Exam 1 - Seizures Flashcards
what is the clinical definition of epilepsy?
1 unprovoked seizure, > 24 hours apart
a disease that results in an enduring predisposition to seizures
what is the clinical definition of refractory epilepsy?
> 6 seizures per year in the face of standard therapy
what are common changes observed in the post-ictal phase?
cortical blindness, behavior change, symmetrical proprioceptive deficits
what are the 3 general causes of seizures?
idiopathic, structural, & reactive
how is idiopathic epilepsy diagnosed?
diagnosis of exclusion
what causes idiopathic epilepsy?
genetic cause is suspected but rarely proven
what age of animals get idiopathic epilepsy?
1-5 year old animals
are dogs or cats more affected by idiopathic epilepsy?
dogs - does happen in cats though
what is the difference between progressive & non-progressive structural epilepsy?
you expect worsening forebrain signs in the progressive form & signs may improve or resolve in the non-progressive form
what can cause the progressive form of structural epilepsy?
neoplasia
inflammation - infectious or immune-mediated
degenerative
what can cause the non-progressive form of structural epilepsy?
vascular insult
trauma
what causes reactive seizures?
electrolyte imbalances - calcium & sodium
hypoglycemia or other energy failure
endogenous neurotoxins - hepatic encephalopathy
exogenous neurotoxins
are most CNS neurotoxins excitatory or inhibitory?
excitatory
what clinical signs are expected with CNS neurotoxins?
seizures, tremors, & tetany
what is the symptomatic treatment for CNS neurotoxins?
stop the seizures
control the seizures - muscle relaxants
control body temperature - watch for hyperthermia
for decontamination of CNS neurotoxins, what should be done for ingested toxins?
gastric lavage with activated charcoal through a stomach tube
for decontamination of CNS neurotoxins, what should be done for cutaneous toxins?
lipid-targeting detergent - dish soap
what clinical signs are seen with bromethalin?
high doses - seizures
low doses - delayed paresis
what is the treatment for Bufo toad toxicity?
wash the mouth & eyes
what neurological clinical signs are typical with ivermectin toxicity?
mydriasis & blindness
what neurological clinical signs are typical with lead toxicity?
diffuse forebrain signs
what neurological clinical signs are typical with macadamia nut toxicity?
posterior limb paresis & stiffness
what neurological clinical signs are typical with ethylene glycol toxicity?
seizures before renal failure
what neurological clinical signs are typical with pyrethrin/permethrin toxicity in cats?
tremors +/- seizures
what is the treatment for ivermectin toxicity?
intralipid iv infusion
what is the treatment for lead toxicity?
chelating agents
what is the treatment for organophosphate toxicity?
atropine +/- 2-PAM
what is the treatment for ethylene glycol toxicity?
fomepizole
what is the treatment for pyrethrin toxicity in cats?
bath with dish soap
what is status epilepticus?
> 5 minutes of continuous epileptic seizure activity or > 1 seizure without recovery between
what are cluster seizures?
> 1 seizure within 24 hours
what critical systemic effects can happen as a result of seizures?
hyperthermia, hypoxia, metabolic acidosis, hypoperfusion, & arrhythmia
what critical neurologic effects can happen as a result of seizures?
energy deprivation, excitotoxicity, & cerebral edema
why benzodiazepines for emergency seizure management?
they act quickly, reliably stop seizures in progress, & are widely available in a wide variety of formulations
what is the role of keppra in emergency seizure management?
help reduce the need of rescue diazepam
what are the risks of using a loading dose of phenobarbital/propofol for stopping seizures?
respiratory depression
unprotected airway
hypotension
T/F: a surgical plane of anesthesia will abolish seizure activity & help with long-acting seizure control
false
anesthesia doesn’t provide long-acting control, but it gives you time to make a plan
how long will you hospitalize a patient presenting for cluster seizures or status epilepticus?
until the current seizure stops
24 hours off a CRI with no seizures
until referred/transferred
usually - 2 days
when looking at if seizures will occur again, what causes can make it likely to not happen?
proven ingestion of a toxin
proven reaction seizure due to metabolic abnormality
concussive seizure
T/F: certain reactive seizures can be ruled out quickly
true
when looking at if seizures will occur again, what causes can make it likely to happen in the future?
idiopathic epilepsy, structural forebrain disease, status epilepticus, cluster seizures as presenting complaint, or persistent neurological abnormality
when looking at intermediate term seizure management, what drugs will be effective within hours & stay effective for hours?
benzodiazepine CRI
levetiracetam
phenobarbital
zonisamide
on a benzodiazepine CRI as intermediate term seizure management, how long until cmax is reached? how is it administered?
> 5 minutes
IV
on levetiracetam as intermediate term seizure management, how long until cmax is reached? how is it administered?
30 - 80 minutes
IV or PO
on phenobarbital as intermediate term seizure management, how long until cmax is reached? how is it administered?
2 - 8 hours
IV or PO
using a benzodiazepine CRI for intermediate term seizure management, how long is the duration of effect?
up to 48 hours
using levetiracetam for intermediate term seizure management, how long is the duration of effect?
5-8 hours
using phenobarbital for intermediate term seizure management, how long is the duration of effect?
> /= 12 hours
using zonisamide for intermediate term seizure management, how long is the duration of effect?
> /= 12 hours
in the real world, what are the goals for minimizing seizures?
less frequent seizures
not as long-lasting seizures
preventing seizures that are dangerous to others
in the real world, what are the goals for minimizing adverse effects?
long term treatment duration is expected
pre-existing dysfunction of an organ system
monitoring isn’t possible in certain drugs
what are the general impacts of adverse effects on your patient on seizure drugs?
direct effect on patient’s health - organ toxicity
direct effect on patient’s quality of life - sedation/ataxia/polyphagia
indirect effect on efficacy of the medication - a medication that isn’t given is 0% effective
T/F: when evaluating seizure meds, you should make changes gradually whenever possible & only change one thing at a time
true
why does the frequency of seizures complicate treatment?
natural variation in the frequency of seizures complicates the assessment of efficacy
T/F: any seizure drug can cause an adverse effect in a given patient & may be unpredictable
true
between phenobarbital/potassium bromide & levetiracetam, which group is more likely to cause adverse effects?
phenobarbital/potassium bromide ***
T/F: there are dose-dependent effects of seizure drugs
true
