CONDITIONS

What Is Huntingtons Disease

Huntington’s disease (HD) is an inherited disorder that causes the progressive degeneration and breakdown of nerve cells in the brain. The disease has a broad impact on a person’s movement and cognitive functions, and typically occurs during prime working years. Most people with the disease develop signs and symptoms in their 30s or 40s, but onset may occur earlier or later in life. When the disease manifests before age 20, it is called juvenile Huntington’s disease, and may result in somewhat different symptoms, and more rapid disease progression.

Huntington’s disease is a fatal condition, and at present there is no cure. It affects both sexes, and all races and ethic groups worldwide. The disease has been described as having the symptoms of Parkinson’s, Alzheimer’s and ALS—all at the same time. Passed genetically, Huntington’s is a family disease—every child of a parent with the disorder has a 50% chance of carrying the Huntington’s gene. Today, approximately 30,000 Americans have active Huntington’s, and more than 200,000 are at risk of potentially inheriting this serious disorder—but the devastating effects of this disease touch many more. Within a family, multiple generations may have inherited the disease, and those at risk of developing the disease may experience extreme stress and trauma from the uncertainty.

For more infomation, please visit the Huntington’s disease slideshow

What Causes Huntingtons Disease

Huntington’s disease is a genetic disorder—specifically an autosomal dominant disorder—this means that a person only needs one copy of the faulty gene in order to develop the disease.

Risk Factors For Huntingtons Disease

Huntington’s disease is an inherited disorder. Every child of a parent with this disease has a 50/50 chance of inheriting the faulty Huntington’s gene. If the child has not inherited this gene, then he or she will never develop the disease or pass it on to their offspring.

Diagnosing Huntingtons Disease

Huntington’s disease is based on a physical exam, review of family medical history, and on neurological and psychiatric assessments, along with genetic testing and counseling.


Genetic testing and counseling

If symptoms suggest Huntington’s disease, genetic testing for the defective gene that causes the disease may be recommended. This test can confirm the diagnosis. Before genetic testing is conducted, a genetic counselor will explain the pros and cons of learning results, and can also answer any questions about the heritability of Huntington’s disease. A genetic test can be given prior to the manifestation of any symptoms—this is referred to as a predictive genetic test. Predictive genetic testing only indicates that a person is a carrier of Huntington’s, not when disease onset will begin, or what symptoms are likely manifest first. A genetic counselor must be consulted prior to doing predictive testing. He or she will help navigate the upside and downside of doing predictive testing—some find it stressful not to know, while others would find it more stressful to know. Others may choose to do predictive genetic testing prior to making decisions about having children. Other risks to predictive genetic testing include possible issues with health insurance, and facing the stresses of knowingly facing a fatal disease.


Neurological examination

If Huntington’s disease is suspected, a neurologist will ask questions and conduct simple tests to judge motor symptoms, like muscle strength and tone, reflexes, balance, sensory symptoms, like vision and eye movement, hearing, and psychiatric symptoms like mood, mental status, and irritability. The neurologist may also perform testing to assess:

  • Memory
  • Cognitive reasoning
  • Language and speech functioning
  • Mental state
  • Reasoning skills

Psychiatric evaluation

A psychiatrist will likely do an exam to judge mental and emotional functioning, to assess:

  • Mental and emotional state
  • Behavioral patterns
  • Coping skills
  • Cognitive ability
  • Check for signs of substance abuse

Brain imaging tests

Brain imaging may be done to assess structure and function of the brain. Tests used may include MRI—which proves detailed cross-sectional images and 3D images, CT scans—which provide cross-sectional images—both of which can reveal structural changes that can indicate Huntington’s. Early stage HD may not show any brain changes.  These tests can be helpful in ruling out other possible brain causes of symptoms.

Symptoms of Huntingtons Disease

Symptoms of Huntington’s disease generally appear between the ages of 30 to 50, and tend to worsen over a 10 to 25 year period. Over time, HD impacts a person’s ability to reason, walk, and talk. Late stage Huntington’s disease puts an individual at much greater risk of pneumonia, choking, heart failure and other complications, and it is ultimately these complications that typically prove fatal for those with the disease.

Huntington’s disease typically causes movement, cognitive, psychiatric, and behavioral and physical disorders that span a large spectrum of specific signs and symptoms. There is great variability from person to person with respect to which symptoms manifest first among those affected by the disease, along with which disorders prove to have the greatest effect on functional abilities.

Symptoms can be broke up into the following categories: Movement disorders, cognitive disorders, psychiatric disorders, and behavioral and physical changes.


Movement disorders  connected with HD include involuntary and voluntary movements and impairments.

  • Involuntary jerking or writhing movements, also known as chorea
  • Muscle rigidity or muscle contracture, also known as dystonia
  • Impaired walking, balance and posture—often seen in an awkward or unsteady gait
  • Difficulty with swallowing
  • Difficulty with producing speech

Physical changes associated with HD include:

  • Brain cells degeneration
  • Tremors
  • Changes in finer motor skills, which can impact writing and drawing
  • Seizures

Behavioral changes associated with HD include:

  • Rapid decline in work or school performance
  • Loss of previously learned skills or information
  • Behavioral problems like acting out or irritability

Cognitive disorders  connected with HD include:

  • Difficulty in learning new information
  • Difficulty staying focused on task
  • Tendency to get stuck on a thought, behavior or action, sometimes referred to as preserveration
  • Lack of impulse control, which may lead to outbursts, sexual promiscuity, and general acting out without thinking
  • Difficulty organizing and prioritizing tasks
  • Slow thought processing
  • Trouble finding the “right” word and other language processing issues

Psychiatric disorders connected to HD:

The psychiatric disorder most commonly connected with HD is depression. This is not just a reaction to receiving a Huntington’s diagnosis; rather, depression seems to occur due to injury to the brain and subsequent changes in brain functioning. Signs and symptoms of depression include:

  • Social withdrawal
  • Feelings of irritability or irritation
  • Lack of energy
  • Apathy
  • Frequent thoughts of death or dying
  • Thoughts of suicide
  • Paranoia
  • psychosis

Other common psychiatric disorders associated with Huntington’s disease include:

  • Obsessive-compulsive disorder—notable for recurring, intrusive thoughts and repetitive behaviors
  • Mania—a disorder that can cause a very elevated mood, hyper energy, impulsive behavior, an inflated sense of self confidence, and can lead to sexual promiscuity
  • Bipolar disorder, a disorder characterized by alternating periods of depression and mania

In addition to the symptoms listed above, weight loss is very typical in those with Huntington’s disease, especially as the disease progresses to more advanced stages.

Prognosis

Huntington’s disease occurs in stages of increasing symptomatic severity, and thought symptoms vary from person to person, even within the same family, disease progression  is divided into three stages.


Early Stage Huntington’s Disease

Early stage Huntington’s disease is characterized by slight changes in cognitive function, coordination, and overall motor ability, including changes in hand writing, muscle twitches, delayed reasoning ability, and memory loss.  Depressed and irritable mood are also often present. The disease may make a person less able to work at their usual level, and less functional in their home life as well. Medications are often effective in treating depression and other emotional problems.

Middle Stages of Huntington’s Disease

During the middle stages of Huntington’s disease, changes in cognitive and motor function worsen, and involuntary twitches may become more pronounced. Diminished speech and difficulty swallowing may necessitate help from speech language therapists, and medication may be recommended by doctors to provide respite from involuntary motor movements.  Significant disruption in day to day activities becomes more common as the disease progresses..

Late Stage Huntington’s Disease

Late stage Huntington’s disease is characterized by extremely severe motor and cognitive impairment, so much so that a patient may be unable to swallow, eat, speak, or walk without assistance.  A person with Huntington’s is totally dependent on the care of others at this stage, though he or she will likely be able to understand language and continue to have awareness of family and friends. Choking becomes a big concern (due to muscle weakness and incoordination involving swallowing), and in fact, when a person with the disease dies, it is often from complications, like choking, or infection, and not from the disease itself.

During all stages of  Huntington’s disease, weight loss can be a major complication that can lead to worsened symptoms. It is important to adjust the diet as necessary to help maintain appetite.

10% of Huntington’ s cases affect children or adolescents—this is known as Juvenile Huntington’s Disease (JHD). Symptoms are somewhat different than with adult onset Huntington’s disease, and Juvenile Huntington’s typically has a more rapid progression than adult onset Huntington’s. Stiff and/or awkward walking, changes in speech, and decline in the ability to learn new information are common symptoms with JHD.

Huntington’s disease is not fatal in itself. It is a progressive, degenerative disease, however, with no known cure. Those who have HD have a shorter life expectancy, and usually die within 10 to 30 years. The cause of death is typically from related complications like infection, choking, or heart failure. Suicide is also common in those with this disease. It is key to point out that HD manifests differently in individuals, and severity and onset of symptoms is specific to the person. Eventually patients require round-the-clock palliative care. Various medications are available to help relieve symptoms associated with this condition.


Huntington’s Disease: Genetic mutation and CAG Repeats

Huntington’s disease is known as an inherited disease, but it wasn’t until 1993 that scientists were able to identify the exact genetic mutation that causes the disease.  The human genome is contained within 23 pairs of chromosomes, rod-like structures that are tightly packed with genetic material coded in sequences of four proteins – cytosine (C),  adenine (A), guanine (G), and thymine(T). We are all born with two copies of the Huntington’s disease gene, one from each parent. Huntington Disease occurs when the sequence cytosine, adenine, guanine—or CAG—repeats too many times in a specific region on the fourth chromosome. The number of CAG sequences on the fourth chromosome of HD patients often increases as the severity of the disease progresses. Simply put, those who develop Huntington’s disease have longer CAG repeats than those that do not develop the disease.


Huntington’s Disease progression

The one clue into disease progression and severity of symptoms comes from the number of defective genes present.  Huntington’s disease is caused by a mutation that occurs in genes located on chromosome 4, is known as an expansion mutation of the trinuceleotide cytosine-adenine-guanine (CAG). The length of this CAG expression determines the severity and onset of the disease, and it is thought that the number of CAG repeats accounts for the majority of the variation in hold old people are when symptoms first emerge. Environmental and other genetic markers are thought to account for the rest of the variability in disease expression. The difference between a healthy individual with no HD ad one with HD lies in the expansion of this gene. Healthy individuals typically have fewer than 36 repeats; those with 36 to 39 repeats develop a mild form of Huntington’s disease that is associated with a much later disease onset and much slower disease progression. This is referred to as reduced-penetrance Huntington’s disease. As Huntington’s disease is passed on through generations, the number of CAG repeats tends to increase, meaning that successive generations tend to have a more severe disease expression, and an earlier disease onset than previous generations

Living With Huntingtons Disease

Good nutrition is key to helping maintain the best possible health for those with Huntington’s disease. Those with HD tend to have lower than average body weight, and generally need a higher than average caloric intake—sometimes 2 to 3 times the caloric intake as compared to someone who does not have the disease. There is some research that indicates that maintaining a body weight slightly above average weight can facilitate control of the disease. Those with HD are encourage to eat, and those that are helping in some caregiver capacity are encouraged to help make eating as enjoyable as possible. HD symptoms can interfere with eating: difficulty swallowing, decline in motor coordination, involuntary movements like twitches, problems with chewing, along with behavioral and cognitive changes that can cause distraction and sensory overload at mealtime. The use of special utensils, like large handled spoons and forks and more, can help someone with Huntington’s eat independently for as long as possible. And having the right kitchen tools, like a blender, juicer, and food processor can also make a big difference in helping someone with Huntington’s get good nutrition.

Here are some top tips for good nutrition-rich eating for those with Huntington’s:

  • Eat smaller, more frequent meals—instead of 3 large meals, go for 5 or 6 smaller  meals
  • Snacks, snacks, and more snacks! Make sure to have snack food on hand at all times, especially calorie-packed items like candy, cheese, cookies, and ice cream
  • Avoid drinking too much liquid at meals as it can fill you up
  • If you drink a supplement shake, do so in between meals
  • Go for whole milk over low-fat, and add cream to your coffee

Starting speech and language therapy on the early side can help those with HD prepare for when things become more challenging in the future. As the disease progresses, it becomes more challenging to get sufficient nutrition and hydration, so all efforts towards improving swallowing function and such can help improve quality of life significantly.

When a person with Huntington’s can no longer eat or drink well independently, tube feedings may be considered. These can be supplemental to regular eating, or may be used to provide extra hydration, though later stage HD generally means that patients are solely fed via tube feedings as patients cannot get adequate nutrients by eating as they once did.

Screening

Those at risk for Huntington’s disease face a difficult choice about genetic testing as there is no effective treatment or cure for HD. Many people see no benefit in knowing that they will develop the disease someday, while others want an end to the uncertainty so they can make informed choices about their future. The decision to test or not to test is deeply personal, and there is not correct answer. Genetic counselors are available to help provide guidance on whether testing is the right choice or not. The Huntington’s Disease Society of America recommends the following: at risk individuals considering genetic testing should do so at a genetic testing center that follows HDSA guidelines. Testing procedures at these centers involves sessions with professionals who are knowledgeable about HD and the local services available. It may take several weeks to receive the results once the genetic test is complete. Genetic testing for children is typically prohibited before the age of 18, though if symptoms of juvenile HD present, testing may be permitted to confirm diagnosis.

Prenatal testing

Many families at risk for the disease undergo prenatal testing so that they can be sure that they have a child who does not have the gene that causes Huntington’s disease. Pre-genetic diagnostic testing (also known as PGD testing) can be done with In-Vitro Fertilization (IVF) to ensure that any fertilized egg implanted is one that is free of the abnormal HD gene. It is important to note that this can be done without informing the at-risk patient whether or not they have the gene that causes HD. If a woman is already pregnant, fetal testing can be done to see if the defective HD gene is present. Chorionic villus sampling, or CVS, can be performed at 10-11 weeks, and amniocentesis can be done at 14-18 weeks

Prevention

While there is no preventive measures that are currently recommended, recent studies, using the nutritional supplement creatine have shown clinical promise in slowing the onset of HD symptoms, and it is theorized that creatine may slow progression of pre-symptomatic HD.

Medication And Treatment

There are medications that can successfully help manage the symptoms of Huntington’s disease. While treatments can help with the physical, mental, and emotional manifestations of HD, however, they cannot prevent the physical, psychological, mental, and behavioral decline associated with this disease.

Medication is likely to evolve over the course of the disease, and treatment goals will shift as the disease progresses. Symptoms vary greatly from person to person, as does the time of onset.


Medications for movement disorders include:

  • Tetrabenazine (Xenazine). Specifically approved by the FDA to suppress the involuntary jerking and writhing movements, also known as chorea, which are associated with Huntington’s disease.
    • A serious side effect of this medication is the risk of worsening, or triggering, of depression or other psychiatric conditions.
    • Other side effects may include drowsiness, nausea and restlessness.
  • Antipsychotic drugs. These types of medications are used to suppress movement and can help with chorea.  Haloperidol (Haldol) and chlorpromazine, are two commonly used drugs for HD.
    • A side effect of these drugs is that they may worsen involuntary contractions (dystonia) and muscle rigidity. Newer drugs, such as risperidone (Risperdal) and quetiapine (Seroquel), may have fewer side effects but still should be used with caution, as they may also worsen symptoms.
  • Other medications that may help suppress chorea include amantadine, levetiracetam (Keppra,) and clonazepam (Klonopin).
    • At high doses, amantadine can worsen the cognitive effects of Huntington’s disease. It is also known to cause swelling of the legs and skin discoloration.
    • Levetiracetam can cause nausea, GI discomfort, and mood swings.
    • Clonazepam may cause drowsiness, and can impact cognitive abilities. It also has a high risk of dependence and abuse.

Medications for psychiatric disorders vary depending on the symptoms and presentation of symptoms, but may include:

  • Antidepressants include such drugs as citalopram (Celexa, Lexapro), fluoxetine (Prozac, Sarafem) and sertraline (Zoloft). These drugs may also have some effect on treating obsessive-compulsive disorder. Side effects may include nausea, diarrhea, drowsiness and low blood pressure.
  • Antipsychotic drugs like quetiapine (Seroquel), risperidone (Risperdal) and olanzapine (Zyprexa) can help suppress violent outbursts, agitation, and other symptoms of mood disorders or psychosis. However, these drugs may cause different movement disorders themselves.
  • Mood-stabilizing drugs can help stabilize mood, as they can prevent the highs and lows associated with bipolar disorder include anticonvulsants, such as valproate (Depacon), carbamazepine (Carbatrol, Epitol, Equetro) and lamotrigine (Lamictal). Common side effects include weight gain, tremor and gastrointestinal problems.

Psychotherapy

A psychotherapist, who can be a psychiatrist (a medical doctor), clinical psychologist or clinical social worker,  can provide talk therapy which can help a person manage behavioral problems, develop personal coping strategies, and help facilitate effective communication among family members.


Speech therapy  

Huntington’s disease can seriously impact control of the muscles of the mouth and throat, which are critical for speech, eating and swallowing.  Speech therapy can improve ability to speak clearly, learn to use communication devices, and can help address difficulties with eating and swallowing.


Physical therapy  

Exercise is extremely important for a person with HD, as it can help maintain independent mobility, for as long as possible, and can help reduce risk of injury from falls. A physical therapist can show you appropriate, safe exercise movements that can increase strength, balance, coordination, and flexibility—which are all key components for maintaining mobility for as long as possible. As well, when movement becomes more impaired, a physical therapist can teach how to use a walker and wheelchair, and can adapt exercise routines to suit current mobility levels to help maintain strength.


Occupational therapy 

Occupational therapists can help a person with HD, family members, and caregivers learn to use assistive devices that aid functional abilities. For example, the use of handrails at home, the use of eating and drinking utensils adapted for use by those with limited fine motor skills, and assistive devices for bathing and dressing.


Music therapy 

Music therapy has been used successfully to help improve symptoms in those with Parkinson’s disease, which presents with similar movement impairment as Huntington’s disease. Modest improvement are seen in motor coordination, speech intelligibility, and vocal intensity, as well as in emotional functions and quality of life.

Complementary and Alternative Treatment

There are some complementary treatments that can help those with Huntington’s disease both function better, and even slow the course of the disease. The most common type of complementary therapy is dietary supplements. There is good scientific evidence that the following have some benefit to those with HD:

  • Creatine
  • Omega-3 fatty acids
  • Vitamin C
  • 5-HTP

Please be sure to speak with your doctor to see what is right for you.

When To Contact A Doctor

Please contact your doctor if you notice changes in your movements, cognitive or thinking ability, or emotional state. While many of the symptoms of HD can be caused by other conditions, if you suspect that you might be at risk, it’s important to get a prompt diagnosis so that symptomatic treatment can be started as soon as possible.

 

 

Questions For Your Doctor

To find a physician that is experienced with Huntington’s disease, please see the Locate Resources section of the Huntington Disease Society of America website.

Questions For A Doctor

If you show signs or symptoms of Huntington’s disease, make a visit to your family doctor. Your family doctor will likely give you an exam, review your symptoms, mental state, and family medical history, and if he or she suspects HD, will likely refer you to a neurologist.

Prior to your doctor’s appointment, make a list that includes the following:

  • Signs or symptoms that are of specific concern—or any changes from “normal”—which you suspect may indicate HD
  • Any recent life changes or stressors
  • ALL medications—including over-the-counter drugs, vitamins, dietary supplements—along with any prescription medications you take
  • Family history of Huntington’s disease or other disorders that may cause movement disorders or psychiatric conditions

It can be a good idea to have a family member or friend accompany you to your visit. This person can support you, and can help facilitate communication in case you get nervous.

It is also smart to have a list of questions prepared ahead of time for your visit. Some good questions to ask may include:

  • What do you think the cause of my symptoms is?
  • What else could my symptoms be caused by if not HD?
  • If an HD diagnosis is made, what are my next steps?
  • What are the available treatments for Huntington’s disease? What are the side effects?
  • If I have HD, at what stage is my disease?
  • Are there any alternative treatments that could help my symptoms, like acupuncture or massage?

Your doctor is likely to ask you a number of questions, which will likely include:

  • When did you first start experiencing symptoms?
  • How long have you been experiencing symptoms?
  • Have these symptoms been intermittent or continuous?
  • Do you have a family history of Huntington’s disease?
  • Has anyone in your family been diagnosed with another movement disorder or psychiatric disorder?
  • Are you having trouble performing work, schoolwork, or daily tasks? If so, what is getting in the way?
  • Is anyone in your family in a nursing home?
  • Is anyone in your family fidgety or moving all the time?
  • Have you experienced a change in your general mood?
  • Do you feel sad all of the time?
  • Have you ever thought about suicide?

Resources

For more information on Huntington’s disease, visit the Huntington’s Disease Society of America.