Parkinson’s and ALS are two progressive neurological conditions. While both affect movement, they do so by different mechanisms. They also have key differences in symptoms, treatment, and outlook.

Neurological diseases affect the nervous system. Parkinson’s disease and amyotrophic lateral sclerosis (ALS) are two types of progressive neurological disease. “Progressive” means that symptoms worsen over time.

Both Parkinson’s disease and ALS can affect movement. However, these conditions differ considerably in their symptoms, diagnosis, treatment, and outlook.

We know which specific nerve cells Parkinson’s and ALS affect, and research links certain risk factors to each condition. But we don’t yet know what triggers either disease or why some people with risk factors develop ALS or Parkinson’s.

Parkinson’s disease is a neurological disorder that primarily affects movement. It can also cause other health problems, affecting your sleep, mental health, and thinking ability.

In Parkinson’s, nerve cells in the basal ganglia of the brain become damaged and begin to die. These nerve cells make dopamine, a chemical messenger involved in movement. As the nerve cells die, you make less dopamine, affecting your movement.

About 1 million people in the United States are living with Parkinson’s, with 90,000 new diagnoses made each year, reports the Parkinson’s Foundation.

According to a 2018 paper, the prevalence of Parkinson’s worldwide has doubled over the past 25 years, making it the fastest-growing neurological disease.

ALS (aka Lou Gehrig’s disease) is a neurological disorder that affects motor neurons, which control muscle movements and breathing. While Parkinson’s primarily affects neurons in the basal ganglia, ALS affects motor neurons in the spinal cord.

In ALS, motor neurons stop functioning and begin to die. Because motor neurons control muscle movement, this leads to muscle weakening and, eventually, paralysis.

Experts estimate that up to 31,843 people in the United States were living with ALS in 2017. Most cases of ALS occur randomly, although sometimes it can run in families.

There are a variety of differences in the symptoms of Parkinson’s and ALS. Let’s explore these now.

Parkinson’s disease

The main symptoms of Parkinson’s are movement-related and include:

Other signs and symptoms of Parkinson’s include:


The main symptom of ALS is muscle weakness that worsens over time, eventually causing paralysis.

Other signs and symptoms of ALS include:

Additionally, about 15% of people with ALS also develop frontotemporal dementia. This type of dementia affects the frontal and temporal lobes of your brain, leading to changes in behavior, personality, and communication.

Although Parkinson’s and ALS both affect movement, doctors don’t usually misdiagnose them for each other. Parkinson’s causes stiffness and limb tremors but no weakness. ALS causes weakness and small twitches but not tremors.

No specific test currently exists to diagnose Parkinson’s or ALS. The diagnostic process begins with a thorough medical history as well as a physical and neurological exam.

A doctor will also order laboratory tests, such as those on blood, urine, or cerebrospinal fluid (CSF) samples, to help rule out other conditions as the cause of your symptoms.

They may also request imaging, like an MRI.

For Parkinson’s, in addition to your medical history and a neurological exam, a doctor can often make a diagnosis based on whether your symptoms improve when you start taking Parkinson’s medications.

For ALS, additional tests may help rule out other conditions. These include electromyography, which looks at how well your nerves and muscles are working, or analysis of a muscle biopsy.

Conditions that mimic Parkinson’s and ALS

Several other conditions can mimic either Parkinson’s or ALS. Sometimes, this can result in misdiagnosis.

Conditions that mimic Parkinson’s include:

Some examples of the conditions that can mimic ALS are:

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There’s no cure for Parkinson’s or ALS. Instead, treatment for both these conditions focuses on managing symptoms, slowing disease progression, and boosting quality of life.

Treatment for Parkinson’s disease

Medications can help manage movement symptoms. The most commonly used one is levodopa/carbidopa (Sinemet, Rytary), which increases dopamine levels in the brain.

Doctors may prescribe additional medications to help manage nonmotor symptoms of Parkinson’s, such as constipation, depression, and sexual dysfunction.

Other treatments or therapies for Parkinson’s include:

Treatment for ALS

Doctors can prescribe several medications to delay disease progression in people with ALS. Examples include:

  • riluzole (Rilutek)
  • edaravone (Radicava)

Additional medications can help manage ALS symptoms like muscle cramping or pain.

Further ALS treatments and therapies can include:

Both Parkinson’s and ALS are progressive. This means they gradually get worse as time passes. But each person’s experience is different, so predicting how the disease will progress can be difficult.

The life expectancy of someone with Parkinson’s is similar to someone who doesn’t have Parkinson’s. However, the effects of Parkinson’s can lead to complications like falls and choking. Most people with Parkinson’s have some level of disability within 10 years.

Most people with ALS survive 3–5 years after symptoms start. However, around 10% of people survive 10 years or more. Most people with ALS die from respiratory failure when breathing muscles become too weak to function.

Both Parkinson’s and ALS affect movement. Parkinson’s does so by leading to the damage and death of nerve cells in the area of the brain important for movement. ALS affects the motor neurons that control muscle movement and breathing.

The main symptoms of Parkinson’s include tremor, slow movement, rigid muscles, and problems with coordination and balance. The main symptoms of ALS are progressive muscle weakening and eventual paralysis.

There’s no cure for Parkinson’s or ALS, and symptoms gradually worsen over time. Treatments for these conditions instead aim to slow progression, manage symptoms, and improve quality of life.