Huntington's disease causes nerve cells in the brain to decay over time. The disease affects a person's movements, thinking ability and mental health.
Huntington's disease is rare. It's often passed down through a changed gene from a parent.
Huntington's disease symptoms can develop at any time, but they often begin when people are in their 30s or 40s. If the disease develops before age 20, it's called juvenile Huntington's disease. When Huntington's develops early, symptoms can be different and the disease may have a faster progression.
Medicines are available to help manage the symptoms of Huntington's disease. However, treatments can't prevent the physical, mental and behavioral decline caused by the disease.
Huntington's disease usually causes movement disorders. It also causes mental health conditions and trouble with thinking and planning. These conditions can cause a wide spectrum of symptoms. The first symptoms vary greatly from person to person. Some symptoms appear to be worse or have a greater effect on functional ability. These symptoms may change in severity throughout the course of the disease.
The movement disorders related to Huntington's disease may cause movements that can't be controlled, called chorea. Chorea are involuntary movements affecting all the muscles of the body, specifically the arms and legs, the face and the tongue. They also can affect the ability to make voluntary movements. Symptoms may include:
People with Huntington's disease also may not be able to control voluntary movements. This can have a greater impact than the involuntary movements caused by the disease. Having trouble with voluntary movements can affect a person's ability to work, perform daily activities, communicate and remain independent.
Huntington's disease often causes trouble with cognitive skills. These symptoms may include:
The most common mental health condition associated with Huntington's disease is depression. This isn't simply a reaction to receiving a diagnosis of Huntington's disease. Instead, depression appears to occur because of damage to the brain and changes in brain function. Symptoms may include:
Other common mental health conditions include:
Weight loss also is common in people with Huntington's disease, especially as the disease gets worse.
In younger people, Huntington's disease begins and progresses slightly differently than it does in adults. Symptoms that may appear early in the course of the disease include:
See your healthcare professional if you notice changes in your movements, emotional state or mental ability. The symptoms of Huntington's disease also can be caused by a number of different conditions. Therefore, it's important to get a prompt and thorough diagnosis.
Huntington's disease is caused by a difference in a single gene that's passed down from a parent. Huntington's disease follows an autosomal dominant inheritance pattern. This means that a person needs only one copy of the nontypical gene to develop the disorder.
With the exception of genes on the sex chromosomes, a person inherits two copies of every gene — one copy from each parent. A parent with a nontypical gene could pass along the nontypical copy of the gene or the healthy copy. Each child in the family, therefore, has a 50 percent chance of inheriting the gene that causes the genetic condition.
People who have a parent with Huntington's disease are at risk of having the disease themselves. Children of a parent with Huntington's have a 50 percent chance of having the gene change that causes Huntington's.
After Huntington's disease starts, a person's ability to function gradually gets worse over time. How quickly the disease gets worse and how long it takes varies. The time from the first symptoms to death is often about 10 to 30 years. Juvenile Huntington's disease usually results in death within 10 to 15 years after symptoms develop.
The depression linked with Huntington's disease may increase the risk of suicide. Some research suggests that risk of suicide is greater before a diagnosis and also when a person loses independence.
Eventually, a person with Huntington's disease requires help with all activities of daily living and care. Late in the disease, the person will likely be confined to a bed and unable to speak. Someone with Huntington's disease is generally able to understand language and has an awareness of family and friends, though some won't recognize family members.
Common causes of death include:
People with a known family history of Huntington's disease may be concerned about whether they may pass the Huntington gene on to their children. They might consider genetic testing and family planning options.
If an at-risk parent is considering genetic testing, it can be helpful to meet with a genetic counselor. A genetic counselor explains the potential risks of a positive test result, which may mean that the parent may develop the disease. Also, couples may need to make additional choices about whether to have children or to consider alternatives. They may decide to choose prenatal testing for the gene or in vitro fertilization with donor sperm or eggs.
Another option for couples is in vitro fertilization and preimplantation genetic diagnosis. In this process, eggs are removed from the ovaries and fertilized with the father's sperm in a laboratory. The embryos are tested for the presence of the Huntington gene. Only those testing negative for the Huntington gene are implanted in the mother's uterus.
A preliminary diagnosis of Huntington's disease is based on your answers to questions, a general physical exam and your family medical history. Neurological tests and an evaluation of your mental health also is done.
A neurologist asks you questions and conducts relatively simple tests of your:
The neurologist also may perform standardized tests to check your:
If needed, more thorough neuropsychological testing may be done by licensed psychologists.
You'll likely be referred to a psychiatrist who can look for a number of factors that could contribute to your diagnosis, including:
Brain-imaging tests can provide information on the structure or function of the brain. These tests may include MRI or CT scans that show detailed images of the brain.
These images may reveal changes in the brain in areas affected by Huntington's disease. These changes may not show up early in the course of the disease. These tests also can be used to rule out other conditions that may be causing symptoms.
If symptoms strongly suggest Huntington's disease, members of your healthcare team may recommend a genetic test for the nontypical gene.
This test can confirm the diagnosis. The test also may help if there's no known family history of Huntington's disease or if no other family member's diagnosis was confirmed with a genetic test. But the test won't provide information that might help determine a treatment plan.
Before having such a test, the genetic counselor explains the benefits and drawbacks of learning test results. The genetic counselor also can answer questions about the inheritance patterns of Huntington's disease.
A genetic test can be given if you have a family history of the disease but don't have symptoms. This is called predictive testing. The test can't tell you when the disease will begin or what symptoms will appear first.
Some people may have the test because they find not knowing to be more stressful. Others may want to take the test before having children.
Risks may include problems with insurability or future employment and the stresses of facing a fatal disease. In principle, federal laws exist that make it illegal to use genetic testing information to discriminate against people with genetic diseases.
These tests are only performed after consultation with a genetic counselor.
No treatments can alter the course of Huntington's disease. But medicines can lessen some symptoms of movement and mental health conditions. And multiple interventions can help a person adapt to changes in abilities for a certain amount of time.
The medicines you take may change over the course of the disease, depending on your overall treatment goals. Also, medicines that treat some symptoms may result in side effects that worsen other symptoms. Treatment goals are regularly reviewed and updated.
Medicines to treat movement disorders include:
Medicines to treat mental health vary depending on the conditions and symptoms. Possible treatments include:
A psychotherapist — a psychiatrist, psychologist or clinical social worker — can provide talk therapy to help with behavioral symptoms. The psychotherapist can help you and your family develop coping strategies, manage expectations as the disease gets worse and help family members communicate.
Huntington's disease can affect the control of muscles of the mouth and throat that are essential for speech, eating and swallowing. A speech therapist can help improve your ability to speak clearly or teach you to use communication devices. A communication device might be as simple as a board covered with pictures of everyday items and activities. Speech therapists also can address trouble with eating and swallowing.
A physical therapist can teach you proper and safe exercises that enhance strength, flexibility, balance and coordination. These exercises can help maintain mobility as long as possible and may reduce the risk of falls.
Instruction on posture and the use of supports to improve posture may help lessen some movement symptoms.
When you need a walker or wheelchair, the physical therapist can advise on the proper use of the device and posture. Also, exercises can be adapted for your level of mobility.
An occupational therapist can assist you, your family members and caregivers on how to use assistive devices to improve function. These strategies may include:
Managing Huntington's disease affects the person with the disease, family members and other in-home caregivers. As the disease gets worse, the person becomes more dependent on caregivers. Several issues need to be addressed, and the ways to cope with them changes over time.
Factors regarding eating and nutrition include the following:
Eventually, a person with Huntington's disease needs help with eating and drinking.
Family and caregivers can help create an environment that may help a person with Huntington's disease avoid things that cause stress. This can help manage cognitive and behavioral symptoms. These strategies include:
A number of strategies may help people with Huntington's disease and their families cope.
Support services for people with Huntington's disease and families include the following:
Huntington's disease causes a loss of function and eventually death. It's important to plan for care that will be needed in the advanced stages of the disease and near the end of life. Early discussions about care allow the person with Huntington's disease to be engaged and to share what they want from their care.
Creating legal documents that define end-of-life care can be helpful to everyone. They empower the person with the disease, and they may prevent conflict among family members as the disease gets worse. Members of your healthcare team can offer advice on the pluses and minuses of care options.
Matters that may need to be addressed include:
If you have any symptoms of Huntington's disease, you'll likely be referred to a neurologist after a visit to your healthcare professional.
A review of your symptoms, mental state, medical history and family medical history can all be important when assessing a potential neurological disorder.
Before your appointment, make a list that includes the following:
You may want a family member or friend to come with you to your appointment. This person can provide support and offer a different perspective on the effect of symptoms on your functional abilities.
You're likely to be asked a number of questions, including the following: