Circadian Dysrhythmia

A circadian rhythm is a biological process that recurs on a twenty-four-hour cycle independent of external influences. Circadian rhythms reflect the body's internal clock. One critical circadian rhythm is the sleep-wake cycle. The master clock in the brain synchronizes various body systems to follow a circadian rhythm. Light and other environmental cues entrain the master clock, such that circadian rhythms like the sleep-wake cycle follow the night and day cycle. While an adequately aligned circadian rhythm promotes consistent sleep, a disrupted circadian rhythm creates sleeping problems, including insomnia.

A circadian rhythm regulates sleep and brain health. A misaligned circadian rhythm gives rise to poor sleep health, specifically insomnia and daytime sleepiness. With improper signaling from the body's internal clock, you may struggle to fall asleep, stay asleep, and awaken in the morning. Your sleep may additionally be shallower, shorter, fragmented, and lower-quality. Circadian rhythms also influence brain health, including the risk of depression and bipolar disorder and the potential for neurodegenerative diseases like dementia.

What we offer at Sleep and Brain

A circadian dysrhythmia is an alteration to the body's internal timekeeping system, the clock's inability to entrain every 24 hours, or a misalignment between the clock and your external environment. Brain conditions such as cerebral palsy, dementia, traumatic brain injury, or Parkinson's Disease can disrupt the functioning of the master clock in the hypothalamus. At Sleep and Brain, we conduct a detailed clinical history and specialized physical examination to elucidate the etiology of your circadian misalignment. We prudently assess for circadian dysrhythmias such as the following:

• Delayed Sleep Phase Disorder

  • Delayed sleep-wake phase disorder occurs when you go to sleep or awaken two or more hours later than a typical sleep schedule. A delayed circadian rhythm causes difficulty falling asleep at night and waking up early in the morning to meet school or work obligations. You may think of yourself as a night owl.

• Advanced Sleep Phase Disorder

  • It is essentially the opposite of delayed sleep phase disorder: you fall asleep and awaken two or more hours before your desired bed and wake times.

• Irregular Sleep Rhythm Disorder

  • You may have an inconsistent sleep pattern without a stable rhythm or entrainment to day-night cycles. The fragmented sleep cycle yields sleep periods that last four hours or less, causing insomnia and daytime sleepiness.

• Non-24-Hour Sleep-Wake Rhythm Disorder

  • If you are blind and cannot receive light-based cues to entrain your circadian rhythm, your body follows its internal biological clock and not the 24-hour clock, causing your sleep-wake cycle to delay by minutes to hours each day. You may have either insomnia or excessive daytime sleepiness when your sleep period does match your life schedule.

• Shift Work Disorder

  • The term shift-work applies to any shift outside the traditional 9 a.m. to 5 p.m. schedule. Working non-standard shifts can make you lose hours of sleep in a 24-hour period, and adjusting to a non-standard shift can become problematic over time. Resultant insomnia and daytime sleepiness can increase the risk of workplace accidents or road accidents during a late-night or early-morning commute. Some develop ulcers and self-medicate with alcohol or drugs to get enough sleep.

• Jet Lag

  • Jet lag occurs when you cross multiple time zones in a short period. Until your circadian rhythm can acclimate to the new location's day-night cycle, you may suffer sleeping problems and fatigue from jet lag. Eastbound travel tends to produce more severe jet lag than westbound travel; northbound and southbound trips usually result in little to no jet lag. Jet lag severity often correlates to the number of time zones crossed. Typically, your body will require one day of adjustment for each time zone crossed.

We then complement your self-reported sleep duration and other parameters from a sleep diary to the actigraphic data to confirm the presence of a circadian dysrhythmia versus another problem.

Our treatment begins with instituting healthy habits to entrain your 24-hour sleep cycle as exampled below:

• Sun

  • Exposure to natural light, especially in the morning, is a potent circadian cue.

• Exercise

  • Daytime activity, albeit not as potent as light, entrains the internal clock and makes it easier to fall asleep at night.

• Sleep Schedule

  • Following a consistent bed and wake time and avoiding long naps can maintain a stable circadian rhythm.

After optimizing your sleep hygiene, sleep environment, and sleep-wake schedule, we treat your specific circadian rhythm sleep disorder. As an example, we utilize light therapy can encourage a healthy shift in circadian rhythm:

• Light exposure in the morning can help delayed sleep-wake phase disorder

• Light exposure in the evening can treat advanced sleep-wake phase disorder.

• Timed light exposure during a shift can help shift-work disorder.

We utilize medications judiciously and timed appropriately to enhance your sleep-wake cycle. Stimulants like caffeine, for instance, can disrupt the natural balance between sleep and wake. However, moderate caffeine intake during your shift may be an effective coping strategy for staying awake. Most hypnotics are a temporary fix and will not correct circadian misalignment. However, when timed and dosed appropriately, melatonin can reorient your circadian rhythm and entrainment schedule.