How Parkinson’s Disease Is Diagnosed

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Diagnosing Parkinson’s disease can be complicated because there isn’t a specific blood test or screening test that can determine whether or not you have it.

Instead, Parkinson’s is diagnosed clinically, which means a doctor will examine you, review your symptoms and medical history, and diagnose accordingly. 

Parkinson’s disease is a neurological condition that can make movement difficult. If your general practitioner (GP) thinks you might have Parkinson’s, they may refer you to a neurologist who specializes in movement disorders for a diagnosis. 

It can be challenging to catch Parkinson’s in the early stages because the symptoms may be too mild to notice or meet the diagnostic criteria. Also, early Parkinson’s symptoms are often mistaken for typical signs of aging.

The symptoms of Parkinson’s disease are also similar to those of other health conditions, which may be misdiagnosed as Parkinson’s at first. Your doctor may suggest specific tests and scans to help eliminate other conditions that can mimic the symptoms of Parkinson’s disease.

Self-Checks/At-Home Testing

There isn’t really a test you can do at home to diagnose Parkinson’s. However, you can make note of your symptoms and report them to your doctor. 

These are some of the symptoms of Parkinson’s you might notice:

  • Tremors in your arms, legs, or head
  • Slower movements and difficulty with daily tasks
  • Hunched posture and poor balance
  • Difficulty walking and shuffling steps
  • Muscle stiffness and cramps
  • Difficulty writing and smaller penmanship
  • Softer, quicker, slurred, or monotonous speech
  • Fatigue or a general sense of unease
  • Difficulty chewing or swallowing
  • Restless leg syndrome
  • Loss of smell
  • Depression or anxiety

Chances are, your loved ones may notice some of these symptoms before you do. For instance, they may observe that your hands shake, your movements are kind of stiff, or you have trouble getting up from a chair.

Tests and Scales

Diagnosing Parkinson’s can involve a detailed medical history, a physical and neurological examination, physical exercises, a review of your symptoms, and tests and scans. These are some of the steps you can expect. 

Medical History

Your doctor will probably require a detailed medical history covering factors like your previous illnesses, medication, and family history to help determine whether you’re at risk for Parkinson’s. 

Age, for instance, is an important risk factor because Parkinson’s typically sets in after the age of 60, although early-onset Parkinson’s can sometimes begin before 50. Family history can play a role because some cases of early-onset Parkinson’s are inherited. While both men and women can get Parkinson’s, it is 50% more common in men than women.

Knowing what medicines you take—as well as those you have taken in the past—is also important because some medicines can cause side effects that mimic the symptoms of Parkinson’s.

Your doctor will also need to know what other medical conditions you have been diagnosed with because certain other conditions can also cause movement-related difficulties that are collectively referred to as “parkinsonism.”

Physical and Neurological Examination

Your doctor will conduct a physical and neurological examination. This can involve observing your behavior, movements, and mental state and conducting tests or asking you to perform certain exercises. 

These are some of the symptoms of Parkinson’s your doctor can determine visually:

  • Fewer spontaneous movements or hand gestures
  • Reduced frequency of blinking
  • Tremors in your hands while they are at rest, often only in one hand
  • Hunched posture or forward lean while walking
  • Stiff movements

These are some of the exercises your doctor may ask you to do to evaluate your movements, balance, and coordination:

  • Opening and closing your fist
  • Tapping your fingers, toes, and heels
  • Holding your arms out in front of you
  • Moving your finger from one point to another
  • Rotating your wrists or ankles
  • Standing from a chair
  • Walking freely
  • Maintaining balance despite a gentle bump or pull
  • Doing a series of rapid movements

Symptom Checklist

Clinicians use a checklist developed by the International Parkinson and Movement Disorder Society to help diagnose Parkinson’s disease. The checklist covers several psychological, physical, and movement-related symptoms. Your doctor will probably ask you if you have experienced each of those symptoms recently and, if so, how severe they were.

They may ask you questions like the following:

  • Have you needed help or been slow with personal hygiene tasks like brushing your teeth, bathing, getting dressed, combing your hair, or shaving?
  • Have you had discomfort in your body like aches, pains, cramps, or tingling?
  • Have you had trouble eating your food or using utensils?
  • Have you had problems following conversations, recalling things, thinking clearly, paying attention, or finding your way around your house?

This checklist reflects the most current understanding of the disease. Previously, clinicians used a checklist by the United Kingdom Parkinson’s Disease Society Brain Bank. 

Imaging and Lab Tests

Your doctor may order some imaging tests and laboratory tests. Imaging tests can include computed tomography (CT) scans and magnetic resonance imaging (MRI) scans. Laboratory tests can include blood tests and urine tests. 

While these tests and scans will not help diagnose Parkinson’s disease, they can help rule out other conditions that have similar symptoms. 

Your doctor may also suggest that you get a dopamine transporter scan (DaTscan). This scan requires a single-photon emission computed tomography (SPECT) scanner. It involves an injection of a small amount of a radioactive drug so that your doctor can study the dopamine systems in your brain (Parkinson's is a disease characterized by low dopamine levels). 

While a DaTscan cannot conclusively prove that you have Parkinson’s, it can help confirm your doctor’s diagnosis and eliminate other conditions. 

Diagnosing Parkinson’s Disease

Based on your physical and neurological exam and your responses to the checklist of symptoms, your doctor may be able to determine whether you have the following symptoms. 

Having two or more of the following symptoms can make Parkinson’s a possibility:

  • Bradykinesia (slower movements): This can happen because the rate at which your brain sends instructions to other parts of your body slows down. 
  • Rigidity: Your muscles may become stiff, which can be painful and make your movements rigid and limited. 
  • Tremors: Your hands, feet, or head may shake while you’re at rest. 
  • Impaired movement and balance: Parkinson’s disease can cause you to develop a hunch or forward lean while you walk and/or walk at a rapid, shuffling gait. It can also make it difficult for you to rise from a chair or maintain balance while standing or walking.

Your doctor will factor in your medical history, test results, and all your other symptoms while arriving at a diagnosis. 

Sometimes, it can be hard to diagnose Parkinson’s immediately, especially if you are in the early stages. In that case, your doctor might require you to come for follow-up visits where you will have to do similar tests and exercises.

How It All Fits Together

Diagnosing Parkinson’s disease can be tricky. The process relies heavily on your doctor’s judgment. In addition, the causes and risk factors of Parkinson’s are not entirely clear yet, which contributes to the difficulty in diagnosing this condition.

However, there have been efforts to try and detect this disease earlier. For instance, clinicians have started focusing more on prodromal symptoms, which are early symptoms that appear before movement-related difficulties begin. 

These symptoms include:

  • Loss of smell, which can sometimes occur years before other symptoms
  • Chronic constipation, without any other explanation
  • Rapid eye movement (REM) behavior disorder, which causes sleep disturbances
  • Mood disorders, like depression and anxiety

If your symptoms indicate Parkinson’s disease, your doctor may start you on dopamine therapy to help treat it. Showing a significant improvement with high doses of dopamine can help confirm that you do, indeed, have Parkinson’s disease.

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By Sanjana Gupta
Sanjana is a health writer and editor. Her work spans various health-related topics, including mental health, fitness, nutrition, and wellness.