siezures Flashcards
(63 cards)
1
Q
What are the inhibitory neurotransmittors?
A
dopamine, serotonin, and GABA
2
Q
What are the excitatory neurotransmitters?
A
ACH (acetylcholine) and norepinephrine
3
Q
Neurotransmitters: Acetylcholine - where is it found, what type of action?
A
- found in the CNS, PNS, and ANS
- can be either excitatory or inhibitory (depends on neurons secreting it)
– PNS: excitatory at neuromuscular junctions
– ANS: inhibitory and slows heart rate
4
Q
Neurotransmitters: Serotonin (5-hydroxytrptamine) - where is it found, what type of action?
A
- derived from tryptophan
- found primarily in the GI tract, platelets, and brainstem
- contributor to feeling of well being
- inhibitory
5
Q
Neurotransmitters: Dopamine - where is it found, what type of action?
A
- located mainly in the substantia nigra of midbrain/basal ganglia region
- numerous functions:
– behavior and cognition
– voluntary motor movement
– motivation punishment and reward
– attention
– working memory
– learning - involved in many neuropsychiatric and voluntary motor movement disorders:
– social phobia, ADHD, drug and alcohol dependence
– Parkinson’s disease
– Tourette’s syndrome
6
Q
Neurotransmitters: GABA (gamma amino butyric acid) - where is it found, what type of action?
A
- chief inhibitory transmitter in the CNS
- has a relaxing, antianxiety, and anticonvulsant effect on the brain
- has inhibitory effect on muscles (decreases muscle spasms and improved tone)
7
Q
Neurotransmitters: Norepinephrine
A
an excitatory neurotransmitter in the brain
stress hormone within the endocrine system
8
Q
Neurotransmitters: Glutamate
A
- major mediator of excitatory signal
- involved in cognition, memory, and learning
9
Q
How do neurons do conduction?
A
action potential (neuron conducts impulses)
- abrupt changes in the membrane potential permit nerve signals to be transmitted from the cell body down the axon
- stimulates sodium, potassium, and calcium ions to move across the axonal membrane
10
Q
What are the three phases of an action potential?
A
- depolarization of the neuron: positively charged ion
- repolarization of neuron: return of neuron to a negative value
- resting period
11
Q
What leads to seizures, regarding the action potential?
A
impulses that do not maintain a systematic order (excitatory, inhibitory, and resting phase) become irregular and chaotic and can lead to seizures
12
Q
What are seizures?
A
a single episode of abnormal electrical discharge from cortical neurons that results in an abrupt and temporary altered state
13
Q
What is epilepsy
A
a group of syndromes characterized by unprovoked, recurrent seizures
14
Q
What is status epilepticus?
A
continuous seizure activity for more than 5 minutes
- OR 2 or more sequential seizures that occur WITHOUT full recovery of consciousness between attacks
- is a neurological emergency
- requires immediate intervention
15
Q
What are common causes of seizures?
A
- trauma
- ETOH withdrawal
- illicit drug use
- brain tumor
- congenital malformations
- stroke
- metabolic disorders (uremia, electrolyte imbalance)
- alzheimer’s disease
- neurodegenerative disease
- idiopathic
16
Q
What are common causes of epilepsy?
A
- genetic causes (mutated genes)
- head trauma
- medical disorders (dementia, meningitis, encephalitis)
- prenatal injury
- developmental disorders (autism, Down syndrome)
17
Q
Pathophysiology of seizures
A
- messages from the body are carried by the neurons of the brain through discharges of electrochemical energy; impulses occur in bursts
- during periods of unwanted discharged, parts of body may act erratically
- for an actual seizure to occur:
– need excitable neurons
– need increase in excitatory glutaminergic activity
– need reduction in activity of normal inhibitory GABA projection - anyone can have a seizure
18
Q
Examples of generalized seizures?
A
- absence (petit mal)
- tonic-clonic (grand mal)
- atonic/akinetic (drop attacks)
- status epilepticus
19
Q
Pathophysiology of focal seizure
A
- starts and remains in one hemisphere
- high-frequency bursts of action potentials and hypersynchronization
- may have motor, sensory, and autonomic symptoms and automatisms
– autonomic: due to stimulation of ANS (pallor, sweating, pupillary dilation, epigastric sensation)
– automatisms: often associated with temporal lobe seizures; patient is unaware
20
Q
What are automatisms?
A
- may happen with focal seizures
- coordinated involuntary movements happening during state of impaired consciousness either during or after seizure
- patient is unaware
- often associated with temporal lobe seizures
21
Q
Types of focal or partial seizure
A
- focal - retains awareness
- focal - altered awareness
- partial seizure
22
Q
Focal seizure - retaining awareness
A
- no impairment of consciousness
- similar to partial seizures
- may have movement of body parts
- may experience an aura
23
Q
Focal seizure - altered awareness
A
- impairment of consciousness
- spreads to both hemispheres (this confuses me though because i thought it should start and remain in one hemisphere)
24
Q
Partial seizure
A
- begins in one part of hemisphere (typically in the temporal or frontal lobe)
- may be simple or complex
25
Pathophysiology of generalized seizures
- **start in one hemisphere and spreads with involvement of both hemispheres**
- may have motor and/or nonmotor symptoms
- affects both hemispheres of the brain
- impairment of consciousness
26
Tonic-clonic seizure
- begin with rigid violent contractions (tonic)
- followed by repetitive clonic activity of all extremities
- body stiffens and relaxes
generalized
27
Tonic seizure
generalized
- muscle stiffness, dilation of pupils, altered respirations
- usually lasts less than a minute
28
Absence seizures
generalized
- short episodes of staring and loss of consciousness for about 10 seconds
29
Myoclonic seizures
generalized
- bilateral jerking of muscles
- no loss of consciousness
30
Atonic seizure
generalized
- sudden loss of muscle
- "drop to the ground"
31
What is needed for a diagnosis of seizure and/or epilepsy
- H&P
- neurological exam
- diagnostic procedures (chemistries, tox screen, CT, MRI, EEG)
32
What are the phases of seizures?
Pre-ictal, ictal, and post-ictal
33
What is the pre-ictal phase of a seizure?
may be started by a trigger and/or preceded by an aura
34
What is the ictal phase of a seizure?
- actual seizure
- increases in metabolic demand (uses a lot of energy)
35
What is the post-ictal phase of a seizure?
- has decreased responsiveness
- feels fatigue
36
What are anticonvulsants used for
AKA antiepileptic drugs (AED)
- used for long-term management of chronic epilepsy
- management of seizures not caused by epilepsy
- off label use: anxiety, bipolar disorder, chronic pain, migraines
37
What are broad-spectrum anticonvulsants used for
effective for treatment of focal and generalized seizures
38
What are narrow-spectrum anticonvulsants used for
used primarily for focal-onset seizures (including focal which evolve to be convulsive seizures)
39
Mechanism of actions by group - fit anticonvulsants (just an image in ppt that may be helpful)
40
Sodium channel blockers: what do they do with seizures
- prevent return of the channel to active state, stabilizes them to inactive state
- prevents repetitive firing
41
Calcium channel blockers: what do they do with seizures
- calcium going in during cells' resting state facilitates development of an action potential
- CCBs slow depolarization which is needed for spike-wave bursts
- CCBs help to "lock the channel"
42
What do GABA enhancers do with seizures
- may enhance Cl- influx which makes cells more negative and harder for the cell to generate an action potential
- some decrease metabolism of GABA so that more GABA is available (GABA is inhibitory)
43
What do glutamate blockers do with seizures?
- bind to glutamate, which is an excitatory neurotransmitter, therefore blocking it from binding and creating excitation
- glutamate receptor has 5 potential binding sites
44
What does "pharmacologic management” mean regarding seizures
- medications are to control seizures NOT cure
- medication prescribed based on the type of seizure
- many drugs require blood monitoring
- patient education (take as prescribed, never stop taking on own, side effect management)
45
Phenytoin (Dilantin): what type of med? How does it work? Indications?
Sodium channel blocker
- works to stabilize the neurons from becoming too excited
- stops the spread of seizure activity in the motor cortex
- **highly (90%) protein-bound drug: increased risk of drug interactions**
Indications:
- tonic-clonic seizures
- status epilepticus
- prophylaxis for surgery
46
Phenytoin (Dilantin): Therapeutic range and administration?
Therapeutic range: 10-20mcg/mL
- very narrow therapeutic window
- need to monitor levels
Given PO, IM, or IV
- if administered IV, w/ NSS
- infuse over 30-60 minutes
- can be very irritating to veins
Tube feeds: need to stop feed for 2 hours before AND after
47
Phenytoin (Dilantin): side effects?
*”pheny” = funny smile *
- **gingival hyperplasia**
- neurologic:
-- drowsiness
-- ataxia
-- irritability
-- visual problems
-- peripheral neuropathy
-- headache
- N/V
- Cardiovascular: hypotension, arrhythmias
- can cause suicidal thoughts
- skin rash including SJS can occur
48
Phenobarbital (Solfoton, Luminal): what does it do? what class? administration considerations?
Classified as a barbiturate
- inactivates fast sodium channels leading to enhanced GABA effects and decreased glutamate release
Administration consideration: very long half-life
- habit forming and dependence
49
Phenobarbital (Solfoton, Luminal): side effects
- sedation
- diplopia
- cognitive skill impairment
- respiratory depression
- hypotension
- hyperactivity and inattention in children
50
Carbamazepine (Tegretol): What class? What does it do? When is it used? Storage?
Sodium channel blocker
- similar to Phenytoin (also an SCB) in mechanism of action
- inhibits spread of seizure activity
Used for several different types of seizures:
- drug of choice for partial and generalized tonic-clonic seizures
- also used for trigeminal neuralgia and bipolar disorder
- WILL MAKE ABSENCE AND MYOCLONIC SEIZURES WORSE
Needs to be in dry location
51
What type of seizures is carbamazepine (tegretol) the drug of choice for?
partial and generalized tonic-clonic seizures
52
What seizures does carbamazepine make worse?
absence and myoclonic seizures
53
Carbamazepine: What needs to be monitored?
Labs:
- CBC: especially WBC
- Drug level: 4-12 mcg/mL
Monitor drug levels, sodium, CBC, LFTs, and BUN/Cr especially in those with renal impairment
54
Carbamazepine: Side effects
- Neuro: headache, diplopia, ataxia, drowsiness, sedation
- N/V
- hyponatremia
- decreased blood counts (neutropenia and thrombocytopenia)
- rashes can be common - watch for SJS
- increases suicidal thoughts
* take with food
* cannot abruptly discontinue
55
Oxycarbazepine (trileptal): How does it work? What class?
Sodium channel blocker
- same efficacy as carbamazepine but is better tolerated
56
Oxycarbazepine (trileptal): What seizures is it used for and NOT used for? Considerations?
- used as adjunctive therapy or monotherapy for partial seizures in children and adults
- NOT used for absence and myoclonic - makes them worse
Considerations:
- increase risk of suicidal ideations
- decreases efficacy of oral contraceptives
57
Valproic Acid/Valproate (Depakote): How does it work? What class? Indications?
GABA enhancer; inactivation of fast sodium channels
Indications: really any seizure activity
- absence, myoclonic, tonic-clonic, partial, neonatal seizures
- used to control symptoms of acute mania in bipolar disorder
58
Valproic Acid/Valproate (Depakote): Administration and monitoring
Can give with? Monitor what? Therapeutic range?
- can be given with phenytoin
- take with food
- can cause liver toxicity, need to monitor LFTs
- **narrow therapeutic range**
-- need to check levels (50-100 mcg/mL)
- must be diluted when given IV with at least 50mL NSS or D5W
-- give over an hour (no more than 20mg/min)
- avoid sudden withdrawal
- monitor CBC because can cause thrombocytopenia
59
Valproic Acid/Valproate (Depakote): side effects
- N/V
- sedation/dizziness
- pancreatitis
- increased ammonia levels
- thrombocytopenia (monitor CBC)
- suicidal thoughts
- can cause liver toxicity (watch LFTs)
60
Gabapentin (Neurontin): Action? Seizure indications?
Thought to act on the calcium channels to decrease glutamate and increase GABA in the brain
Indications:
- partial seizures
- new onset epilepsy
- MAY MAKE MYOCLONIC SEIZURES WORSE
61
Gabapentin (neurontin): off-label uses
- chronic neuropathic pain
- anxiety
- hot flashes/night sweats
- headaches
- hiccups
- alcohol withdrawal
62
Gabapentin (Neurontin): side effects
- fatigue: given at night often
- **mental cloudiness**
- leukopenia
- weight gain
- edema
- emotional lability
- tremors
- GI side effects
- suicidal thoughts
63
Gabapentin (Neurontin): Administration considerations
- reduced dose in renal patients: monitor BUN/Cr
- caution in those with addiction history
- no drug monitoring needing b/c wide therapeutic range
- withdrawal slowly
- doses will be very high for pain control
