Flashcards in Seizures Deck (29):
Seizure: sudden excessive disorderly discharge of neuronal activity in the brain
epilepsy: recurrent unprovoked seizures
convulsion: body muscles contract and relax rapidly and repeatedly, uncontrolled shaking of the body
Causes of Epilepsy?
Seizures beginning after age 20 are usually d/t what?
-epileptogenic neurons (fire more intensely, more often, and with greater amplitude)
-highest in children, 2-5yrs and at puberty. *usually idiopathic or primary generalized epilepsy
-pts older than 50yo
Seizures beginning after age 20 are usually due to a focal process or metabolic derangement.
What are the most common causes of seizures:
infancey/childhood: fever, trauma, hereditary metabolic, injury, infections
young adult: trauma, alcohol, drugs
middle age: cancer, alcohol, vascular dz (stroke)
late life: vascular dz, cancer, degenerative brain disorders
Other: sleep deprivation, fever, withdrawl
What is the difference between provoked and unprovoked seizures?
unprovoked seizures occur in the setting of persistent brain pathology whereas provoked are triggered by factors in an otherwise healthy brain.
exacerbations of seizure disorders are most commonly due to?
Mortality of epilepsy patients is d/t?
Mortality d/t underlying cause of epilepsy or sudden unexpected death of epilepsy (SUDEP; sudden, unexpected, nontraumatic, nondrowning)
Describe the Phases of seizures:
prodrome: feeling, sensation or changes in behaviors hours or days before seizure..deja vu, smell, sounds, taste, fear, HA, nausea
aura: 1st sx of a seizure and considered part of the seizure
Middle: "ictal phase"
-sx: loss of awareness, confusion, distracted/daydreaming, difficulty talking, unable to swallow, repeated blinking of the eyes, lip smacking or chewing movements.
Endin: "postictal phase"
Sx: slow to respond, sleepy, confused, injuries, HA, nausea
What are the types and Describe the difference between focal and generalized seizures?
-focal: limited to one cerebral hemisphere
--focal seizure without impairment of consciousness
--focal seizure with impairment of consciousness
Generalized: involves the cerebral cortex of both sides of the brain
--absence (petit mal)
--clonic, tonic, atonic
--tonic-clonic (grand mal)
Focal seizures w/o impaired consciousness can be categorized into what groups?
-Motor (jacksonian march; jerking stays on one side of the body, weakness, affected speech, coordination of actions)
-sensory: changes sense of smell and taste, clicking, ringing, pins/needles, floating in space, illusions, hearing voices
-autonomic: chest discomfort, changes in heart rate and breathing
-psychic: garbled speech, written language is off, trouble word finding
Features of focal seizure w/o impaired consciousness
-Todds paralysis (temporary, unilateral, 30min-36hrs)
-can progress to focal seiz w/ impaired consciousness to tonic clonic seizure
Focal seizure WITH impaired consciousness
-arise from which lobe?
what: produce unresponsiveness
arise from the temporal lobe
duration: 30seconds to 2 minutes
-same sx as focal w/o impairment, but these pts cannot talk to you.
-confusion and tiredness follow seizure for about 15mins
Generalized onset seizures: Absence
aka: "petit mal seizures"
What: non-convulsive epileptic events
Onset: typically occur in childhood and cease in adulthood.
Duration: onset and termination of attacks are abrupt
Consciousness: disturbances in consciousness; impairment so brief pt is unaware of it, lasts 10seconds
Generalized: Absence seizures:
-stop talking mid sentence
-mild clonic, tonic, or atonic components
-may have automatisms
-no postical period
Generalized: Atypical absence seizures
onset: gradual onset
duration: do not resolve abruptly
appearance: loss of muscle tone in neck and face. twitching of mouth...
consciousness: may not have an altered level of consciousness.
Generalized Myoclonic Seizure:
-what is this?
-most common time of occurrence?
What: rapid recurrent brief muscle jerks that can occur:
*may terminate into generalized tonic-clonic seizure
Most commonly occur shortly after waking or while falling asleep
Generalized: Atonic seizure
-characterized by what?
-aka: "drop attacks"
-characterized by sudden loss of muscle tone that may result in falls with self-injury
-most common in who?
-temp is usually what?
- what are the 2 types?
Fever is most common cause of convulsions in children.
temperature is usually greater than 38 (100.4)
2 types: simple and complex
appearance: body becomes stiff and arms and legs twitch, lose consciousness, Simple lasts 15mins or less, complex lasts greater than 15minutes and happens multiple times in 24hr period
tx: IV lorazepam
Tonic Clonic Seizure
aka: Grand Mal
What: major motor seizure involving all extremities and characterized by sudden loss of consciousness.
Cause: may be primary arising from deep brain structure or represent a focal seizure with secondary generalization
tonic clonic seizure:
-what is tonic?
-what is clonic?
-describe the postictal scene
Tonic: rigid, LOC, collapse, respiratory arrest
*this usually last less than 1 min*
*may last 2-3 minutes*
-tongue and lips may be bitten
-urinary or fecal incontinence
-injury may occur
-may recover consciousness, drift into sleep, have further convulsions w/o recovery of consciousness between attacks (status epilepticus)
*have no memory of this
Secondary Generalized Seizure tonic clonic:
-what is this?
seizure that becomes generalized (spread to both sides of brain) after the initial event (focal seizure) has already begun.
dx: EEG and MRI
Post traumatic epilepsy
-most common causes
What: seizures post trauma, depends on degree of head injury
-penetrating head wounds
-unconsciousness or amnesia lastin more than 24hrs
Objectives of Seizure Dx
-determine if pt has epilepsy
-classify the seizure and type of epilepsy accurately and determine if the clinical data fit a particular epilepsy syndrome.
-identify, if possible, a specific underlying cause
What 4 conditions can mimic a seizure? What is each?
-REM behavior disorder: sudden arousals from REM sleep immediately followed by complicated often aggressive behaviors for which the pt is amnestic
transient ischemic attack
Transient global ischemia: short term memory deficit without other cognitiev or motor impairment
Seizure WOrk up:
-what is the most important dx test?
-what labs might you order?
-eeg; classifies seizures, identifies epileptic syndromes, helps in making therapeutic decisions
-MRI and CT as alternative
-anti-epileptic drug levels (AED)
-CMP, TSH, CBC, drug screen, glucose
WHat: any seizure lasting greater than 30 minutes or prolonged flurry of seizures without return to previous level of consciousness between seizures
*life threatening, especially if generalized tonic clonic status
-drug noncompliance or sudden withdrawl
-alcohol or drug withdrawl
-IV thiamine and glucosse
if the above are ineffective: phenobarbital or depacon ....if these fail; general anesthesia w/ ventilator assistance with NMJ blockade
All seizure tx
-provoked vs unprovoked
Provoked: tx underlying cause
1st seizure = no tx
2nd seizure = diagnosed with epilepsy and treat
other tx options:
-surgery; Anterior temporal lobectomy, corpus callostomy, amygdala-hippocampectomy
-ketogenic diet: high fat; low carb
-vagal nerve stimulator: implantation of device to stimulate vagus nerve to abort seizure
-3 basic MOA of medications
1.Voltage dependent Na or Ca channels:
-Na channel blockers effective for tonic-clonic and partial seizure
-Calcium channel blockers effective for absence seizures
2. Increasing inhibitory neurotransmission (GABA)
3. Decreasing excitatory neurotransmission (glutamate and aspartate)
-common medications & therapeutic plasma conc.
-Dilantin (phanytoin) (first line focal and generalized tonic clonic, plasma conc= 10-20mcg/mL)
*Na and Ca channel
-Tegretol (carbamazapine, 1st line for focal and generalized tonic clonic) Plasma conc = 4-12mg/L
--may cause toxic epidermal necrolysis & steven johnson syndrome
-Depacon (1st line focal, generalized tonic-clonic, absence, myoclonic, atonic, and atypical absence) --Plasma conc = 50-100mg/L
--BBW: liver dysfunction less than 2yrs old
-Phenobarbital (2nd line for focal and generalized tonic-clonic)
--plasma conc = 15-40mg/L
-Zarontin (1st line for absence)
--plasma conc = 40-100mg/L
--SE: bone marrow suppression
*depress motor cortex
What are the common side effects of the seizure medications?
-cognitive or concentration difficulties