atomicai/neurophysiology-eeg
Template
1
0
Copy 0
Documents Lab Tickets Change Requests Projects Wiki Activity
Files
cd6332477f2576a9b1f72572fee6520a8ebfd03c
neurophysiology-eeg/SOPs/Recording-Procedures/SOP-EEG-001-Routine-EEG.md

8.9 KiB
Original text Edit trail Version history
File Word PDF

Standard Operating Procedure: Routine EEG Recording

Document ID SOP-EEG-001
Title Routine Electroencephalography (EEG) Recording
Revision 1.0
Effective Date [DATE]
Author [AUTHOR]
Approved By [APPROVER]
Department Neurophysiology/EEG Laboratory

1. Purpose

To establish standardized procedures for recording routine electroencephalograms (EEG) in accordance with American Clinical Neurophysiology Society (ACNS) guidelines to ensure high-quality recordings for accurate interpretation.

2. Scope

This procedure applies to routine EEG recordings including:

  • Routine awake EEG
  • Routine EEG with sleep
  • Activation procedures (hyperventilation, photic stimulation)
  • Portable/bedside EEG
  • Ambulatory EEG

3. Responsibilities

3.1 EEG Technologist

  • Prepare patient for recording
  • Apply electrodes according to 10-20 system
  • Perform recording per protocol
  • Monitor recording quality
  • Perform activation procedures
  • Document relevant observations

3.2 Electroneurodiagnostic Technologist (R.EEG.T or CNIM)

  • Supervise EEG recordings
  • Perform complex studies
  • Train and mentor technologists
  • Ensure quality standards

3.3 Interpreting Physician (Neurologist/Epileptologist)

  • Review and interpret recordings
  • Provide clinical correlation
  • Generate diagnostic report
  • Recommend follow-up studies

4. Definitions

Term Definition
10-20 System International electrode placement system
Montage Arrangement of electrode channels for display
Impedance Resistance between electrode and scalp
Sensitivity Amplitude of EEG display (µV/mm)
Activation Procedures to provoke abnormalities (HV, photic)

5. Equipment and Materials

  • Digital EEG recording system
  • Electrodes (disc, cup, or disposable)
  • Electrode paste/gel (conductive)
  • Skin preparation materials (abrasive gel/paste)
  • Measuring tape
  • Electrode placement cap or headbox
  • Impedance meter
  • Photic stimulator
  • Video recording system
  • Calibration equipment

6. Procedure

6.1 Patient Preparation

6.1.1 Pre-Procedure Verification

  1. Confirm patient identity (two identifiers)

  2. Verify physician order and indication

  3. Review relevant history:

    • Seizure history
    • Current medications (especially AEDs)
    • Sleep deprivation (if ordered)
    • Recent seizure activity

  4. Patient Instructions Verified:

    • Hair clean, dry, no styling products
    • Sleep deprivation completed (if ordered)
    • Medications taken as instructed
    • No caffeine morning of test (if applicable)

6.1.2 Patient Education

  • Explain procedure and duration
  • Describe electrode application process
  • Explain activation procedures
  • Discuss what to expect during recording

6.2 Electrode Application

6.2.1 Measurement and Marking

10-20 System Measurements:

  1. Measure nasion to inion (anterior-posterior)

  2. Mark Fpz at 10% from nasion

  3. Mark Fz at 30%, Cz at 50%, Pz at 70%

  4. Mark Oz at 10% from inion

  5. Measure preauricular points (transverse)

  6. Mark T3/T4 at 10% from preauricular

  7. Mark C3/C4 at 30%

  8. Mark Cz at 50% (should match A-P)

  9. Measure head circumference

  10. Mark remaining positions per 10-20 system

6.2.2 Standard Electrode Positions

Position Location Hemisphere
Fp1, Fp2 Frontopolar Left, Right
F3, F4 Frontal Left, Right
C3, C4 Central Left, Right
P3, P4 Parietal Left, Right
O1, O2 Occipital Left, Right
F7, F8 Anterior Temporal Left, Right
T3, T4 Mid-Temporal Left, Right
T5, T6 Posterior Temporal Left, Right
Fz Frontal Midline
Cz Central Midline
Pz Parietal Midline
A1, A2 Ear/Mastoid Reference

6.2.3 Electrode Application Process

  1. Part hair at electrode site
  2. Clean scalp with abrasive gel
  3. Apply conductive paste to electrode
  4. Affix electrode to scalp
  5. Secure with tape, collodion, or cap
  6. Repeat for all electrodes

6.2.4 Impedance Check

  • Check impedance for all electrodes
  • Target: <5 kΩ
  • Maximum acceptable: <10 kΩ
  • Document impedance values
  • Reapply electrodes if impedance excessive

6.3 Recording Setup

6.3.1 System Configuration

Parameter Standard Setting
Sensitivity 7 µV/mm
Low frequency filter 1 Hz
High frequency filter 70 Hz
Notch filter 60 Hz (if needed)
Time constant 0.16 seconds
Paper speed/display 30 mm/sec

6.3.2 Standard Montages

Longitudinal Bipolar (Double Banana):

  • Fp1-F7, F7-T3, T3-T5, T5-O1
  • Fp1-F3, F3-C3, C3-P3, P3-O1
  • Fz-Cz, Cz-Pz
  • Fp2-F4, F4-C4, C4-P4, P4-O2
  • Fp2-F8, F8-T4, T4-T6, T6-O2

Transverse Bipolar:

  • F7-Fp1, Fp1-Fp2, Fp2-F8
  • T3-C3, C3-Cz, Cz-C4, C4-T4
  • T5-P3, P3-Pz, Pz-P4, P4-T6

Referential:

  • All electrodes referenced to average or specific electrode

6.3.3 Calibration

  1. Perform square wave calibration
  2. Document calibration signal
  3. Verify all channels responding appropriately

6.4 Recording Procedure

6.4.1 Recording Timeline

Phase Duration Activity
Initial 5-10 min Eyes closed, relaxed wakefulness
Eyes open/closed 2-3 cycles Assess reactivity
Hyperventilation 3-5 min Deep breathing
Post-HV 2-3 min Recovery period
Photic stimulation 5-10 min Flashing lights
Drowsiness/Sleep As able Natural or sleep-deprived
Total Recording 20-40 min Minimum per ACNS

6.4.2 Routine Recording Protocol

  1. Resting Recording

    • Eyes closed, relaxed
    • Minimize movement
    • Record representative sample

  2. Eyes Open/Closed

    • Command to open eyes (10 seconds)
    • Command to close eyes
    • Document alpha reactivity
    • Repeat 2-3 times

  3. Hyperventilation (if not contraindicated)

    Contraindications:

    • Recent stroke
    • Significant cardiovascular disease
    • Respiratory compromise
    • Sickle cell disease
    • Pregnancy
    • Intracranial hemorrhage

    Procedure:

    • Explain deep, rapid breathing
    • Patient breathes deeply for 3-5 minutes
    • Document effort level
    • Continue recording 2-3 minutes post-HV
    • Document any symptoms or findings

  4. Photic Stimulation

    Standard Frequencies: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 18, 20, 25, 30 Hz

    Procedure:

    • Position photic stimulator 30 cm from face
    • Eyes closed
    • 10 seconds at each frequency
    • 10 second pause between frequencies
    • Document any clinical responses
    • Stop if clinical seizure occurs

  5. Sleep Recording (if ordered)

    • Encourage natural drowsiness
    • Record drowsiness transition
    • Record sleep if achieved
    • Document sleep stages observed

6.5 Documentation During Recording

Technologist must annotate:

  • Patient state (awake, drowsy, asleep)
  • Eye movements and blinks
  • Movement artifacts and cause
  • Patient activities (talking, coughing)
  • Clinical events observed
  • Activation procedures (start/stop times)
  • Any technical problems

6.6 Recording Quality Checks

Throughout recording, monitor for:

Issue Action
Electrode pop/artifact Check connection, reapply if needed
Movement artifact Reposition patient, note cause
Sweat artifact Cool patient, apply antiperspirant
Muscle artifact Relax jaw/neck, adjust position
60 Hz interference Check grounds, move cables

6.7 Post-Recording

  1. Electrode Removal

    • Remove electrodes carefully
    • Clean paste from scalp
    • Inspect scalp for irritation
    • Provide patient aftercare instructions

  2. Equipment Care

    • Clean reusable electrodes
    • Disinfect equipment per protocol
    • Store equipment properly

  3. Documentation Complete FRM-EEG-001 including:

    • Recording duration
    • Montages used
    • Activation procedures performed
    • Patient cooperation level
    • Technical quality assessment
    • Technologist observations

7. Special Considerations

7.1 Pediatric Patients

  • May require sedation (per physician order)
  • Age-appropriate electrode sizes
  • Modified activation procedures
  • Parent/guardian present as appropriate

7.2 ICU/Portable EEG

  • Increased artifact sources
  • Document artifact causes
  • Extended recording times may be needed
  • Coordinate with bedside care

8. Quality Control

Metric Target
Electrode impedance <5 kΩ >90% of electrodes
Recording duration meets minimum 100%
Activation procedures completed 100% (unless contraindicated)
Technical quality adequate for interpretation >95%

9. References

  • ACNS Guideline 1: Minimum Technical Requirements for Performing Clinical EEG
  • ACNS Guideline 6: Recording EEG
  • ASET Standards of Practice
  • ABRET Certification Requirements

Revision History

Rev Date Description Author
1.0 [DATE] Initial release [AUTHOR]
Reference in New Lab Ticket View Edit trail Copy Permalink