What Is Huntington’s Disease?
Huntington’s disease is a hereditary condition in which your brain’s nerve cells gradually break down. This affects your physical movements, emotions, and cognitive abilities. There is no cure, but there are ways to cope with this disease and its symptoms.
Huntington’s disease is much more common in people with European ancestry, affecting about three to seven out of every 100,000 people of European descent.
There are two types of Huntington’s disease: adult onset and early onset.
Adult onset is the most common type of Huntington’s disease. Symptoms usually begin when people are in their 30s or 40s. Initial signs often include:
- minor involuntary movements
- poor coordination
- difficulty understanding new information
- trouble making decisions
Symptoms that may occur as the disease progresses include:
- uncontrolled twitching movements, called chorea
- difficulty walking
- trouble swallowing and speaking
- memory loss
- personality changes
- speech changes
- decline in cognitive abilities
This type of Huntington’s disease is less common. Symptoms usually start to appear in childhood or adolescence. Early-onset Huntington’s disease causes mental, emotional, and physical changes, such as:
- slurred speech
- slow movements
- frequent falling
- rigid muscles
- sudden decline in school performance
A defect in a single gene causes Huntington’s disease. It’s considered an autosomal dominant disorder. This means that one copy of the abnormal gene is enough to cause the disease. If one of your parents has this genetic defect, you have a 50 percent chance of inheriting it. You can also pass it on to your children.
The genetic mutation responsible for Huntington’s disease is different from many other mutations. There isn’t a substitution or a missing section in the gene. Instead, there is a copying error. An area within the gene is copied too many times. The number of repeated copies tends to increase with each generation.
In general, symptoms of Huntington’s disease show up earlier in people with a larger number of repeats. The disease also progresses faster as more repeats build up.
Family history plays a major role in the diagnosis of Huntington’s disease. However, a variety of clinical and laboratory testing can be done to assist in diagnosing the problem.
A neurologist will do tests to check your:
- muscle tone
- sense of touch
Brain Function and Imaging Tests
If you’ve had seizures, you may need an electroencephalogram (EEG). This test measures the electrical activity in your brain.
Brain-imaging tests can also be used to detect physical changes in your brain.
- Magnetic resonance imaging (MRI) scans use magnetic fields to record brain images with a high level of detail.
- Computed tomography (CT) scans combine several X-rays to produce a cross-sectional image of your brain.
Your doctor might ask you to undergo a psychiatric evaluation. This evaluation checks your coping skills, emotional state, and behavioral patterns. A psychiatrist will also look for signs of impaired thinking.
You may be tested for substance abuse to see if drugs might explain your symptoms.
If you have several symptoms associated with Huntington’s disease, your doctor might recommend genetic testing. A genetic test can definitively diagnose this condition.
Genetic testing may also help you decide whether or not to have children. Some people with Huntington’s do not want to risk passing the defective gene to the next generation.
Medications can provide relief from some of your physical and psychiatric symptoms. The types and amounts of drugs needed will change as your condition progresses.
- Involuntary movements may be treated with tetrabenazine and antipsychotic drugs.
- Muscle rigidity and involuntary muscle contractions can be treated with diazepam.
- Depression and other psychiatric symptoms can be treated with antidepressants and mood-stabilizing drugs.
Physical therapy can help improve your coordination, balance, and flexibility. With this training, your mobility is improved, and falls may be prevented.
Occupational therapy can be used to evaluate your daily activities and recommend devices that help with:
- eating and drinking
- getting dressed
Speech therapy may be able to help you speak clearly. If you can’t speak, you will be taught other types of communication. Speech therapists can also help with swallowing and eating problems.
Psychotherapy can help you work through emotional and mental problems. It can also help you develop coping skills.
There is no way to stop this disease from progressing. The rate of progression differs for each person and depends on the number of genetic repeats present in your genes. A lower number usually means that the disease will progress more slowly.
People with the adult-onset form of Huntington’s disease usually live for 15 to 20 years after symptoms begin to appear. The early-onset form generally progresses at a faster rate. People may live for only 10 to 15 years after the onset of symptoms.
Causes of death among people with Huntington’s disease include:
- infections, such as pneumonia
- injuries from falling
- complications from being unable to swallow
If you’re having trouble coping with your condition, consider joining a support group. It can help to meet other people with Huntington’s disease and share your concerns.
If you need help performing daily tasks or getting around, contact the health and social services agencies in your area. They might be able to set up daytime care.
Ask your doctor for advice on the type of care you might begin to need as your condition progresses. You might have to move into an assisted living facility or set up in-home nursing care.