Introduction

Huntington’s disease is a rare neurodegenerative disease that causes nerve cells in the brain to slowly decay and die, stopping its normal functioning. Huntington’s disease is inherited from the mutated gene of the parent.¹

The symptoms of Huntington's disease start to appear at ages 30-40 onwards, which include the inability to think clearly, uncontrolled movements, and deteriorating mental health. 

The disease is unlikely to show at early ages, and the symptoms become more prominent later on. Its progression and severity are influenced by the number of CAG repeats in the mutated gene, where a higher count accelerates disease progression. Studies have reported that in the USA, one in every 10,000-20,000 individuals are affected. Since the disease is hereditary, if either of the parents have the mutated gene of Huntington’s disease, then there is a 50% chance this gene would be inherited in the child.²

Currently, there is no complete cure for this disease; however, there are some symptomatic and behavioural treatment options available to improve the quality of life.

Cause of Huntington’s disease

The pathology is traced back to mutation in a single gene called Huntington’s gene (HTT), which is responsible for making the protein Huntington. Huntington protein is important for normal neuronal development and functioning of the brain. The Huntington gene contains DNA sequences which consist of three nucleotides CAG (cytosine, adenosine and guanine) in repeated patterns. This gene is responsible for neuronal function of the brain specifically in basal ganglia (responsible for body movement and coordination) and cortex (responsible for thinking, analytical, and decision-making skills).

So when mutation of HTT occurs, there is an excessive number of the CAG patterns, more than the normal, which leads to the formation of mutated or abnormal forms of Huntington's protein, and thus the brain loses its normal functioning.

People who have the CAG gene less than 27 times are not at risk of developing the condition; however, those who have more than 27 times are at a great risk of developing this condition.

By National Institute of Standards and Technology - Huntington's disease, Public Domain, Link

Signs and symptoms

Physical symptoms

• Chorea: involuntary, dance-like movement affecting arms, legs and facial muscles
• Athetosis: slow, writhing involuntary movements that mostly affect hands and feet
• Abnormal eye movements
• Poor coordination 
• Trouble maintaining proper body posture
• Difficulty in swallowing and speaking
• Cognitive symptoms
• Decreased concentration
• Memory decline
• Trouble focusing
• Difficulty in making decisions
• Disorganized thoughts
• Difficulty in learning new information

Emotional symptoms

• Depression
• Obsessive compulsive disorder
• Irritation
• Fatigue
• Headache
• Suicidal thoughts³

Prognosis

Huntington’s disease has a poor prognosis due to the irreversible damage to the nerve cells in the brain. The initial symptoms are headache, irritation, anxiety, and depression, and as the disease progresses, it further leads to an inability to talk, walk, difficulty making decisions, memory decline, etc. The onset of the symptoms usually starts after the age of 20; in some cases, the symptoms appear at a young age, and it is called Juvenile Huntington’s disease. 

The life expectancy of the patient is usually less, and if it is coupled with other health conditions such as heart disease, lung disease, or diabetes, then the patient's life is at risk. At the moment, there is no proper treatment for the disease; however, supportive treatment is available.

Medications

There is no cure for this condition and the disease progresses; however, some medications are able to reduce the symptoms and provide temporary relief. They include:

• Antidepressants: Fluoxetine, Citalopram
• Antipsychotics: Terbinafine, Haloperidol
• Analgesics: Ibuprofen, Diclofenic

Advanced care planning

Huntington disease (HD) impairs an individual's capacity to make right decisions with a sound mind. Therefore, the individuals having HD will eventually lose the ability to make decisions and are encouraged to plan in advance about what steps, decisions, and actions to take when their condition worsens.

This advance planning ensures that the individual’s wishes and rights are respected by healthcare professionals and family members.The patient has the complete right to involve legal, ethical, and moral matters in order to ensure that his/her decisions regarding treatment are respected. Disregarding this right can lead to serious repercussions.⁴

Importance of ACP

The advanced planning empowers the patient and gives the physician and other people involved to make decisions in accordance to the wishes of the patient as expressed. This way, when the patient has completely lost the ability to make decisions, this advanced planning will help navigate what steps and processes to follow in order to fulfil the individual's wishes.

Key elements of ACP

Living will

A document that provides information about a patient’s agreement/disagreement towards certain medical procedures or medications.

Power of attorney for healthcare

The patient themselves hire a legal person to make decisions on behalf of themself when they are unable to do so.

Healthcare proxies

A legal person hired by the patient who makes decisions and oversees everything to make sure all processes performed are according to the preferences of the affected individual.

Do-Not-Resuscitate (DNR)

A Do-Not-Resuscitate (DNR) can be requested by a patient, instructing healthcare providers to not try to bring back the patient’s life by giving CPR or any other means if the heart stops. This decision is based on the patient's wishes, medical condition, and ethical considerations. However, the final decision is made by medical professionals in the best interest of the patient.

Benefits of early and thorough ACP

Empowerment of the patient 

Advanced planning gives the patient a chance to make their own decisions for the future as their disease progresses. This will keep the patient satisfied and content that the process is being done according to their wishes and will.

Reducing conflict among families 

No one likes to see their loved ones suffer from an incurable disease; for example, while some members of the family might be opting for Do-Not-Resuscitate (DNR), the other family members might be against it. This creates a hostile and negative environment, which affects the patient as well. However, this can be avoided by encouraging the patient to make well-informed decisions while they still have decision-making capacity to avoid any conflicts.

Improved quality of life in the advanced stages of HD

In advanced stages of HD, this can act as a great source in guiding the professionals, legal authorities, and family members to make sure the treatment plan is aligned according to the individual's needs.⁵

Role of healthcare providers in ACP

Health care providers play a crucial role in emphasising the importance of advanced care planning among the patients. Communicating with a professional helps the patient gain confidence and understand the further processes. Research by Dr. Paladino states that when people have talks regarding their disease with health care professionals, they tend to feel less anxious and depressed, and it makes them feel empowered.

Moreover, the healthcare professional can help the HD patients make the best choices for themselves by informing them about various options of supportive care available.

They can also encourage the patient to attend cognitive, physical, and mental therapies to improve the quality of life.

Planning for long-term care

The ACP also includes a long-term care plan because as the disease progresses, the conditions of the patient get worse, and for that, there is a constant need for nurses or other support since the HD patients can’t function independently on their own. This planning ensures that the patient's problems are addressed and they live a comfortable life.

The HD patients might be admitted to healthcare facilities dealing with similar patients to look after their needs. The facilities may offer programs such as cognitive, behavioural, mental, and physical therapies for the patients to increase their quality of life.

Advanced care planning also includes financial considerations. It allows the patient to make decisions regarding the budget and allocation of money for healthcare facilities or medical procedures before the progression of the disease to the last stage.

End-of-life care preferences

Palliative care in Huntington’s disease 

Palliative care is the last option, where the person does not show any sign of recovery. The main goal of this care is to relieve the patient from the symptoms for the ease of the patient and the family. Palliative treatment usually includes medications to relieve the symptoms, sedatives, antipsychotics, etc. It must be kept in mind that palliative treatment does not cure the disease; it just simply makes it bearable.

Do not resuscitate

It is the last option, where the patient has written in his will that he must not be resuscitated if the heart stops beating or due to any other complications. As it is a legal wish of the patient, it must be respected and catered to.

Summary

Huntington disease is a rare disorder that causes the nerve cells in the brain to damage and decay over time. This results in loss of brain functions and causes mental, cognitive, and emotional problems. The cause of this disease is a mutation in the Huntington's gene present in affected individuals. This gene codes for multiple repeated CAG patterns, and if these CAG patterns are more than 30, then the person is highly at risk of developing Huntington's disease. The disease is incurable and cannot be treated by the medications; however, symptomatic treatment can be given, such as pain killers, antipsychotics, antidepressants, etc.

An advanced care planning approach is available for this condition. Since this condition impairs one's ability to think and make decisions, this approach ensures that the patient is prepared in advance and that the patient’s wishes and rights are respected by healthcare professionals and family members.