Epilepsy Flashcards
What does convulsion mean?
Muscles contract and relax in a rapid cycle
What is a seizure?
Paroxysmal (attack) events that may involve motor, sensory systems or are related to consciousness: brain involvement
What is Epilepsy?
A set of disorders that have recurrent, (unprokoved) seizures
What are disorder components involved in epilepsy?
- Muscle rigidity
- Convulsions
- Psychic (changes in sensory perception, anxiety or deja vu)
- Loss of consciousness
In what age groups is epilepsy most common?
Children and elderly
What percentage of people have epilepsy at a singular given time?
0.5-1% of the population
What percentage of the population will experience epilepsy in thier lifetime?
5%
What factors increase the risk of epilepsy in old age?
- Causes to brain structure via….
- Stroke
- Dementia
- Tumours
What is a Myoclonic (myoclonus) seizure?
Involuntary twitching of muscle or muscle group
Can occur in everyday life such as hiccups or jolts when we fall asleep
Does not normally have a rhythm
What is a clonic (clonus) seizure?
Rhythmic muscle contractions
Normally involve large movements
What is a tonic seizure?
A phase in which there is sustained muscle contraction (initial rigidity)
What is an atonic seizure?
Loss of muscle tone
Usually a brief loss of consciousness
What is a common name for an atonic seizure?
Drop seizure
What is an absence seizure?
A short lapse in consciousness
Doesn’t have a motor component
Normally has rapid recovery
What is an Ictal seizure?
Anything pertaining to a seizure
Sometimes this term can also be used for strokes
What are the three first ILAE system seizure classes?
- Focal onset
- Generalised onset
- Unknown onset
In the focal onset category of the ILAE system, what are the following elements of a seizure?
- Aware/ impaired awareness
- Motor onset/ Non-motor onset
- Focal/ bilateral tonic-clonic
In the Generalised onset and unknown categories of the ILAE system, what are the following elements of a seizure?
- Motor (tonic-clonic/ other motor)
- Non motor (absence)
What are the two groups of seizure categorisation for the old system (most common)?
- Partial: simple/complex
- Generalised: grand mal (tonic-clonic)/petit mal (absence)
What are the four epilepsy syndromes as disclosed by the ILAE system?
- Focal
- Generalised
- Combined generalised and focal
- Unknown
What are five electroclinical ways of classifying epilepsy?
- Neonatal
- Infancy
- Childhood
- Adolescence/Adult
- Not age related
How can we classify epilepsy based on brain areas, give examples (3)?
- EEG can identify the particular brain region involved
- This may be included in the naming:
- ADNFLE (autosomal dominant nocturnal frontal lobe epilepsy)
- Temporal lobe epilepsy
- Occipital lobe epilepsy
What is a focus?
- A group of neuronns generating high frequency acitivity
- The initial problem stems from this focal area
- There may be a single focus, or multiple foci
- Can spread
- Symptoms depend on the areas of the brian involved
What are four possible causes of a focus?
- Paroxysmal depolarizing shift (neurons undergo periodic changes in the resting membrane potential)
- Synchronization of activity (generation of the high frequency activity)
- Remodelling (of synaptic connectivity and neuronal loss because of seizures may feed in and worsen it)
- Kindling
What is Kindling?
An animal model where an animal is given a repeated low level stimulation to a particualr brain region
Makes this area more sensitive and then a small stimulation can cause seizures
Eventually, spontaneous seizures occur
What are the triggers of epilepsy?
- Most occur spontaneously
- Stress can increase frequency
- Some have particular triggers:
- Photosensitive (most common, still only 3% of epileptic patients)
- Reading
- Music
- Hot water
What are four ways of diagnosing epilepsy?
- Electroencephalography (scalp recordings)
-Video EEG (can be combined with video recording to correlate with the change in consciousness or motor activity)
- CT/MRI scans (to see underlying causes)
- PET scans (are there regions of the brain that function differently)
What are three main animal models that are used as a model of human disease?
- Genetic models
- Chemically induced models
- Electrically induced models
What is the aetiological classification of epilepsy?
- Direct genetic inheritance
- structural/metabolic such as brain trauma which predisposes a person to epilepsy
- Unknown causes
What percentage of epilepsy is thought to be of genetic origin?
40%
How do genetic epilepsies occur?
- Due to mutations in ion channels and receptors
- “channelopathies”
- May cause more epilepsies than identified by inheritance patterns
What proteins are most likely to be involved in genetic epilepsies?
- GABAA receptors
- neuronal nAChR
- VS channels
What is autosomal dominant nocturnal frontal lobe epilepsy?
- “Channelopathy”
- Seizures happen at night during sleep
- Frequently misdiagnosed as nightmares
- Linked to mutations in neuronsal nAChR alpha and beta subunits (important in regulation of other CNS neurotransmitters)
- Causes the receptors to change sensitivity to ACh and desensitization altered
What is Hyperekplexia?
- “Channelopathy” NOT an epilepsy
- Startle syndrome
- EEG generally normal
- Mutations in proteins associated with glycinergic transmission in the spinal cord such as:
- Glycine receptor subunits
- Glycine transporters
- Cytoskeletal proteins
What are the legal driving implications of having epilepsy?
- Driving licence removed after a seizure
Unless
- Seizure free for one year
- Three years of seizures only at night
What are four social implications of Epilepsy?
- Employment may be difficult for people with severe epliepsy
- Pregnancy may be difficult
- Some people with epilepsy feel a sense of shame (stigma
- There is still a fear of epilepsy in society
What is a tonic-clonic seizure’s classification name?
Grand Mal
What type of seizure is regarded as the ‘classic’ epileptic seizure?
Tonic-clonic
What are the three stages of a tonic-clonic seizure?
- (prodromal phase (20%))
- Aura
- Tonic phase
- Clonic phase
What is the aura phase of a tonic-clonic seizure?
- Altered sensory perception and psychic symptoms such as deja vu, anxiety and hallucinations
- May be a valuable warning that they are about to have a seizure
- Is a form of seizure activity- type of focal seizure with maintained consciousness
What is the tonic phase of a tonic-clonic seizure?
The patients will lose consciousness and their muscles will become rigid, they may make strange sounds during this part of the seizure
What is the clonic phase of a tonic-clonic seizure?
The seizure will progress into convulsions and the patient may suffer from incontinence. This phase can last several minutes
What is the prodromal phase of the tonic-clonic seizure?
- Only happens in 20% of epileptic patients
- A sensation which starts hours or days before the seizure which can serve as a further warning sign
- This is not a form of epileptic acitvity
What are absence seizure’s classification name?
Petit Mal
What age group are absence seizures most common in?
Children
What is an absence seizure?
- Involve a siggen, brief lapse in consciousness
- Have very rapid recovery
- Can happen frequently during the day
- Some people have a brief motor component (more subtle than a proper motor seizure)
- Usually the person has no memory of what has happened.
What is Juvenile Myoclonic Epilepsy?
- Very common type of epilepsy (10% of all epilepsies)
- Frequently inherited
- Myoclonic jerks of the arms or legs