Signs and Symptoms of Parkinson's Disease

Parkinson’s disease is a neurological disorder characterized by tremors, slow or interrupted movements (known as “bradykinesia”), rigidity, and muscle stiffness, as well as an inability to maintain posture and coordination, among others. Primarily affecting people over 60, this chronic and incurable disease is progressive, with symptoms worsening over time. It can also lead to Parkinson’s dementia, in which there are serious cognitive and memory problems.

Parkinson's disease is the second most common neurological disorder worldwide—affecting 2–3% of those over 65. It can significantly impact both physical and mental health. This article breaks down the symptoms of this disease, as well as what signs tell you it’s time to seek help.

Cardinal Symptoms

At its core, Parkinson’s disease is caused by the degeneration and death of brain cells in the basal ganglia of the brain. This region regulates your motor skills—your ability to move and stay balanced—so the primary, or “cardinal” symptoms of this condition affect your ability to move. There are four such symptoms of Parkinson’s disease:

• Tremor: Tremors, or uncontrollable shaking in the arms, hands, feet, jaw, tongue, and lips, are characteristic of Parkinson’s disease. This generally arises on one side of the body first and occurs while these parts of the body are at rest, lessening with activity.  
• Bradykinesia: This is characterized by a slowing or consistent interruption of physical movement. Initiating movements becomes challenging and is accompanied by feelings of fatigue, lack of coordination, and weakness. About 80% of patients experience bradykinesia at the onset of symptoms.
• Rigidity: Rigidity is stiffness in the muscles and resistance to movement or any applied pressure. As with bradykinesia, this symptom tends to set on first on one side of the body before spreading. Characteristic signs include striatal hand—a “locking” of the knuckles and joints in the hand—stooped posture, and reduced arm swing when walking, among others.
• Postural instability: An inability to maintain proper, erect posture is another hallmark of Parkinson’s disease. This issue can affect balance and ability to move, leading to falls. It is typically a sign of more advanced cases.

Additional Motor Symptoms

Parkinson’s disease can also cause a host of other problems with motor function. These can be broken into four categories: those affecting the head or face (craniofacial), movements of the eye (visual), the system of muscles and bones (musculoskeletal), and the ability to walk (gait).

Craniofacial Symptoms

Several Parkinson’s disease symptoms directly affect the face and head. These include:

• Hypomimia, or “masked face,” which is the inability to produce facial expressions
• Reduced amount of time you blink spontaneously
• Hypokinetic dysarthria, an inability to coordinate muscles for speech and breathing
• Hypophonia, which is an inability to speak loudly, leading to a quiet, breathy, or monotone voice
• An inability to chew properly, known as dysphagia
• Excessive drooling

Visual Symptoms

Parkinson’s disease can also affect the visual system and the movements of the eye. This can lead to several issues:

• Hypermetric saccades: Saccades are when your eye rapidly shifts focus from one object to another. Severe cases of Parkinson’s disease impact this ability, leading to difficulties with focusing.
• Blurred vision: Blurriness and lack of focus in the visual field may arise due to the progression of the disease.
• Impaired contrast sensitivity: Contrast sensitivity refers to your ability to see the outlines of small objects and make out subtle differences in patterns and textures. Parkinson’s disease can impair the ability to perceive details.
• Impaired vestibulo-ocular reflex: This is the ability to maintain a gaze and focus during head movements. Parkinson’s disease’s impact on motor function reduces the eyes’ ability to compensate for motion.
• Impaired convergence: Convergence is the ability of the eyes to work together to focus on objects nearby, and this can also be impacted by Parkinson’s disease. In addition, patients may experience an inability to gaze upward.
• Lid-opening apraxia: Another effect of disease progression is the inability to voluntarily open your eyes after they’ve been closed. 

Musculoskeletal

Alongside the cardinal signs of Parkinson’s disease are other impacts on the muscular and skeletal systems. These include:

• Micrographia: An inability to make fine movements, which affects handwriting and speech
• Dystonia: Involuntary muscle contractions cause repetitive and twisting movements, which can affect posture
• Myoclonus: A recurrent period of involuntary muscle twitching and jerking
• Kyphosis and/or scoliosis: Different types of curving or bending of the spine
• Camptocormia, or “bent spine syndrome”: An abnormal forward bending of the spine while upright or walking, potentially resulting in a stooped posture
• Pisa syndrome: A sideways bend in the spine while upright or walking

Gait

Largely as the result of Parkinson’s disease’s effects on muscle and motor control, changes can occur in your pattern and manner of walking. This can lead to a distinctive “Parkinsonian gait,” characterized by shuffling or very short steps, sudden stops or freezing when walking, and festination, which is a tendency to speed up and shorten repetitive movements. Festination can cause muttering or inaudible speech.  

Cognitive Symptoms

Many people with Parkinson’s disease—between 24% and 31% of patients—experience cognitive decline, or dementia. This is characterized by problems with memory, difficulty concentrating or completing tasks, and trouble paying attention. It can develop gradually or rapidly.

Parkinson’s dementia is a type of Lewy body dementia, meaning it is caused by deposits of the protein alpha-synuclein in the brain. Over time, it can severely impact your quality of life and your ability to live independently.   

In addition, Parkinson’s disease is also associated with psychosis and the development of visual hallucinations. This has been found to arise in 20–40% of patients who are taking medications for the condition. It can increase in severity over time. This psychosis has been linked both to the development of Parkinson’s dementia and the medications taken to treat the condition.

Other Non-Motor Symptoms

A range of other symptoms can also arise with Parkinson’s disease, affecting mental health, sleep, digestion and other bodily functions, and sense of smell. In many cases, these non-motor symptoms come before the onset of the condition itself.

Mental Health Impact

Parkinson's disease can have a significant effect on mental health, as is the case for many chronic and debilitating disorders. The most common of these are:

• Depression: The most common mental health impact of this disease is depression, a feeling of persistent sadness, loss of interest in activities, and melancholy mood that affects daily living.
• Anxiety: Anxiety is a severe and constant feeling of worry and fear that is often associated with depression.
• Apathy: This is a persistent lack of interest or excitement in activities and motivation. It can lead to a loss of impulse or will and reduced speech or expression of emotions.    

Sleep Disorders

Disturbances in the quality and quantity of sleep represent another common hallmark of Parkinson’s disease. Researchers have found approximately 64% of patients with the condition experience this issue. Often linked to the other symptoms of Parkinson’s disease, associated sleep disorders include:

• Excessive daytime sleepiness: Characterized by difficulty staying awake during the day
• Insomnia: An inability to fall or stay asleep
• Restless legs syndrome (RLS): Characterized by an uncontrollable urge to move the legs, especially at night, which can impact sleep
• REM sleep behavior disorder (RBD): Excessive body movement during the rapid eye movement (REM) or dreaming stage of sleep

As a result of the above, fatigue is a common sign of Parkinson’s disease. In turn, sleep disturbances can also impact other aspects of mental and physical health.   

Autonomic Function

Parkinson’s disease can also affect a range of autonomic (involuntary) bodily functions. These impacts on autonomic function include:

• Constipation: Difficulty defecating or completely emptying your bowels
• Orthostasis: Low blood pressure upon standing up; this can lead to fainting
• Dysphagia: An inability to properly chew food
• Urinary incontinence: Bed wetting or lacking control of urination
• Diaphoresis: Excessive sweating
• Sexual dysfunction: This can include sexual over- or under-activity, erectile dysfunction, vaginal tightness or dryness, or lack of sexual desire

Other Symptoms

Additional symptoms of Parkinson’s disease include problems with sense of smell. Patients may be unable to distinguish odors or lose their sense of smell completely. Aches and pains are another common feature and have been found to affect about 46% of those with the condition. The quality of this pain may be tingling, burning, or sharp and pointed. It can occur throughout the body or affect specific joints, the genitals, the abdomen, or the face.   

When to See a Healthcare Provider

In general, if you suspect you have Parkinson’s disease and are experiencing typical symptoms, such as tremors, rigidity, and difficulty with motion or staying upright, you should call your healthcare provider. Seek out emergency care if you are experiencing any of the following symptoms (even after diagnosis):

• Sudden onset of or changes to the pattern of your symptoms
• Severe reactions or lack of response to medications
• Any cognitive symptoms, such as difficulty remembering or concentrating
• Worsening pain
• After a fall
• Difficulties eating, including choking or coughing
• Signs of bladder infection, such as burning during urination, frequent urination, or fever

A Quick Review

Parkinson’s disease is a progressive neurodegenerative disorder that primarily impacts motor skills and function. Its primary symptoms are tremors, slow or interrupted movements, muscle stiffness and rigidity, and difficulty maintaining an upright posture. In addition, this progressive disease can impact mental health, control of bodily functions, gait, and sleep.

Signs of the condition warrant medical attention, with cognitive symptoms, worsening pain, and falls among reasons to seek emergency help.