Excessive Daytime Sleepiness (EDS)

Excessive daytime sleepiness is a very real problem experienced by millions and not made up like many argue. EDS is a symptom of most sleep disorders (including sleep apnea, insomnia, and circadian disorders) and is detrimental to a sufferers quality of life.

This condition has been around since the Stone Age, as it is a normal happening of human life and the “real world”. The condition has been recently accepted as medical condition and many still do not understand the seriousness of the problem.

Diagnosis

Yes the term “excessive” is subjective, just like much else in medicine that our doctors are called upon to diagnose. However, there are some tests, not blood or urine, but behavioral tests that are used to determine levels of sleepiness.

The Johns Scale of Drowsiness, the Epworth Sleep Scale, the Maintenance of Wakefulness Test, the Stanford Sleepiness Scale – all these are used in diagnosis of sleep disorders. The psychomotor vigilance test is useful for quantifying impairment due to EDS. There is no set number for what constitutes “excessive” sleepiness on any of these tests.

Some medical practitioners use a pupillography sleepiness test. Doctors use them in conjunction with other indicators. A medical history is useful in diagnosing EDS too. Some patients with EDS may complain about being tired all the time or fatigued, rather than sleepy and be reluctant to admit they are sleepy at all, seeing it as a sign of laziness or a moral failing. 

Causes

Insomnia can result in excessive daytime sleepiness, as can many neurological conditions and illnesses. Traumatic brain injuries (which include strokes), narcolepsy, poisoning, Parkinson’s, Alzheimer’s, and other forms of dementia and general cognitive decline can result in excessive daytime sleepiness. Type 2 diabetics and people with apnea, depression, and asthmas tend to have greater incidence of EDS.

A recent study found 47% of TBI patients had EDS and TBI patients are at high risk of developing sleep disorders. Medicines can also cause EDS – the warning labels of many mention risk of drowsiness. There are so many causes of sleepiness that some estimate that as much as 20% of the population suffers from excessive daytime sleepiness. 

Adenosine, a neurotransmitter in the brain, drops as you wake, building up over the day. The hypothalamus part of the brain is rich in neurons that produce adenosine and is part of the homeostatic sleep process, producing equilibrium in the brain. These cells project into other parts of the brain as well as the cortex.

Effects of Excessive Daytime Sleepiness (EDS)

People with EDS are more likely to have automobile accidents or accidents on the job. They struggle to maintain concentration and are less productive and irritable. Excessive daytime sleepiness is the key problem behind drowsy driving and tests have found it can impair motor skills worse than alcohol intoxication.

EDS makes it difficult to deal with life challenges. It reduces motivation and also negatively impacts body’s immunity. 

As with insomnia, EDS is often overlooked by doctors or misinterpreted. Patients might complain about being tired which is not the same as being sleepy. Note that fatigue is not the same as sleepiness. You can get fatigued after exercise of the body, but not necessarily drowsy. Fatigue manifests as a lack of motivation and energy while sleepiness is a physiological state which causes the need to sleep. 

Treatment

The first thing to try in hopes of EDS disappearing is good regular sleep. Sleep hygiene is important and medicines may be needed as well to ensure sufficient sleep. If these remedies do not work then, as a last resort, stimulants may be prescribed by some doctors to make the daytime sleepiness go away.

Which stimulants? The amphetamine Dextroamphetamine and the ADHD medication Methylphenidate (Ritalin) are sometimes prescribed. However, in recent years, Modafinil is becoming the go-to stimulant for EDS because of its low side effects. Sodium oxybate (GABA) can be used but only in some severe cases.

Caffeine can also be used. Caffeine works and doesn’t have a placebo effect. It has been found in repeated controlled studies that caffeine reduces the propensity for sleep and improves performance on vigilance tests. Also, when the subject stops taking caffeine for a day these effects disappear.

The Mysteries of Sleepiness

The detailed biological causes of sleepiness are unknown. Does sleepiness reflect a failure of the brain’s process in maintaining wakefulness or is it a separate process that fights wakefulness and takes over the brain? Scientists are unraveling the neurological substrates of sleepiness, such as the discovery of the orexin system, but much remains unknown.

Naps combat EDS and are a remedy in many situations. Naps can be a good idea even for people who don’t have formal EDS to increase mental performance in the afternoons. (Click here and find a mattress that will help you get better naps.)

Note also that the body has rhythms and it is common to have a “dip” in the early afternoon. This normal afternoon sleepiness does not count as excessive daytime sleepiness in a clinical sense.

Some people with EDS experience sleepiness in short spurts of heavy sleepiness or lack of concentration. Some may even fall asleep unintentionally during the day. Unplanned sleep periods could be very short (microsleeps) or turn into naps.