Seizures + epilepsy Flashcards
describe ntsm involved in epilepsy
GABA loss, ACh loss (learning, modulatory ntsm), glutamate gain (memory, on switch)
seizure definition
burst uncontrolled elec acti b/neurons = temp abnormalities in muscle tone/mvm (stiff, twitchm limp), behaviours, sensations, states of awareness
classification of seizures
focal = 60% (aware or impaired awareness
generalised = 30%
unknown onset = 10%, could be psychogenic, non-epileptic = not related to electrical act
recognising generalised seizures
tonic-clonid = stiffening then rhythmic jerking limbs
tonic = stiffening limbs
myoclonic = sudden single jerk of muscle
absence = loss awareness, eyes roll up, eyelids flutter, lip smacking, chewing
atonic = loss muscle tone = fall when standing
recognising focal seizures
small area brain -> spreads
aware = full aware, cant respond
impaired awareness = appear confused, not realise have seizure
epilepsy definition
-2 unprovoked seizures, greater than 24 hrs apart
- 1 unprovoked + prob further seizures similar to recurrence risk (60%) after 2 unprovoked seizures occurring over 10 yrs
- diagnosis of epilepsy syndrome
- resolved if past age-dependent age, or remained seizure free for 10 year incl 5 wo/meds
epilepsy classification elveles
seizure type, epilepsy type, co-morbidities, etiology, epilepsy syndromes
prevalence epilepsy
prevalence = 621.5/100,000
aus = 293/100,000
mortality risk kids = 6.4-7, adults = 2.3
epilepsy first aid
tonic clonic seizure = stay with person, time it, keep head safe, roll onto side after jerking stops, observe breathing
DONT put anything in mouth, restrain or move unless in danger
measuring seizure act
electroencephalogram (EEG)
each channel measures from 2 electrodes
for gen seizure = all channels have act simultaneously, seizure marked by inc amplitude of wave pattern, patients may have epileptiform act in EEF b/seizures ‘inter-ictal’
for focal seizure = some channels have epileptiform act, strongest amps indicates location foci (aid surgery, MRI follow-up)
causes of seizures + epilepsy
neonates = CNS infect, develop disorder, drug withdrawal, genetic disorders, intracranial haem + trauma, metabolic disturbances
infants + kids = CNS infect, develop disorders, debrile seizure, genetic, trauma
adolescnets = brain tumour, genetic disorder, illicit drug use, infection, trauma
young adults = acohol withdrawal, autoantibodies, brain tumour, illicit drug use, trauma
older adults = alcohol withdrawal, alzheimers, autoantibodies, cerebrovascular, metabolic
general genetics & epilepsy
monogenic = one allele of major effect. >1500 genes implicated. Na+ chan mut is biggest risk
polygenic = additive effects many alleles + possible env effects (majority of epilepsy)
discovery alleles using genome wide association studies
x2 test = allele observed more frequently than expected in cases vs controls?
genetic risk for gen epilepsy associated with variants in ion channels + ntsm rec
epilepsy genetic relatedness
related to other neurodevelopmental disorders ir same genes that cause epilepsy can cause cerebral palsy, intellectual disability, epilepsy, autism spectrum disorder
but also functional differences ie with DNA binding/transcription
PCDH19 clustering epilepsy
unusual x linked disease
typical x-linked pedigree males affected, females not affected
but with typical PCDH19 pedigree = females affected, males not
PCDH19 = cell-cell adhesion molecule
variants cluster to ec domain
mosaic gene exp due to x activation -> interfere/neuronal connections
