Seizures and Epilepsy

Question 1

what is a seizure?

Answer 1

clinical manifestation of excessive hypersynchronous neuronal activity

Question 2

what does it mean that a seizure is a paraxysmal event?

Answer 2

sudden and transient

Question 3

what are seizures characterized by?

Answer 3

motor, autonomic, and behavioral manifestations

Question 4

how long does a seizure last?

Answer 4

brief: 1-3 minutes

Question 5

where do seizures usually come from in the brain?

Answer 5

prosencephalon/forebrain

Question 6

in the normal state, there is a balance between _______________ and ________________

Answer 6

neuroexcitation
neuroinhibition

Question 7

what structural changes occur with seizure propagation?

Answer 7

loss of lateral and surrounding inhibition
outgrowth of aberrant excitatory axons
loss of inhibitory neurons
denervation hypersensitivity

Question 8

what molecular changes occur with seizure propagation?

Answer 8

increase in number, sensitivity, and distribution of glutamate receptors
decreased GABA receptor expression
decreased GABA production
reduced potassium and glutamate uptake

Question 9

what electrical charges occur with seizure propagation?

Answer 9

paroxysmal depolarizing shift: abnormal fluctuations of neuronal membrane voltage, far outlast depolarization of normal action potentials

Question 10

what is the seizure threshold?

Answer 10

level of neuronal inhibition that, when exceeded, results in uncontrolled discharge of the neurons

Question 11

what happens in seizure propagation?

Answer 11

seizure focus
synchronous paroxysmal discharges in large area
kindling effect

Question 12

what are the phases of an epileptic seizure?

Answer 12

prodrome
ictus
postictal

Question 13

what is the prodrome/preictal phase of an epileptic seizure?

Answer 13

change in disposition before seizure

Question 14

what is the ictus phase of an epileptic seizure?

Answer 14

seizure itself

Question 15

what often occurs during the postictal phase of an epileptic seizure?

Answer 15

disorientation
apparent blindness
ataxia

Question 16

what causes a focal epileptic seizure?

Answer 16

abnormal activity from localized group of neurons or network within one hemisphere

Question 17

what signs are associated with focal epileptic seizures?

Answer 17

lateralized and/or regional signs

Question 18

what motor signs are associated with focal epileptic seizures?

Answer 18

facial twitches

Question 19

what autonomic signs are associated with focal epileptic seizures?

Answer 19

parasympathetic: hypersalivation, dilated pupils

Question 20

where do generalized epileptic seizures originate from?

Answer 20

both sides of cerebral hemisphere

Question 21

what is a tonic only generalized epileptic seizure?

Answer 21

sustained increase in muscle contraction

Question 22

what is a clonic only generalized epileptic seizure?

Answer 22

excessive abnormal muscle contractions, typically bilateral

Question 23

what is the most common seizure type in dogs?

Answer 23

focal epileptic seizure evolving to become generalized

Question 24

does differentiating between focal and generalized epileptic seizures dictate treatment or severity of seizure disorder?

Answer 24

no

Question 25

what is status epileepticus?

Answer 25

seizure activity lasting more than 5 minutes

Question 26

why is it important to recognize cluster seizures and status epilepticus?

Answer 26

both are medical emergencies and hospitalization is recommended

Question 27

what does ATP depletion due to metabolic rate increasing during a seizure lead to?

Answer 27

cytotoxic edema

Question 28

what leads to neuronal necrosis during a seizure?

Answer 28

neuronal death by excitotoxicity increase in intracranial pressure metabolic rate increasing

Question 29

what are the effects of seizures systematically?

Answer 29

hyperthermia (heat stroke) metabolic acidosis (elevated lactate) noncardiogenic pulmonary edema

Question 30

what is epilepsy?

Answer 30

disease of brain characterized by an enduring predisposition to generate epileptic seizures

Question 31

how many seizures does an animal need to have to be considered epileptic?

Answer 31

at least two unprovoked more than 24 hours apart

Question 32

what is a reactive/provoked seizure usually from?

Answer 32

extracranial or problem outside brain natural response in brain to a transient disturbance in function

Question 33

are reactive/provoked seizures reversible?

Answer 33

yes, when cause of disturbance is corrected

Question 34

what therapeutic agent can cause reactive/provoked seizures?

Answer 34

ivermectin

Question 35

what household items can cause reactive/provoked seizures?

Answer 35

caffeine/chocolate xylitol

Question 36

what is a heavy metal that can cause reactive/provoked seizures?

Answer 36

lead

Question 37

what is structural epilepsy from?

Answer 37

intracranial problem provoked by intracranial/cerebral pathology

Question 38

what do you commonly see with structural epilepsy?

Answer 38

inter-ictal neurologic signs or exam abnormalities

Question 39

what does structural epilepsy require to confirm?

Answer 39

diagnostic imaging cerebrospinal fluid analysis

Question 40

what is idiopathic epilepsy?

Answer 40

no demonstrable systemic or brain pathology: rule out diagnosis first seizure between 6 months and 6 years

Question 41

what does status epilepticus double the risk of?

Answer 41

structural brain disorder or reactive seizures

Question 42

what are some important things to gather during a history?

Answer 42

triggering factors duration of ictal phase number and frequency of events concurrent disorders possible toxin exposure diet history

Question 43

what are some things to pay special attention to during the neurologic exam?

Answer 43

signs of forebrain dysfunction lateralizing signs postictal changes and medications may influence neurologic exam

Question 44

what age group is more likely to have a structural cause?

Answer 44

more than 5 years of age

Question 45

when is a full workup recommended?

Answer 45

abnormal interictal neurologic exam less than 1 year or more than 5 years at onset of seizure cats breeds with high prevalence of structural disease status epilepticus, cluster seizures

Question 46

what is the goal in the hospital with seizures?

Answer 46

stop seizure minimize excitotoxicity avoid complications

Question 47

when should you start maintenance drugs for seizures?

Answer 47

status epilepticus cluster seizures two or more seizure events within a 6-month period

Question 48

what rodenticide can cause seizures?

Answer 48

bromethalin

Question 49

what is more likely if seizures are diagnosed in an animal less than a year of age?

Answer 49

metabolic or structural cause

Question 50

what are the add on seizure medications?

Answer 50

levetiracetam zonisamide felbamate gabapentin pregabalin topiramate telmisartan

Question 51

what are some toxins that can cause seizures?

Answer 51

ivermectin caffeine/chocolate xylitol lead bromethalin ethylene glycol

Question 52

how common is idiopathic/cryptogenic epilepsy?

Answer 52

20%

Question 53

what are the first order medications?

Answer 53

phenobarbital potassium bromide