People who have been struggling for years with sleeping problems may have considered having a polysomnography, or sleep study, to analyze their sleep behavior. The procedure may sound a bit daunting, but it really is quite simple. The patient will usually stay at a facility for one night while having different vital signs constantly monitored. Different measurements are taken throughout the course of a normal night of sleep, revealing transitions between the different stages of sleep. Those that have trouble sleeping, or even just suffer from chronic fatigue and tiredness, might be able to find the answer through a sleep study. Once being introduced to the idea of a sleep study, it’s only natural to be curious about the type of answers it can provide, as well as what a set of normal sleep study results might look like.
One of the most important measurements taken during a study is the amount of brain activity through the night. The body undergoes a continued set of physiological changes during a normal sleep cycle and this includes increases and decreases in the amount of activity seen in different regions of the brain.
In particular, doctors will examine an EEG reading to decide whether or not the patient undergoes normal sleep cycles. A standard cycle will include periods of light NREM (non-rapid eye movement) sleep followed by decreasing brain activity and deeper sleep. Deeper NREM sleep is where the patient is less likely to be awakened by slight noises and shows reduced amounts of brain activity.
Upon completion of some amount of NREM transitions, REM sleep will follow. Periods of REM sleep are generally very short at the beginning of the night and gradually make slow increases in later cycles. REM sleep involves very irregular physiological activity that is actually quite similar to being awake. Despite this, REM is actually one of the most essential and necessary states for resting the mind. During REM, which only accounts for around 25% of your time slept, neurotransmitters are no longer sent and results in a state where the body’s muscles do not move. When someone remembers a very vivid dream it is very often from a state of REM sleep.
Measurements taken of brain activity are one of the best ways to determine if a patient has a sleeping disorder that is otherwise not observable. Lack of sleep symptoms in particular are very hard tie to one specific disorder because they are so similar.
Breathing and Heart Rate
The other measurements taken will observe the changing conditions of the body. A normal sleep study will show patients that have decreased and even rates in NREM, but more varied in REM. The body controls it’s temperature as well during sleep and will show a small decrease. These changes are readily observable through sensors placed on the patient during their sleep. These types of measurements can be extremely helpful when trying to monitor or discover cases of obstructive sleep apnea syndrome or other different types of sleeping disorders.