Approach Considerations
Therapy for circadian rhythm disturbances is largely behavioral. Light therapy has been shown to be an effective modifier of circadian cycles. Mixed modalities may be effective in elderly patients with dementia who have irregular sleep-wake rhythms. A combination of planned sleep scheduling, timed light exposure, and timed melatonin administration can be helpful.
Bright light therapy
Circadian rhythm disturbances respond very well to light therapy, especially bright light (>600 lux). For entrainment purposes, bright room light over time may be sufficient; however, a higher intensity of light (>6000 lux over 30-60 min) is often necessary to accomplish acute phase shifts.
The timing of light therapy is also important because it affects the degree and direction of the rhythm shift. For example, light therapy applied in the early evening and nighttime hours delays the cycle (in patients with advanced sleep-phase syndrome [ASPS]), whereas therapy given in the early morning stimulates morning alertness and an earlier bedtime (in patients with delayed sleep-phase syndrome [DSPS]).
Chronotherapy
This behavioral treatment consists of a gradual shift in sleep time in accordance with the patient's tendency. Thus, in DSPS, a progressive delay of 3 hours per day is prescribed, followed by strict maintenance of a regular bedtime hour once the desired schedule is achieved. In ASPS, chronotherapy focuses on advancing bedtime by 2-3 hours per night over 1 week until a desired schedule is achieved.
Enhancing environmental cues
This is an important part of the treatment of circadian rhythm disorders. Patients are encouraged to keep a dark, quiet room during sleep and a well-lit room upon awakening. Bright light exposure in the evening should be avoided, and regular hours of eating and other activities should be enforced.
Pharmacotherapy
Tasimelteon (Hetlioz) was approved by the US Food and Drug Administration (FDA) in January 2014 for treatment of non–24-hour sleep-wake disorder in the totally blind. Approval was based on results of 2 trials: the Safety and Efficacy of Tasimelteon (SET) trial, a 26-week study that included 84 patients, and the Randomized Withdrawal study of the Safety and Efficacy of Tasimelteon (RESET), a 19-week trial that included 20 patients, all of whom had been previously screened during the SET trial and entrained during open-label tasimelteon treatment.
Entrainment of the circadian rhythm, as measured by urinary 6-hydroxymelatonin sulfate (aMT6s), a main metabolite of melatonin, was the primary efficacy endpoint for SET. Scores on the 24-hour clinical response scale were another defined endpoint for SET. Outcomes for RESET included maintenance of entrainment (aMT6s) and maintenance of clinical response. Study results demonstrated that tasimelteon entrains the master clock (both melatonin and cortisol) and has clinically meaningful effects on the sleep-wake cycle in terms of the timing and amount of sleep, and improved measure of global functioning. [10, 11]
Lifestyle
Patients may respond to shifts in their active phases by exhibiting signs of sleep deprivation. For example, teenagers may have difficulty keeping late hours and getting up for an early morning class. Shift workers may have difficulty if shifts are changed too rapidly before they have had a chance to adjust.
Surgical care
Sleep disturbances associated with obstructive sleep apnea (OSA) syndrome may be treatable with surgical intervention.
Consultations
Consultation with the following specialists can be useful in managing circadian rhythm disorders:
-
Sleep medicine specialist
-
Neurologist
-
Psychiatrist
-
Pulmonologist
Diet
Nocturnal eating disorder is an entity distinct from circadian rhythm disorders and is characterized by an inability to maintain sleep over the night. Sleep is interrupted and patients are unable to return to sleep without eating or drinking.
Dietary advice includes the following:
-
Limit large meals
-
Avoid intake of excessive fluids before bedtime; this is an element that is generally emphasized when attempting to improve sleep hygiene
-
Discourage obesity
Additional concerns and follow-up
Address associated psychological issues. Patients with DSPS who initially respond to chronotherapy may gradually shift back to their old sleep pattern. Often, chronotherapy must be repeated every few months to maintain long-lasting results.
Emphasize the importance of good sleep hygiene and avoidance of the use of alcohol, stimulants (eg, nicotine, caffeine), and strenuous exercise before bedtime.
Transfer
The overwhelming majority of patients with insomnia (except elderly patients) are treated as outpatients.
In the elderly, in whom numerous other physical, psychiatric, and pharmacologic concerns can be present, institutional care is often necessary. The presence of significant sleep disruption is often a predictor of which patients require institutionalization.
Deterrence and prevention
Strategies to prevent circadian rhythm disorders include the following:
-
Encourage good sleep hygiene
-
Control of the sleep environment with regulation of light/dark exposure has been helpful to shift workers in maintaining sleep
-
For patients anticipating jet lag, advise that they change their schedule to the time of the new location prior to departure; this can modify the effects of jet lag
-
For shift workers, advise shifting the schedule in a clockwise direction; this is often better tolerated
Activity
In patients with irregular sleep-wake cycles, behavioral modification has been shown to be helpful. This includes encouraging structured daytime activity, even in the presence of fatigue. Attendants in nursing homes can help elderly patients to remain awake by involving them in activities and restricting sleep to conventional time periods. Encourage afternoon naps scheduled daily at a regular time. This helps to avoid multiple brief daytime naps and to consolidate sleep to the desired time.
Emphasizing a program of regular morning exercise is a component of promoting sleep hygiene. Advise patients to avoid strenuous exercise before bedtime.
