[Polysomnography and other methods for the assessment of sleep disorders]

Polysomnography is an essential tool in the assessment of sleep disorders. However, PSG alone not always sufficient to evaluate various sleep disorders patients. For instance, in patients with suspected inadequate sleep hygiene, sleep logs or questionnaires on sleep habits may, be helpful in making the diagnosis. Patients who complain of excessive daytime sleepiness as a result of insomnia should be evaluated with the Epworth sleepiness scale and/or polysomnographic nap studies such as the multiple sleep latency test. In patients with suspected circadian rhythm sleep disorder, continuous temperature monitoring together with sleep log and actigraphy may establish the phase relationship between sleep-wake rhythms and other biological rhythms. Because polysomnographic measurements are cumbersome and expensive, it is necessary to select the suitable methods for the assessment of sleep disorders by the careful examination of the patients' complain.