neurology Flashcards
seizure definition
a hypersynchronous activation of a group of neurons within the brain
isolated seizure definition
seizure lasting less than 5 mins
cluster seizure definition
2 or more seizures within 24hrs, with complete recovery in-between
status epilepticus definition
- seizures lasting longer than 5 mins
or - 2 seizures without complete recovery in-between
partial/focal seizure definition
asymmetric, one part of brain affected
partial/focal seizure clinical signs
- facial twitching
- hypersalivation
- behavioural changes
- consciousness maintained
simple-partial/focal seizure definition
no change in mentation
complex-partial/focal seizure definition
change in mentation
generalised (tonic/clonic) seizure definition
bilateral cerebral hemisphere involvement
generalised (tonic/clonic) seizure definition
bilateral cerebral hemisphere involvement
generalised (tonic/clonic) seizure clinical signs
- autonomic signs (urination/defecation)
- loss of consciousness
- pre-ictal, ictal and post ictal phases
pre-ictal phase of seizure (minutes)
- stage before seizure
- behaviour changes, altered mentation, attention seeking behaviour
ictal phase of seizure (<5 mins)
- loss of consciousness
- muscle contraction
- urination/defecation
post-ictal phase of seizure (mins-days)
- abnormal neurological signs
- wobbly, quiet, varies
extracranial causes of seizures
toxins
- slug bait, antifreeze, permethrin (cats), pesticides, ivermectin (collies), human drugs
metabolic
- portosystemic shunts, hypoglycaemia, hypercalcaemia
intracranial causes of seizures
structural
- brain tumour, inflammation, hydrocephalus
functional
- idiopathic epilepsy
idiopathic epilepsy
- most common causes of seizures
- animals diagnosed >6 months-6 years
- recurrent seizures
- normal inter-ictal neuro exam
- normal MRI, metabolic, CSF exam
diagnostics for seizures
- history
- bloods
- MRI with contrast
- CSF analysis
seizure mimic disorders
- narcolepsy/cataplexy
- fly-catching
- movement disorder
- syncope
- 3rd degree AV block
narcolepsy/cataplexy
- sleep-wake disorder
- inherited
- loss of muscle tone
- no autonomic signs
fly catching
- unknown cause
- minutes to hours
- normal mentation
- no autonomic signs
movement disorder
- episodic
- patient remains conscious
- spontaneous, involuntary movements
syncope
- fainting
- temp loss of consciousness
- due to reduced oxygen to brain
- cardiac/neuro/hypoglycaemia related
3rd degree AV block
- prolonged hypoxic event
- partial seizure like episodes