Epilepsy Flashcards
What are the 5 generalised seizure types?
- Tonic-clonic
- Absence
- Tonic/atonic
- Myoclonic
- Status epilepticus
What are tonic-clonic seizures characterised by?
Loss of consciousness, stiffness, jerking, deep sleep
What are absence seizures characterised by?
Staring and behaviour arrest
What are tonic/atonic seizures characterised by?
Muscle stiffness/loss of control
What are myoclonic seizures characterised by?
Sudden brief muscle contractions
What are status epilepticus seizures characterised by?
> 5m uncontrolled seizure activity
What is the classification of seizures?
Partial and generalised seizures
What is involved in a partial seizure?
One hemisphere
What is involved in a generalised seizure?
Both hemispheres
What are the types of partial seizures?
Simple and complex
What is a simple partial seizure?
Conscious
What is a complex partial seizure?
Unconscious
What are epilepsy syndromes characterised by?
By repeated seizures
What are seizures characterised by?
Sudden bursts of electrical activity in the brain causing changes in muscle tone, behaviour and awareness
How is epilepsy diagnosed?
EEGs (seizure type) and MRI (organic causes)
What are the main drugs that can be used to treat epilepsy?
- Lamotrigine
- Sodium valproate
- Diazepam
- Levetiracetam
What other drugs can also be used to treat epilepsy?
- Carbamazepine
- Topiramate
- Ethosuximide
- Phenytoin
What is the mechanism of action of lamotrigine?
- Blocks voltage-gated Na+ channel on presynaptic glutamatergic neurons
- Prevents Na+ influx
- Prevent depolarization
- Decreased glutamate excitotoxicity
How would you reduce the frequency of skin reactions with regards to lamotrigine?
Introduce lamotrigine gradually and titrate up dose
What are the drug-drug interactions for lamotrigine?
- Safe in pregnancy, present in but not harmful for breastfeeding child
- COCP induced UDPGA, increases lamotrigine metabolism, less seizure control
What are the side effects of lamotrigine?
- Maculo-papular rash (10%)
- Drowsiness
- Steven-Johnson’s syndrome (1 in 1000)
- Suicidal thoughts (rare)
What is the mechanism of action of levetiracetam?
- Inhibits SV2A on excitatory presynaptic neuronal vesicles
- Prevents vesicle exocytosis
- Decreased glutamate secretion presynaptically
- Deceased glutamate excitotoxicity
What are the drug-drug interactions for levetiracetam?
- None - no CYP450 enzyme interaction
2. Requires good renal function
What are the side effects of levetiracetam?
- Dizziness, headache
- Somnolence
- Fatigue
