seizure disorders Flashcards
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
Q
Clincial sxs of generalized onset seizures?
A
- disturbances in consciousness
- involve varying bilateral degrees of symmetric motor responses w/o evidence of localization to one hemisphere
26
Q
examples of generalized onset seizures?
A
- absence (petit mal)
- myoclonic
- atonic (drop)
- febrile seizure
- idiopathic tonic-clonic (grand mal)
- post traumatic epilepsy
27
Q
What are absence seizures?
Typically occur in?
A
- 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
Q
Examples of abscence seizure presentations?
A
- blank stare
- motionless
- stop talking mid sentence
- can have mild clonic, tonic, or atonic components
- may have automatisms
- no postictal period
29
Q
Characteristics of atypical absence seizures?
A
- 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
Q
Myoclonic seizures?
Range?
A
- 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
Q
What are atonic seizures?
A
- 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
Q
What are febrile seizures? Occurs in what population?
diff types?
Tx for prolonged seizures?
A
- 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
