Diagnosing Parkinson’s

Diagnosis of Parkinson’s in its early stages is sometimes difficult because its features may resemble other disorders (eg. some patients can present as a frozen shoulder and may be asked to see an orthopedic surgeon rather than a neurologist). Often the family physician may refer one to a neurologist for confirmation of the diagnosis. Sometimes it may take a few years for one to be diagnosed with Parkinson’s which may be frustrating.

Usually the doctor reviews one’s medical history, followed by a thorough clinical examination. Here the doctor then observers for certain signs and symptoms like generalized slowness of movement (bradykinesia). Your arms will be observed for tremor and your limbs and neck will be checked for stiffness (rigidity).  Also your doctor will observe your walking style and look for small steps.  The doctor may pull you backwards in order to check your balance (postural instability).   Since, tremors, bradykinesia, rigidity and postural instability are the four cardinal symptoms of Parkinson’s, observing any of these in oneself, is reason enough to bring it to the notice of one’s doctor.

Diagnosis of Parkinson’s is purely based on a clinical exam since there are no standard tests developed to diagnose Parkinson’s. At times, additional tests may be ordered by the doctor to rule out other conditions that mimic Parkinson’s.

A favorable response to Levodopa (a drug for Parkinson’s) is also considered as supportive of the diagnosis.  However, the method of diagnosing differs from doctor to doctor. Since Parkinson’s closely resembles other neurological disorders, it may often go misdiagnosed.

Is a second opinion required?

Taking a second opinion is purely a personal choice. Often a physician may refer one to the neurologist for diagnosis. However if one isn’t convinced about the diagnosis, one could consider seeking the opinion of a movement disorder specialist.

Receiving the diagnosis

A diagnosis of Parkinson’s is often life changing and can be emotionally difficult to take. But, remember you aren’t alone.  At this time, it is important to seek the support of your family and healthcare team which will help you in coming to terms with Parkinson’s & managing the condition in an optimum way.

You may find it useful to contact us at our helpline number or write to us at pdmds.india@gmail.com  or visit our section on Dealing with the Diagnosis.

Are there any tests to diagnose Parkinson’s?

There are no simple tests like a blood test etc. to diagnose Parkinson’s.  Researchers are working to develop a test that can identify Parkinson’s in its early stages itself.

Brain scans may help in detecting the loss of dopamine in the brain and reduce misdiagnosis. Neuro imaging that may be done might include:

CT scan (Computerized Tomography):
This includes a series of X-rays that are passed through different directions that provide an anatomical view of the brain. This helps in excluding blood diseases and tumors of the brain which can mimic Parkinson’s.

MRI scan (Magnetic Resonance Imaging):
This uses magnetic currents to create images of the brain. This gives a better view of the deep structures of the brain. MRI scans are usually normal in Parkinson’s but are useful at times in identifying conditions that can mimic Parkinson’s and helps in distinguishing Parkinson’s from other forms of Parkinsonism (like Progressive Supranuclear Palsy (PSP) or Multiple System Atrophy (MSA).

DaTSCAN (Dopamine transporter Scan):
An FDA approved imaging technique since 2011, a DaT scan helps in capturing images of the dopamine system in the brain. In this, a radioactive dye is injected into the body which then binds to dopamine releasing neurons. Signals are then recorded by specialized cameras.  A low signal (i.e. an abnormal DAT scan) indicates that there are fewer dopamine producing neurons, supporting the diagnosis of Parkinson’s.  DaT scans can also be used for differentiating Parkinson’s from essential tremor.However, it should be noted that a DaT scan cannot be used to diagnose Parkinson’s by itself; it also needs to be supported by a clinical examination. DaT scans can be abnormal in other Parkinson mimics as well including PSP and MSA hence have to be interpreted in the light of the clinical findings.