5: Circadian Rhythm Disorders

Section 5 Circadian Rhythm Disorders



Questions



A 22-year-old Man with Excessive Daytime Sleepiness




The patient is a 22-year-old man who recently graduated from Georgia Tech in Atlanta with an engineering degree. He presents to the clinic with severe excessive daytime sleepiness, which has resulted in poor work performance. He has a history of sleepiness dating back to his early teen years. Although the sleepiness has been present for about 6 years, it has gotten worse since he graduated and began working. To combat the sleepiness he drinks 8 to 10 high-caffeine energy drinks per day, mostly before noon. He reports that on weekends he feels “pretty alert” the rest of the day. When he lived at home his parents used to think he was lazy because on weekends he slept until 3 PM. However he was able to get good grades in school. His medical history is unremarkable. He has a history of depression, which is currently being treated with fluoxetine 20 mg hs. He has no history suggesting cataplexy or sleep paralysis.


1 What should be the next step?
A All night polysomnography

B All night polysomnography followed by an MWT

C All night polysomnography followed by an MSLT

D Two-week sleep diary

2 The patient reports that he only sleeps 4 hours per night, except on weekends when he might sleep 10 to 12 hours. Based on the information in the case description, which of the following is the least likely diagnosis?
A Narcolepsy

B Delayed sleep phase disorder

C Paradoxical insomnia

D Psychophysiologic insomnia

3 Which of the following would be consistent with a patient with delayed sleep phase disorder?
A DLMO occurs at about noon

B DLMO occurs after 10 PM

C DLMO occurs randomly

D DLMO occurs at about 8 AM

4 Delayed sleep phase disorder can be caused by all of the following factors except:
A Traumatic brain injury

B Behavioral factors alone

C Hypersensitivity to nighttime suppression of melatonin by light

D Endogenous circadian system dysfunction

5 The most effective treatment for delayed sleep phase disorder is:
A Bright light exposure in the evening

B Bright light exposure in the morning

C 1 mg of melatonin upon awakening

D Chronotherapy

6 Patients with delayed sleep phase syndrome have been shown to have:
A Increased ability to compensate for sleep loss compared to normal controls

B Decreased ability to compensate for sleep loss compared to normal controls

C Identical ability to compensate for sleep loss compared to normal controls

D Sleep loss recovery that is only possible during daytime hours

7 Which of the following disorders is most likely seen in families?
A Delayed sleep phase disorder

B Non–24-hour sleep–wake rhythm

C Irregular sleep–wake disorder

D Advanced sleep phase disorder


A 68-year-old Woman with Early Morning Awakening




A 68-year-old woman presents to the clinic with a 5-year history of insomnia. Her final awakening is usually at 3:30 AM, at which time she becomes frustrated and cannot return to sleep. The problem with waking too early coincided with the death of her husband. She is 5 feet 3 inches and weighs 185 lb. She is unaware of snoring but does complain of fatigue in the daytime. Current medications include metoprolol 50 mg, esomeprazole 20 mg at bedtime, atorvastatin 10 mg at bedtime, trazodone 100 mg at bedtime. The patient denies depression but has occasional bouts of intense anxiety, especially in crowds and on airplanes.


8 The most important clinical issue to explore at this point is:
A Snoring and possible apnea

B Anxiety disorder

C Habitual sleep–wake schedule

D Depression history

9 For assessing advanced sleep phased disorder, a polysomnogram should be conducted:
A At the usual in and out of bed times for the laboratory

B At the patient’s desired sleep and wake times

C At the patient’s habitual in and out of bed times

D There are no established criteria for using PSG in this population

10 A PSG is conducted from 10 PM to 6:30 AM and the results indicate the following:

Sleep latency = 4 minutes; total sleep time = 5 hours; sleep efficiency = 72%; apnea–hypopnea index = 8 events per hour; PLM arousal index = 3 per hour


No cardiographic or EEG abnormalities were seen. Based on these findings you should:


A Initiate a CPAP titration

B Increase trazodone to 150 mg

C Reduce trazodone to 50 mg and add 2 mg of eszopiclone at bedtime

D Consider other clinical factors

11 Treating advanced sleep phase disorder should include:
A Morning bright light therapy

B Chronotherapy, delaying sleep by 3 hours per day

C Evening melatonin

D Morning melatonin

12 In patients with advanced sleep phase disorder:
A The DLMO is much later than normal

B Core body temperature variation is decreased

C The DLMO is significantly earlier than normal

D Core body temperature nadir is 5 hours before sleep offset

13 The most practical way to diagnose advanced sleep phase disorder objectively is:
A Actigraphy

B Polysomnography

C Core temperature

D Sleep diary


The 42-year-old Man Who Cannot Keep a Job




A 42-year-old man comes to the clinic with a complaint of an irregular sleep schedule. He was recently fired from work for tardiness. To assess his sleep–wake schedule, you ask him to wear an actigraph for 2 weeks. The results are shown in Figure 5–1.


image

FIGURE 5–1 Questions 14 to 17.


14 This patient demonstrated a sleep–wake schedule consistent with:
A Delayed sleep phase syndrome

B Advanced sleep phase syndrome

C Free-running disorder

D Irregular sleep–wake disorder

15 Patients with the sleep–wake pattern shown in Figure 5–1 are rarely:
A Older than 45 years

B Blind persons with no retinas

C Supersensitive to light

D Normal sighted

16 Factors that can influence a patient’s circadian rhythm include all but:
A Light–dark cycle

B Watching a favorite TV show at the same time daily

C Using sedating antidepressants

D Morning exercise

17 Bright light therapy for free-running disorder is:
A Effective only in sighted persons

B Not as good as vitamin B12

C Not as effective as a consistent dose of melatonin in the morning

D Worth considering in persons with no light perception


A 12-year-old girl with insomnia and daytime sleepiness




A 12-year-old girl presents to the clinic with difficulty initiating and maintaining sleep as well as involuntary sleep episodes in school. The problem began about a year ago after she was the passenger in a car that was involved in a head-on collision. She suffered trauma to her head and was subsequently hospitalized for 2 weeks. Before the accident she was a good student without any sleep complaints. She has fully recovered from the accident and has only a small scar on her forehead from the head injury. Her mother thinks the sleep problem is somewhat due to hormonal changes associated with puberty. Actigraphy shows a highly variable sleep–wake schedule that is divided up into four short blocks throughout the day.


18 The most likely diagnosis is:
A Delayed sleep phase disorder

B Shift-work sleep disorder

C Free-running type disorder

D Irregular sleep–wake disorder

19 The pathogenesis of irregular sleep–wake disorder includes all but:
A Reduced exposure to light–dark signals

B SCN dysfunction

C Morning melatonin release

D Low levels of physical activity during the 24-hour cycle

20 One of the most successful treatments for irregular sleep–wake disorder has been:
A Chronotherapy, bright light therapy, vitamin B12, and hypnotics

B Melatonin and bright light therapy

C Melatonin alone

D Stimulus control, bright light, and zolpidem

21 Circadian rhythm disorders have been commonly seen in the following medical disorders except:
A Hepatic encephalopathy

B Parkinson’s disease

C Type 2 diabetes

D Dementia


A Case of Hating the Night Shift




A 27-year-old women working a local hospital as a nurse began working a rotating shift about 6 months ago. Her rotation schedule was days to evenings to nights. Her schedule is to work three 12-hour days per week and then rotates to the next later shift. At first the new schedule was working out great for her family. Initially she had no trouble adapting to the rotating shift although she stated that the overnights were the hardest because she has to fight off sleepiness. After a few months of rotating she found it increasingly difficult to stay awake all night on the night shift. A coworker found her asleep in the nurse’s station recently, and now the patient is worried about losing her job.


22 You would expect her condition to remit if she:
A Discontinued rotating shifts and only worked nights

B Discontinued working the night shift and stuck to a regular day or evening shift

Related posts:

4: Pharmacology 2: Physiology 6: Insomnia 10: Sleep-Related Breathing Disorders 11: Sleep in Other Disorders 3: Sleep Evaluation

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Apr 9, 2017 | Posted by in PSYCHOLOGY | Comments Off on 5: Circadian Rhythm Disorders

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