A Closer Look at Parkinson’s: A Journey Through the Nervous System

Research Staff
May 31
13 min read

This article provides a concise overview of Parkinson’s disease (PD)—what it is, its epidemiology, signs and symptoms, diagnosis, and treatment strategies. It also addresses some common questions about PD to help deepen understanding and awareness.

By Dr. Grishma Wosti, MBBS

Parkinson’s disease is a neurological disorder that affects millions worldwide yet remains widely misunderstood and incurable. A clear, up-to-date overview—covering causes, symptoms, diagnosis, and treatment options—helping patients, caregivers, and the public with the knowledge needed to recognize early signs, seek appropriate care, and support ongoing research efforts in the fight against this life-altering condition

Key Takeaways

A chronic progressive neurological condition that slowly gets worse over many years.
There is no cure; treatments are available to manage symptoms and improve quality of life.
About 1 million people in the U.S. have Parkinson’s, or 1 in every 336 people. This number is growing and will keep growing.
People with Parkinson’s can manage symptoms with exercise, eating healthy food, and taking the right medicine.

Introduction to PD

Parkinson’s disease is a chronic and progressive neurological disorder that affects movement, mental health, pain perception, and various other bodily functions. As PD progresses, patients may have trouble walking and talking. They can also develop mental health changes, sleep problems, depression, memory issues, and fatigue. The progression of these symptoms is typically gradual, often affecting only one side of the body initially. Although there is currently no cure, a combination of medications and therapies can help manage symptoms.

PD is primarily caused by the accumulation of misfolded alpha-synuclein proteins in the brain, particularly in the substantia nigra. This leads to the degeneration of dopamine-producing neurons, resulting in decreased dopamine levels in the basal ganglia, which disrupts the control of movement and causes motor symptoms such as tremors, rigidity, and bradykinesia (slowness of movement and reflexes). By the time PD is clinically diagnosed, approximately 80% of these dopamine-producing cells have already been lost.

In addition to decreases in dopamine and the cells that make dopamine, you might also read or hear about a protein called alpha-synuclein. Alpha-synuclein is a protein normally involved in the storage and release of neurotransmitters in the brain. However, excessive and misfolded alpha-synuclein plays a central role in the development of PD. Genetic mutations in the alpha-synuclein gene can directly cause the protein to misfold. But most of the times even without such mutations, nearly all individuals with PD shows an accumulation of abnormal alpha-synuclein. These misfolded proteins clump into aggregates, forming thin protein threads called fibrils, which eventually develop into Lewy bodies—an abnormal structure found inside nerve cells, particularly in the substantia nigra. The presence of Lewy bodies is a key pathological hallmark of Parkinson’s disease.

Family and friends who care for people with Parkinson’s disease often face emotional, physical, and financial stress during this journey. They must spend daily many hours providing care, which can be overwhelming. Therefore, Support is needed from health, social, legal, and financial systems to help relief this burden.

History of PD

In the year 1817, Dr. James Parkinson unveiled a groundbreaking medical essay that shed light on a neurological condition he termed "paralysis agitans," more commonly known as "shaking palsy." His meticulous observations and insights laid the foundation for understanding this perplexing disorder. Fast forward to later years, when neurologist Jean-Martin Charcot recognized the profound impact of Dr. Parkinson's pioneering work and honored him by renaming the condition "Parkinson's disease." This rebranding not only highlighted the significance of Dr. Parkinson's contributions but also brought greater awareness to a condition that affects millions.

Parkinson’s Disease a Growing Health Concern

Parkinson’s disease affects approximately 60,000 Americans each year, where age being the biggest risk factor. Only 5% of patients are diagnosed before age 60, while about 1% of those over 60 and 5% of those over 85 are affected. The prevalence in the general population is about 1–2 per 1,000, but among those over 60, it is approximately 1%. It is the second most common neurodegenerative disorder after Alzheimer’s disease. Men are almost twice as likely to develop Parkinson's disease than women.

According to the Global Burden of Disease Study 2015, Parkinson’s disease is the neurological disease with the fastest growing prevalence and disability.

Who Can Develop Parkinson’s Disease?

In most cases, the exact cause of Parkinson’s remains unknown. Scientists believe a combination of genetic susceptibility and environmental exposures, such as long-term exposure to pesticides /herbicides (especially in rural areas), may contribute to the disease. Parkinson’s disease can affect anyone, but certain factors increase the risk which are given below.

Age is the biggest risk factor, most people are diagnosed in their 60s or older, with the average age of onset around 70. However, about 4% of people develop Young Onset Parkinson’s Disease, which begins before the age of 50.
Men are 1.5 times more likely to develop Parkinson’s than women.
Head injury - Repeated head trauma may increase the risk of Parkinson’s disease by causing degenerative brain changes, inflammation, and loss of brain cells. These injuries can lead to chronic inflammation and tau protein buildup, both of which are linked to neurodegeneration.
Genetics-
- Familial Parkinson’s disease (PD) accounts for around 10% of all Parkinson’s cases and is typically linked to inherited genetic mutations. These inherited forms often show autosomal dominant or recessive inheritance patterns.
- Genes Linked to Familial - - Parkinson’s Disease: SNCA (alpha-synuclein), LRRK2 (Leucine-rich repeat kinase 2), PARK2 (Parkin), PINK1 (PTEN-induced kinase 1), GBA (Glucocerebrosidase), VPS35.
It starts before age 50, may progress slowly, and, in some types, responds well to levodopa. A family history is usually present.
Heavy metal exposure- higher incidence of PD in welders.

Signs and symptoms

Parkinson’s disease presents with a wide range of symptoms that can vary from person to person.

Motor Symptoms

Non- Motor Symptoms

Resting Tremor: Rhythmic, involuntary shaking of a limb (usually hand or foot) while muscles are at rest. Seen in about 80% of Parkinson’s cases; stops with movement.

Bradykinesia (Slowed Movements): Slow and small movements due to poor muscle control. It often feels like weakness, but no real loss of strength exists.

Rigidity (Stiffness): Muscles stay tense, causing stiffness and limited movement. This can lead to reduced arm swing while walking.

1. Lead-pipe Rigidity: Constant, smooth stiffness.

2. Cogwheel Rigidity: Jerky, stop-and-go stiffness due to tremor and rigidity.

Postural Instability (Poor Balance): trouble staying upright, especially when standing or turning. It leads to a stooped posture, a shuffling walk, and a higher risk of falls.

Cognitive & Mood-Related

Depression
Anxiety
Apathy (lack of motivation)
Memory and concentration problems (Parkinson’s-related dementia)

Sleep-Related

Fatigue and daytime sleepiness
REM sleep behavior disorder (acting out dreams)
Restless legs syndrome
Trouble falling or staying asleep

Autonomic Nervous System

Constipation
Urinary urgency/frequency
Lightheadedness when standing (orthostatic hypotension)
Sexual dysfunction

Sensory & Other

Loss of smell (Hyposmia/Anosmia)
Oily skin and dandruff

Other symptoms

A loss of facial expression, often described as a "mask-like" face, and reduced blinking, making the face appear less animated.
People may also experience a soft or hoarse voice, drooling due to decreased swallowing, and difficulty swallowing itself, known as dysphagia.
Small, cramped handwriting (micrographia) is familiar, as is trouble rising from a chair due to muscle stiffness and weakness.
A stooped posture, reduced arm swing while walking, short, shuffling steps, and episodes of freezing while walking-where the person feels as if their feet are stuck to the floor-are characteristic movement symptoms.
Poor balance is another frequent issue, increasing the risk of falls and making everyday activities more challenging.

These symptoms, which may vary in severity and progression among individuals, reflect the broad impact of Parkinson's disease on both motor and non-motor functions.

Parkinson’s Disease Diagnosis

Diagnosing Parkinson’s disease is mostly a clinical process. Healthcare providers diagnose PD by asking medical history, doing nerve exams, and seeing how the patient responds to dopamine medicines. There are no clear blood tests or imaging tests to confirm the diagnosis. Usually, family doctors or nerve doctors give the first diagnosis. Many people consult movement disorder specialists for second opinion too.

Doctors diagnose Parkinson’s disease by checking medical history, doing nerve exams, and seeing how the patient responds to dopamine medicines. There are no clear blood tests or imaging tests to confirm the diagnosis.
Usually, family doctors or nerve doctors give the first diagnosis. Many people ask movement disorder specialists for a second opinion.
Symptoms, family history, and physical signs are carefully evaluated to differentiate PD from other conditions with similar symptoms.
In some cases, tests like blood work, brain MRI, or DAT scans may be used to rule out other conditions. In 2011, the FDA approved the DAT scan, an imaging technique that helps visualize the brain’s dopamine system. However, this scan can't definitively diagnose Parkinson’s.
Researchers are exploring new lab tests to help detect Parkinson’s disease, focusing on the alpha-synuclein protein. These tests look for misfolded alpha-synuclein proteins, which may indicate the disease. While these tests can’t definitively diagnose Parkinson’s, they may assist doctors in making a more accurate diagnosis.
Two methods are being tested:
- Spinal Tap: A needle is inserted into the spinal canal to collect cerebrospinal fluid for testing.
- Skin Biopsy: A small skin sample, including nerve tissue, is taken from areas on the back and legs to check for protein abnormalities.

Treatment options for Parkinson's disease

Parkinson’s disease is treated through a team-based approach, focusing on medication and support from various specialists. The Parkinson’s care team includes a neurologist, primary care physician, nurse, pharmacist, dietitian, speech therapist, physical and occupational therapists, social worker, and psychologist, all working together to provide comprehensive care.

Pharmacological Management:

Medications can help improve walking, movement, and tremor in Parkinson’s disease by increasing dopamine level. Since dopamine itself can't cross into the brain, dopamine-replacement therapies like Levodopa are used widely. Symptoms often improve significantly with treatment, though the effect may lessen over time. However, medicines usually continue to provide good symptom control. But not all the medications available may be useful for everyone, and the short- and long-term effects of each medication are different.

Levodopa/Carbidopa

The most effective agent and mainstay of treatment, especially for controlling bradykinesia (slowness of movement) and rigidity.

Levodopa crosses the blood-brain barrier and is converted to dopamine.
Carbidopa increases levodopa’s effectiveness and reduces side effects (like nausea and vomiting) by preventing peripheral breakdown of levodopa.

Dopamine Receptor Agonists

Used alone or with Levodopa/Carbidopa.
Ergot derivatives: Bromocriptine, Pergolide and Non-ergot derivatives: Ropinirole, Pramipexole.

Monoamine Oxidase Inhibitors (MAOIs)

Block enzyme that breaks down Levodopa.
Used for motor fluctuations with Levodopa.
Common drugs: Selegiline.

Amantadine

For early-onset Parkinson’s.
Reduces tremor and levodopa-induced dyskinesia.

COMT Inhibitors (Catechol-O-methyltransferase)

Drugs: Tolcapone, Entacapone.
Prolong levodopa effect by slowing its breakdown.

Anticholinergics

Reduce tremors and rigidity.
Common drugs: Benztropine mesylate, Trihexyphenidyl HCl.

Anti-Depressant:

Amitriptyline is prescribed because of its both anti-depressant and anticholinergic effects.
Drugs used: Sertraline.
Treatment is personalized and adjusted over time based on symptoms and side effects. It's crucial to follow the prescribed dosing and timing to prevent the medication from wearing off and worsening symptoms.

Nonpharmacologic Treatment

Based on the severity of the patient’s condition and their medical profile, surgery may be recommended as an alternative treatment option for PD. Surgery may not be suitable for everyone with PD. It is usually considered only for patients with severe symptoms who do not respond well to medications. Surgical treatments, such as deep brain stimulation (DBS), are used to help reduce symptoms like tremors and rigidity. In some cases, surgery reduces the burden of the need to take medication daily to control their symptoms.

Deep Brain Stimulation (DBS) is a surgical treatment for Parkinson’s disease that involves implanting a device to send mild electrical pulses to specific brain areas, like the subthalamic nucleus or globus pallidus interna.
Lesion surgery (burning of tissue) involves where deep parts of the brain are targeted and small lesions are made in critical parts of the brain that help control movement. The procedure is often done while the patient is awake to ensure accurate targeting of the area causing symptoms.

Other Treatments

Focused Ultrasound (FUS) is a treatment that uses many ultrasound waves aimed at one specific spot in the brain to create a small lesion. This lesion helps fix abnormal brain activity in Parkinson’s disease (PD), improving movement.
Lifestyle changes in Parkinson’s Disease Staying active, eating well, sleeping properly, and avoiding harmful exposures can help people with Parkinson’s live better and longer. Staying hydrated also helps prevent constipation. A proper exercise program can include cardiorespiratory exercise (fitness training), resistance exercises (strength training), flexibility exercises (stretching), and gait and balance training.
Diet and Nutrition in Parkinson’s Disease helps people are at higher risk for muscle and bone loss, so a diet rich in calcium, vitamin D, and protein is important. Try to focus on small and nutritious meals. A balanced diet with fruits, vegetables, whole grains, healthy fats, and protein can support overall health.
Physical, occupational, and speech therapies are key in managing Parkinson’s disease. Physical therapy helps with movement and exercise, occupational therapy improves fine motor skills, and speech therapy addresses speech and language issues. Early consultations with these experts can be of great benefit.

Complementary Therapies

Includes various treatments used alongside standard care to improve the quality of life for people with Parkinson’s disease. While there is less scientific evidence for these methods, many patients find them helpful. Some common practices include:

Yoga to increase stretching and flexibility
Acupuncture & massage to reduce tension
Meditation supports mental well-being and stress reduction
Music therapy can improve mood and emotional expression.

While these complementary therapies do not replace the standard medical treatment, but they can play an important role in enhancing overall well-being and managing non-motor symptoms of PD. When used under a medical guidance team, these approaches can support physical comfort, emotional balance, and a healthy life for individuals living with Parkinson’s.

Experimental Treatments for Parkinson’s Disease

Several experimental treatments are currently in development nowadays, some aim to relieve symptoms, while others target the underlying causes of Parkinson’s disease. Therefore, ongoing research provides new hope for more effective and possibly disease-modifying therapies in the future. Some are listed below.

Neuron-repair treatments to heal and regrow brain cells.
Gene therapies to target specific mutations or enhance existing treatments like levodopa.
ACI-7104 is an experimental vaccine aimed at slowing or preventing brain damage in early Parkinson's disease. It stimulates the immune system to produce antibodies against a synthetic peptide like alpha-synuclein, a protein linked to Parkinson’s.
NTCELL is an experimental cell therapy that involves a surgical procedure to deliver cells into the brain. It aims to restore nerve cell function and slow the progression of Parkinson’s disease.
Nilotinib, sold as Tasigna, is used in Parkinson's disease, it may help remove toxic proteins from the brain by activating a process that cleans up damaged cells. It is currently being tested in Phase 2 trials.

Technology and Artificial Intelligence (AI) Offers New Hope to Parkinson’s Patients

AI offers new hope for Parkinson’s patients by enabling earlier diagnosis, personalized care, and possibly slowing disease progression. Machine learning and deep learning can find early signs of Parkinson’s disease by studying complex data in a short period of time.

AI-based imaging can detect subtle brain changes associated with Parkinson’s.
Wearable devices track symptoms and disease progression in real-time.
AI accelerates drug discovery and identifies new applications for existing medicines.
Virtual assistants and chatbots help patients stay engaged and manage their simple care.
Remote monitoring makes healthcare more accessible for patients.

Research Funding Initiatives

In the United States, PD research is supported by a diverse range of funding sources, which serves as a major priority for both government and private sectors like the National Institutes of Health (NIH), the Michael J. Fox Foundation, the Parkinson’s Foundation, American Parkinson Disease Association (APDA) and many more. At the NIH, the National Institute of Neurological Disorders and Stroke (NINDS) serves as the lead institute supporting PD research. In fiscal year 2023, NINDS funded approximately $126 million out of the total of $253 million allocated to NIH-supported PD research. NINDS is deeply committed to translating basic scientific discoveries into clinical practice to improve the lives of those affected by Parkinson’s disease and to reduce the burden of neurological disease. The American Parkinson Disease Association has invested over $62 million since 1961 in research to discover the causes and find cures for Parkinson’s disease. Since 1957, the Parkinson’s Foundation has invested over $449 million in Parkinson’s research and clinical care to improve the lives of those affected by the disease.

Conclusion

Parkinson’s disease is a progressive neurological condition that causes both motor and non-motor symptoms. While its exact cause remains unknown, recent advances in understanding genetic risks, disease variations, and improved medical and surgical treatments have helped create more personalized approaches to individual patient’s care. Combining pharmacological treatments along with lifestyle changes can reduce symptoms and enhance quality of life. Ongoing research are bringing new hope to people with Parkinson’s disease, aiming to improve treatments outcomes, and slowing the disease progression.

FAQ

1. What is the progression of Parkinson’s disease over time?

Parkinson’s disease is a chronic, lifelong condition that continues to progress over time, though its duration can vary from person to person. With effective treatment, many individuals can manage symptoms for years. The average life expectancy of a person with PD is generally the same as for people who do not have the disease.

2. Which healthcare professional handles Parkinson’s treatment?

Neurologists treat people with Parkinson’s disease. They have special knowledge about problems with the brain and nerves. Movement disorder specialists are neurologists with extra training in treating conditions that affect movement.

3. Is Parkinson’s contagious?

Parkinson’s disease is not contagious, it cannot be spread through contact, air, or any other way from one person to another.

4. Do Parkinson’s drugs halt disease progression?

Medicines for Parkinson’s only help to make symptoms less and make daily life better. But they cannot stop the disease progression. Medication can make life easier for people with Parkinson’s.

5. How can we prevent Parkinson’s disease?

There is no known cause of Parkinson’s disease, so there are no exact ways to prevent it. However, getting regular check-ups, staying mentally and physically active, eating a high-fiber, and nutritious diet, genetic counseling, moderate caffeine consumption, avoiding head injuries, toxins and taking antioxidants like vitamins C and D may lower the risk.

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About Dr. Grishma Wosti, MBBS

Born and raised in Nepal, a scenic Himalayan country, I earned a medical degree and invaluable clinical experience in rural areas, fostering strong communication and leadership skills. An approachable and positive personality shines through, with a passion for cooking, singing, and bicycle riding that adds vibrancy to life outside of medicine—preparing for the USMLE exams to pursue a medical residency in the United States.