SA seizures Flashcards
What is a seizure?
A transient ocurence of signs and symptoms due to abnormal excessive or synchronous neuronal activity of the brain
Seizures localise to which part of the neural system
Forebrain
What is the pathophysiology of a seizure?
Imbalance in excitation and inhibition (excessive excitation or decreased inhibition)
What are the four phases of a seizure?
Prodrome, aura, ictal and post-ictal
Describe the prodromal phase of a seizure.
Clingy, stay in a certain spot, quiet or agitated. The predictors of a seizure.
Describe the aura phase of a seizure.
Initial manifestation of a seizure - shows abnormal sensation
Describe the ictal phase of a seizure.
Involuntary muscle tone/ movement, abnormal behaviour or sensation
How long does the ictal phase of a seizure usually last?
1-1.5 minutes
Catching flies is an example of what phase of a seizure?
Ictal
Describe the post-ictal phase of a seizure.
Unusual behaviour or neurological deficits lasting minutes to days
During a generalised seizure a dog will be conscious and unconscious?
Unconsciousness - disturbance in both hemispheres of the forebrain!!
Tonic-clonic
Paddling both legs, sustained and regular
Tonic
Muscle contraction and recumbency
Clonic
Spasmodic contractions
Myoclonic
Sudden brief single or group movement - jerk seizure
Atonic
Sudden loss of muscle tone
During a focal seizure will a dog be conscious or unconscious?
Conscious unless complex
What would occur with a motor focal seizure?
Episodic, focal motor contraction - ie one muscle/ area
What may occur with an autonomic focal seizure?
Eg drooling (RARE)
What may occur with a behavioural focal seizure?
Anxious, restless, fly catching, circling
What differentials may be investigated in suspected seizure cases?
Narcolepsy, neuromuscular collapse, syncope, movement disorders, metabolic disease, vestibular disease
Which breeds may be predisposed to movement disorders?
Doberman, english bull dogs, boxers
Hyperkanaesia
Episodic falling - progressive increase in tone of pelvic-thoracic limbs, hunched spine and fall over
Dyskinesia
Epileptoid cramping - falling and cramping - border terriers
What are the three causes of epileptic seizures in small animals?
Reactive (metabolic and toxic effects), idiopathic and structural (intracranial or cerebral pathology)
Name a breed predisposed to idiopathic seizures.
Collies
What constitutes a tier one idiopathic epilepsy diagnosis?
> 2 seizures 24h apart, 6m-6y, no other abnormalities, familial history
What constitutes a tier two idiopathic epilepsy diagnosis?
Tier 1 + normal post-prandial BAST, normal MRI, CSF analysis
What constitutes a tier three idiopathic epilepsy diagnosis?
Tier 1+2 + EEG abnormalities
Define status epilepticus.
Where epileptic fits follow one another without recovery of consciousness between them. >5 mins or >2 seizures without full recovery.
Define a cluster seizure.
Two or more seizures occurring within 24 hours but with the patient regaining consciousness between the seizures.
What criterion would be used to determine when to start epileptic treatment?
Underlying cause, status epilepticus/ cluster seizures, interictal period <6m, post-ictal severe or >24h, seizure frequency/ duration increasing within 3 icteral events, seizures within 1 m of traumatic event
MOA phenobarb. Side effects.
Augments inhibitory effects of GABA.
Side effects: sedation, ataxia, PUPDPP, hepatotoxic, haematological effects
MOA KBr. Side effects.
Preferential GABA movement and effect.
Side effects: sedation, ataxia, pelvic limb weakness
Which species should KBr NOT be used in?
Cats!! Causes eosinophilic bronchitis and respiratory fatalities
MOA Imepitoin. Side effects.
Benzodiazepine partial agonists of GABAa.
Side effects: Sedation, ataxia, PUPDPP, hepatotoxic, haematological abnormalities
What AEDs are licensed in dogs?
Phenobarb, bromide, imepitoin
What AEDs are licensed in cats?
NONE
What side effects may be associated with levetiracetem?
Sedation - minimal
What side effects may be associated with Zonisamide?
Ataxia, sedation, dry eye, inappetence
MOA levetiracetam
Neuromodulation/ reduced NT release
MOA Zonisamide
Suppressed hypersynchronisation of neuronal activity
Which AED requires level monitoring?
Phenobarbitone
Which AED is ONLY licensed as a monotherapy?
Imepitoin - not licensed for structural or cluster seizures
After how long can a sustained seizure lead to neuronal damage?
> 30 minutes
Describe the emergency dosing of a dog with diazepam.
Give if seizure is over 1 minute (1mg/kg)
