All about Huntington’s Disease

According to the Alzheimer’s Society, Huntington’s affects around 8 people in every 100,000 in the United Kingdom. The British Medical Journal has noted that the incidence of the disease has remained constant over the last three decades. It’s usually diagnosed between the ages of 35 and 45 but it can affect young people and children.

What is Huntington’s disease?

Huntington’s disease, which is also referred to as Huntington’s chorea, affects the brain and stops parts of it from functioning properly as time goes on – it is a neurodegenerative disease. The condition is inherited from parents. The condition is caused by a genetic mutation in the huntingtin gene (HTT) or a new mutation.

Huntington’s disease is a progressive condition and is typically fatal after around 20 years of onset. Symptoms usually begin between the ages of 30 and 50. Symptoms include motor skill problems, poor coordination, reduction in mental ability and low mood.

The first mention of the condition was in a letter written in 1842 by Charles Oscar Waters that was published in Practice of Medicine. It was described as a “form of chorea, vulgarly called magrums.”

What are the stages of Huntington’s disease?

There are five stages of this neurological disorder in addition to a pre-clinical stage:

1. The early stage.

2. The early intermediate stage.

3. The late intermediate stage.

4. The early advanced stage.

5. The advanced stage.

Pre-clinical stage

Before diagnosis, some people might start to experience subtle changes in their behaviour and cognition. This might include anxiety, depression or irritability. This pre-clinical stage can also be called the prodromal phase. When in this stage, patients might start exhibiting signs of Huntington’s but would not yet fulfil the diagnostic criteria. This stage can last between seven and ten years.

The early stage

This stage begins when a patient first starts to experience motor symptoms. It typically lasts as long as eight years. When in the early stage, a patient’s motor symptoms are not yet debilitating. Most people are able to function fully at work and at home and they are usually as independent as they’ve always been when it comes to daily activities like eating, dressing, bathing, and managing a home.

This stage can come with mild psychiatric changes and cognitive symptoms.

The early intermediate stage

This stage can last anywhere from three years to 13 years from the onset of symptoms. It is during this stage that individuals start to have impairments in their daily living. For example, a person might still be able to do their job but they may need reasonable adjustments made to enable them to continue in their role.

They might begin to find day-to-day tasks more of a challenge and might need some assistance. The irregular involuntary movements (chorea) start to become more pronounced.

The late intermediate stage

This stage usually lasts anywhere from five to 16 years from when the disease begins. During this stage, patients typically aren’t able to work or manage their household tasks. They usually can’t think clearly and might need support managing finances and domestic responsibilities.

What’s more, behavioural and psychiatric symptoms start to become more evident. This can include anxiety, irritability and impulsiveness. Motor symptoms become worse, as do psychiatric and cognitive ones.

The early advanced stage

This stage lasts anywhere from nine years to 21 years from the onset of the disease. During this stage, the patient will require full assistance during their daily lives and cannot live independently. Some people do stay in their own homes with carers or family supporting them while others will go to care facilities. During the early advanced stage, the patient will know what things need to be done but will need someone else to do them.

The advanced stage

This stage lasts anywhere from 11 to 26 years from the onset of the disease. At this stage, individuals need complete support and nursing care.

The chorea symptoms are less pronounced at this stage but parkinsonism (slowness, teeth grinding, stiffness and abnormal posturing) increases. Mobility, walking and the ability to keep an upright posture are more difficult and patients often suffer from falls. Speech-wise, the patient can find things difficult, and they might scream or be confused. Swallowing also becomes difficult and they can experience large fluctuations in body temperature and blood pressure.

It is at the end of the advanced stage that patients succumb to the disease. The biggest cause of death is a complication like aspiration pneumonia, which is an infection that’s caused by inhaling food. The second most common cause of death is, unfortunately, suicide.

How common is Huntington’s disease

Huntington’s disease is rare. Worldwide, the prevalence of Huntington’s disease is between 5 and 10 cases per 100,000 and the rates are similar for both men and women. People who are of Western European descent have the highest rates of occurrence. One of the highest incidences globally is an isolated population in Venezuela where there are 700 in every 100,000 people with the disease.

Symptoms of Huntington’s disease

There is a huge range of symptoms linked to Huntington’s disease and these usually start between the ages of 30 and 50. They can, however, start earlier or later.

Symptoms generally include:

• Poor concentration.
• Memory lapses.
• Depression.
• Clumsiness and stumbling.
• Involuntary movements.
• Personality changes and mood swings.
• Problems breathing, speaking and swallowing.
• Difficulty moving.

Early symptoms

As soon as symptoms begin, they will start to get worse over time.

The first symptoms noted often include:

• Memory lapses.
• Poor concentration.
• Depression – Lack of interest, low mood, feeling hopeless.
• Clumsiness and stumbling.
• Irritability, mood swings and aggressive behaviour.

At this stage, a GP will probably start doing tests to determine the cause of the symptoms.

Later problems

As the disease progresses, so too do the symptoms.

Patients often develop:

• Involuntary movements like fidgeting and jerking of the body and limbs.
• Problems speaking and communicating.
• Problems swallowing – This might mean choking and lung infections from inhaling particles of food.
• Worsening rigid or slow movements.
• Changes to personality – They won’t seem like their former selves.
• Problems breathing.
• Problems moving – Eventually, they won’t be able to sit up or walk without help.

Causes and risks of Huntington’s disease

Huntington’s disease is inherited. It is caused by a faulty gene which means areas of the brain start to become damaged and gradually become more damaged. You only risk the condition if either parent has it. If one of your parents has the gene, you have a 50% (1 in 2) chance of inheriting the gene and developing the condition and passing it on to your children.

Huntington’s disease is an autosomal dominant disorder. This means you can inherit the gene and, therefore, the disease from a single parent. It is impossible to just be a carrier of the disease; so if you are unaffected, your children can’t develop the disease even if one of your parents has it.

Very rarely, it is possible to have Huntington’s disease without a parent having it.

Diagnosing Huntington’s disease

Though much rarer, it is possible to develop Huntington’s disease at a young age. In this case, it is referred to as Juvenile Huntington’s or JHD. This affects children and adolescents and is characterised by worsening cognitive, motor, psychiatric and behavioural symptoms.

Juvenile Huntington’s

Juvenile Huntington’s is usually diagnosed following the presence of symptoms like Huntington’s in adults.

These include:

• Stiffness in the legs.
• Clumsiness in the legs and arms.
• Cognitive functioning declines.
• Behavioural changes.
• Seizures.
• Oral motor function changes.
• Chorea.
• Disturbances in behaviour.
• Family history of Huntington’s disease, typically paternal.

With young people, the progression rate is typically faster the earlier it starts. Young people will often die within 10 years of onset.

Adult Huntington’s disease

Huntington’s disease is usually easier to diagnose in adults. This is because there is often an already evident family history. Since Huntington’s is a genetic disease, it is easy to diagnose definitively with genetic testing.

Tests to diagnose Huntington’s disease

If you’re showing symptoms of the disease, a GP will refer you to a specialist for testing. Patients will be referred to a neurologist. After referral, patients undergo a number of diagnostic tests.

These include:

• A neurological exam – This tests a person’s psychiatric, sensory and motor systems. It will look for problems with strength, balance, coordination, reflexes, vision, hearing and mental condition.
• A neuropsychological examination – This will test a person’s cognitive ability in areas like reasoning and memory.
• Diagnostic testing – This will include things like a CT scan or MRI that might show structural brain changes to indicate whether Huntington’s disease could be causing symptoms. This will also rule out other potential conditions.
• Genetic testing – If Huntington’s is suspected, a genetic test will be carried out to confirm the diagnosis.

Treatments for Huntington’s disease

There is no cure for Huntington’s disease and no way to halt its progression. However, there is treatment available to manage the symptoms and improve quality of life.

Treatments include:

• Medication – This can be medicines to improve movement issues, depression and hallucinations.
• Occupational therapy to help the patient make day-to-day tasks easier.
• Speech and language therapy – To help with communication and feeding problems.
• Physiotherapy – To help with movement and balance and to maintain strength and motor skills for as long as possible.
• Psychotherapy – To help the person cope with psychological changes.

There is research underway into new treatments and initial signs are promising.

Help with day-to-day tasks

Day-to-day tasks like dressing, moving around and eating can be exhausting and frustrating for people with Huntington’s disease. Occupational therapy can help find ways to manage tasks and help people to continue being as independent as possible.

This might include making changes to the home like:

• Putting in a stairlift.
• Installing ramps to allow for wheelchair access.
• Fitting grab rails near the bed, bath or stairs, etc.
• Providing electric toothbrushes, electric tin openers and kitchen utensils that are easier to use.
• Voice controls around the home for lights and blinds, etc.

Help with communication and eating

A dietician and a speech and language therapist (SALT) can help people with Huntington’s disease who are struggling with eating and communication.

Here are some ways in which they can help:

• Introduce alternative methods of communication like picture charts and speech devices.
• Ensure a high-calorie diet is in place to prevent the patient from losing weight.
• Introduce ways to make it easier to swallow and chew food. For some people, it might be necessary to insert a feeding tube.

Help with balance problems and movement

For anyone who has Huntington’s disease, it’s vital to try and remain as physically active as possible. This is important for helping people to feel better mentally but also to maintain their physical abilities for as long as possible.

Moving around is challenging when you have Huntington’s disease due to balance and coordination problems. People might benefit from walking aids. Physiotherapy is also important for problems with movement.

Patients are often recommended to have things like:

• An exercise plan.
• Massages.
• Physical therapy that involves stretching and moving the joints (manipulation).

Research

There is research ongoing to help find treatments for Huntington’s disease. Scientists are working on identifying ways to slow down or stop the condition by turning off the problematic gene. There are also treatments going through the clinical trial phase currently. If these are discovered to be effective and safe, it’s possible that they’ll be released in a few years.

The Huntington Disease Association has up-to-date information on current research.

Help available

When you have Huntington’s disease, it’s important to get the right support in place. Equally, if you’re supporting a family member with the condition, you need to know the best way to support them.

Social care

When a person starts needing extra support, they should approach their adult social services department and request a ‘care and support needs assessment’. This will provide an opportunity to discuss needs and how unmet needs can be best supported.

If someone is providing care, they can also request a carer’s assessment and get financial support like a Carer’s Allowance.

Driving

If you are a driver with Huntington’s disease, you’ll need to discuss this with your doctor. You will be required by law to inform the DVLA who will then seek advice from your doctor. Some people are still allowed to drive but this is reviewed at regular intervals.

If you have undergone genetic testing and have the Huntington’s gene but have no symptoms, you don’t need to tell the DVLA.

Starting a family

There are genetic tests that will show changes in a person’s DNA to know for sure if they have (or will develop) Huntington’s disease.

If there is a family history of the disease, it is possible to get tested to see if you carry the gene before any symptoms occur. Many people choose not to get tested as they’d rather not know in advance. For those who do want to know, you can ask a GP to refer you to a genetic counsellor who will go through the procedure of weighing up the pros and cons before carrying out the genetic test.

For those carrying the gene who want to start a family, there are ways to check or prevent children from being affected.

These include:

• Using donor sperm or eggs.
• Adoption.
• Testing during pregnancy with chorionic villus sampling.
• Pre-implantation genetic tests – a special form of IVF that checks the embryos don’t have the Huntington’s disease gene before they are implanted.

Final thoughts

Most people who develop Huntington’s disease will be aware of a family history of the disease and know they are at risk.

Despite this potential prior knowledge, a diagnosis of Huntington’s disease is not easily received. Because this condition doesn’t present itself until middle age, many people have already had a family and are then worried about having passed on the gene to their offspring. Research in the area is promising, though, and hopefully will mean new treatments are around the corner.