4. Always Start with Why??
◘ Sudden Thunderclap Headache
(the worst headache of my life).
◘ A warning or sentinel headache
that precedes the aneurysmal in
10 – 43% of patients.
(1) Because Mays7esh Keda for our Neurology
Prestige as PSG is originally an EEG
apparatus with some modifications.
(2) Many times we face sleep EEG e.g. wicked
spikes and POSTS at sleep beginning.
(3) Vacant area of research with rapid progress.
(4) Misdiagnosis of common complaints e.g.
EDS, nocturnal epilepsy and parasomnias
5.
6. Sleep-related Breathing Disorder
(1) Observed apnea during sleep.
(2) EDS.
(3) Snoring.
(4) Resistant hypertension.
(5) Obesity with BMI > 30 kg/M2.
(6) Upper airway soft tissue abnormalities.
(7) Polycythemia of unexplained etiology.
SAS is a common disorder affecting 2–4% of the adult population
10. Wicket Spikes & Vertex Sharp Waves
Usually centro-temporal, occur at sleep onset and not followed by slow waves
11.
12. EEG
◘ The human EEG was
discovered by the German
psychiatrist, Hans Berger in
1929.
◘ The human EEG was
discovered by the German
psychiatrist, Hans Berger in
1929.
13. PSG
◘ In 1930s, Alfred L Loomis
designed a sleep monitoring
system with several
enhancements for processing
EEG waveforms during sleep.
14.
15. Sleep Physiology
◘ Sleep is a periodic cycling characterized by:
- Decreased reactivity to external stimuli.
- Decreased motions.
- Typical body position.
- Typical electrical activity of the brain.
16. Polysomnogram
◘ Refers to the recording, analysis and interpretation of multiple
physiologic signals collected simultaneously during sleep.
17. PSG Components
◘ PSG recording include EEG, EOG, EMG, ECG, Snoring,
Respiratory movement, SaO2 and airflow.
◘ Additional PSG channels include:
(1) End tidal Co2 (PetCo2).
(2) Transcutaneous CO2.
(3) PAP level.
(4) Esophageal pressure monitor.
(5) Additional EEG channels for nocturnal seizures.
(6) Video monitoring.
(7) Esophageal pH.
18. PSG Components
(1) EEG: usually top channels.
(2) EOG: left (E1) and right (E2), referred to the left mastoid (E1M1 & E2M1) or right
mastoid (E1M2 & E2M2).
(3) Chin EMG: Chin 1 (left) and Chin 2 (right).
(4) ECG: modified lead II, below Rt clavicle near sternum.
(5) EMG: on LTIB (left tibialis), RTIB (right tibialis), LGAST (left gastrocnemius), and
RGAST (right gastrocnemius).
(6) Respiratory effort: Chest and ABD belts.
(7) Oronasal airflow: OroNs1-OroNs2.
(8) Nasal pressure transducer recording airflow: Pflw1-Pflw2.
(9) Oxygen saturation by finger oximetry SaO2.
(10) Snoring: by a sensor located on the patient’s neck.
20. - EOG electrodes are placed at left and right outer canthus with one below and
oneabovethehorizontalplane.
- Chin EMG is recorded by 3 electrodes are placed beneath the chin overlying the
mentalisandsubmentalismuscles.
29. Normal Adult Sleep
◘ Total sleep time consists of 4 – 6 consecutive cycles each of
which lasts 90 – 100 minutes.
◘ Sleep is divided according to EEG, EOG & EMG patterns to
wakefulness, NREM and REM sleep.
◘ NREM sleep is further divided to N1, N2 & N3 stages.
◘ Wakefulness, NREM and REM sleep alternate in each cycle.
31. N1 Sleep
◘ EEG: alpha rhythms ˂ 50%
mixed with slow theta and beta
waves. Vertex sharp waves
appear over the central region
which last < 0.5 sec.
◘ EOG: slow conjugate, regular,
rolling eye movements lasting >
500 msec.
◘ Chin EMG: decreased muscle
activities.
32. N1 Stage is detected When
(1) Slowing of the background activities
≥ 1 Hz from those found in stage W
and/or alpha rhythm > 50% of the
epoch.
(2) Slow eye movement.
(3) Vertex sharp waves.
(4) After REM if an arousal is followed
by low amplitude EEG and slow eye
movement.
33. Major Body Movement
◘ Defined as muscle artifact
obscuring more than half of
the EEG epoch.
◘ Usually followed by slow eye
movement and low amplitude
EEG.
◘ The epoch is scored as N1
following any major body
movement
34. N2 Sleep
◘ EEG: theta rhythm with few
delta (˂ 20%). Sleep spindles
and K complexes intermixed
with vertex sharp waves.
◘ EOG: slow conjugate, regular,
rolling eye movements lasting
> 500 msec.
◘ Chin EMG: Relaxed muscles.
35. K-complex & Sleep spindles
(1) K-complex is a negative sharp wave followed immediately by a
positive component with total duration ≥ 0.5 second usually
maximal in frontal electrodes.
- For arousal to be associated with a k-complex, it must commence no
more than 1 second after termination of the k-complex.
(2) Sleep spindle is a short burst of waves with frequency 12 – 14 Hz
and duration of 0.5 – 1.5 seconds maximal in central electrodes.
37. N2 Stage is detected When
(1) One or more K-complex unassociated with arousal.
(2) One or more trains of sleep spindles.
◘ The end of Stage N2 is defined by :
(1) Transition to stage W.
(2) An arousal.
(3) Transition to stage N3 or R.
(4) A major body movement (Staged N1).
38. N3 (Deep or Slow Wave) Sleep
◘ EEG: the delta waves occupies
> 20 % of the epoch.
Sometimes called slow wave
sleep.
◘ EOG: slow conjugate, regular,
rolling eye movements lasting
> 500 msec.
◘ Chin EMG: Relaxed muscles.
39. REM Sleep
◘ EEG: mixed frequency of theta, few alpha activity and low-
amplitude beta intermixed with sawtooth waves.
◘ EOG: rapid conjugate saccadic, irregular, sharply peaked eye
movement lasting < 500 msec, occur in all directions (mainly
transverse).
◘ EMG: atonic or hypotonic muscles.
Sometimes called paradoxical sleep or desynchronized sleep
44. PSG Times
(1)Total in bed time: time from lights out to lights on.
(2) Total sleep time: minutes of stages 1, 2, 3, and REM.
(3) Wake after sleep onset: minutes of wake after first sleep but before
the final awakening.
(4) Sleep latency: refers to the length of time taken in transition from
wakefulness to sleep (N 10 – 15 min).
(5) Sleep period time = Total sleep time + Wake after sleep onset
Or Total in bed time – sleep latency
45. PSG Times
Total in Bedtime
Sleep period timeSleep latency
Total Sleep Time
Wake after sleep onset
46. PSG Terminologies
(6) Sleep efficiency = Total sleep time / total in bedtime (N > 80%).
(7) Sustained sleep efficiency=
Total sleep time
Total in bedtime – sleep latency stage 1
(sleep period time)
47. PSG Terminologies
(8) Sleep fragmentation: number of sleep cycles per night (N 6 – 9 cycles)
or the number of brief arousals occurring throughout the night
reducing the total amount of deep sleep.
(9) Sleep stage transition index: the number of transition between
various sleep stages per hours (N 7 – 13).
49. Apnea & Hypopnea
(10) Apnea: absence of airflow at the mouth for > 10 sec i.e. complete
cessation of the thermestor signal > 10 sec.
(11) Hypopnea: reduction in airflow > 50% for > 10 sec that is followed
by an arousal from sleep or a decrease in oxyhaemoglobin saturation
(3 – 4 %).
(12) Apnea - hypopnea index (AHI): is the total number of apneas and
hypopneas per hour of sleep (N < 5 / hour).
◘ Mild: 5 – 15 / hour.
◘ Moderate: 15 – 30 / hour.
◘ Severe: > 30 / hour.
50. Apnea & Hypopnea
(13) Other related parameters:
◘ Maximum Apnea Duration.
◘ Maximum Hypopnea Duration.
◘ Average Apnea Duration.
◘ Average Hypopnea Duration.
֎ All the apnea and hypopnea parameters are measured in REM, NREM and
total sleep.
51. Types of Sleep Apnea
(1) Obstructive Sleep Apnea: characterized by the PRESENCE of
respiratory effort during the apnea.
(2) Central Sleep Apnea: characterized by the ABSENCE of respiratory
effort during the apnea.
(3) Mixed Sleep Apnea: starts with no effort but effort develop during
the course of the apnea.
52. Respiratory Disturbance Index (RDI)
◘ It is the average number of respiratory events per hour of sleep (N ˂ 5
/ hour).
◘ Includes apneas, hypopneas and respiratory effort related arousals.
◘ REM RDI: the total number of RDI per hour of REM sleep.
◘ Supine RDI: the number of RDI per hour of supine sleep. This is
important because the patient may have only positional apnea and
therefore can be treated with positional therapy.
53. Obstructive Sleep Apnea
Obese patient, short necked, hypertrophied uvula, excessive snoring, morning headache,
dizziness, EDS and multiple sleep arousal
56. Pulse Transit Time (PTT)
◘ It is defined as the time taken for the arterial pulse pressure
wave to travel from the aortic valve to a peripheral site.
◘ It is a noninvasive alternative to esophageal pressure which
measure the intra-thoracic pressure.
◘ It is usually measured from the R wave on the ECG to the
pulse wave arrival at the finger.
57. Pulse Transit Time (PTT)
◘ PTT inversely correlates with the blood pressure and the falls
in blood pressure which occur with inspiration due to high
pleural pressure swings (pulsus paradoxus) results in
lengthening of the PTT.
◘ The size of inspiratory lengthening of PTT correlate well with
the degree of inspiratory effort.
58. Pulse Transit Time (PTT)
◘ Scoring the PTT signal during REM sleep is difficult because
this sleep state is associated with large variations in respiratory
drive and it is better measured by its averaging over a number
of breaths or better the whole sleep study.
59. Pulse Transit Time (PTT)
◘ PTT can differentiate well between obstructive and central
sleep apnea.
◘In the presence of upper airway obstruction, sympathetic
overflow causes an instantaneous rise in blood pressure and
thereby an increase in pulse wave velocity and decrease in
PTT.
(14) Normal value of PTT: 200 – 250 ± 20 msec.
60. O2 Saturation
(15) Desaturation index: refers to how many times had O2 saturation
reduces > 5% of baseline (N ≤ 5 / hour).
(16) Lowest O2 saturation:
◘ Normal: > 90 % ◘ Mild: 85 – 90 %.
◘ Moderate: 75 – 85 %. ◘ Severe: < 75 % .
(17) Other O2 saturation parameters:
◘ Baseline O2 Saturation. ◘ Minimal SpO2.
◘ Number desaturations < 90 % & < 80 %.
◘ SpO2 Time < 90 %. ◘ Longest Desaturation.
◘ Sum all desaturation.
61.
62. Sleep Stages Latencies
(18) Sleep latency stage 1: Time from the 1st epoch of sleep to the 1st
epoch of N1 sleep (N 10 – 15 min).
(19) Sleep latency stage 2: Time from the 1st epoch of sleep to the 1st
epoch of N2 sleep (N 11 – 18 min).
(20) Deep Sleep latency: Time from the 1st epoch of sleep to the 1st
epoch of N3 sleep (N 20 – 40 min).
(21) REM latency: time from 1st epoch of sleep to the 1st epoch of REM
sleep (N 90 minute).
66. Arousal
◘ Arousal refers to abrupt shift of pattern of EEG activities which last for ≥
3 seconds and are preceded by ≥ 10 seconds of sleep.
◘ Arousal represents abrupt shift from a deeper stage of NREM sleep to a
lighter stage, or from REM sleep toward wakefulness, with the
possibility of awakening .
◘ Arousal from REM sleep also requires a concurrent increase in chin tone
for ≥ 1 seconds.
◘ Arousals signify sleep fragmentation and frequent arousals even brief
ones (1 – 5 sec) not shortening the TST results in poor sleep quality and
in turn EDS.
67. Arousal
◘ This means that the
restorative function of sleep
depends on continuity as
well as duration.
(22) Arousal index: the number
of arousals per hour of sleep
(N ˂ 10).
69. Periodic Limb Movement
◘ Characterized by periodic episodes of repetitive limb movements
during sleep, which most often occur in the lower extremities.
◘ When they are recorded from both anterior tibialis muscles, they
should be separated by an interval of at least 5-s for them to be
counted as two separate movements.
◘ They can either be associated with EEG arousals or in severe cases
even overt arousals.
◘ Absent during REM sleep.
70. Periodic Limb Movement Index (PLMI)
(23) Periodic limb movement index: the number of PLMs per hour of
sleep (N ˂ 5).
◘ Mild: 5 – 25 / hour.
◘ Moderate: 25 – 50 / hour.
◘ Severe: > 50 / hour.
(24) Other related parameters:
◘ PLMs relative to sleep stage.
◘ PLMs with arousal.
◘ PLMs with major body movement.
◘ Respiratory limb movement index.
71. PLM versus RLS
◘ Restless Leg Syndrome:
(1) Urge to move the limb.
(2) Worsening of symptoms at rest.
(3) Relief by movement and activity.
(4) Worsening at night and/or sleep which interfere with sleep onset.
- 80% of patients with RLS usually have PLM.
◘ PLM: Characterized by periodic episodes of repetitive limb
movements during sleep.
72. Snoring
◘ Snoring is caused by vibrations that cause air particles to produce
sound waves. Snoring sound level intensity is > 40 decibel.
◘ Snoring per se is associated with EDS.
◘ Snoring may be apneic (obstructive) or non-apneic and usually
increases the supine position and N3 sleep.
◘ Snoring is detected using calibrated snoring sound transducer placed
on the trachea.
76. Body Position Analysis
◘ Supine & Non-supine. The latter is divided to right left and prone.
◘ Each one is analyzed in each of the following parameters:
(1) Duration in whole sleep.
(2) Duration in REM sleep.
(3) Duration in NREM sleep.
77. Technical Impression
◘ The technical impression is the overall breakdown and comments for
the entire PSG.
