Restless legs syndrome
Patients with restless legs syndrome (RLS) typically report a restless, painful feeling in the limbs that occurs in the evening and at night, disrupting sleep. This condition—which affects 10% of the population—is associated with aging, blood loss, anemia, peripheral neuropathies, and pregnancy.11 Onset can occur in childhood, and in some cases there is a familial tendency.
Most patients with RLS have periodic limb movements (repetitive leg jerks or twitches). The clinical significance of periodic limb movements with no subjective disagreeable feelings in the limbs is controversial, and these cases usually are not treated.
The history usually confirms RLS. Order sleep studies only if you suspect a coexisting sleep problem or the diagnosis is unclear.
A suspected mechanism of restless legs is dopamine deficiency. Low serum ferritin levels have been associated with RLS—presumably because iron is a cofactor necessary for dopamine synthesis12—and may be diagnostically helpful.
2 techniques to modify patients’ abnormal sleep schedules
The most common technique is to ask the patient to establish a consistent awakening time and a regular bedtime. Initially this could be unconventional by societal standards—such as bedtime at 5 AM and arising at 2 PM. After this pattern is in place, the patient gradually shifts the timing by 1 hour per day. Most patients find it 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. Provide reinforcement in the morning for patients with delayed sleep phase disorder and in the evening for advanced sleep phase disorder. These interventions take time and discipline.
Another approach is for the patient to skip sleep one night and, in a sleep-deprived state, establish a new bedtime at the desired time. Use the same modalities listed above to reinforce (“entrain”) this schedule; otherwise the patient will slip back into the previous abnormal sleep-wake rhythm.
Treatment can include iron repletion when indicated. Medications include dopaminergic agents, most notably pramipexole and levodopa/carbidopa. Other options include gabapentin, benzodiazepines, and narcotics.
Antidepressants have been suspected to worsen restless legs syndrome, but definitive studies are lacking.13
Circadian rhythm disorders
Instead of compromising the quality or quantity of sleep, circadian rhythm disorders cause sleep to occur at inappropriate times. These disorders are most common in adolescents and young adults.
Delayed sleep phase disorder—a persistent pattern of staying up late and “sleeping in”—is most common. Careful assessment will reveal that the patient is getting adequate sleep but at a socially unacceptable time, sometimes to the extreme that his or her nights and days are reversed.
Patients’ reluctance to acknowledge the severity of this problem can lead to inaccurate sleep diaries and interviews. A portable wrist actigraph can provide data about limb movement and is more objective than self-reports.
Delayed sleep phase disorder is highly comorbid with depressive disorders.14 The cause of this syndrome is unclear, but light exposure, social patterns, psychological issues, and possibly a genetic substrate are known to contribute.
Advanced sleep phase disorder—a less common circadian rhythm disorder—also can cause EDS. Patients have an inappropriately early time of sleep onset and then are fully awake in the middle of the night. A large family with a severe form of this disorder was found to have an abnormality on chromosome 2.15
Treatment. Relatively few treatments are effective for circadian rhythm disorders. Some patients elect not to pursue therapy, instead fitting activities around their unconventional sleep schedules.
Individuals with delayed sleep phase who cannot arrange their lives around their sleep schedules are at risk for poor early morning performance because of sleepiness. Their internal circadian clocks can be gradually readjusted with phototherapy or gradual shifting of the major sleep period (Box 3). Stimulants usually are not used, but hypnotics can sometimes help these patients fall asleep earlier.
Insufficient sleep syndrome
People attempting to “burn the candle at both ends” are at risk for developing insufficient sleep syndrome.16 In our 24/7 society, people trying to make do with less than the required 7.5 hours sleep per night may adversely affect their health. The problem is compounded for shift workers because of the difficulty in obtaining sufficient quality sleep during daylight hours.
Many patients do not seek treatment for fatigue or sleepiness because they are aware of their lifestyle choices. Still, they might develop psychological symptoms such as irritability, mood swings, and strained interpersonal relationships. These symptoms can prompt patients to request treatment.
Take a careful history that includes discussing the patient’s daily and weekly schedule. Avoid psychostimulants; instead, address the nonnegotiable need to get adequate sleep and challenge the patient to prioritize his or her activities around a full night’s sleep.