Epilepsy Flashcards
What is the difference between a seizure and epilepsy?
Seizures are uncontrolled synchronous firing of neurons in the brain that cause behavioral abnormalities. Epilepsy requires recurrent, spontaneous unpredictable seizures
What is an EEG?
An EEG records electrical activity on skull with 21 electrodes in a defined pattern. Each electrode is a summation of 100s of neurons firing
What does ictal mean? Interictal?
Ictal = seizure Interictal = time between seizures
What are the 2 main types of seizures? What are the differences in each?
Generalized seizures: uncontrollable discharge of neurons in both hemispheres
Focal seizure: abnormal activity involving only a small part of the brain
What is a tonic-clonic seizure?
Limbs become rigid and then jerky, loss of consciousness
What is an absence seizure?
Non-convulsive, brief loss of consciousness – patient may stare off into space of freeze
What is a myoclonic seizure?
Twitching or jerking due to motor cortex firing
What is an atonic seizure?
Loss of muscle tone which causes a person to fall down
What is a simple focal seizure?
Short-lasting seizures without loss of consciousness or dyscognia
What is a complex focal seizure?
See dyscognia and not loss of consciousness. Can affect speech, emotion, or memory
Why are babies prone to having seizures?
In the developing brain, intracellular Cl- is higher making it want to leave the cell and depolarize causing GABA to be excitatory
What are 2 examples of mutations that could lead to epilepsy?
Blocking a K+ channel & activating a Na+ channel
What is epileptogenesis?
Seizure free period after previous head trauma results in seizures up to years later
What are the 3 major categories of AED drugs?
- Enhance GABA action
- Nat+ channel blockers
- Ca2+ channel blockers
What can change the E/I balance?
- Change in NT: incr. Glu/reduced GABA
- Change in the number of receptors
- Changes in astrocytes
- Change in ion transporters
