The symptoms of Parkinson’s disease can affect every aspect of life.
Tremors are a very common symptom in PD, with 80% of individuals experiencing this symptom.9 Tremors are the uncontrollable slow, rhythmic shaking which are typically seen at rest in PD. The severity of PD is classified by if a person has tremors on one side or both sides.10
Bradykinesia, or slow movement, is a very common symptom of Parkinson’s Disease. The reduction in speed of movement reduces the ability for muscles to produce force.6 Bradykinesia causes slower and smaller movements. For example, the average walking speed of someone with PD is 94 cm/s whereas a safe speed to cross a crosswalk is 120 cm/s.11-13 If someone is bumped or missteps, they may not be able to step fast enough to catch themselves.14
Rigidity seen in Parkinson’s Disease is when there is a contraction of all the muscles in the trunk leading to overall stiffness and stooped posture.14 This increased stiffness in the trunk can significantly affect balance, and also cause increased muscle fatigue which can decrease the control of balance.15 Luckily, the medication used to treat PD, Levodopa, can significantly improve rigidity.14
Postural control is the ability to maintain balance. Overall postural control is decreased in individuals with Parkinson’s Disease due to extreme stiffness in the trunk muscles. 3 Postural instability has shown to begin within the first two years of diagnosis for about one third of patients.3 People with PD are effected in multiple areas of postural control including their balance while standing and balance during dynamic activities like walking.3 When someone has an outside perturbation, their reflexes aren’t effective to catch themselves like a healthy individual due to the decreased ability for their muscles to create power as seen with bradykinesia.
Gait (walking) changes are the main motor symptom seen in Parkinson’s Disease. Bradykinesia, rigidity, and postural instability all contribute to the gait disturbances seen.16 Specific changes include reduced walking speed, increased time with two feet on the ground (shuffling), and decreased step length.11,17,18 These gait changes are increased during the “off” stage of medication or when the dose is wearing off.19
The motor symptoms seen in Parkinson’s Disease contribute to the increased risk of falls. Individuals have increased risk of fall due to decreased postural control and bradykinesia.3 Not only are falls critical with the potential consequences of injury, but they can lead to fear of falling which effects quality of life. 53% of individuals with Parkinson’s Disease report fall-related activity avoidance due to their fear.20
This symptom is extensively discussed in the Freezing of Gait section. It is defined as reduced ability to step forward despite the intention to walk.5
Parkinson’s Disease involves a structure in the brain called the prefrontal cortex that causes changes in thought processing. This is important because it effects the ability of a person to plan a movement—specifically preparation, initiation and execution of a movement.21,22 Changing direction such as turning and performing tasks one after another are difficult for individuals with Parkinson’s Disease that have cognitive decline.17,22 It also affects the ability to have a goal and to make decisions. Individuals with cognitive deficits have an increased chance of experiencing Freezing of Gait.23
Dual tasking is when there is a motor task and cognitive task being performed at the same time such as walking while talking.11,17,18 Walking changes increase during a dual motor and cognitive task because they are distracted with their through processes and can’t think about walking.24
Individuals with Parkinson’s Disease have decreased frequency of saccades or fast eye movements between the areas of the room a person is looking at. Eye saccades help assess visual information in a room for someone to pay attention to while they walk.26 This plays a role in spatial awareness and overall attention to one’s surroundings during motor activities like walking. It plays a role in visual observation which could lead to trips and falls.26
Sleep disturbances are extremely common in individuals with PD. Individuals with PD sleep an average of 5 hours per night. This is due to a combination of factors including sleep apnea, insomnia, night time urinary frequency, and nighttime hallucinations.9
50% of those with Parkinson’s Disease will experience depression during the course of their diagnosis. Those with PD have changes in the neurotransmitters dopamine, norepinephrine, and serotonin which all regulate mood and motivation, therefore depression is very common. It is very important to discuss these changes in mood with a doctor.2
Hypophonia refers to the soft, hoarse, and monotone voice that many individuals with Parkinson’s Disease have. This is because there are changes in the vocal cord structure, not allowing for proper vibration of the vocal cords to produce sound.9
Fatigue is seen in early PD and can come before motor symptoms. Fatigue does not often improve with medication. It has been shown individuals with deficits in executive function or cognition may have increased fatigue.6
“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.”