Epilepsy Flashcards
(30 cards)
goals of managing epilepsy
no seizures
no side effects
manage comorbidities
optimize quality of life
prevent major complications like status epilepticus and SUDEP
challenges in managing epilepsy
variety of seizure types, causes, epilepsy syndromes
complex underlying mechanisms
high rate of medication failure
psychological consequences of epilepsy
loss of driving
underemployment
under-education
social isolation
morbidity consequences of epilepsy
increased risk of falls, lacerations, burns, fractures
increased rate of anxiety, depression, suicide
reasons for mortality in epilepsy
SUDEP
status epilepticus: mortality rate 20%
seizures
paroxysmal hyperexcitability of population of neurons
10% of people will have at least one seizure, 4% will have 2+
provoked seizure
occuring in the setting of transient CNS or systemic insult
unprovoked seizure
no apparent acute provoking cause
epilepsy
2+ unprovoked seizures 24 hours apart or single unprovoked seizure with >60% likelihood of reoccurrence
3% of people will have epilepsy at some time in their life
diagnosis of epilepsy: history
conducted with patient and witness
discuss risk factors: head injury, CNS infection, stroke, tumor, febrile seizures, autoimmune disease, family history
precipitants: sleep deprivation, stress, illness, alcohol, flashing lights
seizure description
diagnosis of epilepsy: examination
signs of global brain development
signs of focal dysfunction
interictal EEG: in between seizure states
MRI
diagnostic study
epilepsy and genetics
each year the number of known epilepsy genes increases
genes are associated with ion channel function, NT receptors, synaptic complexes, intracellular pathways, metabolism
epilepsy and neurochemistry
seizure initiators include low sodium or high potassium concentrations extracellularly, GABA antagonists, glutamate agonists
How does epilepsy change inflammatory response?
increases
absence seizure hypothesis
hyperexcitable cortex and thalamus produce an excessive reverberating loop
generalized spike wave is recorded from cortex
dormant basket cell hypothesis
in the hippocampus dormant basket cells become inactive
excitation is unopposed creating prolonged depolarization
mossy fiber sprouting hypothesis
mossy fibers synapse back on themselves, producing a positive feedback loop
CA3 cells undergo sustained depolarization
epilepsy treatment strategies: absence
inhibit excitation: calcium channels
neurostimulation
gene therapy
epilepsy treatment strategies: focal/impaired
inhibit excitation: calcium channels, voltage dependent sodium channels
promote inhibition
neurostimulation
surgical resection or ablation
gene or cellular therapy
What is drug resistant epilepsy?
failure to control seizures despite trials of two seizure medications
occurs in about one-third of patients
neurostimulation
electrical current delivered by internalized pulse generator
specific target in CNS/PNS
continuous, intermittent, or on-demand stimulation
types of neurostimulation
closed loop: responds to patient seizure
open loop: programmed
mechanism of neurostimulation
not fully understood
low frequency: enhance neuronal activity
high frequency: reversibly simulate “lesion” of targeted structure
device therapy: VNS
indicated in refractory epilepsy
minimally invasive
HR detection of biomarker for seizures
long battery life
better at reducing seizures than stopping them
side effect: hoarseness or voice change
