Ch 13 - Neurophysiology Flashcards Preview

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Flashcards in Ch 13 - Neurophysiology Deck (33)
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1
Q

what is an EEG

A

summation of excitatory and inhibitory postsynaptic potentials of pyramid neurons.

2
Q

How many cm2 of cortex is needed to produce an EEG field

A

6cm2

EEG = PPP + 6

3
Q

How many frequencies on a delta wave? Theta? Alpha? Beta?

A

D = 0-4

T = 4-8

A = 8-13

B = >13

Dig That Awesome Beat

4
Q

Upward vs downward EEG deflections:

A

Each EEG channel is a comparison of two inputs

+ > - = downward deflection

  • > + = upward
5
Q

Bipolar montage:

A

Input 1 and 2 are adjacent, and input 2 is input 1 in the next channel

Fp1 - F3

F3-C3

C3-P3

6
Q

Referential montage:

A

Input 2 is presumed inactive

Fp1 - Cz

F3 - Cz

C3 - Cz

All channels are in reference to Cz

7
Q

Hyperventilation during EEG is contraindicated in:

A

Stroke

Sickle Cell

Cystic Fibrosis

Congenital Heart Dz

Asthma

Moyamoya

Hyperventilation is a SSCCAM

8
Q

Normal finding on EEG during hyperventilation?

A

Generalized background slowing

9
Q

Prolonged slowing can be seen on hyperventilation on EEG if?

A

Patient is hypoxic or hypoglycemic

10
Q

Photic stimulation is performed after what age?

A

>6 months old

11
Q

photomyoclonic response to photic stim?

A

when muscle contractions, such as contraction of the eyelids occur during photic stim

12
Q

photoparoxysmal response to photic stim?

A

when photic stim results in epileptiform discharge. This is seen in patients with JME

13
Q

photoconvulsive response to photic stim?

A

When stim results in a seizure. (usually seen in primary generalized epilepsy)

14
Q

Background rhythm on EEG with age?

A

At 3 mo, the posterior background rhythm should be 3Hz, and at 5 mo it should be 5Hz.

By age 3 yo, the awake background rhythm should reach alpha frequency.

15
Q

Kappa waves?

A

low amplitude waves in the temporal regions of the alpha or theta frequency (4-13). They occur during cognitive tasks or thinking.

Phi Beta KAPPA members have complex thoughts.

16
Q

Lambda waves?

A

positive sharp transients in the occipital area seen during visual scanning.

You can have lambda waves if you look around at a bunch of lambs.

17
Q

Mu rhythm?

A

7-11 Hz activity seen best over the centroparietal regions. Attenuated by movement of the contralateral body.

Mu is attenuated by MUvement.

18
Q

Wicket spikes/waves?

A

seen during drowsiness or light sleep in adults

6-11 Hz activity in the temporal region

Most adults are wicked drowsy at 6:11am

19
Q

Posterior slow waves of youth?

A

delta activity with overriding alpha frequencies

20
Q

14 and 6 positive bursts

A

seen during drowsiness and light sleep commonly in adolescents

bursts of arciform activity at 14 or 6 hz over posterior temporal head regions lasting for less than 3 seconds

21
Q

Siz hertz spike and wave bursts/ phantom spike and wave

A

seen in teens and adults during wakefulness and drowsiness. Disappear in sleep

Bursts of diffuse 6 Hz very small spike and higher amplitude wave discharges lasting a couple seconds.

22
Q

small sharp spikes of sleep

A

seen in drowsiness and light sleep in adults

brief, low voltage spikes over the temporal regions

23
Q

Rhythmic temporal theta bursts of drowsiness/ psychomotor variant pattern?

A

seen in drowsiness in young adults

5-7 Hz sharply contoured theta activity that occurs in bursts in the temporal region

24
Q

eyeblink artifact?

A

cornea is positive and retina is negative

When the eye closes, a positive deflection is seen in Fp1 and Fp2

When the eye opens, a negative deflection is seen

I’m positive that I’d like to close my eyes and take a nap

NEO has nice PECs

(remember positive is downward and negative is upward on EEG)

25
Q

Lateral eye movement artifact?

A

usually produce an artifact on F7 and F8

Look Left = positive on F7 and neg F8

Look right = negative F7 and pos F8

You look in the direction of positivity

26
Q

2 Types of alpha coma?

A
  1. posterior dominant alpha activity that is poorly reactive. (common in brainstem lesions)
  2. diffuse or frontal alpha activity that is poorly reactive.

Seen in anoxia

Alpha comas are seen in Anoxia and Arrest

27
Q

Bancaud’s phenomenon?

A

When the alpha activity over one hemi does not attenuated with eye opening. The nonreactive hemi is abnormal

28
Q

Beta coma?

A

high amplitude generalized beta activity

Commonly seen in encephalopathy 2/2 medication, and some acute brainstem lesions.

Beta has a BETter prognosis than alpha coma.

Beta coma may be when youre Buzzed

Alpha is awful, Beta is better

29
Q

breach rhythm?

A

due to a skull defect, the EEG activity may be higher in amplitude and spiky looking.

30
Q

burst suppression?

A

can be induced with pentobarbital or midazolam gtt

carries a very poor prognosis in the setting of hypoxic injury

31
Q

delta activity on EEG?

A

if continuous and polymorphic, may be due to a structural lesion

32
Q

Types of epileptiform discharges: Spike vs sharp waves?

A

spike = <70 ms in duration

sharp wave is 70-200 ms in duration

33
Q
A