About Parkinsonian Syndromes

What is a parkinsonian syndrome?

Parkinsonian syndromes (PSs) are a group of disorders (idiopathic Parkinson’s disease, multiple system atrophy, and supranuclear palsy) that may occur when there is a reduction in the ability of dopamine, an essential chemical that works in the brain, to function normally.

Dopamine affects many normal brain functions, impacting our behavior, thought, attention, sleep,
motivation, and movement. There may also be a loss of proteins called dopamine transporters,
known as DaT, which may also impact how dopamine functions in the brain.

Dopamine deficiency

When there is a deficiency in dopamine, the brain may not be able to perform certain tasks. One of the problems caused by a dopamine deficiency is the inability of the brain to control movement and motor functions. The signs and symptoms of a PS may be a result of a dopamine deficiency.

Different parkinsonian syndromes

There are different types of PSs. One of the most common disorders is Parkinson’s disease, also known as PD, which affects an estimated one million Americans. Other types of PSs include multiple system atrophy and progressive supranuclear palsy.

Common movement disorder symptoms

Are you or your loved one experiencing any of these symptoms?

  • Shaking
  • Stiffness
  • Slowness of movement
  • Tremor
  • Difficulty with balance
  • Stiff facial expression
  • Shuffling walk
  • Muffled speech or soft voice

If you or a loved one are experiencing any of the symptoms mentioned, it may be caused by a PS or essential tremor (ET).

If you or a loved one have a movement disorder, such as a PS or ET, you or your loved one may have trouble performing everyday tasks.

When symptoms of a movement disorder such as a PS or ET appear, they may be mistaken for other conditions, especially in the elderly. You should talk to your doctor if you feel that you or a loved one is experiencing any symptoms that you believe may be related to a movement disorder. The doctor will evaluate your or your loved one’s symptoms and medical history, and decide whether testing would be helpful.

It is important to note that symptoms may be different from patient to patient. Many patients experience some symptoms but not others. The progression of the disease, including how quickly or how slowly the disease worsens, may vary on an individual basis.




Diagnosis of a PS can be difficult. For example, the symptoms of a PS are very similar to the signs and symptoms of ET. Unlike a PS, however, ET is not caused by a dopamine deficiency.

What is ET?

ET is the most common movement disorder in the elderly, and it is sometimes misdiagnosed as a PS.

ET is a condition of the brain that may cause:

  • Uncontrollable shaking in the hands, head, and face
  • Trembling (occurs most often in the hands while attempting to do simple tasks such as drinking from a glass, tying shoelaces, or writing)

Unlike with a PS, tremor associated with ET occurs when people are actively moving. Although not usually a dangerous condition, ET can be severe in some people. The condition can occur at any age but is most common in older adults.

ET can be hereditary (runs in families), nonhereditary (does not run in families), or occasional (not often,
but temporary).

Challenges in diagnosis

In several studies, it was discovered that there was a tendency to misdiagnose PD and ET.

  • For example, in one clinical study, about 26% of patients receiving medication to treat PD had been misdiagnosed; they did not actually have PD1
  • In another study, 37% of patients with an initial diagnosis of ET were declared to be misdiagnosed after further clinical evaluation2

How imaging with DaTscan can help with diagnosis

DaTscan can be used in patients who have symptoms of a PS. When used in addition to other tests and clinical assessment, it can help differentiate between ET and a PS. Although DaTscan is not used to diagnose these disorders, doctors are able to take a picture (called a single-photon emission computed tomography, or SPECT, scan) of a part of the brain to help identify whether or not a dopamine deficiency is present. The findings that result from imaging with DaTscan may be used in addition to a clinical assessment to help determine the diagnosis.


There are effective treatments for the symptoms of a PS. Early and accurate diagnosis, potentially including imaging as part of the diagnostic process, can help determine the most effective treatment plan. If you suspect that you or someone you know may have one of these disorders, it is important to see a doctor who can provide appropriate guidance.

If you have any questions, please talk with your doctor. For additional information, please see the Full Prescribing Information for DaTscan.

What is Datscan (Ioflupane I 123 Injection)?

DaTscan is a radioactive drug that is injected into your bloodstream to highlight areas of your brain so that images can be taken with a special camera (called a single-photon emission computed tomography [SPECT] camera). If you are an adult with a movement difficulty, your doctor may decide to order this imaging test, along with other medical tests, to help decide if your movement difficulties are due to a parkinsonian syndrome or a similar condition such as essential tremor.

Types of parkinsonian syndromes are Parkinson’s disease, multiple system atrophy, and progressive supranuclear palsy. DaTscan cannot tell the difference between these parkinsonian syndromes.

DaTscan is available only by prescription and must be ordered by your doctor.

Important Risk and Safety Information About DaTscan

You should not be given DaTscan if:
  • You have ever had a reaction to iodine or are sensitive to any of the components of DaTscan. Talk with your doctor; he or she can help you understand what the drug ingredients are
What is the most important information you should know about DaTscan?
  • Serious allergic and injection-site reactions could occur following a DaTscan injection. If you have any symptoms of a serious allergic nature, including low blood pressure; trouble breathing; throat tightness; swelling of your face, lips, or tongue; or rash and itching, inform your doctor or go to your nearest emergency room right away
  • To help decrease the amount of thyroid accumulation of iodine: Your doctor will give you a medication at least one hour before giving you DaTscan. The purpose of this medication is to minimize the amount of radioactive iodine going into your thyroid gland
  • Pregnancy: Clinical studies have not been conducted with DaTscan on pregnant women. Any radioactive drug, including DaTscan, may cause harm to the fetus. If you are pregnant, your doctor will decide if a DaTscan test is appropriate
  • If your are a nursing mother, your doctor will decide whether you should interrupt nursing and pump and discard breast milk for six days after DaTscan administration to reduce the risks to your nursing infant
  • If you have kidney and/or liver problems: The effects of kidney and /or liver damage from the use of DaTscan are not certain. DaTscan is removed by the kidney, and patients with severe kidney problems may have increased radiation exposure that could change DaTscan images
  • Children: DaTscan should not be given to children
The most common side effects of DaTscan:
  • In clinical studies performed, the most common side effects included headache, nausea and upset stomach, a sensation of motion, dry mouth, or dizziness in less than 1% of patients (1 in 100 patients)
What you should know about taking DaTscan with other medications:
    Some drugs may interfere with DaTscan. Be sure to tell your doctor what drugs you are taking so that he or she can decide whether you should stop any of them for a period of time before using DaTscan
Questions about the procedure:
    Always talk to your doctor if you have any questions about the SPECT imaging procedure or the use of DaTscan
Your doctor should advise you to:
    Increase your level of hydration (fluids) prior to and after receiving DaTscan, and to empty your bladder frequently for the first 48 hours following DaTscan administration

The safety information included here is not comprehensive. If you have any questions, please be sure to discuss them with your doctor.

For more information about DaTscan, call GE Healthcare at 800 654 0118.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch, or call 800 FDA 1088.

For more information about DaTscan, call GE Healthcare at 1-800-654-0118.

Please see the Full Prescribing Information for DaTscan at www.Datscan.com.

References: 1. Meara J, Bhowmick BK, Hobson P. Accuracy of diagnosis in patients with presumed Parkinson’s disease. Age Ageing. 1999;28:99-102. 2. Jain S, Lo SE,
Louis ED. Common misdiagnosis of a common neurological disorder. Arch Neurol. 2006;63:1100-1104.