L2 - Molecular determinants of the epilepsies Flashcards
What is epilepsy?
Chronic neurological disorder characterised by spontaneous recurrent seizures
True or false
Epilepsy has no age, racial, social, gender or geographical boundaries
true
The cause of epilepsy is…
unknown in appox half of those suffering - genetic and acquired
epilepsy is thought to occur as a result of …
an imbalance between excitatory (glutamatergic) and inhibiry (GABA) neurotransmission - which usually work together to maintain neuronal homeostasis
over __% of patients don’t respond to current drug treatments
30%
Describe focal seizures:
Start in one region of the brain - but can then spread
usually result from an acquired brain insult
have underlying structural brain pathology
good candidates for surgery
Describe generalised seizures:
Start in both hemispheres of the brain simultaneously
Mostly genetic causes
No underlying structural brain pathology
Generalised non-convulsive seizures are usually ___ episodes of staring with unresponsiveness. You have have ___ per day. The have a ____ onset. Can be provolked by _______
Generalised non-convulsive seizures are usually brief episodes of staring with unresponsiveness. You have have hundreds per day. The have a sudden onset. Can be provolked by hyperventilation
True or false
Generalised non-convulsive seizures are common in childhood
true
The cause of Generalised non-convulsive seizures are unknown
true
but there is a strong genetic component - but more than one gene involved
Descibe the GAERS model
Genetic absense epilepsy rats from strasbourg (GAERS)
100% develop seizures by 4 months
NEC is the control strain - no seizures
polygenic: more than one gene contributing
most widely used animal model - many of the same features as human epilepsy
Absense seizures result from abnormal, ________ ________ activity
hypersynchronous thalamocortical activity
What makes up the thalamocortical circuit?
Somatosensory cortex
Ventrobasal nucleus of the thalamus
reticular nucleus of the thalamus
Two modes of firing:
awake –> tonic
sleep –> oscillatory
During absense seizures the brains switches to the ____ sleep moide in the thalamocortical circuit, while the person is still awake
Sleep –> oscillatory
What are the multifactorial molecular causes of genetic generalised epilepsy?
High/Low voltage activated Ca2+ channels
AMPA receptors
Stargazin and TARPS
GABA(a) receptors
K+ channels
voltage gated Na+ channels