Epileptic seizures diagnostic approach and classification Flashcards
What is the definition of a seizure?
Transient and involuntary change in behaviour or neurologucal status due to he abnormal activity of populations of CNS neurons
What does hypersycnchronous mean?
All neurons firing at the same time
what is the definition of epilepsy?
2 or more seizures 48 hrs apart
How long (generally) does a seizure need to go on before you can see brain pathology?
30 minutes
How long does a seizure have to go on for before you decide that the brain probably can’t stop that seizure itself?
About 10 mins. Needs intervention
What is the definition of cluster seizuring?
2 or more seizures in 24 hours
More difficult to treat
What are the 4 parts/stages of seizuring?
prodrome
Aura
Ictus
Post-ictal
What is prodrome?
Behaviour changes that occur hours or days before the seizure
What is aura?
Sensory experience pre sensory/focal onset seizures e.g. perceived smell or eeling of deja vu. dif to proove in animals
What is post ictal?
Neurological status alterations hours or days after the seizure
What is ictus?
The seizure event itself
What are the three general classifications of seizures?
Self-limiting
Clustered or continuous
Reflexive
Self limiting and continuous/clustered can both be generalised or focal
:)
What are reflexive seizures?
Seizures which have a precipitating stimulus
What is syncope?
NOT the same as a seizure
Partial or complete loss of consciousness
Lack of motor activit
No post-ictal signs
Short duration
What things commonly stimulae narcolepsy?
Excitement, food, pharmacology
What 4 things can mimic epilepsy but are not?
Syncope, narcolepsy, pain, bestibular syndrome
What are clonic movements?
Rhythmic muscle contractions
How long do seizures normally last?
Around 1 min
Do most recurrent seizures respond to anti epilepic drugs?
yars
What are the four classifications of epilepsy by aetiology?
Symptomatic or secondary seizure
Reactive seizure
Idiopathic/primary epilepsy
Possible symptomatic/cryptogenic epilepsy
What is the cause of symptomatic/secondary seizure?
Structural brain lesion
What is the cause of reactive seizures?
Metabolic or toxic
What is the cause of idiopathic/primary epilepsy seizures?
Unknown, probably genetic
What age of dogs generally present with epilepsy?
6 months to 6 years
beagles, GSDs, labradors, Golden retrievers often get **** seizures
generalised
Viszlas, springer spaniels, standard poodles often get ****** seizures
Focal seizures with or without generalization
Which breed of foals often gets congential seizures which they then grow out of?
Arabs
What are the main causes of seizures in adult horses?
Strucural or metabolic brain disease
Migrating parasite/previous trauma
Intra-carotid injection! Iatrogenic
What age group might you be more suspicious of metabolic cause e.g. PSS, hypoglycaemia, or infectious disease?
Less than 6 months
Which age group might you suspect idiopathic epilepsy, inflammatory/infectious?
6 months to 6 years
Which age group might you be most suspicious of neoplasia as a cause for seizures?
Ovver 6 years
The disease onset and progression can give you clues as to the atiology
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lateralising signs in the neuro exam is mroe likely to be intracranial or extracranial cause?
Intra cranial
If there are symmetrical abnormalities on the neuro exam it is likely to be..
Something affecting the brain as a whole eg Toxic, metabolic, some infectious causes
Hydrocephalus
If you have a normal neuro exam you might suspect..
Idiopathic epilepsy
Could be wax/wane metabolic disease
The following conditions would probably give you symmetrical-generalised onset or assymetical-focal onset?
Idiopathic epilepsy
Metabolic
Toxic
Degenerative
Hydrocephalus
Trauma
Midline structural problems
Symeetrical-generalised onset as affect whole brain
The following conditions would probably give you symmetrical-generalised onset or assymetical-focal onset?
Inflammatory/infectious
Neoplasia
Anomalies
Trauma
Cryptogenic and idiopathic
Assymetrical focal seizure
What tests would you want to do in a patient that you suspect has an extra cranial cause for its epilepsy?
CBC
Biochem
Possibly ammonia
Resting bile acids
Urinalysis
Blood pressure in mature animals
How would you work up a suspected intracranial case?
Advanced brain imaging
CSF tap to look at WBCs, protein content
Possibly positive brain imaging for infectious agents
