The study of sleep disorders
Insomnia was first reported in the ancient Egyptian texts, where opium was used to treat the sleep disorder. In the 17th century, medicine underwent a change from the doctrines of Aristotle, Galileo, to more scientific theories. It was against this background that neurologists Thomas Willis and Thomas Sydenham came up with principles and practice of clinical neurology. Willis contributed to the knowledge of various sleep disorders, including Restless Leg Syndrome (RLS), nightmare and insomnia. He identified that an element in coffee can prevent sleep and sleep was not a disease, but a symptom of underlying causes. In his book, ‘The Practice of Physick’ (1692) he devoted four chapters to disorders producing sleep and insomnia. He also discovered that laudanum, obtained from opium, could treat RLS.
Many theories developed in the late 19th and early 20th century. In 1913, French physician Henri Piéron published his study in the book, ‘Le probleme physiologique du sommeil’, suggesting that sleep problems are due to physiological reasons. In 1918, William Osler associated the connection between obesity and hypersomnolence and coined the term ‘Pickwickian syndrome’. This term is now used for patients with obesity and hypoventilation.
In 1920s, Dr. Nathaniel Kleitman, also known as ‘Father of American Sleep Research’, began work in Chicago quizzing about sleep and circadian rhythms. His work concentrated on characteristics of sleep and the effect of sleep deprivation. In 1951, Dr. Kleitman’s student, Dr. Eugene Aserinsky made an important sighting of rapid eye movements in sleeping infants and later in adults. The experiment was further supported by the application of Electro-Oculography that helped them record bursts of electrical changes connected with eye movements. This finding was published in 1953 explaining REM sleep.
In 1965, the researchers Gastaut, Tassinari and Duron in France and Jung and Kuhlo in Germany, independently published reports on Sleep Apnea, the first evidence of sleep associated with daytime sleep disorder. They observed patients with excessive daytime sleepiness, snoring, abnormalities in breathing while asleep. Then in 1970, Tassinari and Lugaresi in Bologna established the link between Sleep Apnea and non-obese patients.
The first sleep center, established at Stanford University in 1972, carried out polysomnography for the first time. Sleep study was recognized by the American Medical Association in 1996, which gave an enormous boost to study on sleep disorders in North America and other countries too. Today, sleep research consists of areas like narcolepsy, sleep and cardio-respiratory; circadian rhythms, shifts, sleep deprivation, sleep and aging, infant sleep, etc.