Clin Med - Seizures Flashcards
define status epilepticus
-30 min of continuous seizure activity
or
-multiple seizure w/o return to neurologic baseline
-it can look like pt came out of full seizure activity but they never quite do
generalized convulsive status epilepticus is ?
-5 min of pronounced motor activity w/ tonic contractures followed by clonic jerking
generalized nonconvulsive status epilepticus is ?
- typically happens after convulsive status
- more subtle jerks of the face, eyes and extremities with less intense motor activity
how to determine convulsive from non convulsive on EEG
you can’t, they’re often identical
convulsive status epilepticus danger
- more rapidly damaging
- should be aggressively treated
nonconvulsive status epilepticus
- harder to diagnose
- could be finding a pt w/ altered mental status that is worse than expected for his/her underlying condition
- should raise concern
pathophys of status
- first and rapid changed d/t protein phosphrorylation
- opening and closing of ion channels and release of NTs and modulators
- AEDs work at this level
3 things excitation can come from in status
- established epileptogenic circuit from preexisting epilepsy
- excitation from the region surrounding a structural lesion
- diffuse excitation from a toxic or metabolic state
what process during status is described as angina of the brain?
- accumulation of extracellular K+
- increases susceptibility of nuerons to repeated and continuous depolarizations
- causes oscillating paroxysms b/w cortex and subcortical areas
- this process increases 2-3 fold in high O2 need – “angina of brain”
general overview of guidelines for tx of status
- have a plan
- start IV
- therapeutic endpoint = cessation of seizure
- be prepared to ventilate
- use adequate doses
- less risk of giving too much than the risk of under treating
important of timing in the tx of status
- early!!
- tx becomes less effective the longer it lasts
- time to tx is more important than the sequence of meds
drugs to avoid in tx of status
- narcotics
- phenothiazines (antiemetic)
- paralyzing agents (except briefly during intubation)
where/when should tx for status be started?
tx is most effective when started in the field
first line meds for tx of status
- lorazepam
- midazolam
- diazepam
second line meds for tx of status
- phenytoin
- fosphenytoin
- valproate
- levetiracetam
- lacosamide
third line meds for tx of status
- propofol
- midazolam
- pentobarbital
- ketamine
more recent studies show better efficacy for what tx vs lorazepam?
IM midazolam
lorazepam
- dose
- onset
- duration
- 0.1 mg/kg at rate of 2mg/min
- onset: 6-10 min
- duration: 12-24 hrs
- refractoriness often occurs after 1-2 days
diazepam (valium)
- onset
- duration
- side effects
- onset: 1-3 mins
- duration: 15-30 mins
- CNS depressant: decreased BP and respirations
phenytoin
- onset
- rate
- duration
- side effects
- onset: 10-30 min
- *don’t exceed a rate of 50mg/min to reduce risk of cardio events
- duration: 24-36 hrs
- may decrease bp and HR
*don’t use unless no other option
fosphenytoin
- can be given at faster rate
- a prodrug converted to phenytoin in the liver before exerting effect
levetiracetam (keppra)
- no hepatotoxicity, low does in renal failure
- great for pt in ER being noncompliant w/ breakthrough seizure
- SAFE!
valproic acid (depacon)
- dose
- effectiveness
- 25mg/kg followed by 500mg IV q 6 hrs
- effectiveness depends on early admin
when all else fails… what med?
midazalam (versed)
midazalam dose
- 0.2 mg/kg initial bolus w/ maintenance of 0.1-2mg/kg/h
- need EEG monitoring
- best to avoid if possible b/c more likely to cause hypotension and pancreatitis
what specific condition is phenobarbital good for?
-ETOH withdrawal seizures
in status, if you exhaust all the option and pt is still in status, what is the next step?
-put them in deep barbiturate coma (phenobarbital)
phenobarbital
- last resort tx
- associated w/ danger of severe hypotension
- very long half life so could take a long time to wake up pt
timeline of status
- ambulence picks up pt (20 min)
- it’s refractory if > 1 hr and has high mortality rate
- gets to ER (20 min)
- you make diagnosis (5 min)
- start IV
- give lorazepam
- intubate
- give 2nd line drugs
- send pt to ICU/transfer out
what is the single best prognostic indicator of a good outcome for status:
- how many minutes pass b/w onset of status and giving the pt 0.1 mg/kg of lorazepam
- DO NOT DELAY!
categories of epilepsy
- focal
- simple
- complex - generalized
focal epilepsy
involving brain networks confined to 1 hemisphere
simple focal
- don’t impair consciousness
- consist of autonomic, cognitive, emotional, somatosensory, visual or involuntary motor activity
- equivalent to the old term aura
complex focal
- impaired or altered conciousness - can cause behavioral arrest
- staring, oral/manual limb automatisms like chewing, lip smacking, aimless fumbling hand movements
- amnesia most likely to occur
what is the term for when a focal seizure becomes generalized?
secondary generalized
generalized
beginning in b/l distributed networks synchronously in both hemispheres from onset
chacteristics of a frontal seizure
- focal clonic motor
- hypermotor behavior
characteristics of a temporal seizure
- autonomic
- dysmnesic
- deja vu
- jamais vu
- gustatory
- olfactory
- auditory
- complex visual
- dysphasia
characteristics of a parietal seizure
somatosensory
characteristics of an occipital seizure (rare)
simple visual
absence seizure
staring w/ unresponsiveness w/o aura or postictal state
atonic/astatic seizure
loss of muscle tone and falling
tonic seizure
sustained abnormal posturing of the extremities (<15 sec) w/ or w/o vocalization, apnea and falling
myoclonic seizure
-sudden brief jerks or twitching or limp or axial muscles, consciousness usually preserved
clonic seizure
repetitive jerking movements
tonic clonic seizure
- intial tonic posturing phase followed by several mins of postictal stupor, confusion and language or motor dysfunction (Todd paralysis)
- loss of bladder or bowel continence and tongue lac from biting
chart on seizure types
review slide 37
EEG
- can be done on pt awake or asleep, outpatient or inpatient
- uses activating procedures
- may need repetitive EEGs
how do epileptiform abnormalities normally appear on EEG?
- spikes
- sharp waves
- spike-wave discharges distinct from the normal background activity and indicate an increased seizure activity
high predicitor of recurrent seizures on EEG
abnormal EEG after first time seizure
what are causes that could cause epileptiform abnormalities on EEG other than seizure
- occipital spikes if blind
- generalized spikes in relatives of pts w/ genetic epilepsy
- interictal epileptiform discharges d/t meds like buproprion/tramadol or pts w/ renal failure or acute encephalopathy
examples of provoked seizures
- alcohol withdrawal
- severe hypotension
- severe hypoglycemia
- cardiac arrhythmia w/ brief syncope
- drugs
- extreme sleep deprivation
- meds
what meds can provoke a seizure
- tramadol
- imipenem
- theophylline
- buproprion
a provoked seizure is often what kind?
generalized convulsive - not focal
who are the pts that will most likely end up taking AEDs
- hx of remote seizures
- > 60 yo, new unprovoked
- prior brain lesion or insult
- EEG abnormality
- significant brain-imaging abnormality
- nocturnal seizure
- sx of focal seizure
- focal seizure w/ secondary generalization
what seizure type doesn’t follow the general guidelines?
juvenile myoclonic epilepsy
juvenile myoclonic epilepsy
- MC genetic generalized epilepsy
- present w/ generalized tonic-clonic seizure, often provoked
common pt hx in juvenile myoclonic epilepsy
- hx of early morning myoclonic jerks triggered by sleep deprivation
- pt will attribute to nervousness or clumsiness
- so they think the tonic-clonic presentation is the first seizure
tx of juvenile myoclonic epilepsy
- valproic acid but high ADRs
- lamotrigine is a good 2nd choice
- avoid provoking factors
epilepsy drugs???
she talked about a lot of them but…. focus on letassys????
