Pathophysiology of Epilepsy

Question 1

Hyperexcitability of an epileptic brain may be the result of what two factors?

Answer 1

Continuous depolarization or impaired repolarization

Question 2

What is the most common cause of monogenic epilepsies?

Answer 2

Gene mutation involving ion channels

Question 3

What is the difference between the tonic and clonic phases of a seizure?

Answer 3

In the tonic phase, muscles become stiff. In the clonic phase, muscles relax and become jerky and twitch

Question 4

What are the stages of epileptogenesis?

Answer 4

Brain injury/trigger –> latency period –> spontaneous seizures (epilepsy)

Question 5

What is an absence generalized seizure?

Answer 5

A generalized seizure without movement

Question 6

How do focal and generalized seizures differ?

Answer 6

Focal seizures occur in one specific area of the brain. Generalized seizures maybe begin as focal seizures, but spread to wider areas.

Question 7

Generalized onset seizures most commonly involve what group of neurons?

Answer 7

Neurons in thalmocortical circuits

Question 8

Tumors and abnormal neuronal organization are examples of what seizure etiology?

Answer 8

Structural etiology

Question 9

What is primarily responsible for the spreading of a seizure in an epileptic brain?

Answer 9

Loss of inhibition by interneurons

Question 10

What is an example of acquired structural etiology seizures?

Answer 10

Traumatic brain injury, hypoxic ischemic encephalopathy

Question 11

How is epilepsy diagnosed?

Answer 11

Epilepsy is diagnosed based on a tendency for recurrent seizures. A patient must have two spontaneous seizures separated by 24+ hours