||Orthostatic Intolerance and CFS Fact Sheet
Chronic fatigue syndrome
(CFS) is a mysterious
illness marked by
unrelenting exhaustion, muscle pain, cognitive disorders that patients call "brain fog" and a myriad
of other physical symptoms. Orthostatic
intolerance (OI) is the umbrella term for a number of different nervous system-related disorders that
can cause similar symptoms. These two conditions have been associated with one another.
connection between OI and CFS was first explored in 1995 by researchers
Johns Hopkins University, who identified NMH in 96 percent of CFS patients. Since then, scientists have
much more about the broader problem of OI in CFS.
chronic fatigue syndrome (CFS), is characterized by fatigue that is
unexplained, of at least six months' duration, not the result of ongoing exertion, not substantially relieved
by rest, and causes a substantial reduction in previous levels of occupational, educational, social or
This disabling fatigue must be accompanied by four
or more of the
following symptoms: impaired memory or concentration; sore throat; tender neck or armpit lymph nodes;
muscle pain; headaches of a new type, pattern or severity; unrefreshing sleep; post-exertional malaise
lasting more than 24 hours; and multi-joint pain without swelling or redness.
Orthostatic intolerance (OI)
is the umbrella
term for a family of disorders that cause symptoms when a person stands or sits for a prolonged time.
Symptoms of orthostatic intolerance include lightheadedness, dizziness, nausea, fatigue, tremors, breathing
or swallowing difficulties, headache, visual disturbances, sweating, and pallor. The two forms of OI that
have been linked with CFIDS in research studies are:
- Neurally mediated hypotension (NMH), which involves a precipitous
drop in systolic blood pressure (at least 20-25 mm Hg) while standing, plus an increase in symptoms while
- Postural orthostatic tachycardia syndrome (POTS), which causes a
rapid increase in heart rate (pulse) of more than 30 beats per minute (bpm) from baseline, or to more
than 120 bpm total during the first 10 minutes of standing.
THE POTENTIAL CONNECTION
- The causes of CFS and OI are not well understood. Both can start
with sudden onset of a flu-like illness.
- It is now thought that the majority of CFS patients have some
of OI as a co-existing condition.
- A gene for at least one type of OI has been discovered, and it is
not uncommon to find several individuals with CFS and OI in the same family.
- OI seems to be a particular problem in children
and adolescents with CFS.
- Treatment for OI may resolve at least some symptoms for individuals
- CFS is currently a diagnosis by
- Patients are usually diagnosed after they meet the Centers for Disease
Control and Prevention's case definition/diagnostic criteria and a physical exam and laboratory tests
have been done to rule out other possible reasons for symptoms.
- CFS patients with NMH or POTS may not develop heart rate or blood
pressure changes for several minutes after standing. Therefore, brief, routine tests of heart rate and
blood pressure in the usual office visit can miss NMH and POTS.
- Patients with suspected OI typically undergo a head-up tilt table
test (HUT) as an outpatient in a hospital or cardiology office. Patients are strapped to a table that
is slowly tilted upright and their blood pressure and heart rate monitored for a specified period of time
or until OI develops.
of CFS is aimed at relief of symptoms such as sleep disorders, pain and gastrointestinal difficulties.
No single therapy exists to help all patients.
- Drug therapy, physical therapy and lifestyle changes, including
increased rest, reduced stress, dietary restrictions and careful, graduated exercise are often recommended.
- The first line of treatment for OI is non-medical interventions
such as increased water and salt consumption (up to 10-15 g sodium daily), tilting the head of the bed
up a few degrees, wearing compression garments (such as support hose or girdles) and learning to avoid
things that can make OI worse, such as standing in long lines, being in warm environments or eating large,
- Drug therapy may also be used, such as fludrocortisone (Florinef)
to treat low blood volume and vasoconstrictor medications, including methylphenidate (Ritalin), dextroamphetamine
(Dexedrine) and midodrine (ProAmatine) to treat blood pooling. Sometimes drugs to block the release or
effect of epinephrine and norepinephrine are used as well.
THE CFIDS ASSOCIATION
- The CFIDS Association of America is the leading organization dedicated
to conquering CFS and related disorders. Since 1987, the Association has invested nearly $12 million in
CFIDS education, public policy and research efforts.
- The Association publishes the CFIDS
Chronicle, the world's most authoritative and widely read source of information about
CFIDS, the CFS Research
Review , a source of information on diagnosis, treatment and
research for medical professionals.