For some patients, it may be necessary to evaluate their unique issues with sleep, in a controlled, safe setting. An outstanding clinical staff at Barker Sleep Institute has been selected to provide each patient with individualized care and diagnostic testing. A sleep study – or polysomnogram (PSG) – is a multiple-component test that electronically transmits and records specific physical activities while you sleep. The recordings become data that are analyzed by a qualified doctor to determine whether or not you have a sleep disorder.
The three types of polysomnographic studies are:
Diagnostic overnight PSG
This is the general monitoring of sleep stages (such is the amount of NREM and REM sleep, number of arousals and wakings) and a variety of body functions during sleep, including breathing patterns, heart rhythms, and limb movements. It is usually indicated in the evaluation of sleep-related breathing disorders, abnormal movements during sleep and parasomnias.
Diagnostic daytime multiple sleep latency test (MSLT)
This test is used to diagnose sleepiness and narcolepsy and to measure the degree of daytime sleepiness. To ensure accurate results, it is performed on the morning following a diagnostic overnight PSG. The MSLT consists of a series of opportunities for the patient to nap and/or relax in bed periodically during the day.
Two-night evaluation PSG and CPAP titration
CPAP (continuous positive airway pressure) is a sleep apnea treatment that involves the delivery of air into airways through a specially designed nasal mask. On the first night of the two-night protocol, general monitoring, and diagnostic evaluation are conducted. If sleep apnea is discovered, the patient returns for a second night to determine the necessary CPAP pressure required to alleviate apnea. A CPAP (continuous positive airway pressure) machine, is a mask that provides a steady stream of air blowing into the back of the throat to keep the airway open and is used to treat the sleep apnea. Most patients report that they experienced their best night’s sleep after that second night with the CPAP.
What to expect
On the night of your sleep study, you will be assigned to a private hotel-like bedroom. Near the bedroom will be a central monitoring area where the technicians monitor sleeping patients. You will be hooked up to equipment that will allow for easy movement both while you are in the bed and while you are active in your room. However, most patients fall asleep with little difficulty. Expertly trained technicians make each patient as comfortable as possible while overseeing and recording reliable and accurate data with the most up-to-date equipment offered. Throughout the night, the technicians monitor activities like brain waves, muscle movements, breathing efforts, heart rate and oxygen levels. By reviewing and analyzing any abnormalities that were observed during the overnight study, Dr. Barker and her medical staff can then continue to develop your sleep diagnoses and treatments.
The equipment used in a sleep test
Surface electrodes on your face and scalp will send recorded electrical signals to the measuring equipment. These signals, which are generated by your brain and muscle activity, are then recorded digitally. Belts are placed around your chest and abdomen to measure your breathing.
- A bandage-like oximeter probe on your finger is used to measure the amount of oxygen in your blood.
- An EEG (electroencephalogram) is used to measure and record brain wave activity.
- An EMG (electromyogram) records muscle activity such as face twitches, teeth grinding, and leg movements. It also helps in determining the presence of REM stage sleep.
- An EOG (electro-oculogram) is used to record eye movements. These movements are important in determining the different sleep stages, particularly REM stage sleep.
- An EKG (electrocardiogram) to record heart rate and rhythm.
- A nasal airflow sensor is used to record airflow.
- A snore microphone to record snoring activity.
Along with sleep studies, patients are also evaluated through actigraphy and sleep logs. These practices give the professionals at Barker Sleep Institute the most complete, most in-depth look into the cause of the sleep disorder. Actigraphy is designed for documenting physical movements associated with applications in physiological monitoring. An “actiwatch” is used to measure, store and analyze body activity while being worn on the patient’s limb or trunk. Through the use of an accelerometer, motion is measured and the activity is stored within the device, and then read by sleep technicians and physicians. Sleep logs are sleep diaries given to patients to record daily and nightly sleep habits and patterns. Patients are told to answer a set of questions each day for at least a week for the physician to review at the next appointment. Based on the results of the actigraph and the notes in the sleep log, Dr. Barker is able to diagnose and treat sleep disorders more effectively.
Each sleep study and its analysis is a complex process. Many hours of work are required by the specially trained Barker Sleep professionals in order to fully understand the significant amount of data gathered from each patient during the study. Treatment is customized for each patient and may include a combination of medications, oral appliances, a CPAP machine or even surgery. Whatever the treatment, the final outcome will always be a healthy, restful night’s sleep for the patient.