An Update On The Diagnosis And Treatment Of Parkinson Disease
Parkinson disease is the second most common neurodegenerative disorder after Alzheimer disease. Parkinson disease typically develops between the ages of 55 and 65 years and occurs in 1%2% of people over the age of 60 years, rising to 3.5% at age 8589 years. About 0.3% of the general population is affected, and the prevalence is higher among men than women, with a ratio of 1.5 to 1.0. Parkinson disease may be more common among white people than those of Asian or African descent however, the data are conflicting., In 2011, the estimated number of people living with Parkinson disease in Canada had reached 85 200. By 2031, the projected number of people with this disease will double.,
Management remains complicated over the course of the disease and should be individualized based on the patients quality of life at each stage of disease. There have been many advancements in the management of Parkinson disease and ongoing research. Many options are now available. This review presents current treatment strategies and recommendations in managing motor and nonmotor symptoms in the various stages of Parkinson disease. Methods for developing this review are outlined in .
Tests To Rule Out Other Conditions
Blood tests can help rule out other possible causes of the symptoms, such as abnormal thyroid hormone levels or liver damage.
Hydrocephalus due to atrophy can occur with some types of dementia and would be visible with one of these imaging tests. If the person has neurologic symptoms but a normal scan result, Parkinsons disease may be present.
The doctor a lumbar puncture to rule out inflammation or a brain infection.
How Is Parkinson Disease Treated
Dopaminergic medications are the mainstay of symptomatic therapy for motor symptoms in Parkinson disease. The mechanisms of action, starting and target doses and adverse effects of medications are summarized in Appendix 2, available at www.cmaj.ca/lookup/suppl/doi:10.1503/cmaj.151179/-/DC1. Discovered in the 1960s, levodopa was the first symptomatic treatment for Parkinson disease, followed by the availability of dopamine agonists and monoamine oxidase B inhibitors. Until recently, the decision regarding which treatment to initiate has been debated. There is no one medication that is recommended for treatment initiation currently, but factors such as symptom severity, embarrassment, ability to perform activities, cost and patient preference should be taken into account. If symptoms are very mild, the patient may choose not to begin therapy.,
Because patients with early-onset disease are more likely to develop levodopa-induced abnormal movements , dopamine agonists are often introduced as initial treatment however, this early advantage of dopamine agonists over levodopa diminishes over time . There is also some controversial evidence for neuroprotection with the monoamine oxidase B inhibitor rasagiline at the 1 mg daily dose however, its cost is not covered in most provinces and may require application to the exceptional access program, as is done in Ontario.
What Is The Prognosis
Life expectancy is decreased in Parkinson disease , and medical treatments do not appear to alter mortality or delay the onset of nonmotor symptoms. Although progression is slower in patients with early-onset disease and there is longer absolute survival, this comes at the expense of increased years of life lost ., Late-onset Parkinson disease is associated with more rapid disease progression and cognitive decline, which may be related to a lack of compensatory strategies against cell death. Data on the long-term outcomes and in the older population are lacking.
Prognostic factors are summarized in . Patients with early-onset disease were slower to reach stage IIIV on the Hoehn and Yahr scale . The distribution of Hoehn and Yahr staging according to disease duration is listed in Appendix 8b. In the Rotterdam Study, Parkinson disease was associated with an increased risk of dementia and increased risk of death . When dementia prevalence was controlled for, risk of mortality was only slightly higher than among the general population.
What Tests Or Investigations Are Available To Help With Diagnosis
Parkinson disease is a clinical diagnosis, and magnetic resonance imaging may be used only to exclude other causes, as listed in Appendix 1. Advancements in neuroimaging studies, including transcranial Doppler ultrasonography, positron emission tomography , single-photon emission computed tomography , morphometric MRI studies, tractography, functional MRI and perfusion imaging are being used to differentiate idiopathic Parkinson disease from other parkinsonian disorders.,
Radionuclide imaging modalities like PET and SPECT, using a dopamine transporter ligand, have become the best approach to assess dopamine metabolism and deficiency. Tracer uptake is reduced maximally in the posterior or dorsal striatum and is asymmetric in Parkinson disease.,
A subgroup of patients suspected of having new-onset Parkinson disease will have no evidence of dopaminergic deficit on dopamine transporter SPECT and fluorine-18 fluoro-L-dopa PET imaging scans. In this group of patients, progression of disease, by imaging or clinical measures, is minimal, as is their likelihood of developing idiopathic Parkinson disease. However, a few may eventually be diagnosed with Parkinson disease, based on clinical progression, imaging and genetic evidence and a positive response to levodopa.
There are currently no biomarkers of proven clinical utility. Cerebrospinal fluid levels of -synuclein may predict cognitive decline but do not correlate with motor progression.
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How Is Parkinson’s Disease Diagnosed
Your doctor will ask questions about your symptoms and your past health and will do a neurological exam. This exam includes questions and tests that show how well your nerves are working. For example, your doctor will watch how you move. He or she will check your muscle strength and reflexes and will check your vision.
Your doctor also may check your sense of smell and ask you questions about your mood.
In some cases, your doctor will have you try a medicine for Parkinson’s disease. If that medicine helps your symptoms, it may help the doctor find out if you have the disease.
There are no lab or blood tests that can help your doctor know whether you have Parkinson’s. But you may have tests to help your doctor rule out other diseases that could be causing your symptoms. For example:
- An MRI or CT scan is used to look for signs of a stroke or brain tumor.
- Blood tests check for abnormal thyroid hormone levels or liver damage.
Another type of imaging test, called PET, sometimes may detect low levels of dopamine in the brain. These low levels are a key feature of Parkinson’s. But PET scanning isn’t commonly used to evaluate Parkinson’s. That’s because it’s very expensive, not available in many hospitals, and only used experimentally.
What Are My Next Steps
If your doctor doesnt diagnose Parkinsons, they can help you find out what the best next step is depending on what condition they suspect. In some cases, treatment may be as simple as changing the dosage of a medication that may be leading to Parkinsons-like symptoms.
Receiving a Parkinsons diagnosis can be overwhelming. If your diagnosis is confirmed, contact a movement disorder specialist as soon as possible. A specialist can help you develop a strategy to delay the onset of more severe disease and manage symptoms youre already experiencing.
What Tests Might I Have
People who have Parkinsonâs disease donât make enough of a brain chemical called dopamine, which helps you move. If those first tests donât show a reason for your symptoms, your doctor may ask you to try a medication called carbidopa-levodopa, which your brain can turn into dopamine. If your symptoms get much better after you start the drug, your doctor probably will tell you that you have Parkinsonâs disease.
If the medication doesnât work for you and thereâs no other explanation for your issues, your doctor might suggest an imaging test called a DaTscan. This uses a small amount of a radioactive drug and a special scanner, called a single photon emission computed tomography scanner, to see how much dopamine is in your brain. This test can’t tell you for sure that you have Parkinson’s disease, but it can give your doctor more information to work with.
It can take a long time for some people to get a diagnosis. You may need to see your neurologist regularly so they can keep an eye on your symptoms and eventually figure out whatâs behind them.
Can Parkinsons Disease Be Diagnosed By How You Smell
Theres evidence that people with Parkinsons disease may emit a specific type of scent, which is related to increased sebum production. However, doctors have not developed a way to use this odor to diagnose the disease. More research is being done to see how the finding can help with diagnosis and treatment.
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Validating A New Biomarker
Hansson and his colleagues developed a blood test that is, essentially, a variation on an existing test capable of detecting neurofilament light chain protein in spinal fluid. This protein is a component of nerve cells, and when these cells die, it can be detected in both spinal fluid and blood.
Because spinal fluid is not easily obtained by a primary care doctor, this diagnostic test is not very useful, so Hansson developed a blood test and investigated its accuracy in the new study.
When validating a new biomarker for disease, one should always analyze at least two different to make sure that the results are reproducible, said Hansson, who added that participants should also include both early- and late-stage patients established at different clinics.
All told, a total of 244 people with Parkinsons and 79 healthy volunteers serving as a comparison group participated in Hanssons study, along with 181 patients with atypical parkinsonism disorders.
Of these, 88 patients had multiple system atrophy, which impairs the bodys involuntary functions such as heart rate, blood pressure and digestion.
Seventy patients had progressive supranuclear palsy, which affects movement, walking, balance, speech, swallowing, vision, mood and thinking.
And 23 patients had corticobasal degeneration, which causes decreased movement on one side of the body, muscle rigidity, tremor and a disconnection between thought and action.
Medical History And Physical Exam
The process of diagnosing Parkinsons usually begins with the neurologist evaluating your medical history and performing a physical exam. For a formal diagnosis to be made, you need to have a general slowness of movement with either a resting tremor or rigidity.
During the physical exam, your doctor will have you perform a series of tests to monitor your movement. An example of a test they might use is a finger tap, where they measure how many times you can tap your finger in 10 to 15 seconds.
They will also look for signs that you may have another condition. A group of movement disorders collectively called parkinsonisms can produce symptoms that are indistinguishable from those of Parkinsons but are not the same. Usually, additional tests are needed to rule out these conditions as well.
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Datscan: A Test To Help In The Diagnosis Of Parkinsons
In 2011, the Food and Drug Administration approved an imaging test to help diagnose PD. In this test, a radioactive tracer, Ioflupane 123I, also known as DaTscan, is injected into the blood, where it circulates around the body and makes its way into the brain. It attaches itself to the dopamine transporter, a molecule found on dopamine neurons. Several hours after the tracer has been injected, special imaging equipment scans the head to detect the presence of DaTscan.
People with PD will typically have a smaller signal in a part of the brain called the striatum, where the ends of the dopamine neurons are meant to be. Here is a normal scan on the left, which would indicate a healthy dopamine system, next to an abnormal scan on the right, which would indicate an unhealthy dopamine system.
It is important to note that conventional MRI imaging will appear normal in PD and is therefore not helpful in confirming the diagnosis. Other atypical parkinsonian conditions, such as vascular parkinsonism however, can have abnormalities on MRI, so the test may be done to rule out other diagnoses.
Obtaining A Parkinson’s Disease Diagnosis
During the exam, the neurologist will look for cardinal symptoms of the disease. Facial expressions and features will be assessed. The doctor will look for signs of tremor while the patient is at rest. The doctor may watch how easily the patient stands up from sitting in a chair. The doctor may also stand behind the patient and gently pull back on the patients shoulders and look for how easily the patient can regain balance. Good responsiveness to levodopa also helps support the diagnosis of PD. However, taking levodopa may exclude patients from clinical studies that need to recruit recently diagnosed patients who have not yet had treatment . Participation in a clinical trial should be discussed with the doctor.
PD can be challenging to accurately diagnose, particularly in early stages of the disease, which is why a neurologist trained in movement disorders is critical. Approximately 5-10% of patients with PD are misdiagnosed, as many of the symptoms of PD are similar to other diseases. If the patient thinks that he or she has been misdiagnosed, a second opinion may help.1,2
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Why Has My Neurologist Prescribed Levodopa To Confirm My Diagnosis
Depending on your symptoms, your neurologist may ask you to take levodopa for a period of time.
Parkinsons disease is characterized by a deficiency of dopamine in the brain and mainly in the substantia nigra.Taking levodopa, a precursor to dopamine, can reverse the symptoms of Parkinsons disease. One dose is not enough. You will need to take several weeks of treatment with increasing doses until you get a result that will confirm your diagnosis.This test, when negative, can also invalidate the trail of other diseases related to Parkinsons disease
How Is Parkinson’s Diagnosed
This information looks at what parkinsonism is, how Parkinsons and other similar conditions may be diagnosed, and explains some of the tests that may be involved in the process.
Most people with a form of parkinsonism have idiopathic Parkinsons disease, also known as Parkinsons. Idiopathic means the cause is unknown.
Other less common forms of parkinsonism include multiple system atrophy , progressive supranuclear palsy , drug-induced parkinsonism and vascular Parkinsons.
If youre concerned about symptoms youve been experiencing, you should visit your GP. If your GP suspects you have Parkinsons, clinical guidelines recommend they should refer you quickly to a specialist with experience in diagnosing the condition .
Its not always easy to diagnose the condition. So its important that you see a Parkinsons specialist to get an accurate diagnosis and to consider the best treatment options.
Diagnosing Parkinsons can take some time as there are other conditions, such as essential tremor , with similar symptoms. There is also currently no definitive test for diagnosing Parkinsons.
How To Test For Parkinson’s Disease
This article was medically reviewed by Erik Kramer, DO, MPH. Dr. Erik Kramer is a Primary Care Physician at the University of Colorado, specializing in internal medicine, diabetes, and weight management. He received his Doctorate in Osteopathic Medicine from the Touro University Nevada College of Osteopathic Medicine in 2012. Dr. Kramer is a Diplomate of the American Board of Obesity Medicine and is board certified.There are 10 references cited in this article, which can be found at the bottom of the page. This article has been viewed 35,437 times.
Parkinsons Disease is a progressive neurodegenerative disorder affecting both motor and non-motor abilities. It afflicts 1% of those over 60 years of age.XResearch sourceJOHN D. GAZEWOOD, MD, MSPH,D. ROXANNE RICHARDS, MD,KARL CLEBAK, MD, Parkinsons An Update, The American Family Physician, 2013 Feb 15 87:267-273 It is a progressive disorder of the central nervous system. PD is caused by a lack of dopamine, a chemical that helps the parts of your brain responsible for motor function communicate with each other. This condition often causes tremors, muscle stiffness, slowness, and poor balance. If you suspect that you, or someone you love, has Parkinsons, it is important to know how you can diagnose this condition. Begin by trying to identify symptoms of the disease at home, and then see your doctor for an appropriate medical diagnosis.
How A Diagnosis Is Made
The bedside examination by a neurologist remains the first and most important diagnostic tool for Parkinsons disease . Researchers are working to develop a standard biological marker such as a blood test or an imaging scan that is sensitive and specific for Parkinsons disease.
A neurologist will make the diagnosis based on:
- A detailed history of symptoms, medical problems, current and past medications. Certain medical conditions, as well as some medications, can cause symptoms similar to Parkinsons.
- A detailed neurological examination during which a neurologist will ask you to perform tasks to assess the agility of arms and legs, muscle tone, gait and balance, to see if:
- Expression and speech are animated.
- Tremor can be observed in your extremities at rest or in action.
- There is stiffness in extremities or neck.
- You can maintain your balance and examine your posture.