OSAS is defined as collapse of the airway with physiologic sequelae including excessive daytime sleepiness (EDS), hypertension, stroke, myocardial infarction, cardiac arrhythmia, and congestive heart failure. Patients with OSAS may also complain of difficulty concentrating, memory impairment, chronic fatigue, chronic pain, morning headaches, and difficulty initiating sleep or staying asleep. Patients with SDB can also present with kicking during sleep, which is a response to the airway obstruction. Risk factors for OSAS include hypertension, body mass index (BMI) >25, male gender, age >65, menopause, increased neck circumference, craniofacial abnormalities, and family history. Patients with hypothyroidism, particularly women, can present with OSAS. Home sleep testing can be successfully used in adults for whom there is a high pretest probability of OSAS based on the evaluation and examination. For those patients who become surgical candidates for OSAS, it is not clear how home testing results will be viewed by third-party payers.
Explore This IssueJuly 2008
The first line of treatment for OSAS is CPAP. Many patients are successfully treated with CPAP if they receive appropriate education and close initial follow-up. Some patients, despite apparently adequate treatment of OSAS, continue to experience daytime sleepiness. For these patients, further evaluation for additional sleep disorders is warranted.
Children and adolescents frequently present with SDB; their presentation can be quite different from that of their adult counterparts. Snoring in children, even those with normal polysomnograms (PSGs), has been associated with hyperactivity, inattention, learning disabilities, lower IQ, attention deficit/hyperactivity disorder, and excessive daytime sleepiness. The cause of these deficits is not yet clear, but treatment of the airway obstruction with tonsillectomy and adenoidectomy does improve the quality of life and behavior of many of these children.
Restless Leg Syndrome
Restless leg syndrome (RLS) is a clinical syndrome that does not require a PSG for diagnosis. The diagnostic criteria are listing in the second sidebar. If a PSG is preformed, 80% to 90% of patients with RLS will have frequent leg movements, also called periodic limb movements. RLS can be caused or aggravated by pregnancy, antidepressants, renal disease, iron deficiency, caffeine, antihistamines, and neurologic lesions. These movements cause frequent arousals from sleep and daytime sleepiness. Type III and IV home sleep testing does not monitor leg movements or EEG, so arousals and limb movements cannot be detected with this testing modality.
Narcolepsy is a neurologic disorder of unknown cause, which affects one in 2000 Americans. The cardinal symptom is profound sleepiness, with involuntary sleep attacks during daily activity. The onset of symptoms is usually in the teenage years, but it can arise from childhood to middle age. In addition to daytime sleepiness, a triad of symptoms characterizes narcolepsy: cataplexy, a sudden loss of voluntary muscle tone with emotion; vivid hallucinations during sleep onset or on awakening; and brief episodes of total paralysis at the beginning or end of sleep. The diagnosis of narcolepsy is made with PSG and the multiple sleep latency test (MSLT). PSGs in these patients show disruption of the sleep-wake cycle with early onset REM sleep. The MSLT demonstrates short sleep latency and REM sleep during two or more daytime naps. Only a full PSG can be used to diagnose narcolepsy.
Surveys have shown that most people are sleeping less than they were 20 years ago. In adults, research has demonstrated many deleterious effects of inadequate sleep on cognitive ability, motor skills, and judgment. People with acute sleep deprivation have slower reaction times, increased cognitive errors, impaired memory and learning, and more volatile emotional responses. Failure to inquire about the amount of sleep may contribute to treatment failures. Despite the best treatment of sleep apnea, a sleepy patient who sleeps only six hours a night will likely remain sleepy and impaired. It is important to caution our patients with inadequate sleep, no matter what the cause, to avoid driving until their sleep disorder is adequately treated.