Huntington Disease

Huntington Disease

What are Huntington Disease?

Most people with Huntington's disease develop signs and symptoms in their 30s or 40s. But the disease may emerge earlier or later in life.

When the disease develops before age 20, the condition is called juvenile Huntington's disease. An earlier emergence of the disease often results in a somewhat different set of symptoms and faster disease progression.

Medications are available to help manage the symptoms of Huntington's disease, but treatments can't prevent the physical, mental and behavioral decline associated with the condition.

What are the symptoms of Huntington Disease?

Huntington's disease usually causes movement, cognitive and psychiatric disorders with a wide spectrum of signs and symptoms. Which symptoms appear first varies greatly among affected people. During the course of the disease, some disorders appear to be more dominant or have a greater effect on functional ability.

Movement disorders

The movement disorders associated with Huntington's disease can include both involuntary movement problems and impairments in voluntary movements, such as:

• Involuntary jerking or writhing movements (chorea)
• Muscle problems, such as rigidity or muscle contracture (dystonia)
• Slow or abnormal eye movements
• Impaired gait, posture and balance
• Difficulty with the physical production of speech or swallowing

Impairments in voluntary movements — rather than the involuntary movements — may have a greater impact on a person's ability to work, perform daily activities, communicate and remain independent.

Cognitive disorders

Cognitive impairments often associated with Huntington's disease include:

• Difficulty organizing, prioritizing or focusing on tasks
• Lack of flexibility or the tendency to get stuck on a thought, behavior or action (perseveration)
• Lack of impulse control that can result in outbursts, acting without thinking and sexual promiscuity
• Lack of awareness of one's own behaviors and abilities
• Slowness in processing thoughts or ''finding'' words
• Difficulty in learning new information

Psychiatric disorders

The most common psychiatric disorder associated with Huntington's disease is depression. This isn't simply a reaction to receiving a diagnosis of Huntington's disease. Instead, depression appears to occur because of injury to the brain and subsequent changes in brain function. Signs and symptoms may include:

• Feelings of irritability, sadness or apathy
• Social withdrawal
• Insomnia
• Fatigue and loss of energy
• Frequent thoughts of death, dying or suicide

Other common psychiatric disorders include:

• Obsessive-compulsive disorder — a condition marked by recurrent, intrusive thoughts and repetitive behaviors
• Mania, which can cause elevated mood, overactivity, impulsive behavior and inflated self-esteem
• Bipolar disorder — a condition with alternating episodes of depression and mania

In addition to the above symptoms, weight loss is common in people with Huntington's disease, especially as the disease progresses.

The start and progression of Huntington's disease in younger people may be slightly different from that in adults. Problems that often present themselves early in the course of the disease include:

• Loss of previously learned academic or physical skills
• Rapid, significant drop in overall school performance
• Behavioral problems

• Contracted and rigid muscles that affect gait (especially in young children)
• Changes in fine motor skills that might be noticeable in skills such as handwriting
• Tremors or slight involuntary movements
• Seizures

What are the causes of Huntington Disease?

Huntington's disease is caused by an inherited defect in a single gene. Huntington's disease is an autosomal dominant disorder, which means that a person needs only one copy of the defective gene to develop the disorder.

With the exception of genes on the sex chromosomes, a person inherits two copies of every gene — one copy from each parent. A parent with a defective gene could pass along the defective copy of the gene or the healthy copy. Each child in the family, therefore, has a 50 percent chance of inheriting the gene that causes the genetic disorder.

How is Huntington Diseasetreated?

No treatments can alter the course of Huntington's disease. But medications can lessen some symptoms of movement and psychiatric disorders. And multiple interventions can help a person adapt to changes in his or her abilities for a certain amount of time.

Medication management is likely to evolve over the course of the disease, depending on the overall treatment goals. Also, drugs to treat some symptoms may result in side effects that worsen other symptoms. Therefore, the treatment goals and plan will be regularly reviewed and updated.

Medications for movement disorders

Drugs to treat movement disorders include the following:


• Tetrabenazine (Xenazine) is specifically approved by the Food and Drug Administration to suppress the involuntary jerking and writhing movements (chorea) associated with Huntington's disease. A serious side effect is the risk of worsening or triggering depression or other psychiatric conditions.

Other possible side effects include drowsiness, nausea and restlessness.

• Antipsychotic drugs, such as haloperidol (Haldol) and chlorpromazine, have a side effect of suppressing movements. Therefore, they may be beneficial in treating chorea. However, these drugs may worsen involuntary contractions (dystonia) and muscle rigidity.

Other 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, others) and clonazepam (Klonopin). At high doses, amantadine can worsen the cognitive effects of Huntington's disease. It may also cause leg swelling and skin discoloration.

Side effects of levetiracetam include nausea, stomach upset and mood swings. Clonazepam may worsen the cognitive side effects of Huntington's disease and cause drowsiness. It also has a high risk of dependence and abuse.

Medications for psychiatric disorders

Medications to treat psychiatric disorders will vary depending on the disorders and symptoms. Possible treatments include the following:


• Antidepressants include such drugs as citalopram (Celexa), escitalopram (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 — such as quetiapine (Seroquel), risperidone (Risperdal) and olanzapine (Zyprexa) — may suppress violent outbursts, agitation, and other symptoms of mood disorders or psychosis. However, these drugs may cause different movement disorders themselves.
• Mood-stabilizing drugs that can help prevent the highs and lows associated with bipolar disorder include anticonvulsants, such as valproate (Depacon), carbamazepine (Carbatrol, Epitol, Tegretol) and lamotrigine (Lamictal).

Psychotherapy

A psychotherapist — a psychiatrist, psychologist or clinical social worker — can provide talk therapy to help a person manage behavioral problems, develop coping strategies, manage expectations during progression of the disease and facilitate effective communication among family members.

Speech therapy

Huntington's disease can significantly impair control of muscles of the mouth and throat that are essential for speech, eating and swallowing. A speech therapist can help improve your ability to speak clearly or teach you to use communication devices — such as a board covered with pictures of everyday items and activities. Speech therapists can also address difficulties with muscles used in eating and swallowing.

Physical therapy

A physical therapist can teach you appropriate and safe exercises that enhance strength, flexibility, balance and coordination. These exercises can help maintain mobility as long as possible and may reduce the risk of falls.

Instruction on appropriate posture and the use of supports to improve posture may help lessen the severity of some movement problems.

When the use of a walker or wheelchair is required, the physical therapist can provide instruction on appropriate use of the device and posture. Also, exercise regimens can be adapted to suit the new level of mobility.

Occupational therapy

An occupational therapist can assist the person with Huntington's disease, family members and caregivers on the use of assistive devices that improve functional abilities. These strategies may include:


• Handrails at home
• Assistive devices for activities such as bathing and dressing
• Eating and drinking utensils adapted for people with limited fine motor skills

Disclaimer

This article is for information only and should not be used for the diagnosis or treatment of medical conditions. Doctors Catalog has used all reasonable care in compiling the information but makes no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. In the event of an emergency, please call 108 for immediate assistance.