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Pharmacology Test #6 > Anticonvulsants > Flashcards

Flashcards in Anticonvulsants Deck (84)
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1

Seizure

single event of brain dysfunction with various forms, but commonly involving hypersynchrony of neuronal discharge in cortex

2

Epilepsy

disorder of chronic seizures; one of the oldest known brain disorders, associated with demonic possession in ancient times; prevalence is 1%

3

Partial seizure

involves one hemisphere

4

Simple seizure

sensory disturbances, 30-60 sec, retains consciousness

5

Complex seizure

lost consciousness, 1-2 min, aura, automatisms, amnesia after

6

Secondarily generalized seizure

turns into a generalize seizure, treated as such

7

Generalized seizure

involves both hemispheres, lost consciousness

8

Tonic/clonic (grand mal) seizure

stiffening (tonic) then jerking (clonic), 1-2 min

9

Absence

lapse in awareness, children, 100s per day

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Myoclonic and Clonic seizures

brief contractions of body, local or generalized

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Tonic seizures

stiffening only

12

Atonic seizures

loss of tone, falls

13

Status epilepticus

prolonged seizure (5 min), medical emergency

14

Seizure etiology

1. stress
2. head trauma
3. infection
4. fever
5. tumors
6. brain malformations
7. genetic factors

15

What happens with neuronal firing in seizures

neurons fire in synchrony, producing large summations in current recorded from scalp electrodes

16

What happens with neuronal firing post-seizure

possibly less activity than pre-seizure, often termed post-ictal depression

17

Electrophysiological progression of a seizure

1. Large excitatory synaptic current in seizure focus
2. PDS induction and interictal spike/wave generation
3. Secondary spikes/PDS coincide with seizure activity
4. Postictal depression

18

What gives rise to the initial spike in the EEG?

thought to be from some form of enhanced excitatory synaptic current or diminished inhibitory current

19

Post-tetanic potentiation

cellular model where a tetanus (which would model a seizure) can induce a potentiated response from a synapse due to buildup of Ca2+ in the terminal during the tetanus; may be relevant to anticonvulsant drugs that manipulate Ca2+ channels

20

Long term potentiation

phenomenon where repeated stimulation strengthens synaptic connections, which could occur in seizures, perhaps explaining aspects of kindling and mirror foci; relevant to anti-glutamateric drugs that block NMDA and/or AMPA receptors

21

Paroxysmal depolarizing shift

describes cellular phenomenon that there are checks and balances in neurons that maintain proper balance of excitation/inhibition, but excessive excitation or reduced inhibition can result in excessive discharge characteristic of seizures

22

Epilepsy animal models

1. Mirror foci
2. Maximum electroshock
3. Kindling
4. Pentylenetetrazole
5. Channelopathies

23

Mirror foci

a seizure focus is created on one side of the brain using various chemical or electrical methods, which is followed by spontaneous formation of another focus int he same brain area on the other hemisphere

24

Maximum electroshock

current applied to the brain is incrementally increased until a maximal seizure is elicited, providing a measure of seizure sensitivity; drugs are assayed for their ability to reduce the sensitivity to seizure formation, or to increase the current that is necessary to produce a seizure

25

Kindling

a brain area is repeatedly stimulated to produce a seizure focus, and drugs are assayed for their ability to suppress formation of this focus and/or to suppress seizure activity from this focus once formed

26

Pentylenetetrazole (PTZ)

a pro-convulsant drug that likely mediates its effects by blocking GABA-A receptors, thereby reducing inhibition and shifting the balance toward excitation of neurons; anticonvulsant drugs are sued to test suppression of PTZ-induced seizures

27

Channelopathies

genetic animal models that produce mutated ion channels to model mutations in human that are thought to produce seizure disorders

28

Drugs targeted to the VG Na+ channel

1. Phenytoin
2. Carbamazepine
3. Lamotrigine
4. Lacosamide

29

Drugs targeted to the VG Ca2+ channel

1. Ethosuximide
2. Lamotrigine
3. Gabapentin
4. Pregabalin

30

Drugs targeted to the K+ channels

1. Retigabine