Repetitive or prolonged seizures that aren’t responding to treatment
A medical emergency because they can cause profound systemic/neuronal damage
What is the definition of status epilepticus?
More than 2 seizures without full recovery of neurologic function between seizures
OR
Continuous seizure activity for more than 30 minutes (although anything more than 5 minutes is concerning)
What is the treatment for focal epilepsy?
Lamotrigine
Carbamazepine
Levetiracetam
What is the treatment for generalised epilepsy?
Valproate (avoid use in young women)
Levetiracetam
Lamotrigine
How does Lamotrigine work?
A sodium channel blocker
- inhibits volateg sensitive sodium channels
- leading to stabilisation of neurological membranes
How does Levatiracetam work?
Binds to a synaptic vesicle glycoprotein
- inhibits presynaptic calcium channels
- acts as a neuromodulator
- imedes impulse conduction across synapses
How does Carbamazepine work?
Blocks voltage gated sodium channels, preventing repetitive and sustained firing of an action potential
Also a GABA receptor agonist
How does Valporate work?
Blockage of voltage gated sodium channels
Increases brain levels of GABA by inhibiting GABA degrading enzymes
