Conference Consensus on Excessive Sleepiness

Scope of the Meeting

Excessive Sleepiness is a symptom that affects nearly 25% of the general population. However, this symptom has not been widely studied; instruments to assess it are rare and were developed before 1995. Our understanding of the symptom has since then changed considerably. The goal of this symposium is to inform the attendees on the new research development in the acquisition of knowledge related to excessive sleepiness; the evolution of the concept of excessive sleepiness and to familiarize attendees with the legal, clinical and diagnostic implications of the existing tools used to measure excessive sleepiness. More specifically, usefulness and limits of current tools will be discussed along with the avenues to improve the assessment of excessive sleepiness.


  1. To define the place of Excessive Sleepiness inside of the Sleep Disorders and its impact.
  2. To have a consensus on the way to recognize, identify and evaluate Excessive Sleepiness.
  3. To define the constitutive elements of a tool to evaluate the severity of Sleepiness and to follow its evolution.
  4. To plan the development of this in term of method and validation.


Saturday, July 11th, 2015

08:30 - 08:45 Maurice Ohayon, MD, DSc, PhD
Welcome / Overview of the day
08:45 - 09:45 Maurice Ohayon, MD, DSc, PhD
The multiple Facets of Excessive Sleepiness in the General Population
09:45 - 10:45 Meir Kryger, MD, FRCPC
Sleepiness due to Medical Disorders
10:45 - 11:00 Break
11:00 - 11:40 Yves Dauvilliers, MD, PhD
Role of the biomarkers in central hypersomnolence disorders
11:40 - 12:15 Giuseppe Plazzi, MD, PhD
Cataplexy and pseudocataplexy in the differential diagnosis of CNS hypersomnolences: does atypical cataplexy exist?
12:15 - 13:30 Lunch
13:30 - 14:10 Thomas Roth, PhD
Consequences of Excessive Sleepiness
14:10 - 15:00 Max Hirshkowitz, PhD
National Sleep Foundation (NSF) Sleep Time Recommendation Expert Panel (STREP): An application of the RAND Appropriateness Method
15:00 - 15:15 Break
15:15 - 17:45 General Discussion
Future directions
17:45 - 18:00 Conclusions


The Multiple Facets of Excessive Sleepiness in the General Population
Maurice Ohayon, MD, DSc, PhD
Stanford University, Stanford, CA, USA

This population-based study examined the association between excessive somnolence (ES), fatigue, medical and psychiatric comorbidities and consequences on daily functioning. The study involved a representative sample of 19,136 non-institutionalized individuals living in the US, aged ≥18 (participation rate: 83.2%). Sleep-EVAL questionnaire included sleeping habits; health; sleep, mental and organic disorders (DSM-IV-TR, ICSD-II, ICD-10). ES was observed in 27.8% of the sample; 11.8% of the sample reported at least 2 episodes of ES within the same day. Fatigue had a lower prevalence: Mild fatigue was observed in 3.8% of the sample, moderate fatigue in 4.4% and severe fatigue in 3.9% of the sample. Correlation between excessive somnolence and fatigue was r=0.22. Only 1 third of individuals with severe somnolence reported some levels of fatigue. ES was more strongly associated with sleep disorders than fatigue but fatigue was more strongly associated with mood disorders than ES.

Sleepiness due to Medical Disorders
Meir Kryger, MD, FRCPC
Yale School of Medicine, CT, USA

The complexity of the sleep-wake system makes it vulnerable to malfunction and medical disorders can lead to: Excessive sleepiness; Excessive wakefulness; both sleepiness and wakefulness. Diseases in almost all organ systems can cause hypersomnia. Of the 19 categories of disease in ICD-9, disorders in all but 5 categories (and even here there are exceptions) hypersomnia may occur. Most commonly sleepiness in a sleep clinic is seen in patients with respiratory problems (e.g. sleep apnea), circulatory problems (e.g. congestive heart failure, stroke), neurological disorders (e.g., Parkinson's, epilepsy, narcolepsy), and mental and behavioral disorders (e.g. depression), At this time is usually difficult to obtain authorization to prescribe wake promoting agents in patients other than those with narcolepsy and sleep apnea.

Consequences of Excessive Sleepiness
Thomas Roth, PhD
Henry Ford Hospital, Detroit, MI, USA

The importance of understanding excessive sleepiness derives not only from its high prevalence but also from the fact that it has significant associated morbidity. The early research on the effects of sleepiness focused on its effects on psychomotor performance in general and the frequency of lapses in performance specifically. There are seminal studies both in the US and Europe that showed that sleep deprived subjects showed significant impairments. These effects were most clearly seen on long monotonous tasks (not different from driving) and the impairments seen were lapses. Lapses are short periods (less than a second) where people fail to respond to the environment. These lapses can have disastrous impact on behaviors such as highway driving, and other jobs that require sustained attention. Subsequent research has broadened the area of inquiry and demonstrated memory deficits, increased risk taking behavior and impairments in executive function that are also associated with sleepiness. More recently the focus has moved from the behavioral consequences of sleepiness to physiological consequences. Sleepiness has been shown to be associated with a variety of physiological functions including increased pain sensitivity and blunted arousal responses. These have significant implications. For example, in patients with sleep apnea the degree of sleepiness correlates with the time to arousal and the resumption of breathing and hence with degree of hypoxemia.

National Sleep Foundation (NSF) Sleep Time Recommendation Expert Panel (STREP): An application of the RAND Appropriateness Method
Max Hirshkowitz, PhD
Baylor College of Medicine, Menninger, TX, USA

Objective: To make scientifically sound and practical recommendations for daily sleep duration across the lifespan.
Methods: The National Sleep Foundation (NSF) convened a multidisciplinary expert panel ("Panel") with broad representation from leading stakeholder organizations. The Panel evaluated the latest scientific evidence and participated in a formal consensus and voting process. Then, the RAND/UCLA Appropriateness Method was used to formulate sleep duration recommendations.
Results: The Panel made sleep duration recommendations for nine age groups. Sleep duration ranges, expressed as hours of sleep per day, were designated as recommended, may be appropriate, or not recommended. Recommended sleep durations are: 14-17 hours for newborns, 12-15 hours for infants, 11-14 hours for toddlers, 10-13 hours for preschoolers, 9-11 hours for school age children and 8-10 hours for teenagers. 7-9 hours are recommended for young adults and adults and 7-8 hours of sleep are recommended for older adults. The self-designated basis for duration selection and critical discussions are also provided.
Conclusions: Consensus for sleep duration recommendations were reached for specific age groupings. Consensus using a multidisciplinary expert panel lends robust credence to the results. Finally, limitations and caveats of these recommendations are discussed.

This Activity is supported by an Unrestricted Educational Grant from Jazz Pharmaceuticals to Stanford University.