Physiology

Question 1

A Focal/Partial seizure is proceeded by what phenomena? How does it begin physiologically?

Answer 1

Aura-sense of fear

Starts with small group of localized neuron which have the potential to spread and generalize.

Question 2

How are generalized and focal seizures distinguished?

Answer 2

Focal-proceeded by aura, start localized and spread

Generalized-No aura, bilateral from onset

Question 3

A childhood absence seizure is of what type? What regions of the brain does it involve. How is it unique?

Answer 3

Generalized
thalamocortical circuts
Diffuse hyperexcitability
No aura

Unique-inhibition is preserved, but the depolarization and hyperpolarization phases become stronger.

Question 4

The metabolic demands during a partial seizure lead to a 3 fold increase in glucose and O2 which can be detected with imaging techniques. What’s important to remember when considering these effects?

Answer 4

That seizures don’t stop b/c of this

Question 5

What is status epilepticus?

Answer 5

Repeated generalized seizures without a return to full consciousness or about 5-10 mins of continuous convulsive seizures.

Question 6

How do you get brain damage from seizures?

Answer 6

Excitotoxicity from excessive glutamate release and increases in intracellular Ca2+, enzymes, free radicals, and apoptosis, as well as Na+ influx and edema.

Question 7

Why is the limbic system particularly susceptible to seizure?

Answer 7

The hippocampus especially has a lot of feed forward signals….

Question 8

What is Ohtahara Syndrome

Answer 8

It’s a infantile epileptic encephalopathy.
Most severe and and earliest developing in children
Tonic spasms are the main seizure observed

Question 9

What are some examples of severe myoclonic epilepsy in infancy?

Answer 9

Dravet Syndrome

Lennox-Gaustaut syndrome

Question 10

What is Dravet syndrome?

Answer 10

Severe form of myoclonic epilepsy characterized by onset in first year of life. Leads to developmental delay and persistant gait ataxia, and cognitive and behavioral imparement.
Mortality rate is 10%
Very few patients develop normally

Question 11

What is Lennox-Gaustaut Syndrome

Answer 11

Severe form of myoclonic epilepsy characterized by mental retardation and psychotic symptoms. Usually the result of brain damage from seizure.
2-9 y/o

Question 12

What is Landau-Kleffner syndrome?

Answer 12

Epileptic aphasia
VERY RARE
3-6 y/o
Child begins to loose language function, act deaf

Question 13

How could ion channel, neurotransmitter development, and electrical synapses contribute to childhood seizures?

Answer 13

depolarizing channels and excitatory neurotransmitters develop first, and there are also more electrical synapses during childhood.