What Do Sleep Studies Show?
Sleep studies allow doctors to watch sleep patterns
and note sleep-related problems that patients don't know or can't describe
during routine office visits. These studies are needed to diagnose certain
sleep disorders, such as
narcolepsy
and
sleep
apnea.
After the sleep study, your doctor will get the
results. The results will include information that the sleep technician records
about sleep and wake times, sleep stages, abnormal breathing, the amount of
oxygen in your blood, and any movement during sleep.
Your doctor will use your sleep study results and
your medical and sleep histories to make a diagnosis and create a treatment
plan.
Results From a Polysomnogram
Polysomnogram (PSG) results are used to help
diagnose:
-
Insomnia
- Sleep-related breathing disorders, such as sleep
apnea
- Narcolepsy (PSG and multiple sleep latency test
(MSLT) results will be reviewed together)
- Sleep-related seizure disorders
- Parasomnias (such as sleepwalking)
If you have sleep apnea, your doctor also may use a
PSG to find the right setting for you on a continuous positive airway pressure
(CPAP) machine. A CPAP machine uses a small pump to gently supply air to your
nose or mouth through a special mask. The right setting involves adding just
enough extra air to create mild pressure that keeps your airways open while you
sleep.
A PSG also helps doctors:
- Adjust CPAP settings after weight loss or
gain
- Recheck your sleep if symptoms return despite
treatment with CPAP
- Find out how well surgery has worked to correct a
sleep-related breathing problem.
For sleep-related breathing disorders, such as sleep
apnea, technicians use a PSG to record the number of abnormal breathing events.
These include either pauses in breathing or dips in the level of oxygen in your
blood.
In adults, when the number of events is 10 or more
per hour, treatment may be needed. Children who have one to three events per
hour also may need treatment.
Results From a Multiple Sleep Latency Test
MSLT results are used to help diagnose narcolepsy,
idiopathic hypersomnia, and circadian rhythm disorders.
For narcolepsy, technicians study how quickly you
fall asleep. The MSLT also shows how long it takes you to reach different types
and stages of sleep. Sleep has two basic types: rapid eye movement (REM) and
non-REM. Non-REM sleep has four distinct stages. REM sleep and the four stages
of non-REM sleep occur in patterns throughout the night.
People who fall asleep in less than 5 minutes or
quickly reach REM sleep may need treatment for a sleep disorder.
Results From a Maintenance of Wakefulness Test
Maintenance of wakefulness test (MWT) results may be
used to show whether your inability to stay awake is a public or personal
safety concern. This study also is used to show how well treatment is
working.
Results From an Actigraph Test
Actigraph results give your doctor a better idea
about your sleep habits, such as when you sleep or nap and whether the lights
are on while you sleep. This study also is used to help diagnose circadian
rhythm disorders. |