EEG FINAL

Time constant

low frequency filter

If a common mode rejection ratio is reduced,which of the following would occur? a. 60 Hz artifact will be eliminated b. 60 Hz artifact will be reduced c. 60 Hz artifact will be enhanced d. the amplifier will not function

c (60 Hz artifact will be enhanced)

The EEG amplifier is designed so that when input 1 is more negative than input 2, the deflection will be

upward

Voltage = what?

SD

The time constant is defined as the time required for the pen to fall to _______ of the peak deflection?

37%

The initial sensitivity range for an EEG recording should be between?

5-10 uV/mm

What should the standard impedance recording for an EEG be at?

5.0 kOhms or less

By what age should alpha be 'fully developed'?

8 years old

What is the frequency range for alpha?

8-13 Hz

Name four conditions that an EEG helps to diagnose or rule out.

ADHD, tumor, stroke, any neurological disease (ALS)

This is an abnormality of which rhythm: Unilateral failure to attenuate with eye opening.

Alpha rhythm

Which of the following best describes the phase change seen when comparing a recording using a low frequency filter of 1 Hz to one using a low frequency filter of 5 Hz? a. Slow waves are maximally affected; they shift to the right. b. Fast waves are maximally affected; they shift to the right. c. Slow waves are maximally affected; they shift to the left. d. Fast waves are maximally affected; they shift to the left.

C. (slow waves are maximally affected; they shift to the left)

Usually the most prominent rhythmic activity seen in children under two years of age is over which region?

Central

This part of a report provides a concise description of the appearance of the EEG. It allows another electroencephalographer to visualize the appearance of the recording without actually seeing it.

Description

Slow lateral eye movements are seen best in Fp1-F7 and Fp2-F8 leads. Alpha drops out. May see anterior theta. Appearance of POSTS. V waves focal at Cz and also appear at C3/C4.

Drowsy/Stage I

Beta activity is usually (most commonly) present over which head region?

Frontal

Beta activity is usually present over which head regions?

Frontal

Ohms law equation is

I = E/R

A sampling rate twice that of the highest frequency to be accurately reconstructed in an audio signal. The sampling rate must be at least twice that of the highest frequency to avoid aliasing.

Nyquist sampling rate

States that a frequency must be sampled at least twice in order to reproduce it reliably

Nyquist theorem

Muscle tone decreases. Background activity changes from 3 or 4 to look more like stage I. Typically occur at 90 min intervals. Likely to occur shortly before awakening. In males, this stage is associated with penile erection.

REM

In the international 10-20 electrode placements, C4 is located on which part of the head?

Right

Where is T4/T8 located on the head?

Right temporal

A patter seen during the wake state in children is?

Shut eye waves

Shape of the wave

monomorphic

The polarity convention of EEG states that the deflection is up in input____: a. 1 is more negative than input 2 b. 1 is more positive than input 2 c. 2 is more negative than input 1 d. 2 is equal to input 1

a (1 is more negative than input 2)

Which of the following settings will provide the best visualization of slow wave focus in the EEG? a. LF 0.3 Hz, 15 mm/sec b. LF 0.3 Hz, 60 mm/sec c. LF 5 Hz, 15 mm/sec d. LF 70 Hz, 60 mm/sec

a (LF 0.3 Hz, 15 mm/sec)

Referential montage recordings are most appropriate for measuring

voltage

The spread of infection can BEST be prevented by

washing your hands

The ability of an amplifier to reject in phase and amplify out of phase potentials is called

common mode rejection

Which of the following is most attenuated by a low frequency filter of 1 Hz? a. 0.5 Hz wave b. 5.0 Hz wave c. 10.0 Hz wave d. 0.1 Hz wave

d (0.1 Hz wave)

Differential amplifiers are needed to: a. reduce grounding problems b. allow both referential and bipolar recordings c. improve the low frequency response d. provide the rejection of in phase signals

d (provide the rejection of in phase signals

A circuit that allows some frequencies to through it while others are blocked is a

filter

Frequency response curve

filters

near the head

proximal

Common mode rejection is the characteristics of an amplifier that

rejects external interference

How many minutes of technically good EEG recording must be minimally recorded during the awake state?

20 minutes

What is the minimum number of channels that are needed to record most normal and abnormal EEGs?

16

A spike measuring 16mm peak to peak is recorded at a sensistivity of 10uV/mm. What is the voltage of the spike? V= SD

160 uV

Diphasic slow wave transients "shut eye waves" are most prominent in which age group?

1 to 3 years

Frontal theta activity occurring with drowsiness is seen in which age group?

11 to 15 years

If theta activity from a drowsy child recorded at a sensitivity of 7 uV/mm results in a deflection of 20 mm, what is the voltage?

140 uV

Which of the following is not a unit for measuring alternating frequencies? a. cycles per second b. volts c. hertz d. kilocycles

B (volts)

What two types of montages should always be used during a 30 minute EEG recording?

Bipolar and referential

Regulations that require health care providers and organizations, as well as their business associates, to develop and follow procedures that ensure the confidentiality and security of protected health information.

HIPPA

Who is considered the "Fathers of EEG"?

Hans Berger

The filters creating a very narrow bandpass that should rarely be used clinically are

LF 5.0 Hz and 15 Hz

May be similar to photic responses (<3Hz)

Lambda waves

This type of wave is best seen with eyes open

Lambda waves

This type of wave can be seen in the central derivations when the person is awake. It can be blocked by movement of the contralateral side of the body.

Mu waves

What is the indentation between the nose and the forehead?

Nasion

Bursts of 11-15Hz spindles predominantly in the central-vertex regions. K-complexes are sharp, slow waves with associated spindle bursts; predominantly central and midline.

Stage II

Activity of 2 Hz or less are present 20-50% of the time. Spindles still present but to a lesser degree. K complexes may persist. Frontal slow transients may appear.

Stage III

Delta activity is present more than 50% of the time and voltage is greater than 75uV. Sleep spindles are usually slower frequency. Slow wave activity is typically maximal over anterior areas and sharper transients continue to be located centrally.

Stage IV

THESE ARE ALL EXAMPLES OF WHAT? What brings you in today? Describe the feeling (rate it 1-10) Does anything help it? Does anything make it worse? Are you doing anything at a particular time when it happens? Are you taking any medications?

Taking patients history

This type of paragraph in an EEG report is usually standardized per individual lab; it describes the technical elements used for the EEG recording.

Technical Summary

What happens when a 60 cycle sinewave is sampled at 100 Hz?

aliasing

The basic unit for measuring current flow is

ampere

A combination of electronic components designed to increase the power, voltage, or current of a signal is called

amplifier

Converting a continuous signal to a series of discrete numerical values

analog to digital conversion

How do you localize on a referential montage?

by amplitude

Acquisition of EEG date should occur at a minimum sampling rate of a. half the high frequency setting b. two times the high frequency setting c. three times the high frequency setting d. four times the high frequency setting

c (three times the high frequency setting)

Signals common to both inputs of a differential amplifier with like frequency, amplitude and phase are

cancelled

This kind of montage is also known as a hat band montage

circumferential

During an EEG recording, what four things need to be included in the study?

eye opening and closing, mental activation, photic stimulation, hyperventilation

A calibration signal (either square wave or Bio Cal) needs to be made at the end of the recording; TRUE or FALSE?

false

TRUE or FALSE: Montages should be labeled with right over left pairs of electrodes in US and Canada?

false

On an EEG report, what are some examples of identifying information?

name, date of birth, date of study, referring physician

A small fluctuating output recorded by the EEG instrument even when there is no input signal is called

noise

The basic unit of resistance is

ohm

How do you localize activity on a bipolar montage?

phase reversal and cancellation

A downward deflection occurs if input 1 is more ______ than input 2?

positive

Slow wave transients in older people are abnormal if they extend beyond which region of the head?

temporal