Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physiology III > Lecture 17: Cortical Electrical Recordings > Flashcards

Lecture 17: Cortical Electrical Recordings Flashcards

1
Q

What is idiopathic epilepsy

A

Seizures as a result of an unknown cause

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is primary epilepsy

A

Genetic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is symptomatic epilepsy

A

Known, underlying cause: developmental, degenerative, inflammatory, infectious, neoplastic, and traumatic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is reactive epilepsy

A

Metabolic, nutritional or toxic cause

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is reflex epilepsy

A

Sensory stimuli triggers an episode

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a seizure

A

Physical findings and/or changes in behavior that result from abnormal electrical activity in the brain. May include motor, sensory, autonomic or psychic effects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is epilepsy

A

Abnormal activity in the cerebral cortex that results in a seizure. A epileptic seizure is a clinical sign of an abnormal forebrain disorder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is status epilepticus

A

A seizure that lasts for 5 minutes or longer or multiple seizures within a 5 minute period

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are cluster seizures

A

Increased frequency of seizures within a few days or 2 seizures within 24 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the three phases of a seizure

A
  1. Pro-dromal
  2. Citrus
  3. Post-ictal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the prodromal phase

A

Pre-octal period, abnormal behavior that may occur hours before ictus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is ictus

A

Seizure lasting 1-2 minutes, characterized by the loss of consciousness and alteration of muscle tone, repetitive movements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is “aura”

A

Onset of ictus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the post-octal period

A

Return to normal or altered behavior, recovery period

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What do EEG’s measure

A

Collective electrical activity neurons in the cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What layer of the cortex is made of glia cells and dendrites of neurons in lower layers

A

Layer 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What layers of the cortex contain Stellate cells that receive afferents from brainstem; pyramidal cells send axons to other parts of the cortex

A

Layers 2-6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What layer receives thalamic inputs

A

Layer 4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What layer is the motor efferent neurons to the spinal cord

A

Layer 5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What layer of the cortex has projections to basal ganglia and thalamus

A

Layer 6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the major cell types in the cortex

A
  1. Pyramidal neurons- Long distance excitatory
  2. Stellate neurons- local excitatory and inhibitory
  3. Glial cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are focal seizures

A

Partial, originates in a localized portion of the cortex=seizure focus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is a generalized seizure

A

Involves both hemispheres of the brain, originates in the thalamus with abnormal activity in thalamocortical circuit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is a secondary generalized seizure

A

When a focal seizure starts locally and spread to the rest of the cortex, creating a generalized seizure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What what two ion channels are responsible for inhibitory or excitatory activity

A
  1. Voltage gated channels
  2. Ligand gated channels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

GABA binding Cl- causes ___

A

Hyperpolarization

27
Q

Glutamate binding AMPA and NMDA causes

A

Depolarization

28
Q

What is the resting state of Na+ channels

A

Channel is closed

29
Q

What is the active state of Na+ channels

A

Channel is briefly open

30
Q

What is the inactive state of Na+ channels

A

Channel is closed again and not sensitive to membrane depolarization

31
Q

Describe a normal action potential

A
  1. Na+ channels open causing depolarization
  2. Ca2+ open if present
  3. Potassium channels open causing them to repolarize
32
Q

What is epilepsy channelopathies

A

Mutations to these channels results in enhanced excitatbility or loss of inhibition

33
Q

___depolarization is a characteristic of a seizure

A

Paroxysmal

34
Q

What is a paroxysmal depolarization shift

A

Sudden, large (50-200mV), long (50-200msec) depolarization

Triggers a train of action potentials

35
Q

What is the depolarization phase of the PDS

A

Ca2+ and glutamate channel activation

Initial depolarization mediated by AMPA receptors, sustained by NMDA

36
Q

What receptors cause the initial depolarization during the PDS

A

AMPA

37
Q

What receptors cause the sustained depolarization in PDS

A

NMDA

38
Q

What is the hyperpolarization phase during the PDS

A

Termination of the PDS the cell hyperpolarizes because Cl- and K+ flux via GAVA receptors, causing a prolonged period of hyerpolarization

39
Q

When do PDSs remain localized

A

In a healthy nervous system where there are less than 1000 neurons involved

40
Q

What happens when there are more than 1000 neurons involved in PDSs

A

Activity spreads across the cortex, recurrent axons of affected cells activity inhibitory interneurons, increased inhibition dampens spread of seizure to neighboring cells

41
Q

___inhibition contains seizure focus by limiting PDSs

A

Surround

42
Q

When surround inhibition breaks down the ___spreads

A

Seizure

43
Q

Seizure spread can occur in what 2 scenarios

A
  1. Neurons die- loss of inhibitory neurons may occur because of head injury, clot or scarring tumor
  2. Channelopathies- disorders in ion channels, causing increase Na+ and Ca2+ and decrease K+
44
Q

What ions increase when a a seizure occurs due to channelopathies

A

Na+ and Ca2+

45
Q

What ions decrease when a seizure occurs due to channelopathies

A

K+

46
Q

what is indicated by #1

A

Paroxysmal depolarization shift

47
Q

A positive voltage change will cause a ___deflection in the EEG

A

Downward

48
Q

A negative voltage change will cause an ___deflection in the EEG

A

Upward

49
Q

When are EEG’s useful

A
  1. Identifying and classifying epilepsies
  2. Localizing lesions in the cortex
  3. Sleep studies
  4. Legal determination of brain death
50
Q

What do the alpha waves show in an awake EEG

A

Regular, high amplitude, sweeping pattern

51
Q

What do beta waves show in an awake EEG

A

Irregular and have lower amplitude

52
Q

Are alpha or beta waves activated when eyes are closed

A

Alpha

53
Q

Are alpha or beta waves activated when eyes are open

A

Beta

54
Q

What waves are indicated by 1-3

A
  1. Alpha
  2. Beta
  3. Alpha
55
Q

What do delta waves characterize in a sleeping EEG

A

Characterize slow wave sleep

56
Q

What does paradoxical sleep (aka REM) look like during sleeping EEG

A

Characterized by low amplitude, irregular EEG

57
Q

What waves are indicated by 1-2

A
  1. Delta
  2. REM
58
Q

___are bursts of activity from the thalamus to the cortex

A

Sleep spindles

59
Q

___ are extensive activities in the primary sensory cortices

A

K complexes

60
Q

Identify the waves 1-7

A
  1. Awake- beta waves
  2. Drowsy, relaxed- alpha waves
  3. Stage 1 sleep- theta waves
  4. Sleep spindle
  5. K complex
  6. Stage 3/4 sleep- delta activity
  7. REM sleep
61
Q

Is the following EEG representative of a partial or generalized seizure

A

Partial seizure

62
Q

Is the following EEG indicative of a partial or generalized seizure

A

Generalized seizure

63
Q

How do flashing lights induce seizures

A

Photosensitive epilepsy brain responds to excessively to certain visual stimuli, triggering seizures.

Flashes of light at 20Hz are most likely to induce seizures

Physiology III (34 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions