Modified 10-20 Set Up

for Sleep RecordingsJon W. Atkinson, BS, RPSGT

Provide:◦ Historical perspective into 10-20 measurement◦ Detailed measuring/marking procedure◦ Tips to aid in success◦ Demonstration

Goals

Herbert Jasper, 1958. “Report of the committee on methods of clinical examination in electroencephalography: 1957” – described EEG placement based on anatomical landmarks

EEG was at the forefront of non-invasive neurodiagnosis

Provided consistent, replicable location of EEG electrodes and a standard nomenclature

Historical perspective

Alan Rechtschaffen and Anthony Kales, 1968. “A Manual of Standardized Terminology, Techniques and Scoring System For Sleep Stages of Human Subjects”

Adopted C3,4 and O1,2 to contralateral ears in the scoring manual

A need for consistency and replication (largely for research purposed) … Sleep disorders per se was little considered at that time.

Based on “normal” subjects

Historical perspective

Conrad Iber, et al, 2007 The AASM Manual for the Scoring of Sleep and Associated Events: Rules, Terminology and Technical Specifications

Added F3, 4 to the standard electrode placements◦ Enhance the appearance of “qualifying” slow waves

and K complexes◦ Problems

Many technicians/technologists were unfamiliar with the mechanics of F3,4 localization

Not well addressed in training programs or not followed through by students

Personal observation – proper localization of F3,4 was rare, even among RPSGT’s!!!

Historical perspective

Measuring and marking procedure

Anterior-Posterior Midsagittal Plane Find landmarks

nasion & inion; measure distance between the two being sure to keep the tape taut

Mark 50% of nasion-inion distance perpendicular to the tape

50%

50%

Nasion

Inion

Completing the A-P measurement

Measure from nasion to inion

Mark 50% point (Cz) Mark 20% forward

from Cz (Fz) Mark another 20%

forward (Fpz). This leaves 10% to the nasion.

Mark 40% back from Cz (Oz). This leaves 10% to the inion.

Nasion

20%

10%

10%

Inion

20%

40%

A-P measurement

Note position of ring finger and thumb as anchors for tape tautness

50% mark

A-P measurement

20% forward from 50% mark Additional 20% forward, leaving 10% from nasion

A-P measurement

40% back from 50% mark, 10% up from the inion indicated by the

wax pencil

Mid-coronal plane Measure distance

between L-PAN & R-PAN and mark 50% to complete CZ

Measure 20% down from Cz and mark for C3 and an additional 20% and mark T3

Measure 20% down from Cz and mark for C4 and an additional 20% and mark T4

Nasion

20%10%%

Inion

20% 20%10%

20%

L-PAN R-PAN

50% 50%

Mid-coronal measurement

Note again, anchoring of tape with thumb and ring finger or pinkie to pull the tape taut.

Mid-coronal measurement

50% mark perpendicular to tape 20% down from 50% mark

Mid-coronal measurement

Additional 20% down, leaving 10% up from the R-PAN

50% mark (at the pencil) and 20% (C3) down and 20% down

(T3)

Nasion

Inion

L-PAN R-PAN

Circumference Eyeball the middle of

the Fp plane by making a mark in the middle of the forehead sighting down to the nasal septum. (Fpz)

Measure the circumference from the Fpz through the T3 marking through the Oz plane through the T4 marking back to Fpz

Mark the base of the over the inferior frontal areas on each side.

Nasion

Inion

L-PAN R-PAN5% 5%

10%

5% 5%

10%

Circumference Measure and mark 50%

of the circumference from Fpz to locate Oz

Mark 5% of the entire circumference on either side of Oz to locate O1 and O2

Make a mark 5% on either side of FPz (FP1 & FP2)

Mark 10% of the circumference from FP1 and FP2 to localize F7 and F8

10% 10%

Circumference

Measuring the circumference through the 10% lines; I just

mentioned the needle electrodes

“Eyeballing” midline for the FPz mark

Circumference

5% marks on either side of Oz for O1 and O2

50% of the circumference for Oz

Circumference

Additional 10% back from Fp2 on the 10% line for F8

5% mark on either side of Fpz for Fp1 and Fp2

Marking Anterior Coronal Line Measure from L

Inferior Frontal (F7) line through Fz to R Inferior Frontal line (F8).

Mark 50% to finalize Fz

Mark 25% (half of the half) to create initial marks for F3 and F4

25%

50%

Nasion

Inion

L-PAN R-PAN

Marking Anterior Coronal Line

Measuring from F7 to F8 through FZ. Note anchoring and taut

tape.

50% mark and then 25% (half of the half) for F3

Nasion

Inion

L-PAN R-PAN

Finalizing F3, F4, C3 and C4 Measure from FP1

through F3 and C3 to O1 Mark 50% to finalize C3

and 25% (half of the half) forward to finalize F3

Measure from FP2 through F4 and C4 to O2

Mark 50% to finalize C4 and 25% forward to finalize F4

25%50%

Finalizing F3, F4, C3 and C4

Marking 50% of the Fp1-O1 distance and then marking “half

of the half” forward.

Measuring from Fp1to O1 through F3, C3. Note anchoring and taut

tape.

Final product

Antero-superior view. Note the mild bow from Fp’s to F’s to C’s .

Localize M1 and M2. Pull forward and

outward on the pinna.◦ Most people have a little

fold of skin about midway up on the ear where it attaches to the side of the head.

Locate the mastoid just superior to this fold. ◦ Too high will produce higher

amplitude EEG (alpha like) activity and contaminate your signal when used as a reference for the F’s, C’s and O’s

◦ too low will produce muscle artifact from sterno-cleido-mastoideus

A-P, mark Cz, Fz, Fp line and O line Mid-coronal, mark Cz, C3 and C4, T3 and T4 Circumference through the 10 percent line,

mark Fp1 , Fp2, O1 and O2 Anterior coronal, mark Fz, F3, F4 Parasagittal, from Fp’s to O’s, mark C3 and

C4, F3 and F4 Localize mastoids for M1 and M2

Summary

Keep the tape taut Use ring finger or pinkie and thumb as

anchors Mark perpendicular to the tape Remember to mark F7,8 when marking the

circumference Move the tape as few times as possible Practice, Practice, Practice Do it every time

Tips

Jasper, H. "Report of the committee on methods of clinical examination in electroencephalography: 1957". Electroencephalography and Clinical Neurophysiology 10 (2): 370–375, Elsevier, 1958.

Iber, C; Ancoli-Israel, S; Chesson, A; Quan, SF. for the American Academy of Sleep Medicine. The AASM Manual for the Scoring of Sleep and Associated Events: Rules, Terminology and Technical Specifications. Westchester: American Academy of Sleep Medicine; 2007.

Rechtschaffen, A; Kales, A. A Manual of Standardized Terminology, Techniques and Scoring System For Sleep Stages of Human Subjects. US Dept of Health, Education, and Welfare; National Institutes of Health, 1968

References