Many patients do not seek out treatment for fatigue or sleepiness because they are aware of the lifestyle choices that they have made. Still, they might develop psychologic symptoms like irritability, mood swings, and strained interpersonal relationships. These symptoms often will prompt patients to request treatment.
HOW TO MODIFY ABNORMAL SLEEP SCHEDULE ISSUES
The most common technique is to ask the patient to establish a consistent awakening time and subsequently a regular bedtime. Initially this could be unconventional by societal standards, i.e., bedtime at 5 a.m. and arising at 2 p.m. Once this pattern is in place, the patient gradually shifts the timing by an hour a day. For most patients it is easier to delay rather than advance the bedtime until it conforms to the desired time.
Reinforce this new sleep pattern with a structured daytime schedule that includes predictable mealtimes, regular exercise, social activities, and possibly bright light exposure. This reinforcement should occur in the morning for delayed sleep phase and in the evening for advanced sleep phase disorder. These interventions take time and discipline.
Another approach is for the patient to completely skip sleep one night and, in a sleep-deprived state, establish a new bedtime at the desired time. The same modalities listed above must be used to reinforce (or “entrain”) this schedule or the patient will gradually slip back into the previous abnormal sleep-wake rhythm.
WHEN TO REFER TO A SLEEP DISORDER CENTER
Major medical centers and North American metropolitan areas are increasingly developing sleep disorder treatment centers. Insurance companies generally cover a specialty sleep evaluation, particularly if the referring physician documents a suspicion of sleep-disordered breathing or excessive daytime sleepiness (EDS)that jeopardizes safe driving.
The most appropriate conditions for an urgent sleep evaluation are:
- Difficulty staying alert while driving, nocturnal cardiac arrhythmias;
- Frequent observed apneas;
- EDS leading to academic or occupational problems.
Psychiatrists should take a careful history that includes a discussion of the patient’s daily and weekly schedule. Avoid psychostimulant medications. Instead, address the non-negotiable need to get adequate sleep and challenge the patients to prioritize his or her activities around a full night’s sleep.
When to consider narcolepsy
Narcolepsy, a less common sleep disorder, can lead to severe occupational, educational, and family disruption. Narcolepsy, which affects 0.05% of the population, is a potentially debilitating disease of the central nervous system that involves abnormal regulation of REM sleep. EDS is the cardinal symptom, often associated with cataplexy (75%), sleep paralysis (50%), vivid dreams, and insomnia, all of which can represent inappropriate intrusion of REM phenomena.
After obtaining a history suggestive of narcolepsy, the psychiatrist should employ either the history, a sleep diary, or wrist actigraphy to document whether the patient is getting adequate sleep with a consistent sleep/wake cycle. Next, consider referring the patient for polysomnography, primarily to rule out other causes of EDS like sleep disorder breathing. In some cases, the REM latency on the overnight sleep study will be less than 20 minutes after sleep onset, which supports the diagnosis of narcolepsy. A multiple sleep latency test (MSLT), a diagnostic test that consists of the patient taking four to five daytime naps, is performed the following day.
Narcolepsy is confirmed if the patient has a mean initial sleep latency of less than 10 minutes during these naps plus at least two REM episodes occurring within 15 minutes after sleep onset.
Recent research shows that most patients who have narcolepsy with cataplexy have undetectable levels of a specific neuropeptide (which is called either hypocretin or orexin) in the cerebrospinal fluid.17 Hypocretin/orexin replacement therapy is a theoretical future possibility, but for now treatment includes a combination of optimal sleep hygiene, psychostimulants, antidepressants, and hypnotics.
Other causes of EDS
Other causes of EDS include unrecognized alcohol dependence, inappropriate or excessive medication use, and depressive disorders. Overnight sleep studies are seldom indicated unless patients endorse the symptoms in Figure 1.
Before pursuing sleep studies (polysomnography or an MSLT), eliminate medications that might confound the results. Such agents include antidepressants, which alter the timing and duration of REM sleep, and sedating medications, which modify initial sleep latency and sleep efficiency and potentially aggravate sleep disordered breathing. Although initial REM latency provides a potential biologic marker of major depression, this measurement is more often used in research studies than in clinical psychiatry.
Primary insomnia is a distressing inability to sleep at night or nap during the day. This suggests a hyperarousal state in several ways, and is the opposite of EDS.18 In rare cases, however, patients who cannot sleep at night also do have EDS. When evaluated, these patients typically endorse at least one of the symptoms in Figure 1. Overnight sleep studies occasionally demonstrate that the insomnia is a symptom of another underlying specific sleep disorder, such as OSA or restless legs syndrome.