The Causes and Symptoms of Parkinson’s Disease

Parkinson’s Disease can affect every aspect of life

PD is a neurodegenerative disease, which means the symptoms progressively become more noticeable over time. That’s almost the only rule when it comes to PD, because every single person experiences slightly different symptoms, at a different severity, in a different combination, and at different times.

Here, we’ll discuss the most common symptoms. As you read these, be aware that not every symptom may be present, and they progress at different rates in everyone.

Motor Symptoms

Motor symptoms affect movement and balance, and they are usually noticeable enough that others can them.


Tremors: Perhaps the most well known and recognizable symptom, tremors are very common in PD, with 80% of individuals experiencing this symptom.9 Tremors are the uncontrollable slow, rhythmic shaking which is typically seen at rest in PD. The presence of tremors on one or both sides is the measure of severity of PD for any individual.10


Bradykinesia: This Greek word means slow movement, and it’s another very common symptom. Bradykinesia causes slower and smaller movements and reduces the ability of muscles to produce force.6 The average walking speed of someone with PD is 94 cm/second whereas a safe speed to cross a crosswalk is 120 cm/second.11-13 If someone is bumped or missteps, they may not be able to react by stepping fast enough to avoid falling.14


Rigidity: Contraction of all the muscles in the upper body leads to overall stiffness and stooped posture.14 This increased stiffness can significantly affect balance. It also causes increased muscle fatigue, which can further decrease the control of balance.15 Levodopa, a medication used to treat PD, can significantly improve rigidity.14


Balance: About one third of PD patients begin to experience poor and unstable balance within the first two years of diagnosis.3 The rigidity discussed above affects balance while standing and during dynamic activities like walking.3 The decreased speed and power of reflexes resulting from bradykinesia particularly impact balance in the event of a misstep, bumping an object or being nudged.

Walking changes

Walking changes: Distinctive walking patterns are the main motor symptom seen in PD. You may see these referred to as Parkinson’s Walk, or Parkinsonian Gait. Specific changes include reduced walking speed, short steps in which the feet don’t lift far from the floor, and increased time with two feet on the ground, commonly referred to as shuffling.11,17,18

Rapid, short steps may also be evident, especially where the upper body is hunched forward. This, called festinating gait, or festination, uses increased speed to try to keep from overbalancing, as the center of gravity is too far forward.

Bradykinesia, rigidity, and balance instability all contribute to these walking patterns16 and they are usually more evident without medication or when a dose of medication is wearing off.19


Falls: Given the symptoms discussed above, it’s not difficult to see why people with PD are up to 9 times more likely to fall. This not only has the potential of injury, but the understandable fear of falling is a leading cause of avoiding activity.20

Freezing of Gait

Freezing of gait: As PD progresses, people can experience complete freezing, in which their feet feel like they are glued to the floor, and they simply cannot walk. We’ll cover this debilitating symptom in depth on the pages that follow.

Non-Motor Symptoms

In Understanding Parkinson’s , we briefly discussed other structures in the brain that the basal ganglia communicates with, which aren’t directly involved in movement.  Dopamine is the transmitter that conveys messages between all of these structures, so as the body’s dopamine levels drop away, non-movement related symptoms can also appear.

Cognitive Changes

Cognitive changes: The prefrontal cortex at the front of your brain is responsible for thought processing. While it’s not directly involved in movement commands, it takes care of planning and decision making, so it impacts on movements that are not automatic. Difficulty in changing direction, performing tasks one after another, setting a goal and making decisions generally are examples of this kind of cognitive decline. 21,22 These cognitive changes also come with an increased chance of experiencing freezing of gait. 23

Dual Tasking

Dual tasking: Performing a motor task like walking, at the same time as a cognitive or thinking task such as talking, can become progressively more difficult.11,17,18 Changes in walking can be more noticeable during a dual motor and cognitive task, as thinking takes priority.24

Slowed eye movement

Slowed eye movement: Normally, our eyes are capable of extremely rapid movement that assesses visual information. 26 These rapid movements are known as saccades, and they play a key role in keeping us safe by being aware of our surroundings. A reduction in these normally fast movements makes it slower and more difficult for us to identify obstacles and to determine where we are in relation to what’s around us. This in turn can be a contributing factor to falls.

Sleep disturbance

Sleep disturbance: Sleep disorders are a very common symptom. Just as those with PD need more sleep to allow the body to repair, the brain changes that are part of PD can make it more difficult to fall and stay asleep. Sleep apnea, insomnia, frequent urges to urinate overnight, and vivid dreams, which may cause sometimes violent physical reactions because they seem so real, are all commonly reported.9


Depression: Feelings of depression are extremely common, with half of those with PD experiencing depression at some point, as a direct result of the disease.

Dopamine doesn’t just take care of transmitting messages in the brain — it’s also directly responsible for our ability to feel pleasure, so plays a vital role in regulating mood and motivation. It is very important to discuss these changes in mood with a doctor.2

Speech and voice disorders

Speech and voice disorders: A quieter, monotone and breathy sounding voice is common to around 89% of people with PD. You may hear this soft voice referred to as Hypophonia.

The same interruptions to the nervous system that cause tremors, slowness of movement and rigidity can affect the muscles involved in speech, so loudness, clarity and normal breathing become more difficult. 9 Additionally, changes to sensory processing may mean people don’t realize their voice is becoming softer and less distinct.


Fatigue: Feelings of fatigue are often seen in early PD, and can occur before motor symptoms are evident. Fatigue seldom improves with medication.

“It’s a very humbling disease. I mean, you’re humbled because you know it’s your own independence and all of a sudden you don’t have it anymore. You want to take a step, and you can’t.”

~ Earl, a person with Parkinson’s

Learn more about Parkinson’s Disease

What Causes Parkinson’s Disease?

Understanding Parkinson’s Disease

Introducing Cueing

Although Parkinson’s Disease is a very involved neurological disease, latest research shows that physical therapy and external cues from technology such as NexStride can significantly improve quality of life and overall mobility.5

Cueing In NexStride

nextstride laser feature
NexStride is the first multi-cue daily assist mobility device that attaches to any standard cane, walker, or walking pole. Users can activate the audio cue, visual cue, or both, and adjust to preferred speed and distance.

These visual and audio cues help users re-establish the connection between the brain and the body and allow the user to walk smoothly again.

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