The measurement of daytime sleepiness is important in the evaluation of patients with excessive sleepiness. The multiple sleep latency test (MSLT) is an objective test that measures the tendency to fall asleep under controlled conditions.

The diagnosis of narcolepsy is usually supported by test results from a polysomnogram and the Multiple Sleep Latency Test (MSLT). A polysomnogram helps your physician assess brain activity during sleep, in particular, how frequently and when REM activity is occurring.

Narcolepsy can usually be diagnosed by observing how you sleep and ruling out other conditions. See a GP if you think you have narcolepsy. Before your appointment, you may find it useful to record your symptoms in a diary or complete an Epworth sleepiness questionnaire.

A positive MSLT (diagnostic for narcolepsy) is obtained when the patient did fall asleep with a mean sleep latency below 8 minutes in the naps, and had at least 2 naps where REM sleep was reached.

The onset of narcolepsy can occur anytime between early childhood and 50 years of age. Two peak time periods have been identified; one around 15 years of age and another around 36 years of age. Some researchers believe that narcolepsy is under-diagnosed in children.

The test can also be used to diagnose other disorders that influence brain activity, such as Alzheimer’s disease, certain psychoses, and a sleep disorder called narcolepsy.

multiple sleep latency test
In the multiple sleep latency test (MSLT), a person is given 4-5 opportunities to sleep every two hours during normal wake times. The specialist uses the test to measure the extent of daytime sleepiness (how fast the patient falls asleep in each nap, also called sleep latency), and also how quickly REM sleep begins.

Overview. Polysomnography, also called a sleep study, is a comprehensive test used to diagnose sleep disorders. Polysomnography records your brain waves, the oxygen level in your blood, heart rate and breathing, as well as eye and leg movements during the study.

The price of an MSLT varies from sleep center to sleep center. Hospital-based tests generally cost more than free-standing, non-hospital sleep center tests. The price for an MSLT can range from $600 – $2200.

Narcolepsy is often misdiagnosed as other conditions that can have similar symptoms, including: Depression. Anxiety. Other psychologic/psychiatric disorders.

The sleep specialist will likely be a neurologist, but may also be a pulmonologist, otolaryngologist, or other qualified doctor. As narcolepsy is a sleep disorder, it is best treated by a neurologist who specializes in sleep disorders.

The prognosis for narcolepsy depends upon the level up to which the condition is managed. The patients suffering from this disease have excessive daytime sleepiness thus the person is socially isolated. Prognosis is positive for a person who has managed the symptoms of narcolepsy.

Symptoms of narcolepsy differ among individuals. In some, they are mild and may only cause bothersome sleepiness that is relieved by an occasional nap. In others, symptoms can be severe and impact many aspects of life.

People who suffer from narcolepsy have mixed signals sent from their brain about when to sleep, which is why narcoleptics fall asleep at inopportune times. One may develop narcolepsy at any time, although onset of the first symptom usually occurs after puberty, in late teens to young adulthood.