neurology Flashcards
rate of epilepsy occurrence in canada
1-2% of canadians
40 000 people in BC
associated with cerebral palsy, autism, intellectual impairment
what is an epileptic seizure
paroxysmal interference of brain function due to abnormal electrical discharge in the brain
sudden disruption of the brains normal electrical activity
this may result in motor activity, sensory symptoms, behavior changes and/or altered consciousness depending on which areas of the brain are involved
how common are seizures
1 in 12 people will have a seizure
50% of people who do, have only 1
define epilepsy
2 or more unprovoked seizures
name the generalized seizures
tonic atonic absence clonic tonic-clonic myoclonic
name the focal seizures
dyscognitive
bilateral convulsive seizures
what are the 5 questions to ask about a first afebrile seizure?
- was the episode an epileptic seizure
- what was the cause of the seizure
- what investigations should i do
- does the child require treatment
- what else should i think about
how do you determine if a seizure was an epileptic seizure
clinical hx is key
detailed description of the event and circumstances around the event
- -setting in which it occurred
- -observation at onset of the event
- -how did the patient feel just prior to the event
- -other important factors like development, febrile seizures, family hx of epilepsy, history of brain injury/infection
what are the factors that favor an epileptic seizure
aura
brief
post ictal confusion
automatisms
amnesia of event
incontinence
tongue biting
events in sleep
eyes open
what are some non epileptic paroxysmal events
- syncope and reflex anoxic seizure
- day dreaming
- steroetypies
- panic/anxiety attacks
- psychogenic nonepileptic seizures
- sleep disorders
- migraine, complex
- transient ischemic attack/stroke
- paroxysmal movement disorder
what are some examples of syncope/reflex anoxic seizure episodes
vasovagal syncope
breath holding spells
orthostatic hypotension
cardiogenic (i.e prolonged QT, other arrhythmia)
Gastroesophageal reflux (sandifer syndrome)
what causes syncope
sudden decrease in oxygen availability to the brain (via reduced cerebral blood flow or oxygen content of blood)–> reflex anoxic seizures
NOT epileptic seizures
can result in LOC, GTC, incontinence
what causes epileptic seizures in childhood (categories)
50% genetic
30% structural-metabolic
10% unknown
what are the genetic causes of epileptic seizures in childhood
childhood and juvenile absence epilepsy
benign Rolandic epilepsy of childhood
juvenile myoclonic epilepsy
what are the structural-metabolic causes of epileptic seizures in childhood
malformation of brain development
neurocutaneous syndromes like tuberous sclerosis
vascular malformations
congenital or acquired CNS infections
hypoxic ischemic brain injury
stroke
traumatic brain injury
tumour
inborn error of metabolism
how do you distinguish between idiopathic and symptomatic epilepsy
idiopathic–> norma development, neuro exam. no family hx of epilepsy. no hx brain injury. characteristic EEG abnormalities
symptomatic–> developmental delay, hx brain injury, abnormal neuro exam, other congenital malformations
what investigations should be done in a child presenting with first epileptic seizure
a child presenting immediately after this first seizure should have a blood glucose checked
further labs should be guided by clinical judgement at the time i.e vomiting, fever, illness
consider toxicology
ECG with QTc interval (may be syncopal episode)
what is the most useful investigation for seizures
EEG
assessing risk of recurrent seizures
epileptic syndrome or seizures that may be associated with a structural lesion
can guide anticonvulsant meds
helps ID prognosis
when should you do the EEG
does not need to be done in ER
order an outpatient sleep deprived EEG
(may need sedation i.e autism)
does a normal EEG exclude epileptic seizures?
no
in patients with epilepsy, 1st EEG displays epileptiform activity only 50% of the time –> if you suspect epilepsy but EEG is normal, repeat EEG increases yield
what is the significance of an abnormal EEG in the setting of a seizure
if it is true epileptiform activity, there is a two fold increase in tendency to seizure
can epileptiform discharges alone dx epilepsy
no–not diagnostic without appropriate clinical history
certain epileptiform discharges are seen in 4% of children without epilepsy
what kids should get neuroimaging
children who have had more than 1 afebrile seizure
exception is if the clinical history and EEG findings are consistent with genetic etiology
**neuroimaging abnormalities occur in up to 1/3 of children with a first afebrile seizure, but only 2% will demonstrate a clinically significant abnormality that will influence management
**seizures are an uncommon presenting symptom of a brain tumour in kids
what are the indications for a pediatric neurologist
focal lesion on neuroimaging
uncertainty as to seizure type and/or epilepsy syndrome
seizure associated with developmental delay/regression
multiple seizure types
infantile spasms
failed appropriate therapy with two or more AEDs