Epilepsy

Front 1

What is an Epileptic Seizure?

Back 1

Abnormal PATTERN of cerebral neuronal rapid firing.
Sudden Onset
Sudden Cessation
Rapid Firing may cause abnormal behavior
Can have subclinical seizures

Front 2

What is a Non-Epileptic Event?

Back 2

Behavioral features are like a epileptic seizure
Event NOT due to rapid neural firing

Front 3

Examples of Non-Epileptic Events?

Back 3

Pseudoseizure (conversion disorder)
Syncope

Front 4

What is Epilepsy?

Back 4

Intrinsic predilection to recurrent seizures
Seizures not due to transient or reversible medical disorder
Requires meds or surgery

Front 5

Epilepsy Etiologies

Back 5

Genetic Disorders
Developmental Cortical Malformation
Brain Infection
Birth Injury
Brain Trauma
Brain Tumor
Stroke

Front 6

Difference between Symptomatic and Cryptogenic Epilepsy?

Back 6

Symptomatic: known cause
Cryptogenic: unknown cause

Front 7

What is idiopathic epilepsy?

Back 7

NOT UNKNOWN CAUSE
The cause is presumed to be genetic w/ characteristic:
Age of Onset
EEG pattern
Seizure Type

Front 8

Causes of Seizures w/o Epilepsy?

Back 8

Electrolyte Disorder
Uremia
Drug Intoxication
Alcohol/Drug Withdrawal
TRANSIENT/REVERSIBLE

Front 9

What is a Convulsive Seizure?

Back 9

Seizure w/:
Stiffening or Jerking
Involves face, limbs, or trunk

Front 10

What is a Non-Convulsive Seizure?

Back 10

Seizure w/o stiffening or jerking
May have blank stare, unresponsiveness, or confusion

Front 11

What is a Partial Seizure?

Back 11

Seizure involving part of cerebral hemisphere.
Typically confined to one lobe

Front 12

What is a Generalized Seizure?

Back 12

Involves both hemispheres

Front 13

What is a Simple Partial Seizure?

Back 13

Partial Seizure w/o impairment of consciousness

Front 14

What is a Complex Partial Seizure?

Back 14

Partial Seizure with impairment of consciousness

Front 15

What is the difference between a Primary and a Secondary Generalized Seizure?

Back 15

Primary begins generalized.
Secondary begins partial and spreads

Front 16

What is a seizure aura?

Back 16

The earliest conscious awareness of a seizure.
The aura is a simple, partial seizure.
Sx's of aura reflect impairment of brain region at or close to seizure onset

Front 17

What are Automatisms? types?

Back 17

Repetitive movements that occur during seizures.
Oral: lip smacking, chewing, swallowing
Manual: picking, fumbling, patting

Front 18

What is Impaired Consciousness?

Back 18

Inability to respond to others
Inability to follow commands
Failure to make eye contact
Impaired Memory
Automatisms are common

Front 19

what are the most common epicenters for seizures?

Back 19

1. Temporal
2. Frontal

Front 20

Where does the Deja Vu feeling come from in our brain?

Back 20

Medial Temporal

Front 21

What is PDS and what is its significance?

Back 21

Paroxysmal Depolarization Shift
Electrophysiological Abnormality of PARTIAL epilepsy

Front 22

What exactly is PDS?

Back 22

50-200msec depolarizatoin w/ superimposed repetitive spikes in ALL neurons of epileptic zone

Front 23

PDS in relation to:
1. EPSP

Back 23

1. PDS is more prolonged than EPSP

Front 24

PDS in relation to:
2. AMPA

Back 24

AMPA receptors trigger PDS

Front 25

PDS in relation to:
3. NMDA

Back 25

NMDA receptors mediate PDS

Front 26

PDS in relation to:
4. GABA

Back 26

GABA mediates post-PDS hyperpolarization

Front 27

What happens with PDS to cause a seizure?

Back 27

If PDS fails to terminate promptly, you get a seizure

Front 28

What is TLE?

Back 28

Temporal Lobe Epilepsy

Front 29

What is the most common pathology of TLE?

Back 29

Mesial Temporal Sclerosis

Front 30

What are other common pathological findings of TLE

Back 30

-hippocampal neuronal loss greatest in CA1 and least in CA2
-Prominent mossy cell neuron loss in the dentate hilus
-Loss of mossy cell input to Inhibitory GABA basket cell interneurons causes them to go dormant.
-Loss of Inhibition-->rapid firing
-Shrunken Hippo

Front 31

What's that pathogenesis called?

Back 31

The Dormant Basket Cell Hypothesis

Front 32

If the DBC hypothesis is correct, what should be effective Rx's?

Back 32

GABA enhancing drugs
Glutamate Attenuating Drugs
Drugs that reduce maximum neural firing
Surgical Resection of medial temporal lobe

Front 33

Absence Seizures
Induced by?

Back 33

Hyperventilation

Front 34

Absence Seizures
duration?

Back 34

Brief: ~10 seconds

Front 35

Absence Seizures
how often?

Back 35

many per day (100/day)

Front 36

Absence Seizures
what happens after the seizure?

Back 36

they return to normal immediately

Front 37

Absence Seizures
etiology?

Back 37

GENETIC

Front 38

Absence Seizures
EEG?

Back 38

bilateral spike wave (2.5-4 Hz)

Front 39

Absence Seizures
Mechanism

Back 39

--Normally, thalamic relay neurons activate CTX bilaterally in rhythmic bursts during normal, non-REM sleep
--When these occur while you're awake...baddabing

Front 40

What other players are there in Absence Seizures

Back 40

-Thalamic Reticular Neurons depolarize thalamic relay neurons and faciliate the burst
-T-type Ca channels and GABA receptors play some role

Front 41

Rx for Absence Seizures

Back 41

Ethosuximide

Front 42

Ethosuximide
Mechanism?

Back 42

Acts on T-Type Ca Channels and blocks absence seizures

Front 43

What might be the cause of Early morning jerks?

Back 43

Juvenile Myoclonic Epilepsy (JME)

Front 44

What do JME and childhood absence seizures have in common?

Back 44

They're both forms of Primary Generalized Epilepsy

Front 45

Etiology of JME?

Back 45

Genetic Epilepsy Disorder

Front 46

When does JME start up?

Back 46

adolescence or young adulthood

Front 47

Types of seizures associated with JME

Back 47

Primary Generalized Convulsive
Myoclonic

Front 48

How can you distinguish Primary from Secondary Generalized seizures?

Back 48

PRIMARY
Onset in childhood-->young adulthood
No seizure aura
No lateralized postural or clonic motor activities
No post-seizure lateralized signs or symptoms
EEG shows bilateral synchronous seizure related patterns
MRI normal
GENETIC!

Front 49

Other Seizure Mechanisms

Back 49

Ion Channel Disorders (channelopathies)
Developmental Cortical Malformations

Front 50

Types of Developmental Cortical Malformation?

Back 50

1. Abnormal connections between neurons
2. Abnormal neurons e.g. giant neurons of tuberous sclerosis

Front 51

Types of Mutations leading to Channelopathies

Back 51

Na Channel
Potassium Channel

Front 52

Cause of Na Channelopathy?

Back 52

STEPS
1. SCN1B mutation
2. defective Na channel subunit
3. action potential depol enhanced
4. enhanced bursts
5. generalized and febrile seizures

Front 53

Cause of K channelopathy?

Back 53

1. KCNQ2 and 3 mutations
2. Defective K channel
3. K current decreased
4. neonatal convulsions occur

Front 54

When do you initiate Rx for epilpesy?

Back 54

if there is a high risk of recurrent seizures

Front 55

When is there a high risk?

Back 55

2 or more spontaneous seizures
1 seizure and a progressive neurological disorder or an epileptic syndrome

Front 56

Common Med SE's?

Back 56

1. Dose-related: cognitive impairment
2. Allergic/Immune mediated: rash, stevens-johnson
3. Drug Specific: lots
4. Teratogenic

Front 57

What if meds don't work?

Back 57

SURGERY!