Aside from a carefully taken history and physical examination by a sleep specialist, there are certain diagnostic tests that may be used to diagnose insomnia. Typically, these tests are not necessary as most insomnia can be identified and treated without formal sleep testing. However, in some cases, the following additional tests may be used:
This test is largely regarded as the gold standard for the diagnosis of sleep disorders. It may be used diagnose disorders ranging from sleep apnea to restless legs syndrome to parasomnias, and may also be useful in ruling out other causes of insomnia. It generally is only used if the insomnia does not respond to initial therapy and another cause of the problem is suspected.
- Multiple sleep latency test (MSLT)
Multiple sleep latency tests (MSLT) are also often called nap studies. With a set-up similar to the polysomnogram, the MSLT is used to identify pathological sleepiness. It is not routinely used to evaluate insomnia. Since it identifies excessive daytime sleepiness, the test may be negative in individuals who have difficulty falling asleep, as occurs in insomnia. If the insomnia is especially disruptive of sleep, or if other sleep disorders are thought to be present, the MSLT may be useful.
It may be helpful to track your sleep habits over weeks or even months, and the use of actigraphy to measure your activity levels during the day and night may be helpful. This is accomplished with a small, wristwatch-sized device that monitors movement and records this pattern. This can be helpful in assessing sleep-wake cycles, circadian rhythms, and problems associated with insomnia. In general, actigraphy is not routinely used in the evaluation of insomnia. However, its use with a sleep log may help identify circadian rhythm problems.
In the proper setting, these tests can be helpful in identifying potential causes of insomnia. However, whether the tests are needed should be determined by a sleep specialist after careful review of your history and a focused physical examination.
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