seizure disorders Flashcards
(80 cards)
1
Q
definition of a seizure?
A
sudden, excessive, disorderly d/c of neuronal activity in the brain
- sudden or transient
- involves motor, sensory, autonomic, or psychic manifestations
- temporarily alters systemic arousal
- often manifests as convulsions but there are many diff kinds of seizures
2
Q
Definition of seizure disorder/epilepsy?
A
- tendency to have recurrent seizures in absence of any immediately tx cause such as hypoglycemia or ETOH withdrawal
- may also manifest as strange sensations, emotions, and/or behavior including convulsions, muscle spasms, and LOC
3
Q
Definition of a convulsion?
A
- bodies muscles contract and reflex rapidly and repeatedly, resulting in an uncontrolled shaking of the body
4
Q
Pathophys of epilepsy?
A
A: result of complex genetic mutations and enviro factor can cause:
- abnormal brain wiring
- chemical (NT) imbalances
- abnorm connections made when attempting to repair an injury
B: hypersensitive neurons may exhibit a sudden or violent depolarization:
- epileptogenic (able to cause epilepsy)
- easily act by hyperthermia, hypoxia, hypoglycemia, hyponatremia, sensory stim, certain sleep phases
C. epileptogenic neurons fire more intensely, more often, and with greater amplitude than normal neurons
- at threshold pt, cortical excitation spreads to subcortical, thalamic and brain stem areas
- inhibitory neurons in cortex, anterior thalamus, and basal ganglia react to cortical excitation
5
Q
Incidence of seizures?
A
- b/t 0.3-0.7% of US pop
- approx 2 mill Americans have seizure more than 1/month
- prevalence: highest in children b/t 2-5 and at puberty
- second highest incidence of 1st time seizures occurs in pts over 50 yo (usually caused by trauma, stroke)
- seizures can begin at any time of life
- 2-4% of all persons in developed countries have recurrent seizures at some time during their lives
- idiopathic or primary generalized epilepsy is generally apparent by time of puberty
- seizures beginning after age 20 are usually due to a focal process or metabolic derangement
6
Q
Etiology of seizures?
A
- infancy and childhood: birth injury, infection, trauma, metabolic disorders, congenital brain abnormality
- adolescence: trauma, metabolic disorders
- young adult: trauma, ETOH, neoplasms
- middle age: vascular disease, neoplasms
- late life: vascular: strokes, neoplasms
- other causes: physiologic stress: sleep deprivation, fever (esp in kids), withdrawal from ETOH or sedative drugs
7
Q
Diff b/t provoked and unprovoked seizures?
A
- provoked: triggered by certain provoking factors in an otherwise healthy brain: metabolic abnorm ETOH withdrawal illict drug intoxication and withdrawal high fever in kids
-unprovoked seizures: occur in setting of persistent brain pathology
8
Q
How do seizures often manifest?
A
- as strange sensations, emotions and behaviors (including convulsions)
- many may experience the same seizure events over and over, while some have many diff types of seizures that cause diff sxs each time
- pts should be eval thoroughly after an initial seizure (complete hx)
- in some cases: other conditions must be ruled out such as an arrhythmia
9
Q
What does the type of seizure a person has depend on?
A
- area of brain affected
- underlying cause
- focal or generalized
- occurrence during wakefulness or sleep
- known triggers
10
Q
What may exacerbations of known previously controlled seizures be due to?
A
- noncompliance with meds
- ETOH use
- menses
11
Q
Mortality/morbidity of pts with seizures?
A
- 2-3x greater than the general pop
- most deaths are due to underlying cause of epilepsy
- the remainder are due to accidents (trauma, burns, aspiration), suicide, and sudden unexpected death (SUDEP)
12
Q
What is SUDEP?
A
- defined as sudden, unexpected, non traumatic non drowning death in a pt with epilepsy
- accounts for 1/1000 deaths among the general pop with epilepsy and perhaps 50% of pts with refractory epilepsy
13
Q
Social issues that affect seizure pts?
A
- relationships
- financial costs
- school/employment
- driving
- recreational activities
14
Q
Psych issues in seizure pts?
A
- emotional difficulties
- depression, anger, anxiety and or fear
- cognitive problems
- some people with epilepsy may have developmental delays
15
Q
Phases of seizures: prodrome?
A
- may experience feeling, sensations or changes in behavior hours or days before seizure
- common sxs:
deja vu, smells, sounds, taste
fear/panic
dizzy/lightheaded
HA
nausea
16
Q
Phases of seizures: aura?
A
- first sx of a seizure and considered part of seizure
17
Q
Middle phase of seizure?-
A
- called ictal phase
- begins from 1st sx to end of seizure
common sxs: loss of awareness (blackout), blurred vision, flashing lights confused, feeling spacey, difficulty talking, unable to swallow, repeated blinking of eyes, lip smacking or chewing movements
18
Q
Ending phase of a seizure?
A
- called postictal phase
- recover immediately or minutes to hours
- common sxs:
slow to respond, sleepy, confused, injuries: bruising, cuts, broken bones, HA, nausea
19
Q
Seizure classification?
A
- focal: seizure activity starts in one area of the brain: focal - retain awareness (w/o impairment of consciousness) or focal with altered awareness (w/ impairment of consciousness)
- generalized: activity involves both hemispheres of the brain - absence (petit mal), tonic-clonic (grand mal), myoclonic, clonic, tonic, atonic
20
Q
Definition of LOC?
A
- a state of complete or partial unawareness or lack of response to sensory stimuli as a result of hypoxia caused by respiratory insufficiency or shock; from metabolic or chemical brain depressants such as drugs, poisons, ketones, or electrolyte imbalance; or from a form of brain pathologic condition such as trauma, seizures, cerebrovascular insult, brain tumor, or infection
21
Q
Categories of focal seizures?
A
- intial d/c arises from a focal, unilateral area of the brain w/o impaired consciousness categories - motor (jacksonian march) sensory autonomic psychic
22
Q
Jacksonian march seizure?
A
- initiated with abnorm electrical activity within the primary motor cortex
- ***unique in that they travel through the primary motor cortex in succesion, affecting the corresponding msucles, often beginning with the fingers. This is felt as a tingling sensation
- it then affects the hand and moves on to more proximal areas
- other sxs often assoc with Jacksonian seizure are sudden head and eye movements, tingling, numbness, smacking of the lips, and sudden muscle contractions
23
Q
Focal seizures w/o impaired consciousness?
A
- prodrome or aura: warning sign of impending seizure activity
- todd’s paralysis: temporary, unilateral - 30 min to 36 hrs
- can progress very quickly from a seizure (no change in consciousness) to a seizure (consciousness altered - staring spell, automatisms) or generalized seizure (tonic-clonic) seizure
- pt may not recal aura, EEG will show focality
24
Q
Focal seizures with impaired consciousness?
A
- produce unresponsiveness
- 70-80% arise from temporal lobe
- most common type of seizure
- clinical signs, sxs, and supporting EEG changes indicate involvemtn of 1 hemisphere at onset
- lasts from 30 s to 2 minutes
- many evolve from simple focal seizures: simple partial onset followed by impaired consciousness
- some may present with impairment of consciousness at onset
- present with automatisms (set of brief unconscious behaviors - finger rubbing, lip smacking, chewing, sleep walking)
- confusion and tiredness may follow for about 15 min, may take hours to be fully normal
25
Clincial sxs of generalized onset seizures?
- disturbances in consciousness
| - involve varying bilateral degrees of symmetric motor responses w/o evidence of localization to one hemisphere
26
examples of generalized onset seizures?
- absence (petit mal)
- myoclonic
- atonic (drop)
- febrile seizure
- idiopathic tonic-clonic (grand mal)
- post traumatic epilepsy
27
What are absence seizures?
| Typically occur in?
- generalized non-convulsive epileptic events
- expressed mainly as disturbances in consciousness
- referred to as petit mal seizures
- can evolve into generalized motor seizures
- onset and termination of attacks are abrupt
- typically occur in childhood and cease in adulthood (grade school children doing poorly in school should potentially be screened)
28
Examples of abscence seizure presentations?
- blank stare
- motionless
- stop talking mid sentence
- can have mild clonic, tonic, or atonic components
- may have automatisms
- no postictal period
29
Characteristics of atypical absence seizures?
- lapses of awareness that have gradual onset
- don't resolve as abruptly
- are accompanied by autonomic features or loss of muscle tone
- occur most often in children with mental impairment
- don't respond as well to antiepileptic drug tx
30
Myoclonic seizures?
| Range?
- rapid recurrent brief muscle jerks that can occur:
bilaterally, unilaterally, synchronously, asynchronously
myoclonic jerks can range from:
- small movements that simultaneously affect the head, limbs, and trunk
- may terminate into generalized tonic-clonic (grand mal) seizure
- can occur at any time
- often cluster shortly after waking or while falling asleep
31
What are atonic seizures?
- drop attacks
- occur most often in children with diffuse encephalopathies
- are characterized by sudeen loss of muscle tone that may result in falls with self injury
- can occur in repetitive, rhythmic and successive manner
32
What are febrile seizures? Occurs in what population?
diff types?
Tx for prolonged seizures?
- fever is most common cause of convulsions in children
- occur b/t 6 m-5 y
- temp usually higher than 38 C (100.4 F)
- chance of recurrence is greatest if first seizure occurs b/f 1 year or there is a family hx
- are not assoc with nor do they cause mental impairment, poor school performance or behavioral problems
2 types: simple and complex
- during body becomes stiff and arms and legs begin twitching
- lose consciousness
- blood test, imaging, and EEG generally not needed
- tx with IV lorazepam only for prolonged seizures
33
What is a tonic clonic seizure?
- "grand mal" - generalized tonic-clonic seizure, is a major motor seizure which involves all extremities and characterized by a sudden LOC
- it may be either primary (ex: arising from deep brain structures) or represent a focal seizure with secondary generalization
34
Tonic part of tonic-clonic seizures?
- characterized by sudden LOC
- becomes rigid and falls to ground
- respiration is arrested
- usually lasts for less than a minute
35
Clonic part of tonic-clonic seizures?
- jerking of body musculature
- may last for 2-3 minutes
- folowed by stage of alt level of consciousness
36
What may occur during tonic-clonic seizures?
- tongue and lips may be bitten
- urinary or fecal incontinence
- pt may be injured
- immed following:
may recover consciousness
drift into sleep
have further convulsions w/o recovery of consciousness b/t attacks (status epilepticus)
37
Postictal phase of tonic-clonic seizures?
- HA
- disorientation
- confusion
- drowsiness
- nausea
- soreness of muscles
38
What is a secondary generalized seizure?
| signs and sxs?
- seizure that becomes generalized (spread to both sides of brain) after initial event (focal seizure) has already begun
- 30% of people with focal epilepsy
- usually last 1-3 min, but may take a lot longer for a person to recoveer
- may begin with aura or simple focal seizure
- signs/sxs:
stiffening of muscles
LOC
tongue/cheek may be bitten
tonic/clonic phases
- consciousness returns slowly and person may be drowsy, confused or agitated
39
Dx secondary generalized seizure?
| Tx?
- Dx: EEG, MRI
| - tx: carbamazepine
40
Occurence of post traumatic epilepsy?
| Causes?
- depends on degree of head injury
- majority develop seizures within 1-2 years
- 2/3 have focal or secondarily generalized seizures
```
causes - head injuries:
penetrating head wounds
cerebral hematoma
intracerebral hematoma
unconsciousness or amnesia lasting more than 24 hrs
```
41
Dx seizures - 3 objectives?
- 1) determine if pt has epilepsy
- 2) classify seizures and type of epilepsy accurately and determine if clinical data fit a particular epilepsy syndrome
- 3) ID, if possible, specific underlying cause
42
What is impt in hx of pt with seizures?
- pts description of the experience: aura?
- witness's accurate observation
- how it started
- at what age
- family hx
- hx of focal trauma or other insult
- recent drug use
- ETOH (withdrawal)
- hx of CNS infection
- hx of event: recent onset - in adults may indicate new intracranial lesion
chronically sustained or remote hx: suggests chronic epilepsy
- do they occur at particular time?
- are they exacerbated by: emotional stress, menstruation, fever
- other known provocations: flashing lights
- drugs - Rx and other
43
What is impt to look for on PE?
- exam b/t seizures show no abnormality
- lateralized or focal signs postictally suggest seizures may have focal origin
- Postictal (Todd's) paralysis?
- other focal abnorm?
- bruits? heart murmur?
44
Workup of seizure pt? What are other conditions that can mimic a seizure?
- is it a seizure?
- 4 conditions can mimic a seizure:
REM behavior disorder
TIA
transient global amnesia
migraine
45
What is REM behavior disorder? How is dx made?
- parasomnia that consists of sudden arousals from REM sleep immed followed by complicated, often aggressive, behaviors for which the pt is amnestic
- dx is clarified by overnight sleep testing
46
Characteristics of a TIA?
- may last seconds to minutes
- characterized by neg sxs and signs (weakness or visual loss)
- postictal state may include lateralizing "negative" sxs such as weakness
47
What is transient global amnesia?
- condition of vascular etiolgy
- occurs after age of 50
- deficit of short term memory that begins abruptly and persists for minutes to hours, w/o other cognitive or motor impairment
- episodes can be recurrent
48
Migraine manifestations?
- migraine auras such as visual illusions and basilar migraine sxs, including altered consciousness, can mimic complex partial seizures
- HA that follows complex partial and generalized tonic clonic seizures is migrainous in quality and duration
49
Most impt dx test for epilepsy?
- EEG
- classifying seizures correctly
- ID epileptic syndromes
- making therapeutic decision
- to be completely dx - must be obtained during seizure activity
- 40-50% of pts show epileptiform abnorm in their initial EEG
- capture of epileptiform activity is enhanced by sleep deprivation for 24 hrs so that pts sleep during a portion of EEG recording
50
Imaging in dx epilepsy?
- MRI: **study of choice
should be obtained in all pts over 20 suspected of having epilepsy for possibility of underlying neoplasm
- should be obtained on all children with partial seizures, abnorm neuro finding, or focal slow wave abnorm on EEG
- ID structural brain patho
- CT: alt choice
51
Labs needed in epilepsy dx?
- est baseline
- AED levels
- acute/chronci syst disease:
CMP
TSH
CBC
drug screen (blood or urine)
blood sugar levels
- lumbar puncture if indicated
- EKG
52
What is status epilepticus?
Causes?
- any seizure lasting more than 30 min or a prolong flurry of seizures w/o return to previous level of consciousness b/t seizures
- life threatening, esp if generalized tonic-clonic status, if pt arrives in ED still seizing, assume they are in SE and tx accordingly
Causes: drug noncompliance or sudden withdrawal, fever, drug or alcohol withdrawal
53
What is 1st thing you should assess in pt with status epilepticus?
- ABCs
airway: roll to side, head tilt, and oral airway
breathing: oxygen, intubation
circulation: cardiac monitor, maintain blood pressure
54
Tx status epilepticus?
- blood draw for glucose, lights, Ca, Mg, CBC, drugs of abuse, AED levels
- start IV and give thiamine and glucose
- ativan (lorazepam) 2 mg/min
- fosphenytoin (20 mg/kg) IV or
phenytoin 20/Kg IV
- if above not effective after 20 minutes: phenobarbital 20 mg/Kg IV (watch respirations), deacon 15-20 mg/kg IV
- if cont failed measures then general anesthesia with ventilator assistance with neuromuscular jxn blockade
55
Tx for refractory Status epilepticus?
- pentobarbital coma
- midazolam (versed) drip
- propofol (diprivan) drip
- cont monitoring
56
Tx of provoked seizures?
- tx directed to provoking factor
57
Tx of unprovoked seizures?
1st seizure
2nd seizure
- 1st seizure: usually no tx
- tx can be initiated if risk of reoccurence is high
- 2nd seizure:
dx of epilepsy is established and risk of 3rd seizure is high
- most physician tx at this stage
- in children some may wait for 3rd seizure
58
Tx options for seizures?
- neuro referral!!!
- meds
- surgery
- ketogenic diet
- vagal nerve stimulator
- biofeedback
59
effective tx % in pts with seizures?
- approx 60% of pts achieve seizure control after 1st year
- 15% achieve control at later date
- 25% continue to have seizures despite tx
- selection depends on seizure type and SE/toxicity profile
- MOA of each med plays role in what type of seizure for which it may be effective
60
3 basic MOAs of seizure meds?
- affecting voltage dependent Na or Ca channels: Na+ channel blockers effective for tonic-clonic and partial seizures, T-type CCBs effective for absence seizures
- increasing inhibitory neurotransmission (GABA)
- decreasing excitatory neurotransmission (glutamate and aspartate)
61
Common meds used to tx seizures?
- dilantin (phenytoin)
- tegretol (carbamazapine): 1st line for focal and generalized tonic-clonic
- depacon (valproic acid): 1st line for atypical absence
- phenobarbital
- zarontin (ethosuximide): first line for absence
- Valium (diazepam)
- ativan (lorazepam)
- klonipin (clonazepam)
62
Newer antiseizure meds?
- neurontin (gabapentin)
- lamictal (lamotrigine)
- felbatol (felbamate)
- topamax (topiramate)
- trileptal (oxcarbazepine)
- zonigran (zonisamide)
- gabitril (tiagabine)
- cerebyx (fosphenytoin)
63
Common SEs of antiseizure meds?
- lethargy
- memory difficulties
- cognitive or concentration difficulties
- cog or concentration difficulties (diff staying focused)
- hyperactivity
64
Levitiracetam (keppra)
SEs
- 2nd line for generalized tonic-clonic
- dosage based on medical condition, kidney fxn, and response to tx:
1000-3000 mg qday or BID
steady state achieved in about 2 days
```
SEs:
somnolence
ataxia
HA
behavioral changes
```
Preg C
65
Carbamazepine (tegretol)?
Use?
MOA?
SEs? Warnings?
- 1st line for focal and gen tonic-clonic
- blocks Na+ channels
- dosage: 800-1200 mg qd, divided doses bid-qid
- start at 200 mg PO bid
- therapeutic range: 4-12 mg/L
- preg D
- AEs: bone marrow suppression, liver toxicity, rash
- monitor CBC, LFTs
- warnings: serious and sometimes fatal derm rxns to include toxic epidermal necrolysis and SJS
66
Phenytoin (dilantin) use?
MOA?
SEs, warnings?
Monitor?
- first line for focal and gen tonic-clonic
- alters Na+ and Ca2+ conductance membrane potentials
- blocks sustained high frequency repetitive firing
- high doses: inhibits release of serotonin and NE, promotes uptake of dopamine, inhibits monoamine oxidase activity
- dosage: 300-400 mg PO in divided doses qd-tid
- IV dilantin pt must be on *cardiac monitor
- Preg D
SEs: gingival hypertrophy**, hirsutism, coarsened facial features, megaloblastic anemia, lupus like syndrome
- monitor: CBC, LFTs, plasma levels (steady state plasma concentration of 10-20 mcg/ml (reached in 5-10 days)
- warning: CV risk assoc with rapid infusion ( cardiac monitor)
67
```
Valproic acid (depakote)
use?
Preg category?
SEs?
Monitor?
```
- first line for focal, generalized tonic-clonic, absence, atypical absence, myoclonic, and atonic
- MOA: increases level of GABA
- dosage: 10-15 mg/kg/d po in divided doses
- increase by 5-10 mg/kg/day q 7 days, max 60 mg/kg/d
- preg D
SEs: tremor, wt gain, liver dysfxn (high risk under age 2 - BBW), pancreatitis, teratogenic effects
- monitor: LFTs, CBC, and drug levels
therapeutic range: 50-100 mg/L
68
Lamotrigine (lamictal)
use?
Preg?
SEs?
first line for focal and absence
- ***effective in tx of children with newly dx absence seizures
- MOA: stabalizes neuronal membranes by acting on AA release and inhibiting NA+ channels
- dosage: 250 mg PO bid
- pregnancy C
- SEs: dizziness, HA, nausea, somnolence, skin rash (BBW: SJS)
69
```
Gabapentin (neurontin)
use?
MOA?
Preg?
SEs?
```
- second line for focal and generalized tonic-clonic
- MOA: reduce presynaptic GABA release
- dosage: 300-1200 mg PO tid
- pregnancy C
- SEs: somnolence, dizziness, ataxia HA, tremor
70
```
Topiramate (topramax)
use?
MOA?
Preg?
SEs?
monitor?
Caution?
```
- first line for focal
- MOA: blocks Na+ channels, enhancing GABA activity
- dosage: 200-600 mg/day
- pregnancy C
- SEs: somnolence, fatigue, dizziness, cognitive slowing, paresthesias, nervousness, confusion
- monitor: liver and renal status
- Caution: narrow angle glaucoma, and kidney stones (keep pt hydrated)
71
```
Phenobarbital
use?
MOA?
Preg?
SEs?
Warnings?
Monitor?
```
- second line for focal and generalized tonic-clonic
- MOA: enhances GABA, interferes with transmission of impulses from thalamus to cerebral cortex
- dosage: 60 mg PO bid-tid
- preg D
- SEs: sedation in adults and children, irritability, restless muscle movements in eyes, tongue, jaw
- warnings: sleep apnea, COPD, renal problems, suicide
- monitor: drug concentration=therapeutic range 15-40 mg/L, CBC, LFTs
72
```
Ethosuximide (Zarontin)
use?
MOA?
Preg?
SEs?
Monitor?
```
- 1st line use for absence
- MOA: depresses motor cortex
- dosage: 40-100 micrograms/ml
- Preg: C
- SEs: stomach aches. cramps, N/V, hiccups, drowsiness, fatigue, rashes, SLE, bone marrow suppression
- monitor hepatic disease and renal impairment!
73
```
Oxcarbazepine (Trileptal)
Use?
MOA?
Preg?
SEs?
```
- 1st line for focal
- MOA: blocks voltage sensitive Na+ channels, stabilizes neural membranes, inhibits repetitive firing, and decrease synaptic impulse propagation
- metabolized/excreted: liver/urine
- preg C
- dosage: 600 PO bid
- SE: HA, N/V, somnolence, hyponatremia, angioedema, severe rash
74
```
Felbamate (felbatol)
use?
MOA?
Preg?
SEs?
```
- 2nd line for focal, and generalized tonic-clonic
- MOA: inhibitory effects of GABA and benzodiazepine receptor binding
- met/excreted: liver/urine
- preg C
- pt has to sign risk acknowledgement form to take (not a good pick)
- SEs: wt loss, nausea, insomnia, HA, hepatic failure, aplastic anemia (bone marrow suppression), suicide
75
```
Zonisamide (zonegran)
use?
MOA?
preg?
SEs?
```
- only for adjunctive therapy for focal (w/o impairment of consciousness)
- MOA: blocks voltage dep Na+ and Ca2+ channels, metabolized/excreted: liver/urine and feces
- preg: C
- sleepiness, dizziness, rash, fever, sore throat, easy bruising
- don't use in pts with renal failure (CrCl of less tha 50 ml/min), and children
76
Tiagabine (gabitril)
- Use
- MOA
- Preg
- SEs
- monitor?
- 2nd line for focal
- MOA: increases GABA activity in CNS
- met/excreted: liver/feces and urine
- Preg C
- give to kids older than 12 yo
- SE: dizziness, tiredness, nervousness, weakness, confusion
- monitor: CBC, renal fxn test, LFTs, and blood chemistry
77
Meds summary?
- many reqr baseline Cr
- newer meds less sedating, more expensive
- goal: mono-therapy
- start low, don't stop abruptly
- monitor CBC and LFTs
- most preg women with epilepsy should continue seizure meds, and if possible take single AED at lowest dose possible
- potential benefits outweight risk
- Can D/C drugs when pt hasn't had seizure for 3 years
- reduction should be gradual over weeks to months, should be withdrawn one at a time
- if seizures reoccur - tx is reinstituted with prev regimen
78
Alt therapies?
- DON'T REPLACE DRUGS
- biofeedback
- ketogenic diet (high fat/low carb) - body burns fat insteda of glucose for energy, usually used in kids refractory to AEDs
- vagal nerve stim: implantation of device to stim vagus nerve, to abort the seizure
79
Surgery options for epileptic pts?
- anterior temporal lobectomy
- corpus callosotomy
- amygdala-hippocampectomy
- VNS
80
Educating epileptic pts?
- avoid sleep deprivation and ETOH
- avoid jobis that involve working at heights, near heavy machinery, flames or burners
- restrictions on careers:
firefighter, commercial driver, airline pilot
- never swim alone
- most sports are permitted
- but caution on:
hang gliding
scuba
mountain climbing
skydiving
