What Is Pseudoparkinsonism?

Pseudoparkinsonism, also known as drug-induced parkinsonism, is a reversible condition that resembles parkinsonism. Parkinsonism refers to any condition that causes the movement irregularities seen in Parkinson’s disease, a brain disorder.

Symptoms of pseudoparkinsonism can include tremors, slow movement, shuffling gait, and muscle stiffness. This condition is treated by discontinuing the medication or treatment that is causing it, if possible.

Types of Parkinsonism

Pseudoparkinsonism is a condition that resembles parkinsonism. There are several types of parkinsonism, including:

• Dementia with Lewy bodies (DLB), a form of progressive dementia
• Corticobasal syndrome (CBS), which makes it difficult for patients to see and navigate through space
• Progressive supranuclear palsy (PSP), which causes problems with walking, balance, and eye movement
• Multiple system atrophy (MSA), which affects the autonomic nervous system, the part of the nervous system that controls internal functions such as heartbeat, blood pressure, urination, and digestion
• Vascular parkinsonism, which causes walking, balance, and movement symptoms because of small strokes in the brain 

Pseudoparkinsonism Symptoms

Symptoms of pseudoparkinsonism are often very similar to those of Parkinson’s disease. Classic signs of Parkinson’s disease include:

• Resting tremors, which are shaking that occurs when your muscles are relaxed
• Slowed movements known as bradykinesia
• Muscle stiffness and rigidity
• Shuffling gait
• Postural instability

While resting tremors are common in patients with Parkinson’s disease, they are not as common in pseudoparkinsonism. This is one way to tell the two conditions apart during the diagnostic process. 

Another way to distinguish between Parkinson’s disease and pseudoparkinsonism is to observe for nonmotor symptoms. In Parkinson’s disease, there are additional changes, such as excessive sleepiness (hyposomnia) and other sleep disturbances. Other nonmotor symptoms common only in Parkinson’s disease include bowel and bladder dysfunction, as well as attention deficit. 

Pseudoparkinsonism symptoms may also include cognitive changes. Studies have shown that the severity of drug-induced parkinsonism is related to the severity of the cognitive symptoms. Since there is cognitive impairment in both Parkinson's disease and pseudoparkinsonism, it is difficult to distinguish between the two based on cognitive performance alone. 

Causes

While pseudoparkinsonism, parkinsonism, and Parkinson’s disease share many of the same symptoms, their causes are different.

Parkinson’s disease is a motor system disease that occurs when the nerve cells in the brain do not produce enough dopamine. Dopamine is a chemical in the brain that is necessary for making smooth, purposeful motions. 

Unlike Parkinson’s disease and many forms of parkinsonism, pseudoparkinsonism is caused by a drug reaction. Medications that may cause pseudoparkinsonism include:

• Antipsychotic agents
• Antiemetics, which are used to treat vomiting
• Cholinomimetics, which are used to treat glaucoma
• Antidepressants
• Antivertigo medications
• Calcium channel antagonists, which are used to treat high blood pressure
• Antiarrhythmics, which are used to treat irregular heart rhythms
• Antiepileptic drugs 

Medications that are most likely to cause drug-induced parkinsonism are ones that block dopamine receptors in the brain. When this occurs, the brain is still producing an adequate supply of dopamine, but cells cannot utilize it properly. Without enough available dopamine, the body is unable to make smooth, purposeful movements.

Diagnosis

There is no specific test to differentiate drug-induced parkinsonism from parkinsonism or Parkinson’s disease. Your doctor will take a detailed history and then perform a neurological exam to determine the right diagnosis. 

During the history portion of the exam, your doctor will ask about your symptoms. Be prepared to describe each symptom and when it started. 

Your doctor will ask you for a list of medications you are taking, paying special attention to any new drugs that could be causing your symptoms. 

Your doctor will likely order additional tests to rule out other causes of your symptoms, including:

• Blood test to test for liver or thyroid problems
• Brain imaging scan such as a CT scan or MRI to rule out a brain tumor
• DaT-SPECT test to track the movement of dopamine in the brain

It’s helpful to remember that diagnosing drug-induced parkinsonism is a complex process that often takes time. The same goes for Parkinson's disease, which presents with similar symptoms as drug-induced parkinsonism. Research shows that Parkinson’s disease is misdiagnosed in 6% to 25% of cases.

Treatment

Because drug-induced parkinsonism is caused by a medication, treatment usually involves identifying and then slowly discontinuing the drug. 

When the medication can safely be stopped, your doctor will give you a schedule to slowly do that. It’s important to follow the schedule and never stop a prescription medication suddenly. If you begin to develop new symptoms as you wean yourself off the medication, talk to your doctor. 

If the medication cannot be stopped for other health reasons, your doctor may discuss other treatment options with you. Sometimes drug-induced parkinsonism symptoms continue even after the medication has been discontinued. 

Further treatment for drug-induced parkinsonism may include:

• Dopamine-inducing drugs like levodopa 
• Antidepressant medications
• Botox injections

It’s important to note that some treatments for Parkinson’s disease are not as effective in treating drug-induced parkinsonism. For example, the drug levodopa is commonly used to treat Parkinson’s disease, but may not improve symptoms of parkinsonism or pseudoparkinsonism. Your doctor will work with you to determine a treatment plan and then make changes as needed.  

Prognosis 

Drug-induced parkinsonism usually resolves once the drug that is causing it is discontinued. A 2012 study found that symptoms usually resolve within weeks to months of stopping the medication. However, it’s important to note that some or all of the symptoms continue in 10% to 50% of patients even after the drug is stopped. 

Patients who experience a full recovery are considered to have true drug-induced parkinsonism. If you or a loved one continue to experience symptoms or recover but later develop the symptoms again, you may be considered to be in the early stages of parkinsonism or Parkinson’s disease. 

Working closely with your neurologist is important as you gradually stop the medications causing your symptoms and recover. 

Coping 

Being diagnosed with and treated for drug-induced parkinsonism can be a long journey. The diagnostic process may involve several tests and a lot of waiting. Find ways for stress relief, including connecting with loved ones, performing gentle physical activity, and meeting with a licensed therapist. 

You may find that your daily tasks are too difficult right now. Reach out to family and friends for help with grocery shopping, housekeeping, and yard work, if possible. Creating a list of priorities for the day, while taking into account how much you can accomplish, may help as well.

Summary

If you have recently developed symptoms of pseudoparkinsonism such as slow movements or muscle stiffness, talk with your doctor. If you have recently started a new medication, your symptoms could be because of the drug. Your doctor will work with you to determine if you are experiencing pseudoparkinsonism and how to safely stop the medication.

A Word From Verywell 

Once you have been diagnosed with pseudoparkinsonism, you will likely go through a range of emotions. Experiencing the motor and cognitive changes of pseudoparkinsonism can be frightening, especially when you do not know how long they will last. 

It’s helpful to remember that pseudoparkinsonism symptoms usually resolve within weeks to months after discontinuing the drug that is causing them. Work closely with your neurologist to address your symptoms and connect with a support network during your recovery process.