Epilepsy Flashcards
What causes seizures?
Imbalance in inhibitory/excitatory currents/neurotransmission in the brain
Precipitants (5)
Flashing lights drugs sleep deprivation metabolic cryptogenic
Key features from history
Before- what was happening? Prodrome?
During- aura, onset, duration, loss, of consciousness, tongue biting, incontinence
After- recovery, any residual weakness
Main classification of seizures (2)
Partial (focal onset) or generalised (throughout cortex)
What proportion of partial/focal seizures go on to become generalised?
Around 2/3rds
Brief pauses of around 10 seconds, present in childhood
Absence seizures
Loss of consciousness, limbs stiffen and then jerk
Tonic-clonic seizures
Todd’s palsy
Post-ictal flaccid weakness seen in focal frontal lobe seizures
Investigations in epilepsy (3)
CT (if fracture, head injury, deteriorating GCS, focal signs)
ECG
EEG
Atonic seizure
Sudden loss of muscle tone, causing fall, with no LOC
How long must a patient be seizure-free in order to drive?
At least one year
Definition of status epilepticus
Seizures lasting for more than 30 mins, or repeated seizures without intervening consciousness
Status usually occurs in…
Known epileptics
Management of status (3)
Manage ABC (DEFG) Rectal diazepam (10mg adult dose) 2nd line- phenytoin, valproate
What type of drug is lorazepam and how does it work?
Long-acting Benzodiazepene
Works by enhancing GABA binding to its receptor, causing a widespread depression of synaptic transmission
Why would thiamine be considered in treatment of status?
Alcoholics and malnourished are often thiamine-deficient
When should anti-epileptic therapy be commenced?
After a second seizure
Treatment of choice in generalised juvenile epilepsy
Sodium valproate
Treatment of choice in partial epilepsy?
Carbamazepine
Side effects of sodium valproate (4)
Teratogenicity
Hair loss
Weight gain
Fatigue
First-line in generalised tonic-clonic epilepsy (2)
Sodium valproate or lamotrigine
What can be the issues for women of child-bearing age taking AEDs? (2)
Can alter effectiveness of the oral contraceptive pill and morning after pill
Teratogenicity
Possible severe side effect of lamotrigine
Stevens Johnson syndrome
Difference between simple and complex partial seizures
In complex, awareness is impaired and there is more likely to be post-ictal symptoms e.g. confusion
In a history of a first seizure what should be enquired?
Whether there has ever been any similar “funny turns”
When can anti-epileptic drugs be stopped?
Two years seizure-free, drugs stopped over 2-3 months under supervision of a specialist
DDx of seizure? (5)
Epilepsy Isolated due to brain insult e.g. infection, trauma, metabolic Febrile convulsions Alcohol withdrawal Psychogenic non epileptic seizures
What characterises a generalised seizure?
Immediate loss of consciousness
Treatment of absence seizures?
Sodium valproate or ethosuximide
