Antiepileptics Flashcards
_____ people experience a seizure during their lifetime
11%
_____ of people that have a seizure are diagnosed with epilepsy
3%
seizure activity reports ___ of emergency department visits
1%
recurrent seizures are associated with a ____ fold increased risk of sudden death
2.5
what are the impacts of epilepsy on quality of life
- education: inadequate schooling
- employment: unemployment levels are higher
- independence: physical disability, fear of future seizures, cognitive consequences of disease and treatment, ineffective treatments, inability to obtain a drivers license
- social isolation: depression
what is a seizure
a discrete clinical event that results in the abnormal discharge of a set of neurons in the brain
epilepsy is at least:
2 unprovoked seizures
what are acute repetitive seizures
seizure clusters over 1-2 days, usually less than 5 minutes, differs from normal pattern, recover consciousness between seizures
what is convulsive status epilepticus
failure of the mechanisms responsible for seizure termination or from the initiation of mechanisms which lead to abnormally prolonged seizures
- length of seizures beyond 5 minutes
- second seizure without recovery from the first
- repeated seizures lasting 30 mins or longer
what is the pathophysiology of seizures
excessive excitation of cortical neurons (hyperexcitable/hypersynchronization)
- neuronal hyperexcitability
- alterations in the properties of ion channels in the neuronal membrane
- defects in ion transport across neuronal membranes
- abnormal synaptic vesicle protein 2-A
- biochemical modification of receptors
- modulation of second messaging systems and gene expression
- changes in extracellular ion concentrations
- alterations in neuroransmitter uptake and metabolism in glial cells
- modifications in the ratio and function of inhibitory circuits
- transitory imbalance in NTs
what is neuronal hyperexcitability
enhanced predisposition of neuronal depolarization and discharge when stimulated
what ion channels in the neuronal membrane are altered
Na+, Ca2+ and Cl-
what is synaptic vesicle protein 2-A responsible for
fusion of vesicles to membrane but get upregulated in some epilepsies
what are the imbalances in NTs
ehanced excitatory neurotransmission
- glutamate/aspartate
- NMDA/AMPA receptors
what are the epilepsy etiologies
- genetic
- structural
- infectious
- metabolic
- immune
- unknown
describe the genetic epilepsy etiology
- usually present at a young age
- dravet syndrome: mutations in sodium channel, type I alpha subunit
- childhood absence epilepsy- mutations in T-type Ca2+ channels and GABA receptor subunits
what are the structural epilepsy etiologies
- abnormalities found with neuronal imaging- cortical dysplasia, post traumatic epilepsy
what are the infectious etiologies of epilepsy
neurocysticercosis (parasite), meningitis, encephalitis
what are the metabolic epilepsy etiologies
abnormal glycogen metabolism (LaFora Disease)
what is the immune etiology of epilepsy
anti_NMDA receptor encephalitis (autoimmune)
what are the additional seizure etiological considerations
- cerebrovascular abnormality
- tumors
- head trauma
- infection
- hypoxia
- fever
- medications and seizure meds: clozapine (dose), bupropion (dose), carbamazepine (SIADH), TCAs, phenothiazines
- drug intoxication: cocaine, ephedrine
- metabolic distrurbance: high or low
- electrolyte disturbance: calcium, sodium, magnesium
- alcohol withdrawal
- sleep deprivation
- hormonal changes
- stress
- prenatal or birth injury
- congenital malformation
what are the seizure recurrence risk factors
- abnormal EEG
- seizure occurs during sleep
- positive fam history (sibling)
- prior acute seizure
- downs syndrome and cerebral palsy
with downs syndrome and cerebral palsy:
there is no clear associate with seizure type, seizure length or age of onset
what are the seizure types
- focal onset
- generalized onset
- unknown onset