1. By NEVIN FAYEZ LECTURER OF PSYCHIATRY
CIRCADIAN RHYTHMS By
NEVIN FAYEZ
LECTURER OF PSYCHIATRY

2. Circadian rhythm
A roughly-24-hour cycle in the biochemical, physiological or behavioural processes of living entities, The term "circadian”, coined by Franz Halberg, comes from the Latin circa, "around," and Diem or dies, "day", meaning literally "approximately one day
Pandi-perumal 2009

3. Ch. of a Rhythm Period is the length of the rhythm.
Phase is the timing of the rhythm in relation to a stimulus
Amplitude is a measure of the amount of the rhythmic event.

5. Physiology & Anatomy of the Circadian System

10. How to assess the circadian rhythms:
Markers of circadian rhythms
Protocols
Actigraphy
Questionnaires
18 April 2019
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11. Circadian rhythm sleep disorders
CRSDs
are characterized by an alteration of the circadian timing system or a misalignment between the timing of the individuals sleep– wake rhythm and the 24 hour social and physical environment

12. DSPS
Sleep–wake times that are delayed usually more than 2 hours relative to conventional or socially acceptable times.
Sleep onset is typically delayed until 2 a.m. to 6 a.m. and wake time occurs in the late morning or afternoon

15. ASPS
Is a stable advance of the major sleep period, characterized by habitual sleep-onset and wake-up times that are several hours earlier than desired or socially acceptable

17. Free running
Sleep– wake cycle usually longer than the 24 hour period. Due to this, sleep and wake episodes are delayed each day to later hours, thus alternating between synchrony and complete asynchrony with the environmental schedule

19. Irregular sleep–wake type, also known as irregular or
Disorganized sleep–wake pattern, is characterized by lack of a clearly defined sleep–wake circadian rhythm. The timing and the length of sleep and wake episodes are variable and unpredictable throughout the 24 hour period.

21. 2ndry CRSD: Hepatic encephalopathy,
psychoactive substance abuse or dependence,
or as a side effect of a drug.
Dementia,
Movement disorders
Traumatic head injury
Brain tumours

22. Diagnosis A clinical interview
The diagnostic procedures should include 7–4 days of monitoring sleep-wake patterns by means of sleep log and/or actigraphy.
In most cases polysomnography is not required

23. Light therapy (also referred to as phototherapy)

24. Melatonin ttt.
Is able to reset and entrain the circadian pacemaker in a time-dependent mode.
Phase advance is produced by melatonin administered in the evening
Whereas melatonin administration in the morning induces phase delays.
Beneficial effects of 0.5–5 mg/day were demonstrated in several types of CRSDs

25. ‘‘Jet Lag’’
Refers to the lag between the time frame of the biological clock and that of the destination time zone. Because the biological clock is slow to adjust, there will be several days after arrival in the new time zone before the biological clock ‘‘catches up’’ with the new routine.

26. IS EASTBOUND WORSE THAN WESTBOUND?

27. IS OUTBOUND WORSE THAN HOMEBOUND?

28. SWSD
Shift work is generally defined as any schedule that requires work outside a broadly defined ‘‘day shift,’’ usually 6 a.m. to 6 p.m
Evening shifts, typically those between 2 p.m. To midnight
Night shifts, those between 9 p.m. and 8 a.m. are less well tolerated

29. SWSD ctd. Increased difficulty sleeping
increased sleepiness during waking hours .
Sleepiness on the job,
cardiovascular disease , ulcer disease, and breast cancer in women
immunological activity

30. SWSD ctd.
Diagnostic criteria for SWSD established by the AASM call for the presence of either
Insomnia during day sleep or
A complaint of excessive sleepiness during night work hours.
The complaint (or complaints) should not be adequately explained by another medical, psychiatric, or primary sleep disorder and must be temporally associated with the shift exposure.

31. Diagnosis
Clinical history of significant insomnia and/or significant sleepiness during work hours occurring in the setting of shift work.
Sleep diaries
Polysomnography of day sleep and multiple sleep latency test (MSLT) assessments at normal work times are included in the formal definition of SWSD

32. Approach to the Patient with Shift Work Sleep Disorder

35. WORLD SLEEP DAY(18/3) Make sure your child gets enough
Set consistent bedtime and wake-up times on both weekdays and weekends.
Establish a consistent bedtime routine and recommend wearing comfortable clothes in bed
Encourage your child to fall asleep independently.
Avoid bright light at bedtime and during the night and increase light exposure in the morning.
Keep all electronics, including televisions, computers and cell phones, out of the bedroom
Maintain a regular daily schedule, including consistent mealtimes.
Have an age-appropriate nap schedule.
Ensure plenty of exercise and time spent outdoors during the day.
Eliminate foods and beverages containing caffeine.

36. Thank you