Seizuring patient - SA/LA Flashcards
Define seizure
electrical imbalance between excitation and inhibition, they have a certain rhythmicity
How can seizures be classified by CS?
FOCAL: when people appear absent
GENERALISED: tonic, clonic,
* don’t use the petit-mal and grand-mal seizure
Describe focal seizures
SIMPLE FOCAL: no loss of consciousness
COMPLEX FOCAL: impairment of consciousness
FOCAL SEIZURE WITH SECONDARY GENERALISATION
2 types of generalised seizures
Convulsive or non-convulsive
Define status epilepticus
- prolonged seizure activity
- > / 5 mins (clinical)
- > / 30 mins (basic science) –> brain damage
- life-threatening emergency always
Describe cluster seizures
> / 2 seizures in a 24 hour period, very serious!
Name 4 classifications of seizures
- prodrome
- aura
- ictus
- post-ictal
Define prodrome
behaviour changes that occur hours or days before the seizure
Define aura
sensory/ focal onset seizures may start with a sensory experience such as a perceived smell or a feeling of deja vu. The existence of aura in animals is difficult to prove but owners often report a behavior change of their dog minutes before the ictus.
What is ictus?
the seizure event itsel
What is post-ictus?
neurological status alternations hours or days after the seizure
How can seizures be classified over time?
- self-limiting
- clustered or continuous (status epilepticus)
- reflexive
Describe a self-limiting seizure
= focal or generalised types
Describe a clustered or continuous (status epilepticus) seizure
= focal or generalised types
What causes a reflexive seizure?
a precipitating stimuli
Classic - CS - feline seizure
- lip smacking
- hypersalivation
- yowling (consider feline dementia as alternative ddx in older cats with this CS).
Name 5 events that can mimic seizures.
- syncope
- narcolepsy
- pain
- vestibular syndrome
- movement disorders (e.g. Scotty Cramp)
Outline syncope
- partial or complete loss of consciousnesss
- lack of motor activity
- no post-ictal signs
- shorter in duration
- can mimic seizures
What is narcolepsy?
= sleeping disorder, very rare
- stimulated often by excited, food, drugs
- can mimic seizures
Outline different breeds and movement disorders
- scotty cramp
- CKCS - episodes of tetany, hypertonicity, deer-stalking
- Norwich terriers
- Boxers - paroxysmal dystonic choreathetosis
- Bichon frises - similar to boxers
Classic signs of seizures
- typically last 1 minute
- exhibit several stages
- often, but not always, occur at rest or out of sleep
- clonic movemetns (rhythmic mm contractions are common in both partial and generalised seizures)
- most recurrent seizures respond at least in part to AEDs
What is an EEG?
= electroencephalogram, easures the electrical activity of the brain
T/F: a seizure can happen without pathology
True
How can seizures be classified by aetiology?
- SYMPTOMATIC or SECONDARY: structural brain lesion
- REACTIVE SEIZURE: metabolic or toxic cause
- IDIOPATHIC or PRIMARY EPILEPSY: suspected genetic cause
- POSSIBLE SYMPTOMATIC or CRYPTOGENIC SEIZURE: rule out only via PME
What is a cryptogenic seizure?
one of obscure or uncertain origin
How can seizures be classified by location?
INTRA-CRANIAL: functional (idiopathic epilepsy) or structural (symptomatic epilepsy, possible symptomatic epilepsy)
EXTRA-CRANIAL: Intrinsic (metabolic - reactive seizure) or extrinsic (toxic - reactive seizures)
3 categories of extracranial epilepsy
- electrolyte imbalances
- energy deprivation
- organ dysfunction
Give examples of electrolyte imbalances causing extracranial epilepsy
hypernatraemia, hyponatraemia, hypocalcaemia
2 examples of energy deprivation extra-cranial seizures
thiamine deficiency and hypoglycaemia
2 examples of organ dysfunction extracranial epilepsy
- uraemic encephalopathy
- HE
Outline species and idiopathic epilepsy
DOG: 6 months to 6 years
CAT
GENERALISED SEIZURES: various breeds, e.g GSD
PARTIAL SEIZURES with/without 2nd generalisation: springer spaniels
Outline epilepsy in horses (signalment)
- Arab foals - congenital, grow out of it
- Foal with PAS (neonatal maladjustment syndrome)
- Adults (due to structural or metabolic brain disease, migrating parasite, previous trauma etc, intracarotid injection!)
Ddx (ordered) - seizures in animals
- Metabolic (PSS, hypoglycaemia)
- Infectious diseases
- Congenital
- (toxic, trauma)
Ddx (ordered) - seizures in animals 6 months - 6 years
- Idiopathic epilepsy
- Inflammatory/ infectious
- Metabolic
- (neoplasia, toxic, trauma)
Ddx (ordered) - seizures in animals > 6 years
- Neoplasia
- Idiopathic epilepsy (late-onset)
- Inflammatory/ infectious
- (metabolic)
- (toxic, trauma)
Describe disease progression of metabolic seizures
waxing and waning
Ddx - inter-ictal exam findings, normal
- Idiopathic epilepsy
- metabolic (wax and wane phenomenon)
- Neoplasia (silent area of brain, early in disease)
- (toxic)
Ddx - inter-ictal exam findings, abnormal, symmetrical
- Metabolic
- Toxic
- Hydrocephalus
- Degenerative
- (midline structural disease)
Ddx - inter-ictal exam findings, abnormal, Asymmetrical
- Neoplasia
- Inflammatory/ infectious
- anomalies
Ddx = lateralising seizures, symmetrical, generalised onset
- idiopathic epilepsy
- metabolic
- toxic
- degenerative
- hydrocephalus
- trauma
- midline structural problems (pituitary tumour)
Ddx = lateralising seizures, Asymmetrical, FOCAL onset
- inflammatory/ infectious
- neoplasia
- anomalies
- trauma
- cryptogenic and idiopathic
What is the minimum database for extracranial causes of seizures?
- CBC and cytology
- Biochem
- Ammonia (if indicated)
- resting bile acids (in small animals, dynamic bile acid test)
- UA (uncommon in horses)
- BP in mature small animals (especially cats - cardiac work up)
- Further diagnostics depending on signalment/ hx and PE
Diagnostics - intracranial causes of seizures
- Imaging - brain - MRI and CT
- CLINICAL PATHOLOGY:
- CSF (wbc, differential cell count, protein content)
- POSITIVE brain imaging or inflammatory CSF for infectious agents
