Parkinson’s Disease: Understanding Symptoms and Causes

Parkinson's Disease: Understanding Symptoms and Causes
In Parkinson’s disease, the basal ganglia cells responsible for controlling your body’s voluntary movements are affected.

Parkinson’s is a progressive neurodegenerative disorder first identified by James Parkinson in 1817. It is the second most common neurodegenerative disease, affecting over 10 million people around the world. This article will focus on Parkinson’s disease symptoms, causes, and potential treatment options, such as stem cell therapy, to relieve symptoms and slow disease progression among patients.

What is Parkinson’s?

Parkinson’s is a neurodegenerative disorder, with increasing prevalence among men than women. People with the disorder experience uncontrolled movements, such as shaking, stiffness, and difficulty coordinating. As a heterogeneous disorder, the symptoms of the disease can largely vary from person to person. Symptoms of Parkinson’s disease begin gradually and worsen over time while also resulting in mental and behavioral changes within a patient.

Causes of Parkinson’s disease

The early Parkinson’s symptoms become noticeable when nerve cells within the basal ganglia begin to die. The basal ganglia is part of the brain that controls movement; however, as nerve cells deteriorate, dopamine production reduces, and the loss of the dopaminergic neurons results in movement problems.

Parkinson’s causes the loss of nerve endings, which are responsible for producing norepinephrine. The loss of the chief chemical messenger of the sympathetic nervous system, norepinephrine, causes symptoms like fatigue, irregular blood pressure, and reduced digestive track muscle activity.

However, what causes Parkinson’s is still unknown, but like many other neurodegenerative diseases, a combination of genetic mutations and environmental factors is considered to be the leading cause of Parkinson’s disease symptoms development. Most evidence also suggests that patients experiencing the disorder have not only abnormalities in their neuronal cells but also disruptions in their immunological mechanisms.

What are the symptoms of Parkinson’s disease

Due to its heterogeneity, the rate of disease progression and symptoms can vary from person to person. The early symptoms of Parkinson’s disease can be very subtle and gradual. Some major symptoms of Parkinson’s disease can include the following:

Parkinson's Disease: Understanding Symptoms and Causes
Range of symptoms in Parkinson`s disease.

Tremors or shaking in the hands, arms, legs, or jaw

Most patients notice tremors in their hands, arms, legs, or jaw due to the loss of dopamine-inducing cells within the brain. Tremors can be seen both at rest and during movements and also as a result of fatigue, stress, or other factors. 

Stiffness or rigidity in the limbs or trunk

These symptoms are caused by the loss of dopamine in the brain, leading to irregularities in the neurotransmitters responsible for muscle tone. This can cause rigidity, stiffness, or muscle being stuck in a contracted state, leading to a restricted range of motion.

The slowness of movement (bradykinesia)

Bradykinesia is also linked to dopamine deficiency, causing reduced speed and fluidity of movement. Bradykinesia may also result in difficulty moving, walking, getting out of the chair, and speaking. 

Poor balance and coordination

Poor balance and coordination can result from several factors, like stiffness, rigidity, and reduced movement. Losing dopamine-inducing cells can also result in these symptoms.

Difficulty walking or initiating movement

As basal ganglia gets affected, patients feel difficulty controlling and initiating movements, partially because of the stiffness of the muscles. Shuffling gait is a common Parkinson’s disease symptom, where an individual’s walk may look like shuffling steps. 

Small, cramped handwriting (micrographia)

Small, cramped handwriting, also known as micrographia, results from lowered dopamine levels in the brain, leading to cramped and frequent breaks while writing.

Changes in speech

Parkinsonism symptoms also affect the muscles used in speech, thus, making it harder to articulate words clearly or leading to slurred speech. 

Facial masking or reduced expression

Facial masking, also known as hypomimia, is characterized by reduced facial expressions and difficulties with nonverbal communication, like making eye contact and gestures.

Depression and anxiety

Due to altered brain chemistry and the stress of coping with chronic illness, patients start to feel depression and anxiety in their journey to fight early Parkinsonism symptoms. Anxiety can also lead to sadness, hopelessness, and loss of interest in life activities, and it can cause the condition to worsen.

Sleep disturbances

Most Parkinson’s patients suffer from staying asleep, restless legs syndrome, sleep apnea, and rapid eye movement. Changes in brain chemistry that control sleep and wake cycles, as well as medications to treat symptoms, can be the reason for sleep disturbances. 

Early symptoms of Parkinson’s disease

Parkinson's Disease: Understanding Symptoms and Causes
Early Parkinson’s symptoms to look out for.

This progressive neurological disorder may go unnoticed due to mild signs and symptoms of Parkinson’s disease. Some early symptoms that can be attributed to Parkinson’s are:

  1. Tremors or shaking in a limb, often on one side of the body. This is the most common symptom of the disease, where the patient notices tremors on one side of the body, either in the hand or arm. Most patients also notice resting tremors as their body is resting.
  2. Difficulty with balance and coordination. Due to stiffness and muscle rigidity, patients fail to maintain balance and coordination, resulting in gait disturbances like shuffling and taking small steps.
  3. Changes in handwriting, such as smaller letters or cramped writing. As muscles begin to stiffen, patients start to notice cramped handwriting or micrographia due to the inability to control the range of muscle movements.
  4. Loss of smell. Loss of smell, also known as anosmia, is the common earliest symptom of the disease. It is caused by the degeneration of nerve cells involved in the sense of smell, which can also lead to loss of taste in extreme cases. 
  5. Muscle stiffness or rigidity. Muscle stiffness is an early sign of Parkinson’s, characterized by the feeling of tightness or resistance in the muscles, making it very difficult to move around smoothly. This rigidity can also lead to cramping, postural issues, and coordination.

Current treatment options for Parkinson’s 

Treatment options for the disorder are based on its signs and symptoms along with the following parameters:

  • patient’s age, health, and medical history;
  • the severity of the condition;
  • type of condition;
  • tolerance for medications and procedures;
  • treatment expectations.

Since there is no answer to what causes Parkinson’s, the treatment options are still quite limited and mostly targeted to relieve symptoms and disease progression. 

     Common treatment options include:

  1. Medications.
  2. Surgery (Lesion surgery, Deep brain stimulation, neural grafting, or tissue transplant).
  3. Stem cell therapy.
  4. Complimentary and supportive therapies like physical, occupational, and speech therapy.

Stem cell therapy for Parkinson’s disease

Stem cell therapy is one of the most promising treatments for improving the symptoms, preventing further nerve damage, and slowing disease progression. 

Mesenchymal stem cells have been found to secrete neurotrophic growth factors, such as glial cell-derived neurotrophic factors, vascular endothelial growth factor, and brain-derived-neurotrophic factor, that improves neuronal survival and protect them from further damage. 

Some potential benefits of stem cell therapy in Parkinson’s disease are:

  • Improved motor functions, such as tremors, rigidity, and bradykinesia, and reduced symptoms associated with the disorder.
  • Reduced need for medications to alleviate symptoms as stem cells can restore dopamine production and reduce the need for dopamine-inducing medicines. 
  • Immune system modulation and anti-inflammatory effects on the brain.
  • Long-lasting effects that can last up to years.
  • Fewer side effects as compared to medicines used to treat Parkinson’s disease symptoms.

Get a free online consultation

Contact our professionals at the Clinic for a free consultation to discuss the expected results for your case of the disease, the procedure, the cost and the duration of the treatment.

Parkinson's Disease: Understanding Symptoms and Causes
Dr. Aleksandra Fetyukhina, MD

Medical Advisor, Swiss Medica doctor


Parkinson’s is a chronic neurodegenerative disorder affecting millions worldwide. With unknown causes of Parkinsonism, no treatment option can cure the disorder. However, stem cell therapy, along with other interventions, can help alleviate disease symptoms, improve a patient’s quality of life, slow down the disease progression, and even promote its regression.

List of References

  1. Bloem, B. R., Okun, M. S., & Klein, C. (2021). Parkinson’s disease. The Lancet, 397(10291), 2284-2303.

  2. Masato, A., Plotegher, N., Boassa, D., & Bubacco, L. (2019). Impaired dopamine metabolism in Parkinson’s disease pathogenesis. Molecular neurodegeneration, 14(1), 1-21.

  3. Heidemarie Zach, Michiel F. Dirkx, Dominik Roth, Jaco W. Pasman, Bastiaan R. Bloem, Rick C. Helmich. Dopamine-responsive and dopamine-resistant resting tremor in Parkinson’s disease. Neurology Sep 2020, 95 (11) e1461-e1470.

  4. Pelicioni, P. H., Menant, J. C., Latt, M. D., & Lord, S. R. (2019). Falls in Parkinson’s disease subtypes: risk factors, locations, and circumstances. International journal of environmental research and public health, 16(12), 2216.

  5. Chikatimalla, R., Dasaradhan, T., Koneti, J., Cherukuri, S. P., Kalluru, R., Gadde, S., … & Gadde, S. V. (2022). Depression in Parkinson’s disease: A narrative review. Cureus, 14(8).

  6. Zham, P., Raghav, S., Kempster, P., Poosapadi Arjunan, S., Wong, K., Nagao, K. J., & Kumar, D. K. (2019). A kinematic study of progressive micrographia in Parkinson’s disease. Frontiers in neurology, 10, 403.

  7. Walker, I. M., Fullard, M. E., Morley, J. F., & Duda, J. E. (2021). Olfaction as an early marker of Parkinson’s disease and Alzheimer’s disease. Handbook of Clinical Neurology, 182, 317-329.

  8. Church, F. C. (2021). Treatment options for motor and non-motor symptoms of Parkinson’s disease. Biomolecules, 11(4), 612.

  9. Fan, Y., & Ng, S. Y. (2020). Replacing what’s lost: a new era of stem cell therapy for Parkinson’s disease. Translational Neurodegeneration, 9(1), 1-10.

More sources

Medical Advisor, Swiss Medica doctor

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