Epilepsy: Classification and Etiology Flashcards Preview

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Flashcards in Epilepsy: Classification and Etiology Deck (30)
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1
Q

Broadly, what part of the brain do seizures affect?

A

The cortex.

2
Q

What are 3 things that can cause a provoked seizure?

A

Fever, acute head trauma, CNS infection.

3
Q

Are provoked seizures indicative of epilepsy?

A

No.

4
Q

Is an unprovoked seizure epilepsy?

A

No.

5
Q

What is epilepsy? (simple definition)

A

Recurrent unprovoked seizures.

6
Q

How does prevalence of epilepsy vary with age?

A

Bimodal: peaks in infants/children and adults > 70 yrs.

7
Q

What did the Bible get right about epilepsy?

A

Fasting -> ketosis actually helps epilepsy sometimes. (Does this actually happen in the Bible?)

8
Q

What did the 1850’s masturbator-haters get right about epilepsy?

A

Bromide salts are an effective treatment for epilepsy (with the side effect of reduced libido).

9
Q

What’s a “Jacksonian March”?

A

Motor seizure propagating along primary motor cortex. (Jackson correlated seizure signs with anatomic location in brain)

10
Q

What was the first modern medication for epilepsy? (not bromide salts) Drug class? Mechanism?

A

Phenobarbital. A barbituate.

Acts on GABA-A to facilitate inhibitory signaling. (more coverage of this in next lecture)

11
Q

What are 2 basic rules of symmetry / asymmetry in a normal EEG?

A

Front of brain should look different from back.

Left should look the same as right.

12
Q

What do the waves on an EEG actually represent?

A

Extracellular current from summed activity from many neurons, especially pyramidal cells.

13
Q

What are 4 factors in the International League Against Epilepsy (ILAE) revised classification of epilepsy?

A

Mode of epileptic seizure onset.
Epilepsy syndrome type.
Epilepsy etiology.
Evolution over time.

14
Q

What are 3 modes of seizure onset?

A

Generalized.
Focal.
Unknown / unclear.

15
Q

What are 6 types of generalized onset seizures? Brief description of each?

A

Absence - arrest of activity, staring, unresponsive.
Myoclonic - quick muscle jerks, usu. symmetric.
Tonic-clonic - convlusions: bilateral extension progressing to rhythmic shaking.
Tonic - extremity extension and muscle stiffening.
Clonic - rhythmic shaking (without tonic phase).
Atonic - sudden loss of trunk/neck tone -> falling.
(7th bonus type = epileptic spasm/ “West syndrome”: neck and trunk flexion, extremity extension)

16
Q

How do the onsets of generalized seizures look on an EEG?

A

Left and right are the same.

17
Q

Key points of the ILAE description of the onset of generalized seizures? (3ish things)

A

Rapidly engage bilateral networks.
Bilateral networks include cortical and subcortical structures.
Doesn’t necessarily involve all cortical areas.

18
Q

Why might a seizure that looks like it had generalized onset might not actually have had one?

A

Focal onset seizures with rapid secondary generalization can mimic generalized onset seizures.

19
Q

Key points of the ILAE description of the onset of focal seizures? (2ish things)

A

Originate in networks limited to one hemisphere.

Onset consistent from one seizure to the next.

20
Q

Name 4 different localizations within the frontal lobe for focal seizures and a brief description of their signs/symptoms.

A

Motor strip: clonic shaking of contralateral limbs.
Midline premotor area near midline - complex, bilateral hypermotor activity “wild, flailing movements.”
Broca’s area - expressive language dysfunction (non-fluent aphasia).
Fronto-polar - arrest of activity, hypomotor (easy to confuse with Absence).

21
Q

Signs and symptoms of focal onset seizures localized to the temporal lobe? (4 things)

A

Aura.
Arrest of activity.
Unresponsiveness.
Motor automatisms.

22
Q

What are motor automatisms?

A

“Meaningless,” repetitive motions. Recall the guy in the video fiddling with a plastic bag. Associated with temporal lobe seizures.

23
Q

Signs and symptoms of focal onset seizures localized to the parietal lobe? (2 things)

A

Sensory signs.
Signs based on propagation to other lobes.
(Parietal seizures are subtle.)

24
Q

Signs and symptoms of focal onset seizures localized to the occiptal lobe?

A

Visual signs. Can be seeing new stuff, such as auras. Or can lose vision.

25
Q

3 broad causes of epilepsy?

A

Genetic.
Structural / metabolic.
Unknown.

26
Q

What’s a developmental structural cause of epilepsy?

A

Malformations of cortical development.

27
Q

Some epilepsy is caused by mutations in a single gene. What kind of gene are most of these?

A

Ion channels / related proteins.

28
Q

2 different classifications of an epilepsy’s evolution over time?

A

Self-limited (or not).

Treatment-responsive (or not).

29
Q

What’s one reason why it’s important to distinguish between generalized vs. focal epilepsy?

A

Treatments for them are different, and treatments for one often don’t work for the other.

30
Q

Does childhood absence epilepsy (CAE) have effects if the seizures abate? What does this tell you about epilepsy?

A

Yes. People who had CAE as children score much lower psychosocially (income, education level, emotional problems, etc. etc.) later in life than average. Suggests that seizures are a symptom of problem with brain development (which the drugs can’t fix).