ABRET ACNS Guidelines

What is the minimal amount of recording time acceptable when performing a clinical EEG?

The baseline recording should contain at least 20 mins of technically satisfactory recording

What is the minimum number of scalp electrodes required when performing a clinical EEG?

All 21 electrodes and placements following the international 10-20 system should be used

What are appropriate filter settings when performing clinical EEG?

The low frequency filter (LFF) should be no higher than 1 hz and the high frequency filter (HFF) should be no lower than 70 hz

Why is the use of 60 hz filter discouraged when performing EEG?

The 60 hz filter can distort of attenuate spikes and should therefore only be used when other measures against 60 hz interference fail

What are the interelectrode impedance requirements when performing a clinical EEG?

Electrode impedance should not exceed 5000 ohms (5 kOhms)

What is the correct documentation a clinical EEG record should contain?

As a minimum the EEG should have the name and age of the patient, the date of the recording, an ID number, and name or initials of the technologist

What are three reasons it is important to have periods of eye opening and eye closing during the performance of a clinical EEG?

1) Some rhythms can be masked by alpha activity with eyes closed
2) To help differentiate cerebral activity from eye movement
3) Some paroxysmal activity can only be seen with eye opening or closing

What is the minimum number of electrodes required to perform an electrocerebral silence(ECS) or electrocerebral inactivity (ECI) recording?

A full set of scalp electrodes

What are the impedance requirements on ECS/ECI?

Under 10,000 ohms but over 100 ohms

What is the interelectrode distance requirement when performing an EEG to determine electrocerebral silence (ECS)/ electrocerebral inactivity (ECI)?

Interelectrode distances should be at least 10 cm

What are the appropriate filter settings when performing ECS/ECI?

To avoid attenuation of slow ow voltage fast or slow activity, HFF should not be below 30 hz and LFF should not be above 1 hz

Repeating ECI testing in pediatrics and neonates should be done _____ apart

At least 24 hours

Repeat ECI for adults should be at least _____ apart

6 Hours

During Calibrations the recorded signals should be measured and be within _____ of each other

+/- 5%

Which electrode should be used as the system reference?

An additional electrode NOT included in the 10/10 or 10/20 systems

Minimum Horizontal Resolution is _____ pixels

1,280 pixels

Integrity of the recording system is checked in ECI in order to...

1) Verify the electrode board is connected to the recording device
2) Prove that the montage settings match the electrode placement

Why is record storage on a server recommended over other digital media storage? (e.g. DVD or optical drive)

1) To prevent data loss (servers have redundancy and backup)
2) Full HIPAA compliance because it can record a full audit trail of every person accessing the record

When should biocalibration be done?

Only for analog machines

Why are needle electrodes not recommended for routine use?

1) Patient discomfort
2) Risk of injury to tech
3) Higher impedances than surface electrodes
4) More susceptible to noise

For routine recordings, the LFF should be...

No higher than 1 Hz (-3 dB)

ACNS Guidelines state but depth should be...

At least 16 bits per sample

When recording with a reduced electrode array in neonates, which electrodes must be included?

1) Fp1 + Fp2
2) C3 + C4
3) Cz
4) T3 + T4
5) O1 + O2
6) A1 + A2

What should be noted within the EEG of routine recordings / of comatose patients?

• LOC and any changes
• Any commands to the patient
• Movements or clinical seizures
• Frequent notations with standardized abbreviations
Comatose - visual, auditory, somatosensory stimuli applied and response documented

What Activations should be done in routine recordings?

1) Eyes open and close
2) Photic
3) HV
4) Sleep

What system of electrode placement should be used in patients undergoing presurgical evaluation?

10-10 System

Interelectrode impedances should not be below...

100 Ohms

When recording an EEG, the tech should use _____ montages

At least 3 different montages including at least 1 reference montage

After calibrating, the tech should perform a visual review of what?

30 seconds on system reference montage without the notch filter

Electrode impedances should exceed...

10k Ohms

For pediatric EEGs, when should Hyperventilation and Photic Stimulation be performed?

1) HV at beginning
2) PS at the end

This is done to maximize spontaneous sleep

In adult EEG, a minimum of _____ electrodes should be used

21 electrodes

When electrodes have been placed without using the 10-20 system, it should be documented as...

Estimated 10-20 placement

How long should Calibrations last?

At least 10 seconds (or the duration needed to reach a stable recording)

Neonatal recordings must contain a minimum of _____ channels

12 channels

Minimum Sampling Rate

256 Samples per second

When recording ECI, the electrode impedances should be less than _____ but greater than _____

10,000 Ohms; 100 Ohms

The 10-10 system renames T3 and T4 as...

T7 and T8

What physiological parameters should be documented in the ECI?

1) Body temperature
2) Blood pressure
3) O2 Saturation

- Date/Time of last sedating meds

Minimum Resolution for a 10 sec/page screen is _____ data points/sec

128 datapoints per second

The common mode rejection ratio should be at least...

10,000 : 1

90 dB

In pediatric patients, if HV fails to elicit diagnostic findings the tech should wait _____ before performing HV again

At least 10 minutes

When should nasopharyngeal electrodes be used?

Never for clinical use

In adult EEG, when should photic stimulation and HV be done?

PS: before HV or at least 3 minutes after HV

HV: After at least one minute of recording in the montage to be used

The standard method for adding additional electrodes in the 10-20 system is...

10-10 system

A basic data sheet with each recording should include...

1) Pt name
2) Pt age
3) date/time of test
4) tech
5) indication for test
6) time/date of last seizure/episode
7) behavioral state of Pt
8) meds
9) skull defects
10) relevant medical history
11) modifications of 10-20
12) handedness
13) time of last meal
14) sleep deprived
15) imaging/EEG results

Minimum patient information to be included with the recording is...

1) Patient name
2) Age of Patient
3) Date of Recording
4) ID Number
5) Name of Tech

The minimum number of channels for adult EEG

16

When should the patient's clinical state be indicated?

1) Beginning of recording
2) With each montage change
3) With each change in patient's state

What display speed should be used for routine recordings?

10-20 seconds per page

(corresponding to ~30 mm/sec)

What should the tech do to facilitate the assessment of the Patient's awake PDR?

To make sure the patient is maximally alert for a portion of the recording

When should 60 Hz filter be used?

Only after other measures to eliminate 60 Hz have failed

When recording neonates, polygraphic variables are to be used. Which variables must be included?

1) Heart Rate
2) Respirations
3) Eye movements
4) Muscle activity via electromyography

What electrode types can be used for neonates?

Disc electrodes and Paste

DO NOT use collodion OR needles

When should the 10-10 system be used?

• Patient undergoing presurgical evaluation
• Suspected focal epilepsy
• Source localization

In infants over 3 months of age, eye closure should be performed via...

Passive eye closing using hands and/or playing "peek-a-boo"

When recording from stuporous or comatose patients, the tech should apply stimuli. What stimuli should be used?

1) Visual (strobe light)
2) Auditory (call patient's name)
3) Somatosensory

Electrocerebral Inactivity is defined by the ACNS as...

The absence of nonartifactual electrical activity over 2 uV

The only recognized method of electrode measurement/placement is called...

International 10-20 system of electrode placement

How many Montages should the tech view during Acquisition?

At least 3 montages

The 10-10 system renames T5 and T6 as...

P7 and P8

What is the standard monitor speed? Paperspeed?

10-20 sec/page

30 mm/sec

ACNS Guidelines require a vertical scaling with a minimum spacing of...

10 mm per channel for up to 21 channels