Dr. Bakker, Sarah E. Jamieson PA-C or your referring physician will likely order diagnostic tests or procedures to help us gain a better understanding of your condition. Some of the testing will be performed in our center and others may need to be done at an outside laboratory, radiology center or even the hospital. Most of the external test results will take a few to several days to be returned to us. We understand that you may be on “pins and needles” when waiting for test results so as soon as we have them, we will call to schedule an appointment to review your results with you and determine the next steps in your treatment plan
Some of the more common diagnostic tests are listed below:
Polysomnogram (PSG) – Conducted at a sleep center, a polysomnogram is a diagnostic sleep study that measures the quality of a person’s sleep by measuring the body’s involuntary functions during sleep, such as breathing and heart rate. This study typically lasts one night. A typical polysomnogram records the following data:
- Brain waves (electrodes placed on the scalp)
- Eye movement (electrodes placed on the face, by the eyes)
- Chin muscle tone (electrodes placed on or under the chin)
- Heart rate and rhythm (electrodes placed on the chest)
- Leg movements (electrodes placed on the legs)
- Breathing (breathing sensor placed near the nose and mouth)
- Breathing effort (two small belts placed loosely around the chest and abdomen)
- Oxygen level (small sensor attached to the finger)
- Audio and video taping
CPAP Titration Study – Conducted at a sleep center, a CPAP titration study is a sleep study used to determine the appropriate pressure to be used with a CPAP machine. During the night of a CPAP titration study, data will be recorded as during a PSG; however, a CPAP mask will be added at the beginning of the night. Through the night, the pressure released from the CPAP machine will be progressively increased, or titrated, until it is shown that the patient reaches restful sleep without interruption due to abnormal breathing patterns. This study typically lasts one night.
Split Night Study – Conducted at a sleep center, a split night study is a combination of a PSG and a CPAP titration study. A PSG is completed for the first 2 hours of the study. If significant sleep apnea is noted, then a CPAP titration study will be initiated.
Multiple Sleep Latency Test (MSLT) – Conducted at a sleep center, an MSLT assesses daytime sleepiness and is used to diagnose narcolepsy. This test may be performed after a PSG. The MSLT consists of a series of 20-minute naps, during which the patient tries to fall asleep. The test is given every two hours throughout the day, with each nap lasting about 20 minutes. During each nap, sensors and electrodes record data on body functions (heartbeat, breathing, eye movement, etc).
Blood Work – Blood tests may be ordered to identify an iron deficiency, thyroid abnormality or other abnormalities which can be linked to poor sleep.
MRI (Magnetic Resonance Imaging) – An MRI uses a strong magnet to produce pictures of the human body; it does not use X-ray radiation. Some people are unable to have MRIs; examples include those with pacemakers or with metal fragments near the eyes. An MRI may be given with or without dye depending on which condition your provider is concerned you may have. If needed, the MRI dye (called gadolinium) is given through an IV; it is very well tolerated and virtually free of allergens.
CT Scan – Computed tomography, also known as Computed Axial Tomography (CAT Scan) is a painless, sophisticated x-ray procedure. Multiple images are taken during the scan, and a computer compiles them into complete, cross-sectional pictures (“slices”) of soft tissue, bone and blood vessels. Because a CT scan obtains images of the body that cannot be seen on a standard x-ray, they often result in earlier diagnosis and more successful treatment of many diseases. Some CT scans use a contrast agent, sometimes referred to as “dye”, to highlight an organ or area of tissue during the scan. While a CT scan does involve x-rays, the diagnostic benefits generally outweigh the risks of radiation exposure, and it is considered to be a safe examination.
EEG – A brainwave study in which electrodes are applied to the scalp, and the patient is monitored in a quiet environment for approximately 45 minutes. This is a painless procedure and is especially helpful in diagnosing seizures or epilepsy. It also may be ordered in patients with “black out spells” or who have passed out. This procedure is performed in our Frederick office. If the initial EEG is normal, a sleep deprived EEG may be ordered. With this test, the patient will sleep half their normal time the night before in order to increase the likelihood of discovering eleptogenic activity.
EMG – An EMG is useful in determining nerve damage and the muscle’s response to that nerve damage. A small needle is placed in various muscles of the affected limb and in the muscles near but not on the back bone. This test may be uncomfortable but is not terribly painful. If you are worried, please be sure to share your concerns with your doctor.
NCV – Nerve conduction velocity helps to determine damage to nerves; this is a common test for carpal tunnel syndrome. During the test, a small electrical current is applied in various locations along the affected limb. This test may be uncomfortable, but no sustained pain will occur. This is a non-invasive test.