Huntington's chorea: causes, symptoms, phases and treatment

One of the best known inherited diseases is Huntington's chorea, a degenerative and incurable disorder that causes involuntary movements and other symptoms that affect multiple areas of the person's life, progressively disabling it.

In this article we will describe the causes of Huntington's disease, as well as the most common symptoms and the phases through which they progress. Finally, we will talk about the treatments that are usually applied to minimize alterations as much as possible.

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Huntington's chorea: definition and symptoms

Huntington's chorea is an inherited degenerative disease that affects the brain and it causes different symptoms of a physical, cognitive and emotional nature.

It is incurable and ends up causing the death of the person, generally after between 10 and 25 years. Drowning, pneumonia, and heart failure are common causes of death in Huntington's disease.

When symptoms begin before the age of 20, the term "juvenile Huntington's disease" is used. In these cases, the clinical picture is somewhat different from the usual one and the progress of the disease is faster.

The most characteristic sign of this disease is the chorea that gives it its name. It is known as "chorea" to a group of neurological disorders that cause involuntary and irregular contractions of the muscles of the feet and hands. Similar movements also occur on the face.

In the case of juvenile Huntington's chorea symptoms may be somewhat different. Difficulties in learning new information, motor clumsiness, loss of skills, gait stiffness and the appearance of speech disturbances stand out.

Causes of this disorder

Huntington's chorea is due to a genetic mutation that is inherited through an autosomal dominant mechanism. This implies that the children of an affected person have a 50% chance of inheriting the gene, regardless of their biological sex.

The severity of the mutation is also partially dependent on heredity and influences the development of symptoms. In the most severe cases, the affected gene ("huntingtin") manifests itself very early and severely.

This disease affects the entire brain; However, the most important lesions occur in the basal ganglia, subcortical structures related to movement. The area known as the “neostriatum”, which is made up of the caudate nucleus and the putamen, is especially affected.

• Related article: "Basal ganglia: anatomy and functions"

Disease development

The symptoms of Huntington's disease vary depending on the specific case. However, its progress is normally grouped into three distinct phases.

The alterations worsen in conditions of psychophysiological stress, as well as when the person is exposed to intense stimulation. Likewise, weight loss is common in all phases of the disease; It is important to control it since it can have very negative consequences for health.

1. Initial phase

During the early years the disease may go unnoticedHuntington's early signs can be subtle, involving unremarkable impairments in the speed of movement, cognition, coordination or gait, as well as the appearance of choreic movements and rigidity.

Emotional disturbances are also very common already in the initial stage. Specifically, irritability, emotional instability and decreased mood occur, which can meet the criteria for major depression.

2. Intermediate phase

In this phase, Huntington's disease is more visible and interferes to a greater extent in the lives of patients. Korea is particularly troublesome. Difficulties speaking, walking, or handling objects they also increase; Together with cognitive impairment, which is beginning to be significant, these symptoms hinder independence and self-care.

On the other hand, the worsening of emotional symptoms tends to damage social relationships. In large part this is due to the behavioral disinhibition derived from Huntington's disease, which causes aggressiveness or hypersexuality to occur in some people, among other disruptive behaviors. Later the sexual desire will diminish.

Other typical symptoms of the intermediate phase are decreased pleasure (anhedonia) and the disturbances in falling or staying asleep, which are very distressing for patients.

3. Advanced phase

The last stage of Huntington's chorea is characterized by inability to speak and perform voluntary movements, although most people retain awareness of the environment. There are also difficulties urinating and defecating. Therefore, in this period, patients are completely dependent on their caregivers.

Although the choreic movements can be aggravated, in other cases they are attenuated when the disease is very advanced. Swallowing difficulties increase, and can cause death by drowning. In other cases, death occurs as a result of infections. Also there are many suicides in this phase.

The progress of the disease is usually faster when it appears at an early age, especially in children and adolescents, so the symptoms of the advanced phase appear earlier.

Treatment and management

There is currently no known cure for Huntington's disease, so physical and cognitive decline cannot be stopped. However, there are symptomatic treatments that can alleviate the discomfort and increase the independence of those affected to some extent.

Dopamine blockers are used to treat the abnormal behaviors of the disease, while for additional movements drugs such as tetrabenazine and amantadine.

As the disease progresses, physical supports that facilitate or allow movement, like the handrails. Physical therapy can also be helpful in improving movement control, and physical exercise benefits general health, including psychological and emotional symptoms.

Speaking and swallowing difficulties can be reduced through language therapy. Also, special eating utensils are used until tube feeding is necessary. It is recommended that the diet be based on nutrient-rich foods and easy to chew to minimize patient problems.

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