Epilepsy

Question 1

What is epilepsy?

Answer 1

a chronic disorder characterized by recurrent seizures

Question 2

what is a seizure?

Answer 2

short term episode of abnormal firing of cerebral neurons (hyper-synchrony)

Question 3

what are some causes of seizures?

Answer 3

fever
head injury
tumor
heredity
alcohol withdrawal
metabolic disorder

Question 4

What are the two main classifications of seizures?

Answer 4

partial

generalized

Question 5

what is a partial seizure?

Answer 5

initiated in neurons in a localized area of one cerebral hemisphere

Question 6

what are 3 types of partial seizures?

Answer 6

simple
complex
secondary generalized

Question 7

what is a simple partial seizure?

Answer 7

no loss of consciousness; may experience an aura prior to seizure

Question 8

what is a complex partial seizure?

Answer 8

impaired consciousness often with automatisms (ex: picking at shirt repetitively)
unable to recall events afterwards

Question 9

what is a partial seizure with secondary generalization?

Answer 9

starts off localized, then spreads to activate both hemispheres (goes to thalamus first)

Question 10

what are 2 types of generalized seizures?

Answer 10

tonic-clonic

absence

Question 11

what is a generalized seizure?

Answer 11

simultaneous activation of both cerebral hemispheres

Question 12

what is a generalized of tonic-clonic seizure?

Answer 12

tonic = rigid extension of limbs
clonic = spasms, jerking of extremities

Question 13

what is status epilepticus?

Answer 13

if a seizure goes on longer than 5-10min

Question 14

what is a generalized absence seizure?

Answer 14

impaired consciousness sometimes with automatisms
sx: blink rapidly, eyes may roll back, smacking of lips
no aura occurs; happens quickly

Question 15

what are 4 different MoA’s for seizure drugs?

Answer 15

1) blockage of voltage-dependent sodium channels (reduce rate of sodium channel opening)
2) inhibit glutamate exposure and reduce neuronal firing (decr. glutamate exposure and reduce neuronal firing)
3) Increase inhibitory GABA neurotransmission (enhances Cl influx, hyperpolarizes neurons and reduces neuronal firing)
4) block voltage-gated calcium channels (depolarization of thalamic neurons activates cortical neurons)

Question 16

where do anti-epileptics work on voltage-gated sodium channels?

Answer 16

work on the state of converting inactive channel to a closed channel (inhibit conversion)

Question 17

what are 4 drugs that are used to treat seizures?

Answer 17

carbamazepine (tegretol)
phenytoin
valproate
ethosuximide

Question 18

what types of seizures can carbamazepine treat?

Answer 18

partial

generalized tonic-clonic

Question 19

what is the MoA for carbamazepine?

Answer 19

inhibits voltage gated sodium channels

Question 20

What are some adverse effects of carbamazepine?

Answer 20

double vision
ataxia (poor balance, uncoordinated movements)
nausea
drowsiness (high doses)
skin rash
leukopenia (low count of WBCs)

Question 21

what types of seizures can phenytoin treat?

Answer 21

phenytoin

Question 22

what is the MoA of phenytoin?

Answer 22

blocks voltage-gated sodium channels

Question 23

what are some adverse effects of phenytoin?

Answer 23

double vision
ataxia 
eye movements
gingival hyperplasia (gum inflammation)
hirsutism (hair growth)
peripheral neuropathy (Chronic)
megaloblastic anemia (dysfunctional RBCs)
osteomalacia (decreased calcification of bone)

Question 24

What is the MoA of phenobarital and primidone?

Answer 24

enhance inhibitory effects of GABA

Question 25

What are some adverse effects of phenobarbital and primidone?

Answer 25

``` drowsiness ataxia respiratory depression decreased motor skills skin rash psychological/physiological dependence ```

Question 26

what is the MoA of gabapentin?

Answer 26

increases release of GABA from neurons; decreases GABA metabolism

Question 27

what are some adverse effects of gabapentin?

Answer 27

``` sedation dizziness headache tremor ataxia GI (nausea, constipation) ```

Question 28

what can topiramate be used for?

Answer 28

adjunctive therapy | monotherapy in partial and tonic-clonic seizures

Question 29

what is the MoA of topiramate?

Answer 29

inhibits voltage sensitive sodium channels, incrases GABA effects and inhibits glutamate (AMPA) receptors

Question 30

briefly describe the metabolism of topiramate

Answer 30

metabolism is affected by other anti-epileptics

Question 31

what are some adverse effects of topiramate?

Answer 31

fatigue dizziness mental slowing nausea

Question 32

what can lamotrigine be used for?

Answer 32

adjunctive therapy | monotherapy for partial and absence seizures

Question 33

what is the MoA of lamotrigine?

Answer 33

blocks voltage-gated sodium channels

Question 34

what are some adverse effects of lamotrigine?

Answer 34

dizziness headache skin rashes

Question 35

what kind of seizures can ethosuximide be used to treat?

Answer 35

generalized absence seizures

Question 36

what is the MoA of ethosuximide?

Answer 36

blocks voltage-gated calcium channels

Question 37

what are some adverse effects of ethosuximide?

Answer 37

stomach aches vomiting skin rash may increase tonic-clonic seizures

Question 38

what kind of seizure can clonazepam be used to treat?

Answer 38

generalized absence

Question 39

what is the MoA of clonazepam?

Answer 39

enhances inhibitory effects of GABA

Question 40

what are some adverse effects of clonazepam?

Answer 40

sedation | tolerance to anti-seizure effects

Question 41

what kinds of seizures can valproate be used to treat?

Answer 41

generalized tonic-clonic absence mixed seizures (partial seizures, atypical generalized seizure)

Question 42

what is the MoA of valproate?

Answer 42

voltage gated sodium and channel blocker | enhances inhibitory effects of GABA

Question 43

what are some adverse effects of valproate?

Answer 43

risk of spina bifida hepatotoxicity (pts under 2) N/V tremor

Question 44

what are some other medical conditions anti-epileptics can be used for?

Answer 44

``` bipolar disorder (approved = carbamazepine, valproate) anxiety disorder alcohol abuse spascity migraine, cluster headache neuropathic pain (gabapentin) ```

Question 45

what are two different meds used to treat status epilepticus?

Answer 45

``` IV diazepam (Valium) IV lorazepam phenytoin used for longer term control ```

Question 46

can AEDs be used in pregnant women?

Answer 46

AEDs can harm the fetus, but risk/harm from uncontrolled seizures is greater

Question 47

which meds enhance metabolism of oral contraceptives?

Answer 47

phenytoin | phenobarbital

Question 48

which meds can cause enhanced vitamin D metabolism leading to osteomalacia and enhanced vitamin K metabolism leading to bleeding disorder?

Answer 48

phenytoin | phenobarbital