To diagnose sleep-related problems, doctors may use one or more of the following sleep studies:
- Polysomnogram (pol-e-SOM-no-gram), or PSG
- Multiple sleep latency test, or MSLT
- Maintenance of wakefulness test, or MWT
- Home-based portable monitor (PM)
Your doctor may use actigraphy if he or she thinks you have a circadian rhythm disorder.
Polysomnogram
Polysomnography (PSG) is typically conducted overnight at a sleep center and involves recording various physiological parameters to assess sleep patterns and diagnose sleep disorders.
During PSG, several key measurements are recorded, including brain activity, eye movements, heart rate, blood pressure, oxygen saturation levels, nasal airflow, snoring, and chest movements indicative of breathing effort.
The results of PSG are crucial for diagnosing sleep-related disorders such as sleep apnea, narcolepsy, and sleep-related seizure disorders. Additionally, PSG helps in determining the appropriate settings for continuous positive airway pressure (CPAP) therapy, which is a common treatment for sleep apnea.
Sleep apnea is a condition characterized by pauses in breathing or shallow breaths during sleep, often due to airway obstruction. CPAP therapy utilizes gentle air pressure to keep the airway open during sleep.
In some cases, a split-night sleep study may be conducted, where the first half of the night is spent without CPAP to assess sleep patterns and severity of sleep apnea. If sleep apnea is confirmed, CPAP titration is performed during the second half of the study to determine the optimal CPAP settings.
Follow-up PSG may be recommended to adjust CPAP settings after weight changes, reassess sleep if symptoms persist despite CPAP therapy, or evaluate the effectiveness of surgical interventions for sleep-related breathing disorders.
Multiple Sleep Latency Test
This daytime sleep study measures how sleepy you are. It’s typically done the day after a PSG. You relax in a quiet room for about 30 minutes while a technician checks your brain activity.
The MSLT records whether you fall asleep during the test and what types and stages of sleep you’re having. Sleep has two basic types: rapid eye movement (REM) and non-REM. Non-REM sleep has three distinct stages. REM sleep and the three stages of non-REM sleep occur in regular cycles throughout the night.
The types and stages of sleep you have during the day can help your doctor diagnose sleep disorders such as narcolepsy and idiopathic hypersomnia.