Paroxysmal events SA: seizures and movement disorders Flashcards
What is a paroxysmal?
sudden attack or increase of symptoms of a disease that often occurs again and again
What causes an epileptic seizure?
manifestation of excessive hypersynchronous usually self-limiting epileptic activity of neurons in the brain
seizures = ALWAYS FOREBRAIN
What is the definition of epilepsy?
disease of the brain characterised by a predisposition to generate epileptic seizures
at least 2 unprovoked epileptic seizures over 24h apart
What are the phases of an epileptic seizure?
aura: alteration in smell, taste, visual perception, hearing, emotional state
ictal: focal or generalised seizure or focal with secondary generalisation
post ictal: drowsiness, confusion
What is a clustered seizure?
more than 1 in 24h
What is a continuous seizure?
longer than 5min
What are the signs of a generalised epileptic seizure?
both sides of body affected
animal loses consciousness
motor activity present
autonomic dysfunction: salivation, urination/defacation
What are the 4 types of motor activity in generalised epileptic seizures?
tonic: sustained increased muscle contraction
clonic: prolonged, regularly and repetitive myoclonic contractions
myoclonic: sudden, brief, involuntary contractions of muscles or muscle grups. shock-like activity
atonic: sudden loss of muscle tone of a few seconds duration
What are the characteristics of focal epileptic seizures?
lateralised and or regional
What are the 3 types of focal epileptic seizures?
focal motor: motor events or automatisms. level of consciousness unaffected
focal sensory: behavioural seizure often involving limbic system (rage/agression, vocalisation, fly catching, tail chasing)
focal autonomic: rare, may present with vomiting, diarrhoea, drooling
What are the types of causes of intracranial and extracranial seizures?
intra: idiopathic/functional, structural
extra: reactive
What are the types of structural intracranial seizure causes?
vascular
inflammatary
infectious
traumatic
anomaly/degenerative
neoplastic
What are the 2 categories of reactive extracranial causes for seizures?
environmnetal extrinsic: exogenous toxins
metabolic intrinsic: electrolyte imbalance, energy issue, systemic/organ dysfunction, vascular perfusion
What are the usual findings in idiopathic epileptic animals?
6months to 6 years
normal in interictal period
normal physical and neuro exam
metabolically normal
most common in generalised tonic clonic
What causes structural epilepsy?
intracranial/cerebral pathology
What are usual findings in structural epilepsy animals?
6months to 6 years
abnormal neuro exam interical period for most
asymmetric/lateralising deficits
metabolically normal
focal or generalised
What causes reactive seizures?
as a result of a toxic or metabolic insult
reversible when cause or disturbance is rectified
brain is normal: NOT a form of epilepsy
What are the usual findings in reactive seizure animals?
any age
abnormal neuro exam consistent with diffuse, bilateral/symmetric forebrain involvment
signs may wax and wane
neuro signs may be preceded/accompanied by systemic signs
significantly higher risk of developing status epilepticus
most common causes: intoxications and hypoglycaemia
Where do epileptic seizures originate?
ALWAYS in the brain
but cause can be elsewhere AKA seizures are symptoms
What are the potential diagnostics needed for seizure animals?
physical and neuro exam
metabolic screening: haem, biochem, bile acids, urinalysis, b12)
anti-seizure drug trial if indicated
mri brain
csf
eeg
When is a more extensive work-up (mri, csf) indicated?
inter-ictal neuro abnormalities consistent with intracranial neurolocalisation
status epilepticus or cluster seizure
previous presumptive IE dx and dru-resistance
What is paroxysmal dyskinesia?
group of conditions characterised by episodes of abnormal self-limiting movement
dystonic movements (limbs and trunk)
tremors
conscious
no autonomic signs
no post-ictal phase
painless
beginning/end of movement is abrupt
can last seconds, minutes, hours
What are the primary and secondary causes of paroxysmal dyskinesia?
primary: breed specific/inherited, normal neuro exam, most common
secondary/structural: intracranial lesions, drug induced, gluten sensitive, potentially abnormal neuro exam
What is the diagnostic plan when suspecting paroxysmal dyskinesia?
physical and neuro exam
metabolic screening: haem, biochem, urinalysis
then depending: monitor, gluten free diet trials, gluten sensitivity test, advanced images?