WHY DO WE NEED A SLEEP STUDY?

Polysomnography monitors your sleep stages and cycles to identify if or when your sleep patterns are disrupted and why.
The normal process of falling asleep begins with a sleep stage called non-rapid eye movement (NREM) sleep. During this stage, your brain waves, as recorded by electroencephalography (EEG), slow down considerably. Your eyes don’t move back and forth rapidly during NREM, in contrast to later stages of sleep. After an hour or two of NREM sleep, your brain activity picks up again, and rapid eye movement (REM) sleep begins. Most dreaming occurs during REM sleep.

You normally go through four to six sleep cycles a night, cycling between NREM and REM sleep in about 90 minutes. Your REM stage usually lengthens with each cycle as the night progresses. Sleep disorders can disturb this sleep process. Polysomnography monitors your sleep stages and cycles to identify if or when your sleep patterns are disrupted.
Your doctor may recommend polysomnography if he or she suspects you have:
-Sleep apnea or another sleep-related breathing disorder — your breathing repeatedly stops and starts during sleep.
-Periodic limb movement disorder — you involuntarily flex and extend your legs while sleeping. This sleep disorder is sometimes associated with restless legs syndrome.
-Narcolepsy — you experience overwhelming daytime drowsiness and sudden attacks of sleep.
-REM sleep behavior disorder — you act out dreams as you sleep.
-Unusual behaviors during sleep — you do unusual activities during sleep, such as walking, moving around a lot or rhythmic movements.
Unexplained chronic insomnia — you consistently have trouble falling asleep or staying asleep.






Why do you Need a Sleep Study?

Polysomnography, also called a sleep study, is a test used to diagnose sleep disorders. Polysomnography records your brain waves, the oxygen level in your blood, heart rate and breathing, as well as eye and leg movements during the study.
Polysomnography usually is done at a sleep disorders unit within a hospital or at a sleep center. You’ll be asked to come to the sleep center in the evening for polysomnography so that the test can record your nighttime sleep patterns.
Polysomnography monitors your sleep stages and cycles to identify if or when your sleep patterns are disrupted and why.
The normal process of falling asleep begins with a sleep stage called non-rapid eye movement (NREM) sleep. During this stage, your brain waves, as recorded by electroencephalography (EEG), slow down considerably. Your eyes don’t move back and forth rapidly during NREM, in contrast to later stages of sleep. After an hour or two of NREM sleep, your brain activity picks up again, and rapid eye movement (REM) sleep begins. Most dreaming occurs during REM sleep.
You normally go through four to six sleep cycles a night, cycling between NREM and REM sleep in about 90 minutes. Your REM stage usually lengthens with each cycle as the night progresses. Sleep disorders can disturb this sleep process. Polysomnography monitors your sleep stages and cycles to identify if or when your sleep patterns are disrupted.
Your doctor may recommend polysomnography if he or she suspects you have:
Sleep apnea or another sleep-related breathing disorder — your breathing repeatedly stops and starts during sleep.
Periodic limb movement disorder — you involuntarily flex and extend your legs while sleeping. This sleep disorder is sometimes associated with restless legs syndrome.
Narcolepsy — you experience overwhelming daytime drowsiness and sudden attacks of sleep.
REM sleep behavior disorder — you act out dreams as you sleep.
Unusual behaviors during sleep — you do unusual activities during sleep, such as walking, moving around a lot or rhythmic movements.
Unexplained chronic insomnia — you consistently have trouble falling asleep or staying asleep.






To Dream, perhaps to Learn?

A Harvard study suggested that dreaming may reactivate and reorganize recently learned material, improving memory and boosting performance. The subjects were 99 healthy college students who agreed to avoid alcohol, caffeine, and drugs for at least 24 hours prior to the experiment. All the volunteers demonstrated normal sleep patterns before enrolling in the study.
Each of the subjects spent an hour learning how to navigate through a complex three-dimensional maze-like puzzle. After the training period, half of the students were allowed to nap for 90 minutes, while the others read or relaxed. Following a lunch break, all the volunteers tackled the virtual maze again. The only students whose performance substantially improved were the few who dreamed about the maze during their naps. Although the dreams didn’t actually depict solutions to the puzzle, the researchers believe they show how the dreaming brain can reorganize and consolidate memories, resulting in better performance on learned tasks. And all the amazing dreams occurred early in NREM sleep.






The Benefits of Sleep

Every 90 minutes, a normal sleeper cycles between two major categories of sleep — although the length of time spent in one or the other changes as sleep progresses.
During “quiet” sleep, a person progresses through four stages of increasingly deep sleep. Body temperature drops, muscles relax, and heart rate and breathing slow. The deepest stage of quiet sleep produces physiological changes that help boost immune system functioning.
The other sleep category, REM (rapid eye movement) sleep, is the period when people dream. Body temperature, blood pressure, heart rate, and breathing increase to levels measured when people are awake. Studies report that REM sleep enhances learning and memory, and contributes to emotional health — in complex ways.
Although scientists are still trying to tease apart all the mechanisms, they’ve discovered that sleep disruption — which affects levels of neurotransmitters and stress hormones, among other things — wreaks havoc in the brain, impairing thinking and emotional regulation. In this way, insomnia may amplify the effects of psychiatric disorders, and vice versa.