Question: "…My friend suffers from idiopathic hypersomnia.
Please let us know about this condition. "
July 15, 2003
Some Facts on Normal Sleeping Process
Sleep is a dynamic process, during which the brain is very active.
There are recognized stages of sleep, each of which exhibits different
type of brain wave activity. Generally, sleep is divided in five
different stages, that cycle repeatedly during a single night's
rest. The stages are numbered as one, two, three, four and REM (rapid
eye movement) stage. Stages 1 through 4 are known as non-rapid eye
movement sleep (NREM). It is believed that about 50% of our sleeping
time is spent in stage two and about 20% in REM stage. A complete
sleep cycle, usually takes about an hour and a half and an adult
normally sleeps more than 2 hours a night in REM. A complete sleep
cycle, from the beginning of stage 1 to the end of REM usually takes
about an hour and a half. An adult normally sleeps more than 2 hours
a night in REM.
Disorders in General
According to the National Institute of Neurological Disorders and
Stroke, about 40 million Americans suffer each year from some sort
of chronic sleep disorder.
Many different sleep disorders are generally classified into three
· Lack of sleep, or insomnias;
· Disturbed sleep, such as obstructive sleep apnea; and
· Too much sleep, as in narcolepsy. You can read more here
Patients with primary hypersomnia usually present with complaints
of long but non-refreshing sleep over nighttime, difficulty awakening
(referred to as sleep drunkenness), daytime sleepiness
and intellectual dysfunction. Some often report frequent headaches
and Raynaud's phenomena. Previously called non-REM narcolepsy, this
relatively rare disorder is represented by up to 10% of patients
reportedly suffering from hypersomnia.
The diagnosis is based on
polysomnographic test findings of hypersomnia, as subjective complaints
of excessive sleepiness are not sufficient for diagnostic purposes.
In some cases family history of excessive sleepiness may be present.
The diagnosis of primary hypersomnia includes presence of recurrent
forms of excessive sleepiness of at least 3 days' duration occurring
several times a year for at least 2 years. One known syndrome among
the recurrent or intermittent hypersomnia disorders is the Kleine-Levin
syndrome, mainly seen in adolescent boys; another is the menstrual
cycle-associated hypersomnia syndrome. In addition to hypersomnia,
patients with Kleine-Levin syndrome are known to often demonstrate
aggressive or inappropriate sexuality, compulsive overeating, and
other somewhat bizarre behaviors. The rare nature of this syndrome
and its behaviors may be mistaken for psychosis, malingering, or
a personality disorder. It is worth noticing that the frequency
and importance of hypersomnia and daytime sleepiness in otherwise
healthy individuals have been increasingly recognized (ref.
This disorder is considered to be a neurological
disorder in which nocturnal sleep is prolonged but not refreshing.
Daytime naps may be long and unsatisfactory. Patients may sleep
for periods of up to 20 hours a day. PSG or Polysomnography Test shows a relatively normal
sleep pattern. The PSG is an all-night sleep study. The multiple
sleep latency test (MSLT) demonstrates pathological sleepiness,
but REM sleep does not occur during the two or more naps. Hypersomnia
may also be secondary to medical conditions such as viral infections,
especially mononucleosis and encephalitis, or hydrocephalus. It
is usually necessary to obtain a PSG in order to distinguish among
the disorders leading to EDS.
Many conditions can cause excessive sleepiness; therefore, sleep studies are generally required for accurate diagnosis.
One of these studies, the Nocturnal Polysomnography
can determine the presence and severity of sleep disorders such
as sleep apnea, periodic limb movements, and nocturnal sleep disturbance.
Another test called Multiple Sleep Latency Test (MSLT), usually
performed the following day, provides a measure of the severity
of sleepiness and an indication of the presence or absence of early
onset of Rapid Eye Movement(REM) sleep. In narcolepsy, the presence
of two or more sleep-onset REM periods during the four to five nap
periods is sufficient for diagnostic purposes. However, this finding
is not specific. Other causes of early-onset REM sleep may include
circadian rhythm disturbances, REM sleep deprivation, sleep disturbance
from sleep apnea or other disorders, and drug or alcohol withdrawal.
Some patients with brain pathology in areas concerned
with sleep regulation also may have early onset of REM sleep.
of Sleeping Disorders
Medications and behavioral measures are designed
to enhance alertness during critical times of the day such as at
work, during school, and while driving. Medical doctors also emphasize
the importance of good sleep and the risks associated with
sleepiness while driving. Naps during lunch or other breaks are
often helpful. Stimulants such as methylphenidate, dextroamphetamine,
and pemoline improve alertness in most narcoleptics. It is recommended
that stimulants be initiated at low doses and increased gradually
until symptoms are controlled or side effects appear. In general,
the lowest effective dose should be used, but some patients may
not recognize the severity of their sleepiness and reports from
family members should also be obtained to assess the effectiveness
of treatment. It is also widely believed that the risk for amphetamine
abuse is no higher among narcoleptics than in other population groups.
Your doctor should help you exclude known conditions
that are related to sleep disorders.
Appropriate treatment might include some changes in your lifestyle,
physical and social activities in addition to any medication that
you may have to take.