Exam 3 - Lec 46-47 Seizures Yang Flashcards
focal onset seizures have what 4 classifications?
-aware/impaired awareness
-motor onset/non-motor onset
focal onset seizures may progress to
bilateral tonic-clonic (pt will have loss of consciousness)
generalized onset seizures has what 2 classifications?
-motor: tonic clonic/other motor
-non-motor (absence seizures)
absence seizures fall into which category?
a. focal onset
b. generalized onset
c. unknown onset
b. generalized onset (non-motor)
unknown onset seizures are either motor (tonic clonic/other motor), non-motor, or _________
unclassified
what is it called when seizure activity spreads from a focus in one part of the brain?
a. focal seizure
b. focal to bilateral seizure
c. primary generalized seizure
a. focal seizure
which seizures propagate via diffuse interconnections between the thalamus and cortex, with the earliest clinical signs show involvement of both brain hemispheres?
a. focal seizures
b. focal to bilateral seizures
c. primary generalized seizure
c. primary generalized seizure
what is it called when a focal seizure progresses to secondary generalized seizures via projections to the thalamus?
a. primary generalized seizure
b. focal to bilateral
c. focal to trilateral
b. focal to bilateral
“impaired awareness” was previously referred to as _____ ______
complex partial
what are automatisms?
repetitive motor behaviors which pts have no memory of; common in “impaired awareness” focal seizures
true or false: aura is common in impaired awareness focal seizures
true
what is a postictal state?
confused/disoriented state after a seizure subsides
which has a slower onset?
a. typical absence seizure
b. atypical absence seizure
b. atypical absence seizure
typical absence seizures are also referred to as ?
petit-mal
which type of absence seizure is described?
-10-45 sec loss of consciousness
-staring or eye flickering
-begin abruptly
-often repetitive
-pt may not realize it after
-no convulsions, aura, or postictal periods
a. typical
b. atypical
a. typical
which is more difficult to control pharmacologically?
a. typical absence
b. atypical absence
b. atypical absence
which type of seizure is referred to as grand-mal?
a. typical absence
b. primary generalized tonic-clonic
c. focal to bilateral tonic-clonic
b. primary generalized tonic-clonic
what are paroxysmal depolarizing shifts (PDSs)? (from internet)
abnormal fluctuations of the neuronal membrane voltage; hallmark of epilepsy disorders; consists of a large depolarization that triggers a burst of APs
paroxysmal depolarizing shifts: depolarization involves the activation of _____ and _____ channels by the NT _________, and voltage gated calcium channels leading to an _____ of Ca2+ ions
AMPA; NMDA; glutamate; influx
paroxysmal depolarizing shifts: depolarization is followed by __________ involving activation of _______ receptors (influx of Cl-) and voltage- and calcium-dependent K+ channels leading to an ______ of K+
hyperpolarization; GABA; efflux
in paroxysmal depolarizing shifts, which is normally dampened by feed-forward and feedback inhibition - involving GABAnergic neurons - in a typical cortical neuron circuit?
a. repolarization
b. hyperpolarization
c. depolarization
c. depolarization (neuronal signaling)
main pathophysiological reason for paroxysmal depolarizing shifts
disrupted balance of excitation/inhibitory NTs
Which of the following occurs during the hyperpolarization phase of a PDS?
a. influx of Cl- ions resulting from GABA-A receptor activation
b. influx of K+ through voltage- and calcium-dependent K+ channels
c. activation of NMDA receptors
d. all of the above
a. influx of Cl- ions resulting from GABA-A receptor activation
(B is efflux; C is involved in depolarization)
what is the inhibitory NT?
GABA
what is the excitatory NT?
glutamate
which of the following activates the GABA-A receptor? SELECT ALL THAT APPLY
a. barbiturates
b. benzodiazepines
c. valproate
d. gabapentin
e. vigabatrin
f. tiagabine
a. barbiturates
b. benzodiazepines
which of the following increases GABA levels?
a. barbiturates
b. benzodiazepines
c. valproate
d. gabapentin
e. vigabatrin
f. tiagabine
c. valproate
which of the following increases GABA release?
a. barbiturates
b. benzodiazepines
c. valproate
d. gabapentin
e. vigabatrin
f. tiagabine
d. gabapentin
which of the following inhibits GABA transaminase?
a. barbiturates
b. benzodiazepines
c. valproate
d. gabapentin
e. vigabatrin
f. tiagabine
e. vigabatrin
which of the following inhibits GAT-1?
a. barbiturates
b. benzodiazepines
c. valproate
d. gabapentin
e. vigabatrin
f. tiagabine
f. tiagabine
which of the following is an antagonist of NMDA receptors?
a. felbamate
b. topiramate
c. phenytoin
d. carbamazepine
a. felbamate
which of the following is an antagonist of kainate/AMPA receptors?
a. felbamate
b. topiramate
b. topiramate
phenytoin elimination kinetics are
a. dose-independent, leading to non-linear PK
b. dose-independent, leading to linear PK
c. dose-dependent, leading to non-linear PK
d. dose-dependent, leading to linear PK
c. dose-dependent, leading to non-linear PK
therapeutic plasma level range for phenytoin
7.5-20 ug/mL
true or false: phenytoin can be displaced from plasma proteins by other drugs, and can induce CYP P450 enzymes in the liver
true
what two drugs are iminostilbenes?
carbamazepine and oxcarbazepine
MOA of carbamezipine
binds and stabilizes the inactive state of Na+ channels
carbamazepine can cause what serious skin rash?
Steven-Johnsons Syndrome/toxic epidermal necrolysis
what hypersensitivity reaction is possible with carbamazepine? (not Stevens-Johnson Syndrome)
DRESS (drug rxn with eosinophilia and systemic sx)
what TWO drugs that we discussed are classified as barbiturates?
a. phenytoin
b. carbamazepine
c. phenobarbital
d. clonazepam
e. primidone
f. gabapentin
g. diazepam
c. phenobarbital
e. primidone
MOA of phenobarbital
binds to allosteric site on GABA-A receptor, inc DURATION of Cl- channel-opening events (and thus enhancing GABA inhibitory signaling)
which barbiturate is the drug of choice in infants up to 2 months of age?
a. primidone
b. phenobarbital
b. phenobarbital
toxicities for phenobarbital (2 of them)
-sedation
-physical dependence (potential for abuse)
what TWO drugs that we discussed are benzodiazepines?
a. phenytoin
b. carbamazepine
c. phenobarbital
d. clonazepam
e. primidone
f. gabapentin
g. diazepam
d. clonazepam
g. diazepam
Diazepam is especially useful for which seizure disorder? What is its route of administration for seizure control?
tonic-clonic status epilepticus; administered as rectal gel
diazepam MOA
binds to allosteric site on GABA-A receptor, inc FREQUENCY of Cl- channel-opening events (and thus enhancing GABA inhibitory signaling)
true or false: diazepam is useful for chronic tx of seizures
false (due to tolerance)
which drug is useful for acute tx of epilepsy and absence seizures?
a. diazepam
b. clonazepam
b. clonazepam
vigabatrin MOA
irrev inhibitor of GABA transaminase (GABA-T), the enzyme that degrades GABA
vigabatrin is used as ________ therapy for _____ pts with seizures
adjunct; refractory
true or false: tiagabine is used as first line therapy for seizures
false (adjunct)
tiagabine MOA
inhibits GABA- transporter (GAT-1)
which is a shared toxicity of vigabatrin and tiagabine? SELECT ALL THAT APPLY
a. sedation
b. weight gain
c. depression
d. ataxia
e. psychosis
f. tremor
g. visual field defects
a. sedation
c. depression
which of the following drugs can cause visual field defects?
a. vigabatrin
b. tiagabine
a. vigabatrin
which of the following drugs can cause ataxia?
a. vigabatrin
b. tiagabine
b. tiagabine
do tiagabine and vigabatrin target a presynaptic or post-synaptic target?
presynaptic (GAT-1 and GABA-T)
do phenobarbital and benzodiazepines target a presynaptic or postsynaptic target?
postsynaptic (GABA-A receptors)
what is the main toxicity of felbamate?
severe hepatitis
which is used as a 3rd line drug for refractory cases (especially for focal seizures)?
a. felbamate
b. topiramate
c. gabapentin
a. felbamate
which drug’s MOA is to block T-type calcium channels (low-threshold current) in thalamic neurons?
a. phenytoin
b. carbamazepine
c. ethosuximide
d. felbamate
e. topiramate
c. ethosuximide
(these channels are involved in generating the rhythmic discharge of an absence attack)
ethosuximide is only used to treat which type of seizure?
absence
Which of the following statements is TRUE?
a. Tiagabine inhibits GABA transaminase.
b. Gabapentin increases Cl- influx in postsynaptic neurons.
c. Topiramate is an NMDA receptor antagonist.
d. Phenytoin is stabilized by the co-administration of carbamazepine.
b. Gabapentin increases Cl- influx in postsynaptic neurons.
(A targets GABA transporter; C is an AMPA receptor antagonist; D can work by itself to block Na channel)
gabapentin and pregabalin MOA (2 things; this slide did not have a star on it)
-inc GABA release
-dec presynaptic Ca2+ influx, thereby reducing glutamate release
levetiracetam MOA (3 things to know)
-binds the synaptic vesicular protein SV2A and interferes with synaptic vesicle release and neurotransmission
-interferes with calcium entry through calcium channels and with intraneuronal calcium signaling
-candidate for tx of status epilepticus cases that are refractory
what drug is an analog levetiracetam, but has a higher affinity for SV2A?
brivaracetam (Briviact)
molecular targets at the excitatory synapse: what is the common target of ethosuximide, lamotrigine, levetiracetam, and valproate?
a. Na+ channels
b. Ca2+ channels
c. NMDA receptors
d. AMPA receptors
b. Ca2+ channels (valproate also does a)
molecular targets at the excitatory synapse: what is the common target of phenytoin, carbamazepine, lacosamide, lamotrigine, and valproate?
a. Na+ channels
b. Ca2+ channels
c. NMDA receptors
d. AMPA receptors
a. Na+ channels (valproate also does b)
valproate inhibits what two channels?
Na+ and Ca2+
Slide 36 is a picture and has a star on it, make sure to look at it
Ok
