What are the other Names for this Condition? (Also known as/Synonyms)

• Dementia due to Huntington Chorea (Disorder)
• HD Dementia
• Huntington Disease Dementia

What is Dementia due to Huntington Disease? (Definition/Background Information)

• Dementia (NOS) is a type of disorder accompanied by a collection of symptoms that indicate brain impairment and loss of brain function. It leads to a progressive decline of all cognitive aspects such as behavior, memory, attention, analytical ability, thinking, language skills, etc.
• The onset of Dementia can be gradual or sudden. There can be a gradual deterioration of the brain’s abilities, due to age factor; or a sudden event like an accident or illness, might cause Dementia
• Huntington Disease (HD) is an autosomal dominant condition that adversely affects the brain causing irreversible degeneration of mental and emotional features. It is also accompanied by sudden and involuntarily flailing, limbs and body
• Progressive Huntington Disease Dementia sets in with personality and behavior modifications, which may be extremely radical or irrational. Tendencies such as suicide, mania, insanity, and other psychiatric manifestations, are observed
• The condition does not respond to any treatment, and with a steady decline of the individual’s health and mental status, the outcome of HD Dementia is often unpredictable

Who gets Dementia due to Huntington Disease? (Age and Sex Distribution)

• Adult Onset ‘Dementia due to Huntington Disease’ is the most common type, occurring within the age range of 30-50 years. However, HD has been noticed in children, as young as 2 years, and in elderly adults, as old as 80 years
• Both, males and females are equally affected
• West Europeans are more prone to the disorder than Asians or Africans

What are the Risk Factors for Dementia due to Huntington Disease? (Predisposing Factors)

• Huntington Disease runs in the families; hence, individuals born in families with a medical history of the condition are at a serious risk

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Dementia due to Huntington Disease? (Etiology)

• Genetic study and analysis have implicated anomalies in chromosome 4, with abnormal repetition of certain genetic material/sequence, as a primary factor for Huntington Disease
• This feature of genetic mutation is normally inherited in an autosomal dominant manner; although in a few cases, spontaneous development of the condition has been noted

Based on speed of progression, Huntington Disease Dementia can be classified as:

• Slowly Progressive Dementia: When neurodegenerative disorders cause slowly progressing Dementia; and the nerve cells (neurons) lose their function over many years
• Rapidly Progressive Dementia: A sudden advancement of the condition may occur, where more and more neurons die increasingly faster, causing a kind of brain shrinkage (cerebral atrophy)

What are the Signs and Symptoms of Dementia due to Huntington Disease?

Huntington Disease type Dementia presentations affect the physical, mental, and emotional personality. They are diverse and may be initially mild, gradually/rapidly getting more severe, later. These are:

Physical, movement-related signs and symptoms:

• Sudden bursts of involuntary spasms with jerking arms, legs, and body movement (termed as chorea)
• Muscle rigidity, contraction, difficulty walking, maintaining balance, performing basic and routine activities becomes very challenging; loss of basic motor (physical and spatial) skills
• The individual is more prone to accidents and falls
• Speech incoherence, eating/swallowing difficulty, reduced appetite

Mental and emotional quality-related signs and symptoms:

• Progressive deterioration of the senses, memory loss, communication difficulties, unable to plan or organize
• Changes in overall personality; regression or absence of reasoning/rationale, agitation, delusions, depression, aggression, feeling of guilt
• Loss of social abilities, social awkwardness, withdrawal
• Extremely irrational mental/emotional/physical behavior (may be completely inappropriate for the situation); lack of control and awareness, sexual hyperactivity, or absence of sexual drive
• Other extreme behavior include: Suicidal tendencies, mania, bipolar disorder, obsessive-compulsive disorder, impulsiveness, insanity

Children and juveniles may suffer from:

• Academic disorientation, poor performance at regular school activities (both at sports, or exams); gradual memory loss, loss of previously acquired/learned skills
• Behavioral problems, mood swings
• Mild seizures, involuntary physical movements
• Muscle contraction causing stiffness, walking difficulties (affecting gait)

How is Dementia due to Huntington Disease Diagnosed?

To examine for Dementia due to Huntington Disease, a variety of tests are usually conducted. The evaluation is usually based on the set of signs and symptoms present. The main diagnostic tools include:

• Physical exam with a comprehensive evaluation of medical history, including collecting details on any underlying conditions/disorders and their progression
• Neurological and cognitive assessment: Checking intellectual ability, memory, mental health and function, language skills, judgment and reasoning, coordination and balance, reflexes, sensory perceptions (space, sight, hearing, touch)
• Psychiatric examination
• Imaging studies performed are: MRI scan of the central nervous system (brain and spine), CT scan (head), PET imaging of brain
• Blood analysis: Total blood count, blood chemistry, glucose, ammonia, blood gas analysis, electrolytes, vitamin levels
• Urine analysis: Screening for toxic substances, alcohol, determination of vitamin deficiencies
• Cerebrospinal fluid analysis
• Liver and kidney function tests
• Thyroid function tests, such as TSH, T3, and T4
• Electroencephalogram (EEG)
• Genetic study and analysis; particularly when there exists a family history of the condition

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Dementia due to Huntington Disease?

Complications with ‘Huntington disease caused Dementia’ depend on the severity of the condition, age, and overall health of the individual. These include:

• Memory loss and neurological function impairment to a great extent such that institutionalized care might be required for prolonged periods, or for rest of an individual’s life. There is a progressive inability of the individual to take care of themselves, due to complete degeneration of mental and emotional health
• Loss of any inhibition, spontaneous incontinence (involuntary bowel or bladder movement), , prone to fall-related injuries
• Complete loss of personality causing extreme insanity, irrationality, anxiety, delirium, risk of suicide
• The individual may become susceptible to opportunistic infections, heart disease; organ failure chances are higher; due to a reduced sense of hygiene, decreased intake of food/nutrition. Often, these factors  lead to an overall reduced lifespan
• Feeding and swallowing problems; food may get blocked in the airways/lungs resulting in pneumonia, choking
• Treatment medication may have significant side effects

How is Dementia due to Huntington Disease Treated?

There is no standard cure or treatment of the condition. Patients receive supportive care and may be given medications to control abnormal spasmodic movements and pain, if any present. Dementia management (due to Huntington's disease) is undertaken on a case-by-case basis. Some of the methods include:

• Addressing general health problems that are mostly linked to mental balance and well-being. This includes the treatment of anemia, dietary or vitamin deficiencies, heart-related ailments, infections, thyroid disorders, hormonal imbalances, and regulating blood pressure
• Treatment of the underlying illness, to prevent progression of Dementia
• Ensuring that the individual has a nutritious diet with medical supplements (balanced diet that include proteins, fiber-rich fruits and vegetables, milk shakes, juices, and plenty of water)
• Ensuring that the individual is well-cared for in a safe environment (at home, or outside) and is under regular (and maybe constant) care and support
• Use of medications to control involuntary jerky movements (tetrabenazine), and for behavioral issues, to prevent further loss of mental stability; like stimulants, mood stabilizers, dopamine blockers, antipsychotic, antianxiety drugs, sedatives, anti-depressants, etc. Many of these medications may cause side effects like nausea, stomach problems, drowsiness, vomiting, and depression
• Physiotherapy, exercises, to help strengthen the muscles; speech therapy to help muscles in the neck, throat have control of oral activities like chewing, swallowing, and speaking
• Home and work environment can be suitably modified to make it a lot safer and convenient for performing regular activities. This includes safety features normally designed for the physically challenged or the elderly, furniture rearrangement, and use of ramps
• Wheelchairs, walkers, braces are used to provide physical support and promote mobility
• Hospitalization may be required (for short or long duration), depending on the condition of the individual. This is usually followed by regular check-ups

A healthcare provider may utilize the following treatment measures on a case-by-case basis. These are meant to provide mental and emotional support, and develop or retain communication skills:

• Psychiatric treatment
• Group therapy interactive sessions
• Support groups

How can Dementia due to Huntington Disease be Prevented?

Current medical research has not indicated effective preventive measures for Huntington's disease, and the Dementia associated with it, since it is an inherited genetic disorder. Nevertheless, progression of the condition may be delayed or controlled, to some extent by ensuring that:

• Factors associated with diet, lifestyle, and health in general like; alcoholism, smoking, obesity, cholesterol levels, stress, nutritional deficiencies, hormonal problems, use of certain medications, diabetes, etc. may be regulated and/or controlled
• Individuals who fall in the high risk category (and all others over the age of 60 years) should be encouraged to be socially active and physically fit (with regular exercising). A healthy diet rich in fruits, vegetables, fish, whole grains, and low in fats and sugar, is recommended
• High-risk individuals should constantly maintain a healthy mind, by undertaking mentally stimulating activities like; reading/writing/teaching, solving puzzles, playing video games, listening to music, learning new skills (painting, language, playing an instrument), etc.

What is the Prognosis of Dementia due to Huntington Disease? (Outcomes/Resolutions)

The prognosis for an individual with Dementia from Huntington disease is normally unpredictable, and is based on a combination of many factors:

• Age of the adult; children with the disease, often live less longer than adults
• Degree of severity; often rapidly progressing HD bring about a speedy decline in the condition
• General health and medical history
• Tolerance level/health of the individual, when subjected to various medications; and response to Dementia management
• Complications observed, if any

An early detection and aggressive management of Huntington Disease (and the Dementia associated with it) should be attempted. This may prevent a rapid deterioration of the condition, and help sustain the quality of life.

Patients diagnosed with HD may live anywhere between 10-30 years following the onset of symptoms. Death usually results from heart problems, accidents, fall injuries, pneumonia, and even from suicides.

Additional and Relevant Useful Information for Dementia due to Huntington Disease:

There are voluntary organizations and support groups for Dementia (due to Huntington disease) that provides counsel, help, and understanding, to the affected individuals and their families.