A look into the most common causes of death in people with Huntington's disease.
Huntington's Disease (HD) is not fatal in
itself. People with HD have a shorter life expectancy and die of other
life-threatening complications related to this disease. Pneumonia and heart
disease are the two leading causes of death for people with
HD. Additionally, HD patients have higher incidence of choking and
respiratory complications, gastrointestinal diseases (such as cancer of
the pancreas), and suicide than the non-HD population. Why are HD patients more prone to the above complications than the rest of the population? This chapter aims to answer that question and draw connections between the symptoms of HD and the most common causes of death (see the table below). Although researchers have not explicitly proven these links in every case, the following information hopes to demonstrate a logical connection.
Primary cause of death (in rank order)
Persons (total=182)
Percentage
Pneumonia Other respiratory diseases
93 5
51.1 2.7
Myocardial infarction/degeneration (heart attack
Congestive cardiac failure (heart failure)
coronary disease
Other diseases of the cardiovascular system
5 18 11 2
2.7} 9.9} 6.0}19.7 1.1}
Unspecified Huntington's-related causes
23
12.6
Vascular lesions of central nervous system
10
5.5
Non-vascular lesions of central nervous system (e.g. meningitis)
4
2.2
Genito-urinary diseases (e.g. kidney failure)
5
2.7
Gastro-intestinal diseases (cancer of the pancreas)
3
1.6
Suicide
3
1.6
Reed TE, Chandler JH, Hughes EM, et al. Huntington's chorea in Michigan: I. Demography and Genetics. Am J Hum Gen 1958; 10: 201-225.
One of the chief symptoms of HD is the inability to
produce coordinated movements. In the latter stages of the disease, this
problem becomes more pronounced to the point that people have difficulty
swallowing. Although it is so common that we hardly think about it,
swallowing is actually a complex series of movements by muscles in our
throat to ensure passage of food into the esophagus (gastrointestinal
tract) rather than the trachea (respiratory tract). As a result of these
movements, the epiglottis, a flap that acts as a valve in our throat,
prevents food from entering the airway. People with HD often lack this
coordination, and food will accidentally enter the respiratory tract,
leading to choking. Moreover, when food particles manage to get into the
trachea (the "wind pipe" leading to the lungs), instead of the esophagus
(the "food pipe" leading to the stomach), the lungs can become infected
and cause what is known as aspiration pneumonia.
Although pneumonia is relatively common among people in the
general population, it is only fatal in about 5% of these cases. However, pneumonia
is much more dangerous in people with compromised immune
systems. Researchers have demonstrated that stresses imposed on a person
for prolonged periods of time can severely damage the body's ability to ward
off diseases. The physical, cognitive, and psychiatric symptoms of HD add a
great deal of stress to everyday life for these patients (for more information
on these symptoms, click here).
As a result, their immune systems are compromised and diseases such as pneumonia
are therefore more likely to result in death. For instance, in a long-term study
conducted from 1952 until 1979 in Victoria, Australia, researchers found that
more than 51% of patients with HD died from pneumonia.
The increased physical and emotional stress associated
with HD can cause other problems as well. Chronic stress has been linked
to high blood pressure, increased risks for heart attacks, and tumor
growth. In addition, although studies have shown that suicide is not a
leading cause of death for HD patients, suicide rates are higher than
among the rest of the population. This is probably due to a combination of
factors, including neuropsychiatric changes induced by HD and the added
stress of daily life.
Although researchers have yet to find a cure for the
disease, people with HD can take measures to prolong their
lives. For example, extra care should be taken when eating to
prevent choking and pneumonia caused by food going the wrong
way. Regular exercise and sleeping in an elevated position can
reduce the risk of respiratory infections. Patients can also
maintain a healthy diet and reduce or eliminate other risk factors
for heart disease, such as smoking and alcohol, from their lives.
Last Modified: 2-15-04
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