Huntington´s Disease (HD) is a rare, hereditary, neurodegenerative illness that affects people of all races worldwide. The disease was named after Dr. George Huntington, a physician from Long Island, United States of America, who first published a description of “hereditary chorea” in 1872. It was due to his essay, entitled On Chorea, that the disorder became known as Huntington´s Chorea. The term chorea is the Greek word for “dance” and refers to the involuntary movements which are seen in many individuals with HD. Since Chorea is not the only symptom, the disorder has in later years been called Huntington´s Disease.
For a long time, little was known or published about HD. In the last 30 years, however, we have learnt a lot about the cause of HD and its effects, as well as the therapies and techniques for managing its symptoms. The gene that causes HD was discovered in 1993 and since then important scientific advances have been made. To date, there are no drugs to slow or stop the progression of Huntington’s Disease, but scientists are getting closer each day to finding a disease modifying treatment.
HD causes gradual degeneration of brain cells which in turn can result in physical, cognitive and emotional symptoms, which typically become apparent between the ages of 35 and 55, but can also appear much earlier (Juvenile-Onset HD) or later (late onset HD).
In most cases, individuals affected by HD can maintain their independence for several years after the first symptoms appear. A knowledgeable physician can prescribe treatment to minimize the impact. Allied health professionals, such as social workers, occupational and physical therapists, speech therapists and nutritionists, can all play a useful role in maximizing abilities and prolonging independence.
Huntington´s Disease is a hereditary disorder. Each child of a parent who has HD has a 50% chance of inheriting it. HD occurs in all races. Males and females are equally at risk. Carriers of the HD gene will eventually develop the disease should they live long enough.
Globally, there is estimated to be between 3.6 and 5.7 people with HD for every 100,000 of population.
HD symptoms can vary significantly from person to person, even among siblings. Symptoms don’t appear in any specific order. Over the course of the disease, some symptoms may be more dominant than others. For some, involuntary movements may be more dominant, even in the early stages, while for others emotional and behavioural disturbances are more worrying, and often go undiagnosed.
Slight intellectual changes are often the first signs of cognitive disturbance. These can lead to the reduced ability to cope with new situations or perform routine tasks. Below are the most common cognitive HD symptoms:
- Difficulty organizing, prioritizing or focusing on tasks
- Lack of flexibility or the tendency to get stuck on a thought, behaviour or action
- Lack of impulse control that can result in outbursts, acting without thinking and sexual promiscuity
- Lack of awareness of one’s own behaviours and abilities
- Slowness in processing thoughts or finding words
- Difficulty in learning new information
Physical symptoms can include involuntary movements and the impairment of voluntary movements. Involuntary movements typically progress through the middle stages of HD but decline as rigidity increases in the later stages. Listed below are some of the symptoms:
- Involuntary jerking or writhing movements (chorea)
- Muscle problems, such as rigidity or muscle contracture
- Slow or abnormal eye movements
- Impaired gait, posture and balance
- Difficulty with the physical production of speech or swallowing
According to the Mayo Clinic, impairment in voluntary movements — rather than the involuntary movements — may have a greater impact on a person’s ability to work, perform daily activities, communicate and remain independent. In addition to the above symptoms, weight loss is common in people with Huntington’s Disease, especially as the disease progresses.
The most common emotional/psychological disturbance associated with HD is depression. Some people can experience depression for months or even years before it is recognised as an early symptom of HD. Listed below are some of the other emotional symptoms:
- Feelings of irritability, sadness or apathy
- Social withdrawal
- Fatigue and loss of energy
- Frequent thoughts of death, dying or suicide
According to Dr. Ira Shoulson, the progress of HD can be divided into five stages that are flexible after diagnosis:
The person is diagnosed as having HD and can function fully both at home and work.
People with HD usually die about 15 to 20 years after their symptoms first appear. The cause of death is not the disease itself but complications such as pneumonia, heart failure or infection developing from the body’s weakened condition.
HD and the Family
HD impacts the entire family. As it progresses, the role of the patient gradually changes. The partner/spouse often has to assume more and more responsibility for housekeeping, decision-making and parenting and often assumes the role of primary care giver as well. It takes a physical, emotional and financial toll.
Children and adolescents must face living with a mother or father who is ill and whose behaviour may be erratic. They may even be asked to participate in the parent’s care. For parents, telling children about HD can pose difficulties. Should a child be told about HD? If so, at what age? When is a child old enough to cope with the idea of being at risk for HD?
There are no easy answers, particularly since children mature differently and each family situation is different. Generally, it is a good idea to be as open as possible without being alarmist, and to convey the facts bit by bit. This way, a child can develop a gradual awareness of HD rather than being suddenly overwhelmed by information.
The Huntington Disease Youth Organization (HDYO), is dedicated to helping young people and their parents learn about HD and learn to live and cope with it.