Huntington's Disease

Huntington's disease (HD) is an inherited disorder that affects the brain. HD causes slow, progressive degeneration of nerve cells in certain areas of the brain. Eventually, HD results in:

• Abnormal body movements
• Gradual deterioration or loss of intellectual abilities ( dementia)
• Behavior problems

HD is caused by a faulty gene on chromosome #4. All people who inherit the faulty gene may eventually develop HD.

Risk Factors

These factors increase your chance of developing HD:

• Family members with HD: Each person whose parent has HD has a 50% chance of inheriting the disorder.
• Age: Onset of symptoms range from 35-50 years old. Juvenile cases occur in people less than 20 years of age.

Symptoms

Symptoms are mild at first and are often barely noticeable but usually worsen over 15-20 years.

Physical symptoms may include:

• Abnormal body movements that worsen over time, including:
  • Sudden jerks or uncontrolled movements of the limbs or trunk
  • Facial grimacing
  • Continuous need to turn head and shift gaze
  • Walking that is unsteady or dance-like
• Difficulty with eating, dressing, sitting, and caring for oneself
• Difficulty swallowing
• Grunting or poor articulation of speech
• Weight loss

Intellectual and emotional symptoms may include:

• Trouble with attention and awareness
• Confusion or disorientation
• Loss of memory
• Loss of judgment
• Loss of ability to think rationally
• Irritability and moodiness
• Depression (common)
• Anxiety
• Social withdrawal or antisocial behavior
• Irresponsible behavior
• Obsessive-compulsive behavior
• Personality changes
• Psychosis—a severe emotional and behavioral disorder that often interferes with a person's ability to relate to others and to function in daily life
• Paranoia—a mental disorder that involves feelings of being watched, followed, or harmed by others
• Hallucinations—the perception of a thing or person that is not present

Ultimately, HD can:

• Cause the loss of the physical and mental ability to care for oneself
• Cause severe disability, making full-time or nursing home care necessary
• Result in death, often due to a fall or pneumonia

Diagnosis

The doctor will ask about your symptoms and medical history (including family medical history). A physical exam will be done. Tests may include:

• CT scan —a type of x-ray that uses a computer to make pictures of the brain
• MRI scan —a test that uses magnetic waves to make pictures of the brain
• PET scan —a test that uses radioactive isotopes (substances that are absorbed by certain areas of the brain) to assess brain function
• Blood tests—to rule out other causes of symptoms

CT Scan of the Head

© 2011 Nucleus Medical Media, Inc.

There is a test that can determine if a person has inherited the gene for HD. This test may help to make the diagnosis of HD. It may also help to determine if a person has inherited the HD gene before symptoms appear. Genetic counseling is recommended before taking this test to review risks and benefits.

Treatment

There is no cure for HD. Treatment aims to help control symptoms.

Medications

Drugs can help control abnormal movements and emotional symptoms of HD. These include:

• Tetrabenazine
• Sedatives or minor tranquilizers, such as benzodiazepines
• Major tranquilizers, like haloperidol or phenothiazine
• Antidepressants

Physical Fitness

Staying physically active helps people with HD to function better and longer. Often physical and occupational therapy may be of some benefit.

Prevention

There is no way to prevent the onset of HD if a person has inherited the gene for the disorder. Medicines aimed at slowing and treating the disease progression are being studied. A prospective parent with HD or a family history of HD can seek genetic counseling when deciding whether or not to have children. Genetic counseling is extremely important since children of parents with HD will have a 50% chance of inheriting the condition.