Parkinson’s disease and Huntington’s disease are both progressive brain disorders.

Both get worse over time as nerve cells in the brain become damaged and die.

Both diseases can affect movement, thinking, mood, speech, and swallowing. However, these problems may appear in different ways.

The main difference between Parkinson’s disease and Huntington’s disease is their cause. Huntington’s disease is usually passed down through families. Parkinson’s disease usually doesn’t have one clear cause.

Understanding Huntington’s disease versus Parkinson’s can help you better understand how these conditions differ and have informed conversations with your healthcare team.

What Is Huntington’s Disease?

Huntington’s disease is a rare genetic disorder and much less common than Parkinson’s disease. About 41,000 Americans have symptomatic Huntington’s disease. Many more are at risk of developing the condition.

Huntington’s disease is often passed from a parent to a child through a gene change. Symptoms often begin between the ages of 30 and 50, though they can start earlier or later. When a rarer form of Huntington’s disease develops before age 20, it’s called juvenile Huntington’s disease.

Huntington’s disease can shorten lifespan, with death often occurring 10 to 30 years after the first symptoms.

What Are the Symptoms of Parkinson’s and Huntington’s?

For both conditions, symptoms may be mild at first and can be different from person to person. There’s a lot of overlap in the symptoms of these conditions. For instance, Parkinson’s and Huntington’s diseases can both cause involuntary movements.

Parkinson’s often causes a rhythmic shaking, or tremor, in the hands, fingers, feet, or jaw. It can also cause bradykinesia, which means movements become slower and harder to start.

Huntington’s disease often causes chorea (involuntary jerking movements), which can affect the arms, legs, face, tongue, and other muscles.

Both conditions can cause:

• Balance problems
• Difficulty walking
• Soft or slurred speech
• Mood changes
• Difficulty with thinking and memory
• Rigid muscles
• Depression
• Swallowing difficulties

Additional symptoms of Parkinson’s disease include:

• A stooped posture
• Smaller handwriting
• Reduced facial expressions
• Loss of smell
• Long-term constipation
• REM sleep behavior disorder

Huntington’s disease may cause symptoms such as:

• Personality changes and irritability
• Impulsiveness and poor risk awareness
• Difficulty concentrating or planning
• Loss of motivation
• Weight loss

How Are Parkinson’s and Huntington’s Treated?

There’s currently no cure for Parkinson’s or Huntington’s disease. Treatments can improve symptoms, but they don’t slow or stop either disease from progressing.

Neurologists with extra training in movement disorders often treat both conditions. Your care team may also include physical, occupational, and speech therapists, as well as mental health professionals, nutritionists, genetic counselors, and others.

There’s no one-size-fits-all treatment plan for either disease. Your healthcare team can help weigh possible benefits, side effects, and goals of care.

Treatment for Parkinson’s Disease

The most effective medication for Parkinson’s disease is levodopa. It’s often combined with carbidopa. Levodopa is a natural chemical that the brain converts to dopamine. Carbidopa helps more levodopa reach the brain and reduces side effects such as nausea.

Because low dopamine levels cause many movement symptoms of Parkinson’s, medications that increase dopamine or mimic its effects can often ease symptoms.

Other Parkinson’s medicines include drugs that act like dopamine and others that help dopamine stay active in the brain longer. Additional medicines may be used for specific symptoms.

Deep brain stimulation may also be used to help with symptoms. This surgical treatment uses electrodes implanted in the brain to send electrical pulses to areas involved in movement.

MRI-guided focused ultrasound may help control tremor in some people with Parkinson’s. Infusion pumps can deliver carbidopa-levodopa continuously to help some people with advanced Parkinson’s whose movement symptoms change throughout the day.

Regular exercise and physical therapy are also important parts of Parkinson’s treatment and can help improve balance, mobility, flexibility, and strength.

Treatment for Huntington’s Disease

There are fewer treatment options for Huntington’s disease than for Parkinson’s disease. Medicines can’t change the course of Huntington’s disease, but they may lessen some symptoms. For example, there are medications that may help with chorea.

Because Huntington’s affects movement, thinking, and mental health, treatment focuses on managing symptoms in all three areas.

VMAT2 inhibitors are medications that change how certain brain chemicals are stored and released. Drugs such as deutetrabenazine and tetrabenazine can help reduce chorea.

Antidepressants, mood stabilizers, and antipsychotic medications may be used to help treat depression, irritability, anxiety, and other mental health symptoms.

Some Huntington’s medicines can cause side effects such as fatigue or slowed movement, which can sometimes look like symptoms of the disease getting worse. Regular follow-up can help your healthcare team monitor symptoms and side effects. Genetic counselors can also help with genetic testing and family planning.

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