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What happens during a sleep study?

December 06, 2018 | UCI Health
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Sleep deprivation is one of the most common problems among Americans today, and sleep — or the lack of it — can affect every area of our health.

For most, the problem is too much to do and too little time in the sack. But millions of others drag all day or snooze during the daytime even after a full night in bed.

When that happens, Ruth Benca, MD, PhD, professor and chair of the UCI Department of Psychiatry & Human Behavior, suggests a sleep study might be in order to find out what’s going on.

What is a sleep study?

“The reason we do sleep studies is that many sleep disorders are difficult to diagnose,” says Benca, a leading sleep medicine researcher who has studied the causes and treatments for the inability to get a good night’s rest.

“That’s not surprising, because people aren’t conscious during sleep and can only report on how they’re feeling in the daytime.”

Sleep studies monitor what’s happening as a person sleeps, examining:

  • Breathing patterns
  • Respiratory efforts
  • Oxygen levels
  • Heart rhythms
  • Body positions
  • Snoring 

Objective data gathered during a sleep study allow doctors to make an accurate diagnosis and prescribe appropriate treatment.

What happens in the sleep lab?

At the UCI Health Sleep Medicine Center in Newport Beach, patients come in at night and are asked to sleep in a room much like a hotel room. They’re connected to hundreds of surface monitors — there are no needles or X-rays — to track nighttime behavior from head to toe.

Devices measure things like:

  • Muscle activity in the eyes, chin and legs
  • Brain waves
  • Sleep duration
  • Breathing effort
  • Oxygen saturation in blood
  • Heart rhythms

The center is also equipped with the latest technology to measure sleep activity with 256 electrodes placed across the surface of the head. While patients sleep, highly trained technicians listen via microphones, watch with infrared cameras and score data as it comes in.

“People do not sleep exactly as they do at home,” Benca acknowledges. “But most people eventually fall asleep, and we are able to get enough information to make a diagnosis. We also do daytime nap tests or home tests, depending on the clinical situation.”

Who needs a sleep study?

Sleep studies are appropriate for certain types of disorders, but are not typically used for insomnia.

They can help understand people’s problems with some fairly rare sleep disorders like narcolepsy — where people nod off in low-stimulus situations — or problems with disruption of circadian rhythms (daily time cycle), seizures, sleep walking and abnormal behaviors or movements.

But by far, the most frequently seen problem is sleep apnea. It’s estimated that more than 20 million Americans have it.

Sleep apnea sufferers stop breathing during the night, usually because of an obstruction in the back of the throat.

Benca explains how it works: “The soft tissue of upper airway behind the tongue collapses so that too little oxygen gets into the lungs. When that happens the body sends a signal to wake up. The person wakes and takes a deep breath.”

What happens after the study?

The day after the study, sleep specialists analyze over a thousand pages of collected data to make sure everything has been scored correctly before entering details into a computer program that creates digital representations of the data. From this, they make a diagnosis and recommend treatment.

Treatments for mild sleep problems might include behavioral modifications, such as:

People with more severe apnea may need a machine that pumps moist air into the nose through a face mask to keep the airways open or a device that pulls the jaw forward.

“We don’t advise people to buy snoring devices in the drug store without seeing a doctor,” Benca says. “We want to make sure the diagnosis is correct, plus the devices should be fitted by a professional.”

Light therapy and daily schedule adjustments can help people who have trouble sleeping because their circadian rhythms have been disrupted. Medications or behavioral changes may also help other sleep problems.

Advancing what we know about sleep disorders

Benca says the researchers at the UCI Health sleep center are working to advance the understanding of sleep disorders as well as how such problems affect health in general.

Current projects they are investigating include:

  • New technologies to monitor sleep disorders in the lab and at home, as well as medications and behavior modifications
  • The role of sleep disorders in the development of neurological disorders such as Alzheimer’s disease and psychiatric disorders such as depression
  • The relationship between sleep and exercise in adolescents

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