Huntington’s Disease: Causes, Symptoms and Treatments

Huntington’s Disease is a rare, neurodegenerative disorder that affects about 30,000 people in the United States. According to the Rare Disease Report featured on HCP Live, there are more than 200,000 Americans who are at risk for inheriting this disease, which creates a significant impact upon a person’s cognitive, physical and psychiatric abilities.

What is Huntington’s Disease?

Huntington’s Disease is a type of dementia with a genetic cause that causes damage to specific nerve cells in the brain. Even though people are born with this inherited disease, symptoms don’t often appear until an individual reaches middle age. The condition is named for the doctor who first described this condition in the late 1800s, Dr. George Huntington.

If an individual’s parent has Huntington’s Disease, they have a 50% chance of having it as well. There is currently no known cure for Huntington’s Disease. Instead, individuals must manage its symptoms. Treatments won’t cure the disease, but they can lessen the severity of the symptoms and improve the quality of life for those who have it.

A mutation in a certain gene – the HTT gene – will cause someone to develop Huntington’s Disease. This is a dominant defect. This means that a person who has the mutation in this gene will go on to develop Huntington’s Disease eventually.

More specifically, Huntington’s Disease comes as a result of a defect that creates a repeating CAG triplet series within Chromosome 4. This creates a protein with an abnormally long polyglutamine sequence. While the condition was described by Dr. Huntington, the actual HD gene defect wasn’t identified officially until 1993. The defect causes 40 or more repeats in the sequence, compared to a normal amount between 17 and 20. This leads to excessive numbers of glutamine units within a protein.

Huntington’s Disease Symptoms

In most cases, the symptoms of Huntington’s Disease first appear in individuals when they are between 30 and 50 years old. Symptoms develop gradually and then worsen over the following decades. Eventually, many people who have Huntington’s Disease will develop complications that are worsened by the disease, such as heart failure or pneumonia.

One notable symptom associated with Huntington’s is the inability for sufferers to control their upper body, face, head, legs and arms. Huntington’s Disease symptoms may appear similar to those who have Alzheimer’s, Parkinson’s or ALS. The following symptoms often go along with Huntington’s Disease:

  • Difficulty swallowing, slurred speech, significant weight loss
  • Involuntary movements and an unsteady gait
  • Impaired judgment and forgetfulness
  • Depression, mood swings and personality changes

Symptoms of Huntington’s Disease in Juveniles

While most cases of Huntington’s Disease do not develop until a person is older, when it does appear in younger people or children, symptoms can present differently. These can include the following:

Behavioral Changes:

  • Behavioral problems
  • Significant drop in school performance
  • Having difficulty paying attention in school

Physical Changes:

  • Seizures
  • Clumsiness or frequent falls
  • Slight involuntary movements or tremors
  • Rigid or contracted muscles that impact the gait (particularly in small children)

Diagnosis of Huntington’s Disease

Since the discovery of the HD gene defect in 1993, a test is now available that can confirm the presence of the defective gene and the huntingtin protein, even in people who have no symptoms yet. The test works by counting the number of repeats in a person’s huntingtin protein gene to look for excessive repeats.

Stages and Progression of Huntington’s Disease

There are several stages of Huntington’s Disease that characterize its progression from onset to severe. They are as follows:

Stage 1: Early Stage

This stage begins at onset and may continue for about eight years. During this stage, there has been a Huntington’s Disease diagnosis, but the individual can fully function at work and home. Patients usually remain independent through this stage and remain active. The symptoms associated with the disease at this stage are minor and are usually only mild psychiatric or cognitive changes.

Stage 2: Early Intermediate Stage

This stage of Huntington’s Disease can last between three and 13 years. Patients are still able to function at work and home but at a lower capacity than before. They might experience some difficulty carrying out daily activities, but they can still do so with only slight assistance – or perhaps with no assistance at all. Some patients develop irregular voluntary movements during this stage, which is called chorea.

Stage 3: Late Intermediate Stage

The late intermediate stage of the disease can occur between five and 16 years from the onset of the disease. During this stage, patients are often unable to work and are no longer able to handle household tasks. They will require substantial help with daily living. Their ability to think might also be negatively affected in the late intermediate stage of the disease. Behavioral and psychiatric symptoms like anxiety, irritability and impulsiveness might become more evident. Overall, motor, psychiatric and cognitive abilities begin to decline.

Stage 4: Early Advanced Stage

This stage of the disease can last between nine and 21 years. By this stage, many people with Huntington’s have lost their independence. They may be able to remain living at home, but they require significant help from professionals or family members to aid them in regular daily tasks. It’s during this stage that patients are often moved into an extended care center or assisted living community.

Stage 5: Advanced Stage

Patients in the advanced stage need complete support from professional caregivers for all daily activities. This stage can last between 11 and 26 years. The symptoms of chorea lessen during this stage, but other symptoms emerge, including abnormal limb postures, teeth grinding, stiffness and slowness. In addition, patients are often unable to maintain an upright position, and they may be at risk of falling. A patient’s speech is also significantly affected in this stage, which can cause them to become confused and frustrated. Patients also experience extreme fluctuations in temperature and blood pressure and their ability to swallow decreases further.

Patients diagnosed with Huntington’s Disease often succumb to the disease about 15 to 20 years after the onset of symptoms. The cause of death is not often Huntington’s Disease itself but instead a complication of the disease, like heart failure, infections or pneumonia.

Causes and Risk Factors of Huntington’s Disease

Huntington’s Disease is caused by the inherited mutation in the single gene as outlined above. Therefore, the only risk factor known for the disease is genetic. If a person is found to have the defective gene, they have a 50% chance of passing that gene along to their child. It is this inherited gene defect that causes the disease, though, so there is nothing that can be done to reduce one’s risk for developing this genetic degenerative disease.

Huntington’s Disease Treatments

Unfortunately, there is no known cure for Huntington’s Disease right now, nor can its progression be slowed. However, there are some treatments that can improve the symptoms of the disease. They are:

Involutory Movements: Some experts feel that using atypical antipsychotic drugs, like olanzapine or tetrabenazine, is an effective way to treat the involuntary movements associated with Huntington’s.

Obsessive Thoughts: Experts believe SSRI’s can treat the obsessive-compulsive tendencies associated with this disease.

Irritability: For the threatening and irrational behavior that can come with Huntington’s Disease, experts recommend atypical antipsychotic drugs or an SSRI.

Team Approach to Huntington’s Care

While the above strategies and treatments can work to reduce the symptoms associated with Huntington’s Disease, sufferers primarily need a welcoming place to live with highly skilled medical professionals who are able to ensure their safety and communicate what is going on as they live with this disease. It is also best to approach Huntington’s as a team, with several doctors, nurses, and other professionals working together to ensure a high quality of life for as long as possible.

If your loved one or family member has Huntington’s, you understand the importance of having a skilled, caring team on your side. Our memory and dementia care communities in the Atlanta GA area are here for you and your family member, with daily assistance for activities of daily living, as well as special programming that offers cognitive and social enrichment.

We care for residents with all kinds of dementia, including Huntington’s Disease. To learn more about our community, request our free Guide for Finding the Right Memory Care Community.