This document summarizes the history and milestones in the field of sleep medicine. It discusses investigations of sleep disorders including sleep history, medical history, examinations, laboratory tests, neurologic assessments, imaging studies, and sleep tests like polysomnography and multiple sleep latency tests. Key aspects of sleep physiology are reviewed such as sleep architecture, biological rhythms, and the neuroanatomy of sleep-wake regulation. Common sleep complaints and approaches to patient assessment are also outlined.

2. Investigations
of sleep disorders
BY
Dr.Jaidaa Mekky
Lecturer of Neuropsychiatry
Sleep Medicine Consultant
Member of the American Academy of Neurology
Member of the American Academy of Sleep
Medicine
Faculty of Medicine
Alexandria University

3. Background
• One-half to one-third of life asleep
• Sleep medicine relatively new field
• Sleep is a co-morbidity in a long list of
diseases
• It was mentioned in the holy Quran 9
times, describing the sleep fnctions and
stages
‫وقال إن أبقراط قال: إذا كان النوم فى المراض المزمنة يس ّب وجعً، فذلك‬
‫ا‬ ‫ب‬
‫. من علمات الموت‬

4. Milestones
• 1837 – Dickens – describes
overweight/hypersomnolent boy in the
Posthumous Papers of the Pickwick Club (term
“pickwickian” used by Osler)
• 1875 – Caton – EEG in dogs
• 1928 – Berger – Human EEG alpha waves
• 1937 – Loomis – EEG Sleep stages
described

5. Milestones
• 1953 – Aserinsky & Kleitman – REM sleep
• 1970s – Polysomnography
• 1972 – Guilleminault – coins term OSA
• 1990 – International Classification of Sleep
Disorders

6. Sleep Physiology
• What is Sleep?
– “a reversible behavioral state of perceptual
disengagement from and unresponsiveness to
the environment”
• 75% in Non-REM sleep
• 25% REM sleep – muscle atonia,
autonomic activation

7. Sleep Architecture: NREM & REM Sleep
Pace-Schott EF, Hobson JA. Nat Rev Neurosci. 2002.

8. Biological rhythms
(periodic physiological fluctuations)
Types of rhythms
3. Ultradian (Basic Rest-Activity Cycle)
4. Circadian (sleep-wake cycle)
5. Infradian (menstrual cycle)
6. Circannual (annual breeding cycles)

10. A major input to the relay and reticular nuclei of the thalamus (yellow pathway) originates from cholinergic (ACh) cell
groups in the upper pons, the pedunculopontine (PPT) and laterodorsal tegmental nuclei (LDT). These inputs facilitate
thalamocortical transmission. A second pathway (red) activates the cerebral cortex to facilitate the processing of inputs
from the thalamus. This arises from neurons in the monoaminergic cell groups, including the tuberomammillary nucleus
(TMN) containing histamine (His), the A10 cell group containing dopamine (DA), the dorsal and median raphe nuclei
containing serotonin (5-HT), and the locus coeruleus (LC) containing noradrenaline (NA). This pathway also receives
contributions from peptidergic neurons in the lateral hypothalamus (LHA) containing orexin (ORX) or melanin-
concentrating hormone (MCH), and from basal forebrain (BF) neurons that contain γ-aminobutyric acid (GABA) or
ACh. Note that all of these ascending pathways traverse the region at the junction of the brainstem and forebrain where
von Economo noted that lesions caused profound sleepiness.

12. Sleep architecture over the
lifespan

14. The main sleep c/o:
• Insomnia
• EDS
• Parasomnia
• Symptoms of SDB(snoring)

19. Approach
Sleep history( SLEEP LOG)
( from the patient & bed partner)
Medications ( hypnotic dependant sleep
disorder)
Medical history( COPD, Hypothyroidism, end
organ failure)
Neurological ( Parkinson,s disease, dementia)
Psychiatric ( depression, anexiety)
Social history( marital ,social & occupational
functioning)

20. Sleep Diary

22. Sleep Log

23. Epworth sleepiness scale
Situation Chance of dozing
Sitting and reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Watching TV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sitting, inactive in a public place (e.g. a theatre or a meeting) . . . . . . .
As a passenger in a car for an hour without a break . . . . . . . . . . . . . . .
Lying down to rest in the afternoon when circumstances permit . . . . .
Sitting and talking to someone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sitting quietly after a lunch without alcohol . . . . . . . . . . . . . . . . . . . . .
In a car, while stopped for a few minutes in the traffic
Total . . . . . . . . . . . . . . . . . . . . . . . .
:Score
Normal range 0-10
Borderline 10-12
pathological 12-24

24. Examination
• Body habitus( obesity, poor hygiene)
• Neck( circumference ,thyroid etc.)
• Craniofascial abnormalities (retrognathia,
craniosynsitosis)
• Otolaryngeal examination( nasal mucosa,
tongue ,uvula)
• Pulmonary & cardiac examination
• Neurological & Psychiatric assessment

26. Mallampati classification

27. Investigations
Laboratory Tests:
Thyroid function
Serum ferritin, hemoglobin
HLA typing(HLA DQB1*0602 )
Toxocological screening
Liver & kidney function

28. Investigations( cont.)
Neurologic Assessment:
Videomonitored EEG
Imaging Studies:
CT& / MRI

29. Assessment of the upper airway
• Fluoroscopy
• Nasopharyngoscopy
• Cephalometry
• CT, Volumetric reconstruction
• MRI

33. Investigations( cont.)
Sleep Tests
•Overnight Polysomnography
(Videomonitored )
•MSLT
•MWT
•Actigraphy
•OSLER test

34. Polysomnography
Polysomnography is a simultaneous
recording of multiple physiologic
parameters related to sleep and wakefulness
– EEG
– EOG
– EMG

41. Aapplication

42. Parameters monitored:
1-Four (EEG) channels
2-Two (EOG) channels
3-One (EMG) channel
4-Airflow( nasal and
oral) for the detection
of apnea
5-Sound recordings to
measure snoring

43. 6-ECG
7-Pulse oximetry
8-Respiratory effort (Thoracic
and abdominal belts)
9- Tibialis anterior EMG
10-Detector of the body
position
11-Esophageal manometry

46. Videomonitored PSG

47. Neurologic monitoring Techniques
• Extended EEG ( 12-36) channel
• Repeated studies ,video monitored
DD:
• Nocturnal seizures
• Parasomnias
• REM behavioral disorders

49. Hypnogram
Standard Hypnogram

50. S taging
M ove m e nt T im e
Awak e
RE M
S tage 1
S tage 2
S tage 3
S tage 4
11 Õ 12 ã 01 ã 02 ã 03 ã 04 ã 05 ã 06 ã
Pos ition
Le ft
R ight
S upine
P rone
U pright
PL MS
With Arou s al
W/O Arou s al
Respiratory E vents
Mixe d Apne a
O bs tructive Apne a
C e ntral Apne a
Hypopne a

52. The main data presented in PSG are:
• 1) Total sleep time, wake time, total recording time;
• 2) Sleep efficiency (total sleep time/total recording time);
• 3) Latency for sleep onset, latency for REM sleep and other sleep
stages.
• 4) Duration (in minutes) and proportion of total-sleep-time sleep
stages (5) Frequency of apneas and hypopneas per hour of sleep
• 6) Saturation values and events of oxyhemoglobin desaturation
• 7) Total number and index of periodic lower limb movements per hour
of sleep.
• 8) Total number and index of micro-arousals per hour of sleep and
their relationship with breathing events or lower limb movements;
• 9)Esophageal ph anormalities
• 10)Penile tumecence

53. Portable PSG

54. MSLT -MWT
• 4-6 naps with 2h interval
• Parameters monitored:
• EEG(4channel)
• EOG
• Chin EMG
• ECG
• Respiratory flow (if needed)
• Microphone (if needed)

55. GERD

56. Actigraphy

58. Actigraphy
• Cost efficient
• Records motor movements
• Aallows estimates for several days,
avoiding the sampling error of NPSG
• It gives an idea about TST,SL, Nocturnal
arousals
• It is superior to sleep log

59. Uses:
• Used in assessment of Insomnia
• Useful in children and old age
• Circadian rhythm disorders
• Epidemiologic sleep studies
Limitations:
• It is not standardized yet for diagnosing
PLMS,SDB or RBD.

60. Osler test
The Oxford Sleep Resistance Test

61. Sleep tight