Epilepsy Flashcards
What is epilepsy?
recurrent tendency to have unprovoked seizures
What are seizures?
an abnormal paroxysmal discharge of cerebral neurons
What are convulsions?
the motor signs of electrical discharges
What is the main cause of epilepsy?
2/3 idiopathic
What is an acronym to remember causes of seizures?
VITAMINS
What does vitamins stand for?
- Vascular e.g. stroke
- Infection: brain abscess, meningitis, encephalitis
- Trauma + toxins
- Autoimmune e.g. lupus
- Metabolic: hyponaetraemia, hypocalcaemia
- Idiopathic: epilepsy
- Neoplasms
- Syncope or psychogenic siezures or eclampsia
What are structural causes of epilepsy?
- Cortical scarring (head injury years before)
- Development
- SOL
- Stroke
- Hippocampal sclerosis
- Vascular malformations
What are the other possible causes of epilepsy?
- Tuberous sclerosis
- Sarcoidosis
- SLE
- Tumours, infection, inflammation, trauma
What are two different types of seziures?
- Focal seizures
2. Generalised seizures
What are two different types of seziures?
- Focal seizures
2. Generalised seizures
What are different types of focal seizures?
- Without impairment of consciousness
- With impairment of consciousness
- Evolving to a bilateral, convulsive seizure
- Can have aura in focal seizures
Which focal seizures have a post-ictal phase?
With impairment of consciousness do and without don’t
What are different types of generalised seizures?
- Absence seizures
- Tonic-clonic seizures
- Myoclonic seizures
- Atonic seizures
- Infantile spasms
What are the characteristics of absence seizures?
- <10s
- In childhood
- Loss of consciousness but maintain posture
- No change in muscle tone
- Can happen hundreds of times a day
What does tonic limb mean?
stiff
What does clonic limb mean?
jerking
What are the characteristrics of tonic-clonic seizures?
- loss of consciousness
- Limb stiffens (tonic) then jerks (clonic) may have one without other
- Post-ictal drowsiness and confusion
What are the characteristics of myoclonic seizures?
- Repetitive sudden jerk of limb, face or trunk very fast
- Common in puberty
- Usually in morning and can be triggered by lack of sleep and stress
What are atonic seizures?
- Sudden loss of muscle tone causing a fall
- No loss of consciousness
- Common in children
What are infantile seizures?
associated with tuberous sclerosis
What are different area of focal seizure?
- Temporal lobe
- Frontal lobe
- Parietal lobe
- Occipital lobbe
What are the characteristics of a temporal lobe focal seizure?
- Aura (epigastric discomfort,)
- Automatism: playing with fingers, lip smacking
- Hallucinations
- Emotional disturbances
What are characteristics of a frontal lobe focal seizure?
- Motor arrest
- Subtle behavioural disturbances
- Motor symptoms: Jacksonian march
- Post ictal flaccid weakness
- Todd’s palsy
- Involuntary actions (disinhibition)
What are characteristics of parietal lobe focal seizures?
- Sensory disturbances, tingling, numbeness, pain
2. Motor symptoms
What are the characteristic occipital lobe focal features?
Visual phenomenon such as spots, lines, flashes
What may suggest it is a focal seizure that is a secondary generalised over a generalised tonic-clonic seizure?
- history of aura
- turning head to one side
- Todd’s paralysis
What is status epilepticus?
seizure lasting >5mins or repeated seizures without recovery or regain of consciousness in between
What are some triggers for status epilepticus?
- Non-adherence to medication
- Alcohol abuse
- OD and toxicity
What is the management of status epilepticus?
- Secure airway: 100% O2
- IV access and continuous monitoring: sats, BP, ECG, glucose
- IV lorazepam (repeat after 10 mins if seizure does not terminate or PR diazepam
- IV phenytoin
- ICU
What are symptoms and signs of epilepsy?
- Some experience prodrome (can last hours or days)
- Some have aura
- Post-ictally may be headache, confusion or myalgia
- During can have tongue biting, limb jerking
What are possible DDx for epilepsy?
- Non-epileptic attack disorder
2. Syncope
What may suggest it is non-epileptic attack disorder: psychogenic?
- if prolonged duration
- abrupt termination
- are accompanied by closed eyes, rapid breathing – can coexist with actual epilepsy
Why do you need to rule out provoking cause?
As could be seizure but not actually epilepsy
What are some provoking causes that could cause seizure?
trauma, stroke, haemorrhage, metabolic disturbances
How do you determine epilepsy and syncope?
syncope won’t have post-ictal phase and regain consciousness quickly
What is needed for the clinical diagnosis of epilepsy?
need 2 or more UNPROVOKED seizures occurring > 24 hr apart
How do you refer for epilepsy?
- Difficult as >40 types of epilepsy
- All patients with seizure must be referred for specialist assessment and investigation in less than 2 weeks
What is important to ask in history of epilepsy?
- Ask about witnesses
- Tongue biting
- Slow recovery
- Any triggers?
- Déjà vu feeling
- Look for provoking cause
What investigations do you do for epilepsy?
- EEG
- MRI
- Drug levels
- Drug screen
- Bloods
- Brain imaging
Why do you do an EEG
- cannot exclude epilepsy and can give false positive
2. can show if generalised or focal
Why may you do a brain MRI?
suspect structural lesion
Why do you need to counsel a patient with epilepsy?
Counselling: after fit, no swimming, driving, heights until diagnosis known and then give individualised
What is treatment for focal seizures?
- Carbamazepine
2. Lamotrigine
What is treatment (1st and 2nd line) for generalised seizures?
1st line: sodium valproate
2nd line: carbamazepine
What treatment do you use for epilepsy if pregnant?
AVOID SODIUM VALOPRATE as teratogenic (use lamotrigine instead)
What are some SE of carbamazepine?
neutropenia and osteoporosis
What can be a SE of lamotrigine?
Skin reaction (Steve Johns)
What are other SE for AEDs?
- psychiatric (depression)
2. Weight gain
What are the different type of mechanisms for drugs for epilepsy?
- Enhance GABA inhibition
- Reduce glutamate-mediated excitation (pre-synaptic)
- Reduce glutamate-medicated excitation (post-synaptic)
- Block action potential Na+ channel depolarisation
How do you stop epileptic drugs?
can stop under specialised supervision if seizure free for >2 years and assessing risk and benefits
What are possible complications of epilepsy?
- SUDEP: sudden death in epilepsy
- Behavioural problems
- Fractures (from seizure)
- Complications from drugs
Where do generalised seizures arise from?
both cerebral hemispheres at the same time
Where do focal seizures arise from?
specific areas in one cerebral hemisphere
Can focal and generalised seizures overlap?
focal seizures can spread to both cerebral hemispheres, causing a generalized seizure
How to benziodiazapines work?
- bind to the GABA-A receptors and increase channel opening frequency
- increased chloride conductance and neuronal hyperpolarization, leading to enhanced inhibitory neurotransmission
What are dissociativce seizures?
can resemble epileptic seizures but have NO biological correlate
When should you suspect dissociative seizures?
- Prolonged duration
2. History of abuse, psychological or emotional precipitants
What is the management for dissociative seizures?
psychotherapy
