What are sleep studies?

Depending on the sleep disorder to be evaluated the study may be simply a clinical interview with a physical examination and some analytical, cardiology and radiology tests. In the case of the evaluation of any disorder that goes with excessive daytime sleepiness we always need one or more polysomnographic studies. The polysomnographic study is the sleep study for excellence and it consists in the continuous recording of different physiological signals throughout the whole night, which is usually performed in a sleep laboratory. This provides valuable information referred to the diagnosis and assessment of the severity of any sleep apnea and we can also see the consequences of the apneas in the cardiac and brain activity throughout the night. Among other things we can get what is known as hypnogram where we can see how the suject travels across the different sleep phases, including the sleep phase in which the dreams area supposed to appear. In some cases it is needed to add a diurnal sleep study to the nocturnal one. This diurnal test gives great information related to every patient suffering from excessive daytime sleepiness. In many times a second night of study is needed in order to do a trying of treatment with totally harmless sleep devices while sleeping.
In the case of insomnia, this symptom does not imply a polysomnographic sleep study due to the fact that the information that it provides is not relevant and given that properly done sleep studies are expensive it would be a waste of money for a very scarce information in return. Only in very special cases a person affected by insomnia requires a study of this type, such as insomnia secondary to periodic involuntary movements of the arms or legs during sleep. There are many causes of insomnia and its proper evaluation requires a long interview with the patient and, among others, filling a sleep log. Treatment usually is very complex and laborious and the results can only be seen in the long term. Hopefully insomnia, in contrast with hypersomnia, is a process that usually involves no physical consequences for the suffering, but that is not a reason for not being to be studied and addressed.

14 Feb 2015