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Highlights From the 21st Annual Meeting of the Associated Professional Sleep Societies, LLC, Minneapolis, Minnesota, June 9-14, 2007

Authors: Andrew N. Wilner, MD, FAAN, FACP   Faculty and Disclosures



Sleep experts from around the country presented several sleep research "firsts" at the 21st Annual Meeting of the Associated Professional Sleep Societies (SLEEP 2007), which met in June in Minneapolis, Minnesota. These included a new screening test for sleep apnea, a behavioral indicators test for restless legs syndrome (RLS) in demented individuals, a pictorial description of the RLS phenotype, a modified maintenance of wakefulness test, the first formal assessment of insomnia and mental health in otherwise healthy college students, and the first formal assessment of insomnia in epilepsy patients. Early identification of sleep disorders such as sleep apnea, RLS, and insomnia may speed treatment that addresses excess daytime sleepiness and other symptoms. These presentations are summarized here.

Obstructive Sleep Apnea

Sleep Apnea Screening in Preoperative Patients

A new screening tool for obstructive sleep apnea (OSA), the STOP questionnaire, has been validated with polysomnography and compared with 2 other screening tools, the Berlin questionnaire (9 questions), and the American Society of Anesthesiologists (ASA) Checklist (16 items).[1] The STOP Questionnaire contains 4 'Yes/No' questions:

  1. Do you snore loudly (louder than talking or loud enough to be heard through closed doors)?

  2. Do you often feel tired, fatigued, or sleepy during daytime?

  3. Has anyone noticed you stop breathing during your sleep?

  4. Do you have or are you being treated for high blood pressure?

Balaji Yegneswaran, MBBS, a Research Fellow at the University of Toronto, Toronto, Ontario, Canada, and his colleagues[1] validated the STOP and Berlin questionnaires and the ASA Checklist with polysomnography in 178 patients. For an apnea hypopnea index (AHI) > 5/hr, the STOP questionnaire demonstrated a sensitivity of 65.6%, compared with 68.9% for the Berlin questionnaire and 72.1% for the ASA Checklist. Specificity was 58.9% for STOP, 55.4% for Berlin, and 37.5% for the ASA Checklist. For an AHI of >15/hr, the STOP questionnaire demonstrated a sensitivity of 74.3%; Berlin, 78.6%; and ASA Checklist, 78.6%. Specificity was 52.8% for STOP, 50% for Berlin, and 37% for the ASA Checklist. Yegneswaran concluded that the 3 questionnaires have a similar ability to identify patients at high risk for OSA, "but STOP is shorter and easier to use than other sleep apnea screening questionnaires."

Postoperative Complications in Patients With Sleep Apnea

In a companion paper, Peter Liao, MD, a Research Fellow in the Department of Anesthesia, Toronto Western Hospital, Toronto, Ontario, Canada, reviewed the postoperative course of 262 patients (195 male, 67 female, mean age 55.5 years) with OSA.[2] In all, 112 patients (42.8%) suffered complications. Most of these occurred in the hospital ward (25.2%); followed by the intensive care unit (ICU) (17.2%); postanesthesia care unit (8%); and intraoperatively (2.3%).

The most common complications were respiratory (32.8%), including mild oxygen desaturation ≤ 95% but > 90% (13.4%); and severe desaturation ≤ 90% (16.4%). Eight (3.1%) patients developed pulmonary edema, 6 (2.3%) experienced bronchospasm, 3 (1.15%) had to be reintubated, 2 (0.76%) suffered pneumothorax, and 2 (0.76%) had hypercapnea. In addition, 5 patients had unplanned ICU admissions.

A total of 38 patients (14.5%) experienced cardiovascular complications, including dysrhythmia (n = 21, 7.63%); hypertension (n = 18, 6.87%); hypotension (n = 10, 3.8%); bradycardia (n = 9, 3.44%); tachycardia (n = 7, 2.67%); cardiac arrest (n = 3, 1.15%); and ischemia (n = 2, 0.76%). Neurologic complications occurred in 16 (6.11%) patients, including agitation (n = 9, 3.44%); confusion (n = 4, 1.5%); motor deficit (n = 3, 1.15%); sensory deficit (n = 3, 1.15%); excessive drowsiness (n = 1, 0.38%); and stroke or transient ischemic attack (TIA) (n = 1, 0.38%). These complications often required extra treatment.

Preexisting conditions in addition to the sleep apnea included obesity (n = 160, 61.1%); hypertension (n = 129, 49.2%); cigarette smoking (n = 98, 37.4%); coronary artery disease (n = 72, 27.5%); gastroesophageal reflux disease (GERD; n = 69, 26.3%); diabetes (n = 58, 22.1%); depression (n = 15, 5.7%); arrhythmia (n = 14, 5.4%); stroke or TIA (n = 9, 3.4%); myocardial infarction (n = 3, 1.15%); and angina (n = 2, 0.76%).

Anesthesiologists stratify patients preoperatively on the basis of general health and severity of illness with an ASA score of I to V. For example, a normal, healthy individual would receive an ASA rank of I while someone with severe systemic disease would receive an ASA rank of III or higher. Thus, patients in this study included those with ASA rankings of I (n= 5, 1.9%), II (n = 85, 32.7%), III (n = 135, 51.9%), and IV (n = 35, 13.5%). Dr. Liao observed that patients with OSA have a high postoperative complication rate. But he noted that it remains unclear whether these complications are related directly to OSA or to concomitant heart disease, hypertension, obesity, diabetes, and other medical risk factors.

However, Joshua Rotenberg, MMS, MD, a sleep specialist and neurologist in San Antonio, Texas, commented, "It is hard to get the message to surgeons that sleep apnea is a treatable health care problem and that patients should be screened for sleep apnea before going to the operating room. Treatment may reduce postoperative complications."

Restless Legs Syndrome

Restless Legs Syndrome Diagnosis in Demented Elderly

Kathy Richards, PhD, RN, FAAN, Director, Tailored Biobehavioral Interventions Research Center, University of Arkansas for Medical Sciences, Little Rock, Arkansas, presented the results of the Behavioral Indicators Test, a new tool for the diagnosis of RLS in demented elderly patients.[3] The Behavioral Indicators Test includes 'complaint of leg discomfort' as one item; however, because demented patients may not be able to communicate symptoms of RLS, the test focuses on 8 observable behaviors: pacing/walking, periodic leg movements, flexing legs, stretching legs, crossing legs repeatedly, rubbing legs, other leg activity, and general restlessness. A 3-night pilot trial of 39 elderly, noninstitutionalized, demented patients (13 women, 26 men, mean age 79.9 years, mean Mini Mental State Examination score, 21) revealed that 16 (41%) demonstrated at least 4 of the behaviors suggestive of RLS. Symptoms correlated significantly with the periodic leg movement index obtained simultaneously on 2 nights of polysomnography (r = 0.41).

"RLS is associated with decreased cognitive function in normal people, and it is possible that treating restless legs syndrome in demented patients may improve the dementia," Dr. Richards observed. "But first, RLS has to be diagnosed. In the future, we plan to validate this tool in nondemented elderly."

Pictorial Phenotype of Restless Legs Syndrome

Reddiah Mummanei, MD, a sleep medicine fellow at Emory University School of Medicine, Atlanta, Georgia, asked 73 patients (32 men, 41 women, mean age 51.8 years) to illustrate the distribution of their RLS symptoms on a pictorial representation of the human body).[4] The patients had already been diagnosed with RLS using the International Restless Legs Syndrome Study Group (IRLSSG) criteria for idiopathic RLS.

A total of 53 patients (73%) indicated that their symptoms were both anterior and posterior; 14 (19%) patients had anterior only and 6 (8%) had posterior only symptoms; 69 patients (94%) experienced bilateral symptoms, whereas only 4 (6%) noted unilateral symptoms.

"No one said that only the feet are involved," Dr. Mummanei observed. "Patients with symptoms restricted to the feet may not have RLS." Dr. Mummanei recommended that practitioners give patients the opportunity to use pictorial diagrams along with the RLS screening questionnaire.

John Shephard, MD, a sleep specialist at the Mayo Clinic, Rochester, Minnesota, added, "These results correlate well with what we see in clinical practice. A few patients have unilateral symptoms. If symptoms are only proximal, they can be confused with meralgia paresthetica. If the clinical picture is not clear, we try a medication trial."

Maintenance of Wakefulness Test

A tool to assess a person's ability to stay awake may be important for airline pilots, police officers, firefighters, medical personnel, and others who must stay alert to remain effective at their jobs. Sylvie Arroyo, a research lab technician at the Division of Sleep and Chronobiology, Department of Psychiatry, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, and her colleagues Siobhan Banks, PhD, and David Dinges, PhD, also from the University of Pennsylvania, used polysomnography to monitor 9 healthy adults (6 women, 3 men, age 23-37) for 11 consecutive nights. To assess daytime wakefulness, they performed an abbreviated maintenance of wakefulness test on Days 2 and 7.[5] Subjects were asked to try to stay awake during the test, which was terminated after 30 minutes if no sleep onset occurred. Sleep onset was defined as the time to the first microsleep (10-second burst of EEG theta activity). Investigators conducted the trial between 2:30 and 4:00 PM. Sleep latency increased for 5 subjects and stayed the same for 4 subjects on the second test (Day 7). The test-retest reliability was 0.65 (P = .05).

Allen Foster, MD, an internist and sleep fellow at the University of Texas, Houston, commented, "This test is important to measure one's ability to stay awake, but it has not been validated yet. Currently, people are using a 40 minute maintenance of wakefulness test that is administered 5 times a day, which is very time consuming. This modification would make the test less cumbersome to use because it's shorter."

Insomnia and Mental Health in College Students

College students with insomnia scored significantly higher on 8/9 mental health symptom dimensions on the Symptoms Checklist-90 than students without insomnia.[6] Christie Gardner, a senior at University of North Texas, Denton, and her colleagues assessed insomnia in 365 undergraduates (67% female, 33% male, mean age 21 years) using a 1-week sleep diary. Those with insomnia scored significantly higher for anxiety (P < .01), depression (P < .05), hostility (P < .01), interpersonal sensitivity (P < .05), obsessive-compulsive symptoms (P < .001), phobic anxiety (P < .05), psychoticism (P < .05), and somatization (P < .01). Scores on paranoid ideation were not significantly different between the groups.

Daniel Taylor, PhD, Assistant Professor in the Department of Psychology and Behavioral Sleep Medicine Clinic, University of North Texas, Denton, and second author of the paper, observed that, "College students are prone to insomnia because of irregular schedules during weekends or summer, watching too much TV, and associating the bedroom with insomnia. Insomnia may also be precipitated by a stressor like an exam and then uncouple and become a self sufficient disorder."

"Insomnia is a stressor for mental health problems, and we hope to find the reasons why some students develop insomnia," Ms Gardner added.

Insomnia in People With Epilepsy

Using the Insomnia Severity Index, a 7-item validated insomnia scale, Nancy Foldvary-Schaefer, DO, and colleagues[7] from the Neurological Institute, Cleveland Clinic, Cleveland, Ohio, determined that 70% of 61 subjects with uncontrolled epilepsy (73% female, 27% male, mean age 41.5 years, 1.1-10 seizures/month) experienced mild (38%), moderate (25%), or severe (7%) insomnia). In addition, 48.5% of the study population reported depression as measured by the Beck Depression Inventory (21% mild, 18% moderate, 10% severe). Multivariate analysis found a significant association between insomnia and depression (P < .001), but not age, body mass index, gender, mean number of seizures/month, or number of antiepileptic drugs.

"Neurologists should check for insomnia and other sleep related issues in people with epilepsy and address them," advised Farid Talih, MD, a sleep medicine fellow at the Cleveland Clinic Foundation and lead author of the paper. "Most are amenable to treatment, which will improve quality of life and may improve seizure control and reduce the number of antiepileptic drugs; but that still is a question that needs to be answered. We hope to raise awareness of sleep disorders among epilepsy doctors."


These papers from the Sleep 2007 meeting reinforce the importance of screening for OSA, RLS, and insomnia in special populations. In preoperative patients, the new STOP questionnaire, consisting of merely 4 questions, may be a pragmatic tool to screen for sleep apnea. Elderly people are at higher risk for RLS, and the diagnosis may be obscured in patients with dementia because of their limited ability to communicate. The new Behavioral Indicators Test may provide an alternative means to make this diagnosis. Treatment of RLS in this population may improve their restlessness, wandering, and possibly other symptoms. In addition, the use of a pictorial representation of sensory symptoms may be a useful adjunctive instrument for the diagnosis of RLS. An abbreviated maintenance of wakefulness test may become a useful means to identify individuals with sleep disorders and assess the safety of individuals for potentially hazardous activities such as driving or police work.

College students with insomnia had higher scores on the Symptoms Checklist-90, indicating more mental health symptoms. Whether treatment of the insomnia will diminish or eliminate their mental health symptoms is an important question and needs to be answered. Depression commonly occurs in people with epilepsy. The study by Talih and colleagues demonstrated a high prevalence of insomnia as well as an association between insomnia and depression in this population. Consequently, epilepsy patients should be screened for both insomnia and depression and treated accordingly.

Supported by an independent educational grant from Cephalon



  1. Yegneswaran B, Chung S, Khajehdehi A et al. What is the best screening questionnaire for obstructive sleep apnea? Program and abstracts of the 21st Annual Meeting of the Associated Professional Sleep Societies, LLC; June 9-14, 2007; Minneapolis, Minnesota. Abstract 579.
  2. Liao PP, Yegneswaran B, Vairavanthan S et al. Postoperative complications among obstructive sleep apnea patients. Program and abstracts of the 21st Annual Meeting of the Associated Professional Sleep Societies, LLC; June 9-14, 2007; Minneapolis, Minnesota. Abstract 582.
  3. Richards KC, Lambert CW, Beck CK. Behavioral indicators test-restless legs. Program and abstracts of the 21st Annual Meeting of the Associated Professional Sleep Societies, LLC; June 9-14, 2007; Minneapolis, Minnesota. Abstract 314.
  4. Mummaneni R, Bliwise D, Rye D. Pictorial phenotype of restless legs syndrome. Program and abstracts of the 21st Annual Meeting of the Associated Professional Sleep Societies, LLC; June 9-14, 2007; Minneapolis, Minnesota. Abstract 845.
  5. Arroyo S, Banks S, Dinges DF. Maintenance of wakefulness test: Reliability and predictors in normal, healthy subjects. Program and abstracts of the 21st Annual Meeting of the Associated Professional Sleep Societies, LLC; June 9-14, 2007; Minneapolis, Minnesota. Abstract 1000.
  6. Gardner CE, Taylor DJ, Tatum JI, et al. The interrelationship of insomnia and mental health cross-sectionally and longitudinally. Program and abstracts of the 21st Annual Meeting of the Associated Professional Sleep Societies, LLC; June 9-14, 2007; Minneapolis, Minnesota. Abstract 236.
  7. Talih F, Budur K, Ioachimescu O, Foldvary-Schaefer N. Measuring insomnia with the Insomnia Severity Index in epilepsy patients. Program and abstracts of the 21st Annual Meeting of the Associated Professional Sleep Societies, LLC; June 9-14, 2007; Minneapolis, Minnesota. Abstract 267.