Classification of sleep disorders
Classification of sleep disorders, as developed in the 19th century, used primarily three categories: Insomnia, Hypersomnia and Nightmare. In the 20th century, increasingly in the last half of it, technological discoveries led to rapid advances in the understanding of sleep and recognition of sleep disorders. Major sleep disorders were defined following the development of Electroencephalography (EEG) in 1924 by Hans Berger. Three systems of classification are in use worldwide: The ICD and DSM lump different disorders together while the ICSD tends to split related disorders into multiple discrete categories. There has, over the last 60 years , occurred a slow confluence of the three systems of classification. Diagnoses of sleep disorders are based on self-assessment questionnaires, clinical interview, physical examination and laboratory procedures. The validity and reliability of various sleep disorders are yet to be proved and need further research within the ever-changing field of "Sleep Medicine". Admittedly, the development of sleep disorder classification remains as much an art as it is a science. History. Milestones. The first book on sleep was published in 1830 by Robert MacNish; it described sleeplessness, nightmares, sleepwalking and sleep-talking. Narcolepsy, hypnogogic hallucination, wakefulness and somnolence were mentioned by  other authors of the nineteenth century. Westphal in 1877 described first case of narcolepsy, the name coined later by Gelineu in 1880 in association with cataplexy. Lehermitte called it paroxysmal hypersomnia in 1930 to differentiate it from prolonged hypersomnia. Roger in 1932 coined the term parasomnia and classified hypersomnia, insomnia and parasomnia. Kleitman in 1939 recognized types of parasomnias as nightmares, night terrors, somniloquy (sleep-talking), somnambulism (sleepwalking), grinding of teeth, jactatians, enuresis, delirium, nonepileptic convulsions and personality dissociation. Broughton in 1968 developed classification of the arousal disorders as confusional arousals: night terrors and sleep walking. Insomnias were classified as  primary and secondary till 1970 when they were recognized as symptoms of other disorders. Sir William Osler in 1906 correlated snoring, obesity and somnolence (sleepiness) to Dicken's description of Joe. Charles Burwell in 1956 recognized obstructive sleep apnea as Pickwickian syndrome. Circadian rhythm sleep disorders were discovered in 1981 by Weitzman as delayed sleep phase syndrome in contrast to advanced sleep phase syndrome in 1979. The International Classification of Sleep Disorders (ICSD). The International Classification of Sleep Disorders (ICSD) was produced by the American Academy of Sleep Medicine (AASM) 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 (DCSAD) that was produced by both the Association of Sleep Disorders Centers (ASDC) and the Association for the Psychophysiological Study of Sleep and was published in the journal Sleep in 1979. The International Classification of Sleep Disorders (ICSD) uses a multiaxial system for stating and coding diagnoses both in clinical reports or for data base purposes. The axial system uses International Classification of Diseases (ICD-9- CM) 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 (nonsleep diagnoses). ICSD - I Revised 1997. Proposed Sleep Disorders. ICSD 2 is tabulated in the main article International Classification of Sleep Disorders ICSD - 3. The last edition of ICSD-3 is a unified classification of sleep disorders. It includes seven major categories: insomnia disorders, sleep-related breathing  disorders, central disorders of hypersomnolence, circadian rhythm sleep-wake disorders, sleep-related movement disorders, parasomnias, and other sleep disorders. Each of these categories has several subgroups: International Classification of Disease (ICD). ICD-7R 1955. 780.7 Disturbance of sleep ICD-8 1965. 306.4 Specific disorder of sleep 780.6 Disturbance of sleep ICD-10-CM 2016. P28.3. Applicable To Approximate Synonyms DSM Classification of Sleep Disorders. DSM-5 Sleep Wake Disorders. Major changes from DSM IV. Sleep-wake disorders comprise 11 diagnostic groups: