The overnight sleep study is called polysomnography. It charts brain waves, heart beat, muscle activity, and breathing during sleep. It also records arm and leg movement. It will show if there are other sleep disorders that are causing or increasing the problems with ISWD. Management Treatment for irregular sleep–wake rhythm tries to enable the body clock in the brain, such that a normal long sleep period at night can be achieved. Education about sleep hygiene is important, and counseling can be helpful. Melatonin, vitamin B12, sleep aids, wake aids, and other medications may also be used. Exposure to light during the daytime and activities occurring at regular times each day may help to restore a normal rhythm. The management of this disorder may vary for different subgroups of patients. Affected individuals with dementia should not be prescribed sleep-promoting medications (sedatives) for ISWD due to the increased prevalence of adverse effects in this group outweighing the possible benefits. Research There is currently a great deal of active research on various aspects of circadian rhythm; this often occurs at major universities in conjunction with sleep research clinics at major hospitals. An example is the program with Harvard Medical School and Brigham and Women's Hospital. This research includes programs that are staffed by researchers from various departments at the university, including psychiatry, neurology, chemistry, biology. Other major sleep research centers are in Tel Aviv in Israel, Munich in Germany and in Japan. A wide variety of sleep disorders are actively being researched. Measuring body temperature or melatonin levels may be used. Some hospitals do blood tests for melatonin levels. Saliva tests for melatonin are now available for online purchase; its metabolites can also be tested in urine. Nomenclature The current formally correct name of the disorder is Circadian Rhythm Sleep Disorder: Irregular Sleep Wake Rhythm Type. This disorder has been referred to by many other terms, including: Irregular Sleep Wake Pattern, irregular sleep wake syndrome, Irregular Sleep Wake Rhythm (ISWRD), Irregular Sleep Wake Cycle, Irregular Sleep Wake Schedule and Irregular Sleep Wake Disorder (ISWD). Sometimes the words sleep and wake are hyphenated (sleep-wake), sometimes joined with an en dash (sleep–wake) and sometimes open (sleep wake). Sometimes the words are capitalized and sometimes they are not. See also Advanced sleep phase syndrome Chronobiology Circadian rhythm Delayed sleep phase disorder References External links Circadian rhythm Sleep disorders Syndromes Congenital disorders of nervous system