What is Huntington’s disease?
Huntington’s disease is an inherited brain disorder. A defective gene causes nerve cells in the brain to degenerate or break down. The disease usually strikes during middle age and gets progressively worse over time. It gets its name from the doctor who first described the condition in the late 1800s. Currently, there is no cure for the disease and it eventually becomes fatal.
Huntington’s disease causes broad effects in the brain. Problems develop with movement, thinking, reasoning and mood. The combination of symptoms in these areas overlap with three other degenerative diseases—ALS (amyotrophic lateral sclerosis), Parkinson’s disease, and Alzheimer’s disease.
There is only one risk factor for Huntington’s disease. It is a faulty gene that parents pass to their children. If you have the defective gene, you will eventually develop the condition.
Treatment can’t reverse or slow the progression of Huntington’s disease. Instead, Huntington’s disease treatment focuses on managing symptoms with medications. Physical, occupational and other types of therapy may also be part of a comprehensive treatment plan. This approach can help people overcome limits to their abilities for some time.
Seek prompt medical attention if you notice any changes in motor or cognitive skills or mental or emotional problems. Huntington’s disease symptoms are similar to a variety of other, more common conditions. Only a thorough diagnostic process can identify the true cause of your symptoms.
What are the symptoms of Huntington’s disease?
Huntington’s disease symptoms fall into three main categories—cognitive, movement and psychiatric. Symptoms usually begin between the ages of 30 and 50. The symptoms that appear first vary from person to person. However, the disease is always progressive.
Cognitive symptoms of Huntington’s disease
Common cognitive symptoms of Huntington’s disease are:
Difficulty concentrating, planning or organizing
Forgetfulness or slowness processing thoughts
Problems learning new information or making decisions
Movement symptoms of Huntington’s disease
Common movement symptoms of Huntington’s disease are:
Abnormal eye movements
Rigid muscles and uncontrolled movements of the head, face, arms, legs or upper body; these involuntary movements are known as chorea
Unsteady gait and problems with posture and balance
Psychiatric symptoms of Huntington’s disease
Common psychiatric symptoms of Huntington’s disease are:
Social withdrawal, sleep problems, fatigue, and suicidal thoughts
It is possible for symptoms to occur in children and teenagers. This is juvenile-onset Huntington’s disease. The symptoms are somewhat different in this age group and will progress faster than in adults.
Common symptoms of juvenile-onset Huntington’s disease
Common symptoms of juvenile-onset Huntington’s disease are:
Loss of academic skills and declining cognitive function
Problems with school performance and behavior problems
Tremors, problems with fine motor skills, clumsiness, and gait changes
Various other conditions can also be responsible for these symptoms. Seeing your doctor is the only way to know for sure what is causing them. If Huntington’s disease runs in your family, talk with your doctor about genetic testing. Knowing whether or not you have the faulty gene can help you plan your medical care.
What causes Huntington’s disease?
A single defective gene causes Huntington’s disease. The gene is located on chromosome 4—one of the 23 human chromosomes. Everyone has this gene. However, in Huntington’s disease, one section of the gene repeats itself too many times. Scientists call this an expanded sequence. In essence, the section is longer than it should be. This means the protein the gene is responsible for making also ends up being too long. Scientists do not fully understand the function of this protein. But they know the expanded sequence somehow makes the protein toxic to the brain’s nerve cells.
What are the risk factors for Huntington’s disease?
The only risk factor for developing Huntington’s disease is having a parent with the faulty gene. The gene is dominant. This means if you inherit the gene you will get the disease.
You inherit one copy of every gene—except sex genes—from each parent. The two copies can be the same or they can be different. If both parents have two healthy copies of the gene, you will not get Huntington’s disease. However, if one parent has a faulty copy and a healthy copy, you have a 50/50 chance of inheriting the faulty gene and developing the disease.
Reducing your risk of Huntington’s disease
Currently, there is no way of preventing Huntington’s disease. However, genetic testing can give you some control over your healthcare. If you have a parent with Huntington’s disease, talk with your doctor about genetic testing. If you have the gene, you can make decisions about your future care before symptoms begin to rob you of your capacities. It can also help you decide whether or not you want to have biological children or not. Of course, it can also give you peace of mind if the results come back negative.
Because these issues are very complex, it is vital to work with a genetic counselor. This healthcare provider can help you understand the implications of testing and guide you through the process.
How is Huntington’s disease treated?
Medications are the main treatment for Huntington’s disease. While they can’t alter the course of the disease, they can help manage the symptoms. Depending on your symptoms, your doctor may recommend the following:
Antidepressants, especially the SSRIs (selective serotonin reuptake inhibitors)
Antipsychotics, which can help both psychiatric and movement problems
Antiseizure drugs, which can also act as mood stabilizers
Tetrabenazine (Xenazine), which has FDA (U.S. Food and Drug Administration) approval to treat Huntington’s chorea
Other medications, such as amantadine and clonazepam (Klonopin)
These medications require close monitoring from your doctor. While they can benefit some symptoms, the same drugs can also worsen other symptoms. Sometimes, there is a fine line between helping and hurting the disease. Your doctor may need to make several adjustments as the disease progresses.
Your doctor may also recommend various forms of therapy to manage symptoms. This may include physical and occupational therapy, speech and swallowing therapy, and cognitive behavioral therapy. Social service providers can also help create optimal home, school or work environments and provide access to support services.
What are the potential complications of Huntington’s disease?
A Huntington’s disease prognosis is ultimately fatal. However, the rate of disease progression varies from person to person. In general, people with the disease survive anywhere from 10 to 30 years after diagnosis. The juvenile form of the disease tends to progress faster.
As the disease progresses, people lose the ability to care for themselves and communicate. They also lose awareness of people and their surroundings. Eventually, the disease weakens them to the point where body functions are affected. Common causes of death include pneumonia, heart failure, injuries from falls, and complications from not being able to swallow. A dedicated caregiver is essential for a person in the later stages of Huntington’s to live safely. Both the person with Huntington’s and the caregiver(s) need a network of friends and family to lend support.
Because Huntington’s disease is always fatal, people with the disease need to plan for end-of-life care. This includes choosing care facilities or hospice care for the later stages of the disease. Several types of legal documents can help people express their wishes while they are still functional. Talk with your doctor about living wills and advanced directives to ensure your wishes are honored.