Huntington's Disease

1 What is Huntington's Disease?

Huntington's disease is a progressive degenerative brain disorder characterized by problems with movement, cognition and behavior. Mostly, the symptoms appear in 30's or 40's.

Juvenile Huntington's disease develops before the age of 20. Disease progression in people with earlier onset is rapid and presents with slightly different sets of symptoms.

Treatments help to control the symptoms of Huntington's disease but can't prevent physical, mental and behavioral deterioration.

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2 Symptoms

Usual signs and symptoms include movement, cognitive and psychiatric disorders. The appearance of first symptoms indicating a particular disorder differs among individuals.

During the course of the disease, symptoms of a particular disorder may be prominent.

1. Movement disorders

Both voluntary and involuntary movements are affected. Symptoms include:

A person's movement and daily activities are affected if voluntary movements rather than the involuntary movements are impaired.

2. Cognitive disorders

  • Inability to focus, organize or prioritize
  • Repeated thoughts or actions (perseveration)
  • Uncontrolled emotions resulting in outbursts, acting without thinking and sexual promiscuity
  • Being unaware of one's own behaviors and abilities
  • Impaired ability to process thoughts or find words
  • Impaired learning skills

3. Psychiatric disorders

Most people with Huntington's disease have depression. Depression is believed to occur due to injury to brain. Signs and symptoms are:

Other common psychiatric disorders include:

Symptoms of juvenile Huntington's disease

Symptoms of Huntington's disease in younger people include:

1. Behavioral changes

  • Tendency to forget previously learned academic or physical skills
  • Markedly reduced academic performance
  • Conduct disorder

2. Physical changes

  • Abnormal gait caused by muscle contraction and rigidity
  • Impaired fine motor skills (noticeable in skills such as handwriting)
  • Shaking or slight involuntary movements
  • Convulsions

When to see a doctor?

Seek immediate medical care if you have impaired movements, emotional state or mental ability.

3 Causes

Huntington's disease is caused by inherited defective gene. It is an autosomal dominant disorder which means if you inherit a single defective gene, you will develop Huntington's disease.

It implies that if anyone of your parents carries a defective gene, you have 50 percent chance of inheriting the gene.

4 Making a Diagnosis

If you have sign and symptoms of Huntington's disease, your family doctor will refer you to a neurologist to receive a diagnosis.

How to prepare yourself for the visit?

Getting prepared for the visit can optimize the therapy and help make the visit more fruitful. List out all the symptoms. Write down your key medical information. Write down the names of all your medications, vitamins or supplements.

Ask a friend or a family member to accompany you during the visit. Mention your family history of Huntington’s disease or other similar disorders, if any.

Make a list of the questions to ask your doctor. Some typical questions can be:

  • When did the symptoms start appearing?
  • Do your symptoms occur continuously or occasionally?
  • Do you have a family history of Huntington's disease or other psychiatric disorders?
  • Do you experience problem performing your daily tasks?
  • Do you know if someone in your family died young?
  • Do you know if someone in your family is restless or agitated most of the time?
  • How about changes in your general mood?
  • Do you have suicidal thoughts?

Your doctor diagnoses Huntington's disease by physical, neurological and psychiatric examination as well as by evaluating your family medical history.

  • Neurological examination: Your doctor will assess your motor response such as reflexes, muscle strength, balance, and coordination. S/he can also test your sensory symptoms including sense of touch, vision and eye movement, hearing. You may be asked about your moods and thoughts.
  • Neuropsychological testing: It includes tests to evaluate your memory, logical thinking, mental sharpness, language skills and spatial reasoning.
  • Psychiatric evaluation: You will be recommended to psychiatrist for evaluation of your emotional state, patterns of behaviors, quality of judgment, coping skills, signs of disordered thinking, and evidence of substance abuse.

The diagnostic tests might also include:

  • Brain imaging and function: MRI or CT scans can help your doctor detect structural or functional changes in the affected areas of brain and to rule out other possible causes.
  • Genetic counseling and testing: If your doctor suspects Huntington's disease, s/he may order genetic test to confirm the diagnosis. The genetic counselor will clarify the advantages and disadvantages of knowing the test results.
  • Predictive genetic test: It can be used to determine future risk in people who are currently asymptomatic but have a family history of the disease. The choice to have a predictive genetic test is yours. Consult a genetic counselor to evaluate the risks and benefits of the test.

5 Treatment

Huntington's disease cannot be cured, but treatments can reduce the severity of some movement and psychiatric symptoms.

Different treatments can make it easier for people to adapt the changes in his/her abilities for a particular period of time. Treatment options and goals will regularly be evaluated and revised.

1. Medications for movement disorders

  • Tetrabenazine: It is given to treat chorea (jerking movement). It can exacerbate depression or other psychiatric condition. Other side effects are sleepiness, nausea and restlessness.
  • Antipsychotic drugs: Haloperidol and chlorpromazine may be used to treat chorea since they suppress movements. But they can aggravate dystonia (abnormal muscle contraction) and muscle rigidity. Newer drugs, such as risperidone and quetiapine, have fewer side effects, however, they may also worsen symptoms.
  • Amantadine, levetiracetam and clonazepam can be used for chorea. High doses of amantadine can cause swelling leg, discoloration of skin and severely impair cognition. Nausea and mood swings may be caused by levetiracetam. Clonazepam, a drug with high abuse potential, causes sleepiness and can deteriorate the cognitive ability.

2. Medications for psychiatric disorders

  • Antidepressants: Citalopram, fluoxetine and sertraline can be used to treat depression and obsessive-compulsive disorder. They may cause nausea, diarrhea, sleepiness and hypotension.
  • Antipsychotic drugs: Quetiapine, risperidone and olanzapine are used to treat symptoms of mood disorders or psychosis. But they are likely to impair movement.
  • Mood-stabilizers: Valproate, carbamazepine and lamotrigine can be used to treat bipolar disorder. They are likely to cause weight gain, tremor and gastrointestinal problems.

Other treatment approaches include:

  • Psychotherapy: A psychiatrist, psychologist or clinical social worker can help you control behavioral problems and teach you other problem-handling techniques.
  • Speech therapy: A speech therapist may help you speak clearly or train you to use communication devices. Speech therapists can also deal with your difficulties in eating and swallowing.
  • Physical therapy: A physical therapist can teach you certain exercises that improve strength, flexibility, balance and coordination. You can learn to use supports to improve posture.
  • Occupational therapy: An occupational therapist focuses on improving your functional abilities and minimizing dependence on the others for daily tasks. Following strategies may be adopted:

       o Handrails at home
       o Devices to help you during activities such as bathing and dressing
       o Specially designed eating and drinking utensils

6 Prevention

Since Huntington's disease is genetic, the only way to prevent occurrence is through careful family planning when it comes to future children.

People with a family history of Huntington's disease may consider genetic testing and family planning options. A genetic counselor can explain about the possible risk of a positive test result.

A positive test result indicates the parent will have the disease in future. In such case, the couples can make choices about whether to conceive child or opt for alternatives such as prenatal testing for genetic defect, in vitro fertilization with donor sperm or eggs, and preimplantation genetic diagnosis.

7 Lifestyle and Coping

Lifestyle modifications are necessary in order to cope with Huntington's disease.

Huntington's disease actually cripples an individual making him/her dependent on others. Following things need to be addressed in people with this disease:

Eating and nutrition

Huntington's disease causes weight loss, difficulty in chewing and swallowing. Swallowing problems increase risk the chances of choking. If you have someone in your family with this condition, arrange for at least three meals per day to meet the body's nutritional demand. Impaired fine motor skills can also limit the amount of food intake. You can used specialized utensils to minimize the problem.

Managing cognitive and psychiatric disorders

Family and caregivers can help a person with Huntington's disease to avoid stressors and control cognitive and behavioral problems. Following measures may be helpful:

  • Use calendars and schedules to maintain a regular routine
  • Remind and assist the person to do tasks
  • Prioritize work or activities
  • Break complex task into simpler ones
  • Maintain peaceful, simple and structured environment
  • Avoid any factors that trigger stress
  • For school-age children or adolescents, discuss with the school staff to develop suitable education plan for your child
  • Try involving the person in social interactions.

Support services

Some agencies that support people with Huntington's disease and families include:

  • Nonprofit agencies, such as the Huntington's Disease Society of America, educate caregiver, refer to outside services, and provide support groups.
  • Local and state health or social service agencies may offer daytime care for people with the disease, assist while having meal.

Planning for residential and end-of-life care

Progression of Huntington's disease eventually causes death so it is important to plan the care needed in the last few months of life. You can also consider the sufferer’s preferences while planning. You can discuss with your doctor about the advantages and limitations of care options. Following things should be addressed:

  • Care facilities: Nursing care in home or nursing home is required for person with advanced Huntington's disease.
  • Hospice care: Hospice care can be useful to a person approaching death.
  • Living wills: Living wills help to know a person's preference when s/he is unable to make decisions.
  • Advance directives: These documents will transfer decision-making power to other person.

8 Risks and Complications

There are several risks and complications associated with Huntington's disease.

It usually takes 10 to 30 years for a person to die after the onset of the disease. Juvenile Huntington's disease causes death within 10 years.

Depression caused by Huntington's disease may increase the risk of suicide. Risk of suicide is increased prior to diagnosis and in the stage when the person starts becoming dependent.

Death occurs due to:

  • Pneumonia or other infections
  • Fall injuries
  • Complications due to swallowing difficulties

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