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

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

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.

Physiology & Anatomy of the Circadian System

How to assess the circadian rhythms: Markers of circadian rhythms Protocols Actigraphy Questionnaires 18 April 2019 Sample footer

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

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

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

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

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.

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

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

Light therapy (also referred to as phototherapy)

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

‘‘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.

IS EASTBOUND WORSE THAN WESTBOUND?

IS OUTBOUND WORSE THAN HOMEBOUND?

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

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

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.

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

Approach to the Patient with Shift Work Sleep Disorder

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.

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