Pediatric Scoring Review
Cindy Nichols, PhD, FAASM, CBSM
Munson Sleep Disorders Center
Traverse City, MI
I do not have any potential
conflicts of interest to disclose.
Objectives
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Describe the context for the AASM Scoring
Manual
Describe pediatric PSG scoring rules and
recent updates
Compare and contrast adult and pediatric
scoring
Opening Comments
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Pediatric PSGs often have more artifact that
adult PSGs, and are more susceptible to
GIGO. Excluding artifact from real data is
one of the most important tasks of the scoring
technologist.
PSG scoring rules artificially dichotomize
developmental and other aspects of sleep
scoring, but this is not a rationale for breaking
the rules.
Scoring tech thought this was “pop artifact”;
acquiring tech made no observational comment
Same with PS = 10mm/sec
Introduction
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Pediatrics are defined as children age 2
months post term (vs. neonates).
There is no precise upper age boundary for
pediatric visual (staging) rules; age 18 is
conventional.
Criteria for respiratory events can be used for
children <18 years, but an individual sleep
specialist can choose to score children >13
years using adult respiratory criteria.
• Prior to using this manual, there
was no certainty that events were
scored similarly between sleep
centers.
• This lack of inter-center
consistency in scoring led to a
reimbursement crisis, with the
potential that sleep studies would
not be paid for by Medicare or
other third party payers
Iber C et al. American Academy
of Sleep Medicine (AASM), 2007.
• The AASM responded by inviting
experts in all aspects of PSG who
volunteered thousands of hours
to review the literature and
establish new scoring rules. The
AASM provided administrative
and clerical support for this effort.
Terminology of Sleep
Stages in Children
Similar to adults for stages W, N1, N2,
N3, and R.
 An added category of N (NREM) is used
for infants 6 months post-term and
younger.
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Electrode Placement and
Sensitivities
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Electrode placement for chin EMG can be reduced
from 1 cm to 0.5 cm in children with small head size,
at the discretion of the technologist.
Begin with EEG sensitivity (vertical scaling) of 7
µV/mm but it is permissible to reduce this to 10 or 15
µV/mm. This will result in some difficulty viewing
spindles and other low voltage fast frequencies
(LVFF), so scoring and review should be performed
with portions of the recording at 7 µV/mm to
accurately recognize these frequencies.
Scoring W
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In some children age 2 months – 6 months, and in
children with developmental delays, NREM sleep
may contain no spindles, K-complexes, or high
amplitude 0.5-2 Hz slow wave activity. Score these
epochs as N.
For the purpose of scoring W and NREM sleep in
children, the term “dominant posterior rhythm” (DPR)
replaces the term “alpha rhythm”.
DPR gradually increases in frequency until it meets
criteria for alpha.
DPR is usually slightly asymmetrical (higher on the R)
More About Dominant
Posterior Rhythm (DPR)
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This is defined as the dominant reactive EEG rhythm
over the occipital regions in relaxed wakefulness with
eyes closed (evolves into “adult alpha”).
DPR is reactive, attenuating with eye opening or
attention.
DPR amplitude is usually >50 μV.
DPR is slower in infants and younger children.
DPR first develops by age 3-4 months post-term;
frequency is 3.5-4.5 Hz in infants 3-4 months, 5-6 Hz
by 5-6 months, and 7.5-9.5 Hz by age 3 in most.
Dominant Posterior
Rhythm (DPR) is not all
“pseudo-alpha”
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DPR typically contains intermixed slower EEG rhythms
including posterior slow waves of youth (PSW) which
are:
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intermittent runs of bilateral but often asymmetric 2.5-4.5
Hz slow waves superimposed, riding upon, or fused with
the DPR (looks a little like “alpha-delta”; can be mistaken
for low frequency artifact or N3)
usually >120% of DPR voltage
usually blocked with eye opening and disappear with
drowsiness and sleep
uncommon in children <2 years, have maximal incidence
in age 8-14, and are uncommon after age 21
Other Waves Seen Mixed
In With DPR
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DPR typically contains intermixed slower EEG
rhythms including:
 Posterior slow waves of youth (PSW)
 Random or semi-rhythmic occipital slowing
 is <100 μV, 2.5-4.5 Hz rhythmic or arrhythmic
activity lasting <3 seconds.
 is a normal finding in EEGs of children 1-15
years, especially prominent in age 5-7.
 With increasing age, the amount of intermixed
slowing decreases and its frequency increases.
A Few More Wake Rhythms
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Mu
 8-10 Hz
 Resembles alpha but does not block with eye
opening
 Blocks contralaterally with movement, intent to
move, or tactile stimulation of an extremity
 More common in females
Lambda
 Sharp, fairly rhythmic waves with negative
deflection
 Often present unilaterally
 Usually seen in well-lighted room if child is looking
at a patterned design
MU
Sens 7uv/mm HFF 70Hz LFF 1.0 Hz PS 30mm/sec
Same with sens 15uv/mm
Same with PS 10mm/sec and only central and occipital channels
Lambda
Sens 5uv/mm HFF 70Hz notch off LFF 1.0Hz PS 30mm/sec
Same sample with central and occipital only, same settings
Same sample at 10mm/sec
Scoring W
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Score epochs as W when more than 50% of the
epoch has either reactive alpha or age-appropriate
DPR over the occipital region.
If there is no discernable reactive alpha or no ageappropriate DPR, score W if any of the following are
present:
 eye blinks at a frequency of 0.5-2 Hz
 reading eye movements
 irregular conjugate REMs associated with normal
or high chin muscle tone
Scoring W
It is important to differentiate occipital sharp
waves occurring in stage W from K-complexes
which are characteristic of stage N2.
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Occipital sharp waves typically occur 100-500
msec after an eye blink or eye movement.
Occipital sharp waves are typically single
monophasic or biphasic <200 V sharp waves over
the occipital derivation and usually last 200-400
msec.
The initial component is surface-positive, the next
is negative and has a steep ascending wave front,
and the final descending phase of the second
component is less steep.
Eye Movements in W
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Spontaneous eye closure in children,
particularly infants, typically signals
drowsiness. (Zoom video in on eyes while
scoring!)
The highest amplitude and sharpest
component of reading eye movements in
children is usually surface-negative in the
occipital derivations, typically lasts 150-250
msec, and has amplitude up to 65 μV.
Scoring N1
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In children who generate DPR, score N1 if the
posterior rhythm is attenuated or replaced by low
amplitude mixed frequency activity for more than
50% of the epoch.
In children who do not generate a DPR (often seen
with psychoactive medications), score N1
commencing with the earliest of any of the following
phenomena:
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4-7 Hz activity with slowing of background frequencies
by >1-2 Hz from stage W
slow eye movements
vertex sharp waves or rhythmic anterior theta activity
hypnagogic hypersynchrony
3-5 Hz diffuse or rhythmic occipital predominant high
amplitude rhythm
Drowsiness in W-N1
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Drowsiness in infants up to 6-8 months is
characterized by the gradual appearance of diffuse
high amplitude (75-200 μV) 3-5 Hz activity which is
typically of higher amplitude, more diffuse, and 1-2
Hz slower than the waking EEG background activity.
Drowsiness in children 8 months-3 years is
characterized by either diffuse runs or bursts of
rhythmic or semi-rhythmic bisynchronous 75-200 μV,
3-4 Hz activity often maximal over the occipital
regions and/or higher amplitude (>200 μV) 4-6 Hz
theta activity maximal over the frontocentral or central
regions.
Drowsiness in W-N1
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Sleep onset from 3 years on is often characterized by
a 1-2 Hz slowing of the DPR frequency and/or the
DPR rhythm becomes diffusely distributed then is
gradually replaced by relatively low voltage mixed
frequency EEG activity.
In most children sleep onset will be the first epoch of
stage N1 but in infants younger than 3 months postterm, this is often stage R.
Rhythmic anterior theta activity is commonly seen in
adolescents and young adults when drowsy, and may
first appear at age 5 years.
Terms Related to
Scoring N1
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Slow eye movement: conjugate, reasonably regular,
sinusoidal eye movements with an initial deflection
which usually lasts >50 msec
Vertex sharp waves: sharply contoured waves with
duration <0.5 sec maximal over the central region
and distinguishable from the background activity; can
be seen in bursts or runs
Rhythmic anterior theta activity: runs of 5-7 Hz
rhythmic theta activity maximal over the frontal or
frontocentral regions
Terms Related to
Scoring N1 (continued)
 Hypnagogic hypersynchrony:
 paroxysmal bursts or runs of diffuse high
amplitude sinusoidal 75-350 μV, 3-4.5 Hz
waves which begin abruptly, are usually
widely distributed but often maximal over
the central, frontal, or frontocentral scalp
regions and alternate with LVMF activity
(always score N1 if you see this)
 becomes less prevalent after age 4-5 years
and is rarely seen after age 12 years
Scoring N2
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Same as adult rules
Developmental notes
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Spindles are usually first seen at age 4-6 weeks
and are usually well-developed by age 8-9 weeks.
Spindles are more prominent in frontal placement
up to age 13, then become more prominent in
central placements.
K complexes typically develop at 5-6 months postterm and are maximal over the pre-frontal and
frontal regions (like adults).
Scoring N3
Same as adult rules
 Developmental notes
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Slow wave activity first appears as early as 2
months, more often about 3-4.5 months post-term.
Amplitude of slow waves is typically 100-400 μV.
The decrease in voltage with increasing age is
ascribed to increasing skull bone density.
Scoring R
Same as adult rules
 Developmental notes
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The LVMF dominant frequencies tend to increase
with age and resemble adult LVMF activity by age
5-10.
Scoring Arousals
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Same as adult rule
Scoring Cardiac Events
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Same as adult except for definition of sinus rates.
There is a paucity of heart rate data on children
during sleep.
Bradycardia for age 6 years and older is defined as a
sustained HR <40 bpm.
In children under age 6, sinus bradycardia can be
defined as 2 SD below the mean heart rate during
sleep.
It is suggested that sinus tachycardia in children is
defined as 2 SD above the mean heart rate during
sleep.
Scoring Cardiac Events
age
1-1.5
2-4
5-7
8-11
-2 SD (brady)
92
67
64
53
+2 SD above (tachy)
136
119
100
92
Scoring Movements
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Same as adult rules
Monitoring Devices for
Respiration in Children
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Best sensor for detection of apnea is oronasal
thermal sensor (same as adults).
Best sensor for detection of hypopnea (and alternate
sensor for apnea) is a nasal air pressure transducer
without square root transformation of the signal.
Acceptable sensors for detection of respiratory effort
are esophageal manometry, or calibrated or
uncalibrated inductance plethysmography (same as
adults). IC EMG is no longer recommended.
Acceptable methods for assessing alveolar
hypoventilation are either transcutaneous (TC) or endtidal (ET)PCO2 monitoring.
Monitoring Devices for
Respiration in Children
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Alternative sensors are to be used when the signal
from the recommended sensor is not reliable.
 The alternative signal to detect apnea is a nasal
air pressure transducer.
 Alternative signals for identification of apnea are
end-tidal PCO2 and summed calibrated inductance
plethysmography.
 Alternative sensor for detection of airflow for
identification of hypopnea is an oronasal thermal
sensor.
Monitoring Devices for
Respiration in Children
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End-tidal PCO2 often malfunctions or provides falsely
low values in patients who have
 marked nasal obstruction
 profuse nasal secretions
 are obligate mouth breathers
 are receiving supplemental oxygen
It is crucial to obtain a plateau in the end-tidal
waveform for the signal to be considered valid.
Transcutaneous PCO2 monitoring provides only a
semi-quantitative index of trends in alveolar
ventilation, and varies unpredictably from the PaCO2
(typically lower, and lagging after the event).
Apnea Rules: Obstructive
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Must meet all of the following:
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event lasts for at least 2 missed breaths (or the
duration of 2 breaths as determined by baseline
breathing pattern)
event is associated with a >90% fall in the signal
amplitude for >90% of the entire respiratory event
compared to the pre-event baseline amplitude (same
as adults but without the “9 second rule”)
event is associated with continued or increased
inspiratory effort throughout the entire period of
decreased airflow (same as adults)
duration of the apnea is measured from the end of the
last normal breath to the beginning of the first breath
that achieves the pre-event baseline inspiratory
excursion (same as adults)
Apnea Rules: Mixed
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Must meet all of the following criteria:
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event lasts for at least 2 missed breaths (or the
duration of 2 breaths as determined by baseline
breathing pattern)
event is associated with a >90% fall in the signal
amplitude for >90% of the entire respiratory event
compared to the pre-event baseline amplitude
(same as adults except for the 9 second rule)
event is associated with absent inspiratory effort in
the initial portion of the event, followed by
resumption of inspiratory effort before the end of
the event (same as adults)
Apnea Rules: Central
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Event is associated with absent inspiratory
effort throughout the entire duration of the
event and one of the following criteria is met:
 event lasts 20 seconds or longer
 event lasts at least 2 missed breaths (or
the duration of 2 breaths as determined by
baseline breathing pattern) and is
associated with an arousal, an awakening
or a >3% desaturation.
Pediatric Hypopnea Rules
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Score a respiratory event as hypopnea if it meets all
of the following criteria:
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event is associated with a >50% fall (adult is 30%) in
the amplitude of the nasal pressure or alternative
signal compared to the pre-event baseline excursion
event lasts at least 2 missed breaths (or the duration
of 2 breaths as determined by baseline breathing
pattern) from the end of the last normal breathing
amplitude
fall in the nasal pressure signal amplitude must last for
>90% of the entire respiratory event compared to the
signal amplitude preceding the event (same as adult)
event is associated with an arousal, awakening, or
>3% desaturation (adult is 4%)
Pediatric RERA Rules
for Use with the Nasal
Pressure Sensor
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All of the following must be met:
 Event is associated with arousal
 discernible fall in the amplitude of signal but less
than 50% in comparison to the baseline level
 flattening of the waveform
 event is accompanied by snoring, noisy breathing,
elevation in the end-tidal PCO2 or transcutaneous
PCO2, or visual evidence of increased work of
breathing
 duration is at least two breath cycles (or the
duration of 2 breaths as determined by baseline
breathing pattern)
Comments on Hypopneas
and RERAS
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Intolerance and malfunction of the nasal pressure sensor
occurs more commonly in infants and children than in
adults. When this occurs, hypopneas may be scored using
a thermal sensor if the signal quality is adequate, following
the same criteria used for scoring hypopneas with a nasal
pressure sensor.
RERA in children cannot be scored without adequate nasal
pressure or esophageal pressure signal.
Classification of hypopnea as obstructive, central, or mixed
should not be performed without a quantitative assessment
of ventilatory effort (esophageal manometry or calibrated
respiratory inductance plethysmography) more on this ….
Use of a derived signal is promising technology but not yet
acceptable for scoring of respiratory events.
Proposed Definition for Central
Hypopnea
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Central hypopnea: 50-90% reduction in
oronasal airflow for at least 10
seconds, associated with 50-90% in-phase
reduction of thoracoabdominal movement,
followed by oxygen desaturation of at least
3% (4% in adults). The event should not be
scored as central in the presence of snoring
or increase in submental EMG activity.
Follow-up – will using this
proposed rule jeopardize our
accreditation status?
Per Dr. Rosenberg (AASM):
“Given the ambiguity of the scoring
rules you will not be penalized on
accreditation for specifying scoring
criteria for central hypopnea.”
Hypoventilation and
Periodic Breathing Rules
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Score hypoventilation when >25% of the TST
(include only the time in which CO2 measure
is valid!) as measured by either the
transcutaneous PCO2 and/or end-tidal CO2
sensor(s) is spent with a CO2 >50 mmHg.
Score periodic breathing if there are >3
episodes of central apnea lasting >3 seconds
separated by no more than 20 seconds of
normal breathing.
This is the Last Slide . . . .
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An understanding of the ontogeny of sleep is critical
to expert pediatric sleep scoring.
Be on the lookout for interesting EEG waveforms in
children. Capture examples and share with your
colleagues.
Identification of artifact by the acquiring tech is critical
to accurate scoring.
Review your AASM 2007 manual and the articles in
the accompanying JCSM issue at least once per year
and keep these references at your work station.
Check the AASM Scoring FAQs at least 4 times per
year for scoring updates.