International Classification of Sleep Disorders


The International Classification of Sleep Disorders is "a primary diagnostic, epidemiological and coding resource for clinicians and researchers in the field of sleep and sleep medicine". The ICSD was produced by the American Academy of Sleep Medicine in association with the European Sleep Research Society, the Japanese Society of Sleep Research, and the Latin American Sleep Society. The classification was developed as a revision and update of the Diagnostic Classification of Sleep and Arousal Disorders that was produced by both the Association of Sleep Disorders Centers and the Association for the Psychophysiological Study of Sleep and was published in the journal Sleep in 1979. A second edition, called ICSD-2, was published in 2005. The third edition, ICSD-3, was released in 2014.

Milestones of Sleep Disorder Classifications

YearICSDICDDSM
1974DSM-III
1975ICD-9
1979Nosology
1980ICD-CMDSM-III
1987DSM-III-R
1990ICSD
1992ICD-10
1994DSM-IV
1997ICSD-R
2000DSM-IV-TR
2005ICSD-2
2006ICSD-2 Pocket Version
2010ICD-10-CM
2014ICSD-3DSM-5
2015ICD-11 Beta

Introduction

In 1979, the first Diagnostic Classification of Sleep and Arousal Disorders was developed by the Association of Sleep Disorders Centers and the Association for the Psychophysiological Study of Sleep. Disorders were divided into four main categories.
  1. Disorders of initiating and maintaining sleep - Insomnias
  2. Disorders of Excessive somnolence - Hypersomnias
  3. Disorders of the Sleep-Wake Schedule - Circadian Disorders
  4. Dysfunctions Associated with Sleep, Sleep Stages, or Partial Arousals - Parasomnias
In 1990, the first comprehensive classification of disorders of sleep and arousal, the International Classification of Sleep Disorders, was developed by the American Academy of Sleep Medicine in association with the European Sleep Research Society, the Japanese Society of Sleep Research, and the Latin American Sleep Society. 84 sleep disorders were inventoried, based on pathophysiological characteristics. It was later revised as the ICSD-R in 1997.
The International Classification of Sleep Disorders uses a multiaxial system for stating and coding diagnoses both in clinical reports or for database purposes. The axial system uses International Classification of Diseases coding wherever possible. Additional codes are included for procedures and physical signs of particular interest to sleep disorders clinicians and researchers. Diagnoses and procedures are listed and coded on three main "axes." The axial system is arranged as follows:
Axis A ICSD Classification of Sleep Disorders
Axis B ICD-9-CM Classification of Procedures
Axis C ICD-9-CM Classification of Diseases.

ICSD - I (1990) and ICSD-Revised (1997)

  1. Dyssomnias
  2. # Intrinsic Sleep Disorders
  3. # Extrinsic Sleep Disorders
  4. # Circadian Rhythm Sleep Disorders
  5. Parasomnias
  6. # Arousal Disorders
  7. # Sleep-Wake Transition Disorders
  8. # Parasomnias Usually Associated with REM Sleep
  9. # Other Parasomnias
  10. Sleep Disorders Associated with Mental, Neurologic, or Other Medical Disorders
  11. # Associated with Mental Disorders
  12. # Associated with Neurologic Disorders
  13. # Associated with Other Medical Disorders
  14. Proposed Sleep Disorders
  15. # Shorter Sleeper
  16. # Long Sleeper
  17. # Menstrual-Associated Sleep Disorders

    ICSD -2

In 2005, the International Classification of Sleep Disorders underwent minor updates and modifications resulting in version 2.
The ICSD-2 thus lists 81 sleep disorder diagnostic categories divided in 8 major categories. Each diagnostic is detailed in a description that presents the diagnostic criteria. The 81 diagnostics are divided into 8 main categories, namely insomnias, sleep-related breathing disorders, hypersomnias of central origin, circadian rhythm sleep disorders, parasomnias, sleep-related movement disorders, isolated symptoms apparently normal variants and unresolved issues, other sleep disorders. The two last categories are presented in the appendices and count 13 diagnostics.
In 2006, a pocket version of the ICSD-2 was released. In this version, a pediatric section was added listing the following diagnostic categories:
  1. Behavioural Insomnia in Childhood
  2. # Onset Type
  3. # Limit Setting Type
  4. Primary Sleep Apnea of Infancy
  5. Obstructive Sleep Apnea, Pediatric
  6. Congenital Central Alveolar Hypoventilation Syndrome
  7. Sleep Enuresis
  8. Restless Legs Syndrome
  9. Sleep-related Rhythmic Movement Disorder
However, this classification brought some confusion into the field, which led to the revision of the classification in 2011. The classification was much more discussed by experts of the field and led to the third edition of the ICSD.

ICSD-3 (2014)

The revision of the ICSD-2 was firstly made by the AASM and other International Societies. This revision ntergrates pediatric diagnosis into clinical adult diagnosis ane led to the third edition of the ICSD, which was released in 2014.
ICSD-3 includes specific diagnoses within the seven major categories, as well as an appendix for classification of sleep disorders associated with medical and neurologic disorders. The International Classification of Diseases codes corresponding to each specific diagnosis can be found within the ICSD-3. Furthermore, pediatric diagnoses are not distinguished from adult diagnoses except for sleep-related breathing disorders.
In addition, significant changes have been made in the nosology of insomnia, narcolepsy and parasomnia. Primary vs. secondary insomnia have been reunited into a single disorder: chronic insomnia. Narcolepsy have been dived into narcolepsy Type 1 and narcolepsy Type 2. These two types are distinguished by the presence or absence of cataplexy and the cerebrospinal fluid hypocretin-1 level. Concerning parasomnia, the sections have been modified, grouping together common features. Finally, a section on treatment-emerging CSA has been added to the CSA syndromes section.
It also discusses common isolated symptoms and normal variants. Some occur during normal sleep: as an example, sleep talking occurs at some time in most normal sleepers. Some lie on the continuum between normal and abnormal: as an example, snoring without associated airway compromise, sleep disturbance, or other consequences is essentially normal, whereas heavy snoring is often part of obstructive sleep apnea.
Furthermore, some features are no longer disorders and are reunited in the AASM Manual for the Scoring of Sleep and Associated Events. Therefore, ICSD permanently refers to this manual. The latter allows, for instance, to find definitions of polysomnography or specific features.
The ICSD-3 counts 383 pages for 83 disorders. It is divided into 7 main categories:

1. [Insomnia]

  1. Chronic insomnia disorder
  2. Short-term insomnia disorder
  3. Other insomnia
    Isolated symptoms and normal variants

2. Sleep-related breathing disorders

Obstructive sleep apnea (OSA) syndromes">Obstructive sleep apnea">Obstructive sleep apnea (OSA) syndromes

  1. OSA, adult
  2. OSA, pediatric

    Central sleep apnea syndromes">Central sleep apnea">Central sleep apnea syndromes

  3. Central sleep apnea with Cheyne-Stokes breathing
  4. Central sleep apnea due a medical disorder without Cheyne-Stokes breathing
  5. Central sleep apnea due to high altitude periodic breathing
  6. Central sleep apnea due to a medication or substance
  7. Primary central sleep apnea
  8. Primary central sleep apnea of infancy
  9. Primary central sleep apnea of prematurity
  10. Treatment-emergent central sleep apnea

    Sleep-related hypoventilation disorders

  11. Obesity hypoventilation syndrome
  12. Congenital central alveolar hypoventilation syndrome
  13. Late-onset central hypoventilation with hypothalamic dysfunction
  14. Idiopathic central alveolar hypoventilation
  15. Sleep-related hypoventilation due to a medication or substance
  16. Sleep-related hypoventilation due to a medical disorder

    Sleep-related hypoxemia disorder

Isolated symptoms and normal variants
  1. Snoring
  2. Catathrenia

    3. Central disorders of hypersomnolence

  3. Narcolepsy type 1
  4. Narcolepsy type 2
  5. Idiopathic hypersomnia
  6. Kleine-Levin syndrome
  7. Hypersomnia due to a medical disorder
  8. Hypersomnia due to a medication or substance
  9. Hypersomnia associated with a psychiatric disorder
  10. Insufficient sleep syndrome

    4. Circadian rhythm sleep-wake disorders

  11. Delayed sleep-wake phase disorder
  12. Advanced sleep-wake phase disorder
  13. Irregular sleep-wake rhythm disorder
  14. Non-24-hour sleep-wake rhythm disorder
  15. Shift work disorder
  16. Jet lag disorder
  17. Circadian sleep-wake disorder not otherwise specified

    5. [Parasomnia]s

NREM-related parasomnias
  1. Confusional arousals
  2. Sleepwalking
  3. Sleep terrors
  4. Sleep-related eating disorder
    REM-related parasomnias
  5. REM sleep behavior disorder
  6. Recurrent isolated sleep paralysis
  7. Nightmare disorder
    Other parasomnias
  8. Exploding head syndrome
  9. Sleep-related hallucinations
  10. Sleep enuresis
  11. Parasomnia due to a medical disorder
  12. Parasomnia due to a medication or substance
  13. Parasomnia, unspecified
    Isolated symptoms and normal variants
  14. Sleep talking

    6. Sleep-related movement disorders

  15. Restless legs syndrome
  16. Periodic limb movement disorder
  17. Sleep-related leg cramps
  18. Sleep-related bruxism
  19. Sleep-related rhythmic movement disorder
  20. Benign sleep myoclonus of infancy
  21. Propriospinal myoclonus at sleep onset
  22. Sleep-related movement disorder due to a medical disorder
  23. Sleep-related movement disorder due to a medication or substance
  24. Sleep-related movement disorder, unspecified
    Isolated symptoms and normal variants
  25. Excessive fragmentary myoclonus
  26. Hypnagogic foot tremor and alternating leg muscle activation
  27. Sleep starts

    7. Other sleep disorders

Other sleep-related symptoms or events that do not meet the standard definition of a sleep disorder