Scoring and Staging Flashcards
What are the EEG leads to detect eye movements?
E1 and E2
What lead are E1 and E2 (Left and Right eye outer canthus) referenced to?
M2 (Right mastoid)
Definition of slow waves
Peak to peak amplitude greater than 75 microvolts
Frequency 0.5 to 2 Hz
The EEG background for REM sleep is low voltage mixed frequency but what will frequently appear and is not an arousal?
Alpha bursts
Is a K complex or sleep spindles necessary to score an epoch as N2?
No. Once N2 has been determined (by a K complex or sleep spindle) then all subsequent epochs of low amplitude-mixed frequency will also be N2
- Unless there is an arousal
- Unless criteria met for N3 or REM
Describe a K complex
- Negative sharp wave followed immediately by a positive component (per convention a negative wave goes up)
- Stands out from the background
- 0.5 seconds or longer
- Amplitude is not a criterion
Rule for K complex associated arousal
Must commence no more than 1 second after the end of the K complex
EEG criteria for vertex waves
- Sharply contoured negative deflection (upward on EEG)
- Most often in central leads
- Usually seen in N1 sleep
EEG criteria for a slow wave
- At least 75 microVolt peak to peak amplitude
- 0.5 to 2 Hz (subset of delta: 1 - 4 Hz)
- Defining characteristic of N3 sleep
What are the sensors needed to detect:
- Apnea
- Hypopnea
Apnea = Oronasal thermal sensor (thermistor or thermocouple)
Hypopnea = Nasal pressure transducer (more sensitive than a thermal sensor)
What are the AASM criteria for scoring an apnea?
- Drop in the peak signal excursion by >/= 90% of present baseline using an oronasal thermal sensor, PAP device flow or an alternate apnea sensor
- Duration of drop is >/= 10 seconds
- Drop in Sa02 is not a criteria
What are the AASM rules for scoring a hypopnea? Rules 1A and 1B
Both
- 30% or > drop in peak signal excursion from baseline
- 10 or > seconds
1A
- 3% drop in SaO2 or associated with an arousal
1B
- 4% drop in SaO2 and no arousal
You can use one or the other in scoring a study but not both
What is normal REM latency?
90 - 120 minutes
What has to happen to end N2 sleep?
- Arousal
- Wakefulness
- Transition to N3
- Transition to REM
- Major body movement
What are the rules for scoring REM sleep?
All of the following
- Low amplitude mixed frequency without K complexes or sleep spindles
- Low chin EMG for the majority of the epoch with concurrent REM
- REMs at any position within the epoch
What are the rules for scoring REM sleep in the proceeding and following segments without Rapid Eye Movements?
All of the following
- LAMF without K complexes or sleep spindles
- Low chin EMG tone
- No intervening arousal
- Slow eye movements following an arousal or stage wake are absent
Are sleep spindles seen in N3 sleep?
Yes. They can continue into N3 sleep.
Are eye movements seen in N3 sleep?
Usually, no
Criteria for N3 sleep
> 20% delta
What can be used to detect hypoventilation during a PSG?
- PcO2 in ABG
- PcO2 via end-tidal CO2 sensor
- PcO2 via transcutaneous CO2 sensor
What are the definitions of sinus tachycardia and sinus bradycardia in sleep?
Sinus tachycardia: > 90 bpm
Sinus bradycardia: < 40 bpm
(Note: This is different than during wake: 100 and 60)
What are the 2 different sensors on PSG for hypopnea and apnea respectively?
Pressure or PTAF = Pressure transducer for hypopnea
Flow or Airflow = Thermistor for apnea
What is the rule for a Major Body Movement with alpha?
If alpha is present for any part of an epoch with a MBM then it is scored as state Wake
What is the rule for an epoch with a Major Body Movement without alpha?
The epoch is scored the same stage as the epoch that follows it
What is used to measure chest and abdominal movements?
Inductance plethysmography (not piezoelectric belts)
Where on the EEG are slow waves and K complexes typically seen?
Frontal leads
Where on the EEG are sleep spindles typically seen?
Central leads
Where on the EEG are theta waves typically seen?
Central and temporal leads. Usually seen in N1 and REM
Where on the EEG are vertex waves typically seen?
Central leads
Where on the EEG are sleep spindles typically seen?
Central
What is the frequency range for sleep spindles?
11 - 16 Hz
EEG criteria for arousals
- Abrupt shift in EEG frequency for at least 3 seconds
- At least 10 seconds of stable sleep preceding
- If during REM must have at least 1 second of increased chin EMG during episode
What is the Respiratory Disturbance Index (RDI)?
RERA + AHI
Criteria for RERA
All of the following
- >/= 10 seconds
- Increased respiratory effort or flattening of inspiratory portion of nasal pressure (diagnostic) or PAP device flow waveform
- Arousal from sleep
- Not an apnea/hypopnea
Criteria for hypoventilation
Either of the following:
- PcO2 increases > 55 mm Hg for 10 or more minutes
- An increase >/= 10 mm Hg PcO2 during sleep (compared to awake supine) to a value > 50 mm Hg for 10 or more minutes
Respiratory rules in children (< 13 y/o)
Obstructive Apnea
- Event lasts for at least 2 missed breaths
- 90% fall in signal amplitude for 90% of the respiratory cycle compared to baseline
- Continued respiratory effort occurs throughout the period of decreased airflow
Respiratory rules in children (< 13 y/o)
Hypopnea
- At least 30% fall in nasal pressure signal
- At least 2 missed breaths
- Fall in nasal pressure lasts at least 90% of hypopnea duration
- Associated with arousal or at least 3% desaturation
Respiratory rules in children (< 13 y/o)
Hypoventilation
PcO2 > 50 mm Hg for > 25% of the sleep time
Respiratory rules in children (< 13 y/o)
Central apnea
- Drop in thermal signal by >/= 90% in amplitude and duration
- Plus one of the following
- Event lasts >/= 20 seconds
- Events last duration of what would be 2 pre-event breaths and is associated with an arousal or a >/= 3% O2 desat
- Events last duration of what would be 2 pre-event breaths and is associated with a decrease in HR to less than 50 bpm for at least 5 seconds or less than 60 bpm for 15 seconds (infants under 1 year of age only)
Respiratory rules in children (< 13 years old)
Mixed apnea
- Drop in thermal signal by >/= 90% in amplitude and duration
- Event lasts for 2 breaths (pre-event baseline)
and
- Absent respiratory effort during one portion of the event
and
- Presence of inspiratory effor during another portion of the event (does not matter which comes first)
Respiratory rules in children
Scoring of hypoventilation
> 25% of the total sleep time, arterial (or surrogate) PCO2 > 50 mmHg
