Sleepiness during the daytime is a common problem.
It generally goes unrecognized until tragedy strikes.
Texas highways are more dangerous because of sleepiness.
During 1992 it was estimated that 35,000 motor vehicle accidents occurred
due to drowsy Texas drivers. Falling asleep while driving alone at night
increases the risk of a fatal crash fivefold. The National Commission on
Sleep Disorders Research reported in 1993 that inappropriate sleepiness
during the day costs the nation over 15 billion in direct expenses and
nearly 70 billion dollars in lost productivity.
The assessment of daytime
sleepiness requires a physician to have a high index of suspicion. Patients
may call it "tiredness" or "fatigue".
Others may not speak of their problems for fear of being labeled as “lazy”.
If national surveys hold true, it would be estimated that 6% of patients
in a typical medical practice would have moderate to severe daytime sleepiness.
To assist physicians in their recognition of daytime
sleepiness, Dr. Murray Johns of Melbourne, Australia designed and validated
the Epworth Sleepiness Scale (ESS)1. It asks a patient to rate
the chance of dozing during various daytime activities. The ESS is easy
to complete and score with the cut-off points listed at the bottom of this
page.
Scoring the Epworth Sleepiness Scale
Patients with scores
of 10 or above would benefit from a thorough review of their sleep pattern
and possible sleep disorders.
Epworth Sleepiness Scale
In contrast to just feeling tired, how likely are you
to doze off or fall asleep in the following situations? (Even if you have
not done some of these things recently, try to work out how they would
have affected you.) Use the following scale to choose the most appropriate
number for each situation:
0 = Would never doze
1 = Slight chance of dozing
2 = Moderate chance of dozing
3 = High chance of dozing
Epworth Sleepiness Scale
| Situation |
Chance
of Dozing |
| Sitting
& Reading |
|
| Watching
TV |
|
| Sitting
inactive in a public place (i.e. theater) |
|
| As a car
passenger for an hour without a break |
|
| Lying down
to rest in the afternoon |
|
| Sitting
& talking to someone |
|
| Sitting
quietly after lunch without alcohol |
|
| In a car,
while stopping for a few minutes in traffic |
|
| Total Score |
|
A score of less than 8 indicates normal sleep
function:
8-10 mild sleepiness
11-15 moderate sleepiness
16-20 severe sleepiness
21-24 excessive sleepiness
1Johns MW. A new method
for measuring daytime sleepiness: The Epworth Sleepiness Scale. Sleep
1991; 14(6):540-5.
NREM Sleep
NREM
sleep consists of four different stages and dominates the first third
of a normal phase. Stage one is short and characterized by half wake-half
sleep cloudiness. Hypnagogic hallucinations and sleep starts (sudden
body jerks) are normal in this stage of sleep. In stage two sleep,
it is easy to awaken and if that occurs the person may feel as though
they were not asleep. If someone is awakened in stage three or four
sleep (sometimes these stages are grouped together as slow wave sleep),
he/she will feel very groggy. These are the stages of sleep where sleep
walking can occur. In contrast with REM sleep, the main purpose for
NREM sleep seems to be restoration of the body.
REM Sleep
REM sleep, rapid
eye movement sleep, is the sleep stage during which dreaming occurs.
This form of sleep occurs about 4 times per night depending on the length
of the sleep time. REM sleep occurs at 90 minute intervals, the first
REM period being the shortest, only a few minutes; and the last being
the longest at around 30 to 60 minutes. The main purpose of REM sleep
seems to be mental restoration and preparation for the next day. Memories
are stored and problems are dealt with through the creation of dreams.
