How is Parkinson's Disease Diagnosed?
My personal journey to a Parkinson's Disease diagnosis was long, complicated, and often frustrating. Most of the doctors I saw didn't even consider PD as an option due to my age (most people are diagnosed at 60 or older, and I'm "only" 45). I finally made it to a neurologist who was unwilling to give me a firm diagnosis and instead declared, "I don't want you to leave thinking you don't have it." This led me further on my journey to find a movement disorder specialist. Finally, after a brief examination, he declared me "as close to the textbook definition of Parkinson's Disease as any living human can be." It wasn't my favorite news to receive, but I was glad to finally put a name to my symptoms and begin treatment. It was closure, but instead of actually closing anything, it opened a whole new set of doors for me.
The problem is that there is no definitive test for Parkinson's Disease. It doesn't show up in a blood test. There is no scan that will result in a 100% positive diagnosis. Instead, the diagnosis is "clinical." This means a specialist evaluates several aspects ranging from physical symptoms to mental health and even sense of smell.
I started thinking about this post when I read my doctor's notes after that first fateful visit that I was formally diagnosed. Buried in the report was a chart with some numbers and a score: 21. It's not a pass or fail scoring system, but a way to more objectively track the progression of the disease. A higher score means more symptoms and/or increased severity of those symptoms.
Three things can help symptoms: healthy food, regular exercise, and drugs. Only one of those is known to slow the progression of the disease, and that's intense exercise. I started training every day, doing The Jangle first thing in the morning, followed by burpees, plank holds, squats, and push-ups. I also jog 2 - 3 times per week and on the other days follow 20 to 30-minute Amplitude, Mental Agility, and Power (AMP) workouts designed specifically for Parkinson's Disease. I was looking forward to my next score.
The combination of training and taking a dopamine agonist (ropinirole) is working well because my score dropped to 16 at my last visit. Here's what that improvement looks like:
So where does this mysterious score come from? I'll explain in a minute.
As of me writing this, there is no definitive test for Parkinson's Disease. It is considered a "clinical diagnosis" performed by a specialist familiar with the disease. There is no single symptom that by itself indicates Parkinson's Disease, no blood test that can indicate a positive result, and no special scan that, by itself, can make the determination. Let's explore what's involved with how Parkinson's Disease is diagnosed.
A Clinical Diagnosis
A firm diagnosis relies heavily on a movement disorder specialist (a neurologist with special training in movement disorders like Parkinson's disease). The specialist will assess a variety of symptoms. Some are based on questions, like:
👨⚕️ "Have you ever physically acted out your dreams while sleeping?"
👨🦲 "Why, yes. Just the other day, I had a dream that I was falling. I threw out my arms right when I was about to hit the ground and managed to hit my wife. Sorry, love."
👩 "You're lucky it's a symptom of the disease, or you'd be sleeping on the couch from now on."
During the visit, the specialist is constantly making observations. Some symptoms include apathy, mood swings, memory loss and difficulty thinking. I am happy I don't exhibit those symptoms right now. Here is the official assessment from my last visit:
Mental Status: Alert, oriented x 3. Able to relate history without difficulty. Attentive. Language is fluent with intact repetition and comprehension. Normal prosody. There were no paraphasic errors. Recent and remote memory intact. Good fund of knowledge.
(I had to look up prosody: "the patterns of rhythms and sounds used in poetry." It makes me wonder what would have happened if I broke into freestyle rap during my visit). Paraphasia is a speech disturbance.
Next, he asked me to cross my arms in front of me and rise from the chair using just my legs. Then I did some walking.
Walk This Way
Parkinson's Disease disrupts the way I walk. If you look carefully, you'll notice that I don't swing my left arm. It's not intentional. Here is what my specialist had to say about my gait:
Rises from chair without use of arms. Good initiation. Narrow-based. Normal stride length, step height, and absent left arm swing. No freezing or festination. Turns in 2 steps. Pull test is normal.
The "pull test" plays out like this: I stand tall, facing a wall. The doctor walks up behind me, grabs my shoulders, and yanks me back so I lose my balance. I quickly catch myself by stepping back. Apparently as the disease progresses, I'll be less able to stop the fall and therefore will end up in his startled embrace.
All of these assessments feed into a standard system known as...
(Drum roll, please 🥁🥁🥁)
... the "Movement Disorder Society-Sponsored Revision of the Unified Parkinson’s Disease Rating Scale (MDS-UPDRS)." It makes for light weekend reading if you're interested. The score he recorded is the "motor symptoms" portion of the test (MSD-UPDRS-Motor). Each element is ranked on a scale from 0 (normal) to 4 (severe). These are the areas and my scores between the first and second visits (improvements in bold):
0 - 0 🗣 Speech
0 - 0 😲 Facial expression (a slack face is one symptom)
0 - 0 ➡ Right ⬆ upper body rigidity
2 - 2 ⬅ Left ⬆ upper body rigidity
2 - 0 ↔ Center ⬆ upper body rigidity
1 - 0 ➡ Right ⬇ lower body rigidity
1 - 0 ⬅ Left ⬇ lower body rigidity
0 - 0 ➡ Right ✋ finger tapping
1 - 2 ⬅ Left 🤚 finger tapping
0 - 0 ➡ Right ✋ hand open/close
2 - 1 ⬅ Left 🤚 hand open/close
0 - 0 ➡ Right ✋ hand pronation
2 - 2 ⬅ Left 🤚 hand pronation
2 - 1* ➡ Right 🦶 toe tapping
2 - 2 ⬅ Left 🦶 toe tapping
0 - 0 ➡ Right 🥾 foot stomping
0 - 0 ⬅ Left 🥾 foot stomping
0 - 0 🪑 Rising from chair
1 - 1 🚶♂️ Walking
0 - 0 ❄ Freezing (body stops moving)
0 - 0 🧍 Postural stability
0 - 0 🧍 Posture in general
1 - 1 Global Bradykinesia (slow movement)
0 - 0 ➡ Right 🧍 Postural tremors
0 - 0 ⬅Left 🧍 Postural tremors
0 - 0 ➡ Right kinetic (moving) tremors
1 - 1 ⬅ Left kinetic (moving) tremors
0 - 0 ➡ Right ⬆ upper 🛌 resting tremors
2 - 2 ⬅ Left ⬆ upper 🛌 resting tremors
0 - 0 ↔ Center ⬆ upper 🛌 resting tremors
0 - 0 ➡ Right ⬇ lower 🛌 resting tremors
0 - 0 ⬅ Left ⬇ lower 🛌 resting tremors
1 - 1 Constancy or prevalence of resting tremors over time
I put an asterisk next to the score for "➡ Right 🦶 toe tapping" because that's the only symptom I have on the right side. That is also what puts me at Stage 2 out of 5 of the disease. It's OK ... the improvements were cause for celebration!
It's like DaT
... and that's the way it is. Huh!
A DaTSCAN™ is another component of overall PD diagnosis. The procedure can identify areas of the brain that have low dopamine levels. By itself, that's not enough for a diagnosis of Parkinson's Disease because there are a variety of diseases that can contribute. It is typically used to confirm a diagnosis when it's uncertain whether the cause is PD or something else, like essential tremors. In my case, it was a home run. I'll explain what I mean in a minute.
The procedure involves (and is named for) a radioactive molecule that shares a molecular structure similar to cocaine. Don't ask me why they use a cocaine analogue; your guess is as good as mine. Here's a selfie I took with the radiopharmaceutical that is generically named ioflupane i-123.
The thyroid does a great job of filtering out radioactive isotopes from the bloodstream, so administering the drug by itself would result in uptake by the thyroid and increase the risk of cancer. To minimize this risk, I started my morning by drinking potassium iodide. This is almost all absorbed by the thyroid and has a "thyroid blocking effect." Essentially the thyroid can't extract any more chemicals because it's saturated with the non-radioactive solution. I waited an hour for my thyroid to be satisfied, then received the injection of radiation. Then I waited another four hours to begin glowing before they brought me in for the actual scan.
The result of my scan:
"There is decreased radiotracer uptake within the bilateral putamen. There is also decreased radiotracer uptake in the right caudate head. Abnormal DaTscan, scintigraphic findings are consistent with nigrostriatal degeneration as can be seen in Parkinsonian syndromes."
In plain English, there is significantly less dopamine in the right side of my brain. That portion of the brain controls the left side of my body where most of my symptoms are present. It confirmed that I wasn't experiencing "just" an essential tremor. I have Parkinson's Disease.
Drugs Tell All
The only other way I'm aware of confirming the diagnosis is through drugs. I've seen it mentioned in quite a few places that doctors unsure of a definitive diagnosis will prescribe the canonical Parkinson's Disease treatment: Levodopa. If symptoms don't improve after several weeks, it means the patient probably does not have Parkinson's Disease. If they do improve, it is much likelier they do have PD.
Tale of a Nosy Biomarker
Several years ago a Scottish nurse noticed her husband had a distinct scent that she assumed was unique to him. She later realized that other people in his support group smelled the same. She suspected she could smell Parkinson's Disease. A test was arranged for her to smell shirts and determine if they belonged to someone with Parkinson's Disease or not. She was highly accurate. In fact, one person she said had the scent who did not have the disease was diagnosed a short time later.
As a result, researchers have begun work to identify the components of the scent. Some programs are training dogs to detect PD. It turns out a certain combination of chemicals may prove to be a positive biomarker for the presence of PD. If this is true, a definitive test may finally be in sight. If you're interested in learning more, read: The Smell of Parkinson's Disease.
No one wants a Parkinson's Disease diagnosis. People with Parkinson's (PWP) often share the same joke when I join a support group or online community. "Welcome to the club you never wanted to join." It's helpful to know how it's diagnosed and what to expect. I certainly wish I knew more when I started my journey. Fortunately, I was able to obtain a highly confident diagnosis and start down the path of addressing my symptoms. A huge source of knowledge and inspiration has been the Michael J. Fox Foundation for Parkinson's Research.
I donate a portion of every paycheck to further research for a cure. If you would like to help out, consider donating to my Parkinson's Disease blog fundraiser. Thanks for your time and attention, and have a phenomenal rest of your week.