Overview and Facts about Huntington's Disease
Huntington’s disease is an inherited brain disorder that causes certain brain cells to waste away, resulting in uncontrolled movements, emotional problems, and loss of thinking ability. Adult-onset is the most common form of this disorder, affecting people between the ages of 30 and 50. Huntington’s disease affects an estimated 3 to 7 per 100,000 people, and studies show that people of European ancestry are more likely to develop this disease.
Symptoms of Huntington’s Disease
Huntington’s disease is progressive, meaning symptoms worsen over time. Early symptoms may include uncontrolled movements, clumsiness, and balance problems. As the disease progresses, people may develop impaired coordination, slurred speech, and difficulty feeding and swallowing.
The disease may also cause a decline in thinking and reasoning skills, including memory, concentration, and judgment. Alterations in mood can also occur, especially depression, anxiety, anger, and irritability.
Causes and Risk Factors of Huntington's Disease
Huntington’s disease is caused by a mutation (change) in the HTT gene. The HTT gene provides instructions for making a protein called huntingtin; therefore, alteration of this protein is a key factor in the gradual destruction of neurons (brain cells).
Huntington’s disease is an autosomal dominant disorder, meaning an affected person usually inherits the altered gene from one affected parent; if a parent has the gene, each child has a 50/50 chance of inheriting it.
Tests and Diagnosis of Huntington's Disease
A diagnosis is made by a neurologist — a specialist in neurology (movement disorders) — based on findings from neurological, psychological, and genetic testing.
- Neurological tests: review reflexes, balance, coordination, movement, muscle tone, muscle strength, and walking. Sensory tests evaluate vision and eye movement, hearing, and sense of touch
- Neuropsychological testing: assesses memory, reasoning, language function, and mental agility
- Psychological tests: review mood and mental statuses, such as signs of disordered thinking, emotional state, and quality of judgment
- Imaging tests such as magnetic resonance imaging (MRI) or computed tomography (CT) scans, along with blood tests, may be performed to see if any other diseases may be causing symptoms
- Genetic testing: when Huntington’s disease is suspected, a neurologist may recommend a genetic test to identify the defective gene. In some instances, family members may want to be tested to know if they carry the abnormal gene, even if they’re asymptomatic
Treatment and Care for Huntington's Disease
There is no cure for Huntington’s disease. Certain treatments can help lessen symptoms, but cannot stop the progression of the disease. Assessments by physical, occupational, and speech therapists can help provide insight into the best treatments. Medications are available to help treat movement disorders and psychiatric conditions.
Physical therapy and regular exercise can enhance strength, flexibility, balance, and coordination, while occupational therapy can instruct patients and caregivers on the use of assistive devices to improve daily living and task capabilities.
As the disease progresses, people can become physically dependent on caregivers. It’s estimated that people live with the disease for 15 to 20 years after developing symptoms.