Epilepsy Flashcards
What is a seizure?
rapid, synchronous, uncontrolled spread of electrical activity due to abnormal function of ion channels and dysregulation of neural networks
What is epilepsy?
conditions in which a person has a tendency to recurrent seizures
True or false: men have more seizures than women
false
no significant differences by sex
What is the age that has the greatest prevalence of epilepsy?
18-44 yrs
75% are diagnosed before age of 30
How many cases of epilepsy enter long-term remission with treatment?
65-85%
What are the causes of epilepsy?
may be genetic
may be secondary to tumors, infection, head injury, lack of oxygen, metabolic factors, alcohol abuse and stroke
in >50% cases, the cause is unknown
Describe the new classification of seizure types.
focal onset
-motor or non-motor (focal to bilateral, tonic-clonic)
generalized onset
-motor (tonic-clonic, other motor), non-motor (absence)
unknown onset
-motor (tonic-clonic, other motor), non-motor (absence)
What is generalized epilepsy?
starts on both sides (hemispheres) of the brain
What are the different phases of epilepsy?
tonic: stiffening of muscles
atonic: limp muscles
clonic: repeated jerking movements
absence: interruption of consciousness, with blank stare, possibly some motor symptoms
What are the motor symptoms of epilepsy?
may be tonic, clonic or aclonic, or brief muscle twitching (myoclonus)
may also be automatisms or repeated automatic movements, like clapping of hands, lipsmacking or chewing, pacing in circles
What are the non-motor symptoms of epilepsy?
changes in senations, emotions, thinking or cognition, autonomic functions (such as GI sensations, waves of heat or cold, goosebumps, heart racing, etc) or lack of movement
Describe what occurs do the different lobes of the brain during seizures.
frontal lobe:
-loss of motor control, change in behavior, or change in language expression
occipital lobe:
-changes in vision
parietal lobe:
-numbness/tingling, burning or cold sensations
temporal lobe:
-odd smell or taste, changes in hearing, panic
Differentiate between excessive excitation and not enough inhibition.
excessive excitation:
-inward Na and Ca currents
-excitatory neurotransmitters: glutamate, aspartate
not enough inhibition:
-inward Cl and outward K currents
-inhibitor neurotransmitters: GABA
What is surround inhibition?
focuses signals via stimulating inhibitory GABAergic neurons to block excitation lateral to the main stimulus
What are the drugs used for partial seizures?
carbamazepine
lamotrigine
oxcarbazepine
sodium valproate
What are the drugs used for tonic-clonic seizures?
carbamazepine
lamotrigine
sodium valproate
What are the drugs used for myoclonic seizures?
sodium valproate
What are the drugs used for absence seizures?
ethosuximide
sodium valproate
What are the drugs used for atonic seizures?
sodium valproate
lamotrigine
clonazepam
What is the MOA of sodium channel blockers?
blocks voltage-gated sodium channels by selectively binding to the channel in the inactive state and slowing its rate of recovery
enhanced Na channel inactivation
What are examples of sodium channel blockers?
phenytoin
carbamazepine
lamotrigine
lacosamide
What are the two types of calcium channels?
T type (slow) calcium channels
-usually inactive in the awake state
-used for absence seizures (ethosuximide)
high-voltage activated calcium channel
-controls entry of calcium into the presynaptic nerve terminal and regulates neurotransmitter release such as glutamate and norepinephrine
-these drugs also have other effects
-used mainly for focal seizures as adjunct therapy
-gabapentin, pregabalin
What are examples of calcium channel blockers?
ethosuximide
valproic acid
gabapentin
pregablin
Differentiate between AMPA and NMDA.
AMPA: glutamate receptor (excitatory), also ion channel for Na and K
NMDA: glutamate receptor (excitatory), also ion channel for Na, K, and Ca
