A person experiences a new symptom and is concerned that something is wrong. The person has heard about Parkinson’s disease (PD) and is worried that his/her new symptom is indicative of PD. How can they find out? What are the first symptoms of Parkinson’s? Could these symptoms be related to Parkinson’s? These seems like straightforward questions, but they aren’t simple to answer.
What are the early signs of Parkinson’s Disease?
Non-Motor Symptoms Typically Show First
Parkinson’s symptoms can broadly be divided into two categories – motor and non-motor. Motor symptoms are ones that affect movements and include rest tremor, stiffness, slowness, difficulty with balance, shuffling gait, expressionless face and others. Non-motor symptoms are ones that do not affect movement and include mood disorders, cognitive disorders, sleep disorders, blood pressure variability, constipation, urinary frequency, pain syndromes and others.
It turns out that non-motor symptoms often precede motor symptoms, sometimes by decades! Typically, there are certain non-motor symptoms that are the most likely to appear early. These include:
- Loss of smell
- Constipation
- Sleep disorders – specifically rapid eye movement behavior sleep disorder (RBD)
- Depression
The tricky thing is, these four symptoms are relatively common in the population at large and therefore screening for these symptoms (for example in a primary care setting), to identify people who are at risk for developing PD will invariably capture more people than necessary and create much needless worry. However, once motor symptoms develop, it is incredibly common for people with PD to look back and be able to identify a non-motor symptom that was present first.
Why do non-motor symptoms develop first?
One theory is that Lewy bodies (clumps of the abnormally accumulated protein, alpha-synuclein found within nerve cells of PD patients’ brains) develop in the lowest parts of the brainstem first, causing specific non-motor symptoms that are controlled by the lower brain stem including constipation, sleep disorders and depression. Over time, the Lewy bodies migrate up the brainstem until they reached the midbrain, where they cause the motor symptoms of rest tremor, slowness and stiffness. This theory explains why particular non-motor symptoms are often the first to appear in PD.
“Pre-motor Parkinson’s Disease”
The research community has begun to call the constellation of early non-motor symptoms of Parkinson’s “pre-motor PD.” Currently however, a diagnosis of pre-motor PD can only be made with certainty after the motor symptoms have developed. Therefore, a true PD diagnosis continues to require the presence of motor symptoms.
What do I do if I have early non-motor symptoms of Parkinson’s?
You or someone you know may be concerned that you exhibit the classic early non-motor symptoms of Parkinson’s disease including loss of smell, constipation, RBD and depression, and that you may be at risk for PD. If this is the case and you want to look into it further, your next step should be to make a non-urgent appointment with a neurologist, who will conduct a neurological exam, the results of which may be normal or may show subtle motor symptoms consistent with PD.
If there are no motor symptoms present, the question of next steps is more complicated. It is not current clinical practice to perform DaTscans on people with only non-motor symptoms of PD to determine whether or not they have a dopamine deficiency. It may however, be prudent for such a person to be followed yearly by a neurologist to see if there is emergence of motor symptoms. As of yet, there is unfortunately no neuroprotective agent (drug) that has been proven to delay or prevent progression of symptoms of PD. Therefore, the medical community does not advocate such “screening” for PD in the same way that it advocates for cancer screenings, for example. When we have a neuroprotective medication or technology for PD, then screenings for PD will become essential.
One could argue however, that there is in fact such a treatment available, and that is exercise. There is evidence that exercise is neuroprotective, potentially affecting the progression of the disease. It may therefore be prudent for a person who is experiencing only the non-motor symptoms of PD to start or increase their level of exercise. First however, a visit to the neurologist to discuss his/her symptoms and concerns is strongly advised. For information on exercise and wellness for people with PD, take a look at our Be Active & Beyond booklet.
The first motor symptoms of Parkinson’s disease
When people ask “what are the early signs and symptoms of PD?” the answer they are typically expecting is one that involves motor symptoms. Early motor symptoms of PD (which usually, but not always, start after the appearance of at least one non-motor symptom) can be a subtle rest tremor of one of the arms or hands (sometimes of just one finger). A rest tremor is one that occurs when the limb is completely at rest. If the tremor occurs when the limb is suspended against gravity or actively moving, this may still be a sign of PD, but may also be a sign of essential tremor.
The initial motor symptom of PD may be a sense of stiffness in one limb, sometimes interpreted as an orthopedic problem (e.g. frozen shoulder). This sense of stiffness may be noted when a person is trying to get on his/her coat for example. A person may also experience a sense of slowness of one hand or a subtle decrease in dexterity of one hand. For example, it may be hard to manipulate a credit card out of a wallet or perform a fast, repetitive motor task such as whisking an egg. A person may notice that one arm does not swing when he/she walks or that one arm is noticeably less active than the other when performing tasks. Another motor sign may be a stoop with walking or a slowing down of walking. A family member may notice that the person blinks infrequently or has less expression in his/her face and voice.
These motor symptoms may be very subtle. Bottom line – if you are concerned that you may have an early motor or non-motor symptom of Parkinson’s disease, make an appointment with a neurologist for a neurologic exam to discuss your concerns.
Studies of patients with non-motor symptoms
The Parkinson’s Associated Risk Study (PARS) is an ongoing large study whose goal is to evaluate specific tests for their ability to predict an increased risk of PD. The ultimate goal is to find a set of tests that can predict the future development of PD. The study has evaluated smell tests, questionnaires that probe mood, bowel habits and sleep disorders, as well as the dopamine transporter (DAT) imaging test, commonly referred to as DaTscan.
A DaTscan involves injecting a small amount of a radioactive tracer into the bloodstream. The tracer makes its way into the brain and binds to the dopamine transporters, which are molecules on the surface of the dopamine neurons. In PD, there are fewer of these neurons and therefore there is less uptake of the tracer in the brain. A brain scan then determines if the amount of uptake of the tracer is normal or decreased. Currently, this test is approved to distinguish between PD and a neurologic condition known as essential tremor, a tremor disorder which is not caused by an abnormality of the dopamine system.
DaTscan is not yet approved to determine if patients who are experiencing only the non-motor symptoms of PD, in fact have PD. However, it is known that a DaTscan can be abnormal even before motor symptoms are present. The PARS study is investigating whether in the future, a DaTscan can be part of an algorithm (along with a smell test and perhaps non-motor symptoms questionnaires) to determine who is at risk of developing PD.
Another study following people with non-motor symptoms who have not yet developed motor symptoms is the Parkinson’s Progression Markers Initiative. This study follows people at risk of PD over time to see what is most predictive of developing PD.
Tips and takeaways
- The first symptom of PD often does not involve a problem with movements.
- However, non-motor symptoms associated with PD are quite common in the general population, so don’t panic. These symptoms are often only noted as consistent with PD once the motor symptoms emerge.
- Motor symptoms that tend to occur first are subtle rest tremors, changes in facial expression, slowing down of walking and decreased arm swing on one side with walking.
- If you are concerned about any motor or non-motor symptom, make an appointment with a neurologist. Try to make note of how often the symptoms affect you so you can give the doctor the most information possible.
- Exercise may be neuroprotective and may alter the progression of PD, so get moving! (with your doctor’s approval, of course).