Parkinson's Disease: A Comprehensive Guide

Overview

Parkinson's disease is a progressive nervous system disorder that primarily affects movement. It develops gradually, sometimes starting with a barely noticeable tremor in just one hand. While tremor may be the most well-known sign of Parkinson's, the disorder also commonly causes stiffness or slowing of movement.

In the early stages, your face may show little or no expression, or your arms may not swing when you walk. Speech may become soft or slurred. Symptoms worsen as the condition progresses over time.

Who it affects: Parkinson's disease typically begins around age 60, but about 5-10% of people with Parkinson's have "early-onset" disease that begins before age 50. Men are 1.5 times more likely to develop Parkinson's than women.

Prevalence: According to the Parkinson's Foundation, nearly 1 million people in the U.S. are living with Parkinson's disease, and approximately 60,000 Americans are diagnosed each year. Worldwide, more than 10 million people live with Parkinson's.

Symptoms

Parkinson's disease signs and symptoms can vary from person to person. Early signs may be mild and go unnoticed. Symptoms often begin on one side of the body and usually remain worse on that side, even after symptoms begin to affect both sides.

Motor Symptoms

• Tremor: A rhythmic shaking, usually beginning in a limb, often your hand or fingers. You may notice a back-and-forth rubbing of your thumb and forefinger, known as a pill-rolling tremor.
• Bradykinesia (slowed movement): Over time, Parkinson's disease may reduce your ability to move and slow your movement, making simple tasks difficult and time-consuming.
• Rigid muscles: Muscle stiffness may occur in any part of your body. The stiff muscles can limit your range of motion and cause pain.
• Impaired posture and balance: Your posture may become stooped, or you may have balance problems.
• Loss of automatic movements: You may have a decreased ability to perform unconscious movements, including blinking, smiling, or swinging your arms when walking.
• Speech changes: You may speak softly, quickly, slur, or hesitate before talking. Your speech may be more of a monotone rather than with the usual inflections.
• Writing changes: Writing may appear small and become difficult.

Non-Motor Symptoms

• Cognitive changes: You may experience thinking difficulties (cognitive impairment) and problems with memory, concentration, and planning. These issues usually occur in the later stages of Parkinson's.
• Mood disorders: People with Parkinson's may experience depression, anxiety, or other emotional changes.
• Sleep problems: Common sleep disturbances include insomnia, excessive daytime sleepiness, and rapid eye movement sleep behavior disorder (acting out dreams).
• Fatigue: Many people with Parkinson's lose energy and experience fatigue, especially later in the day.
• Pain: Some people with Parkinson's experience pain in their muscles, joints, or nerves.
• Autonomic dysfunction: This can include orthostatic hypotension (a sudden drop in blood pressure when standing), constipation, urinary problems, sexual dysfunction, and excessive sweating.
• Loss of smell: You may have difficulty identifying certain odors or a reduced sense of smell.

Causes and Risk Factors

In Parkinson's disease, certain nerve cells (neurons) in the brain gradually break down or die. Many of the symptoms are due to a loss of neurons that produce a chemical messenger in your brain called dopamine. When dopamine levels decrease, it causes abnormal brain activity, leading to impaired movement and other symptoms of Parkinson's disease.

The cause of Parkinson's disease is unknown, but several factors appear to play a role, including:

• Genes: Researchers have identified specific genetic mutations that can cause Parkinson's disease, but these are uncommon except in rare cases with many family members affected by Parkinson's. However, certain gene variations appear to increase the risk of Parkinson's disease.
• Environmental triggers: Exposure to certain toxins or environmental factors may increase the risk of later Parkinson's disease, but the risk is relatively small.
• Lewy bodies: Clumps of specific substances within brain cells are microscopic markers of Parkinson's disease. These are called Lewy bodies, and researchers believe these Lewy bodies hold an important clue to the cause of Parkinson's disease.
• Alpha-synuclein: Found within Lewy bodies, this natural and widespread protein's normal function isn't yet known. But it's a focus among Parkinson's researchers studying the protein's potential role in disease development.

Risk Factors

• Age: Young adults rarely experience Parkinson's disease. It ordinarily begins in middle or late life, and the risk increases with age. People usually develop the disease around age 60 or older.
• Heredity: Having a close relative with Parkinson's disease increases the chances that you'll develop the disease. However, your risks are still small unless you have many relatives in your family with Parkinson's disease.
• Sex: Men are more likely to develop Parkinson's disease than women.
• Exposure to toxins: Ongoing exposure to herbicides and pesticides may slightly increase your risk of Parkinson's disease.

Diagnosis

No specific test exists to diagnose Parkinson's disease. Your doctor trained in nervous system conditions (neurologist) will diagnose Parkinson's disease based on your medical history, a review of your signs and symptoms, and a neurological and physical examination.

Your doctor may order tests, such as blood tests, to rule out other conditions that may be causing your symptoms. Imaging tests — such as MRI, ultrasound of the brain, and PET scans — may also be used to help rule out other disorders. Imaging tests aren't particularly helpful for diagnosing Parkinson's disease.

In addition to your examination, your doctor may give you carbidopa-levodopa (Rytary, Sinemet, others), a Parkinson's medication. You must be given a sufficient dose to show the benefit, as low doses for a day or two aren't reliable. Significant improvement with this medication will often confirm your diagnosis of Parkinson's disease.

Sometimes it takes time to diagnose Parkinson's disease. Doctors may recommend regular follow-up appointments with neurologists trained in movement disorders to evaluate your condition and symptoms over time and diagnose Parkinson's disease.

Treatment Options

Parkinson's disease can't be cured, but medications can help control your symptoms, often dramatically. In some later cases, surgery may be advised. Your doctor may also recommend lifestyle changes, especially ongoing aerobic exercise. In some cases, physical therapy that focuses on balance and stretching also is important. A speech-language pathologist may help improve your speech problems.

Medications

Medications may help manage problems with walking, movement, and tremor by increasing your brain's supply of dopamine. However, dopamine can't be given directly, as it can't enter your brain. You may have significant improvement of your symptoms after beginning Parkinson's disease treatment. Over time, however, the benefits of drugs frequently diminish or become less consistent.

Medications your doctor may prescribe include:

• Carbidopa-levodopa: The most effective Parkinson's disease medication is a natural chemical that passes into your brain and is converted to dopamine. It's combined with carbidopa (Lodosyn), which protects levodopa from early conversion to dopamine outside your brain. This prevents or lessens side effects such as nausea.
• Dopamine agonists: Unlike levodopa, dopamine agonists don't change into dopamine. Instead, they mimic dopamine effects in your brain. They aren't as effective as levodopa in treating your symptoms. However, they last longer and may be used with levodopa to smooth the sometimes off-and-on effect of levodopa.
• MAO-B inhibitors: These medications include selegiline (Zelapar), rasagiline (Azilect), and safinamide (Xadago). They help prevent the breakdown of brain dopamine by inhibiting the brain enzyme monoamine oxidase B (MAO-B). This enzyme metabolizes brain dopamine. Selegiline given with levodopa may help prevent wearing-off.
• Catechol-O-methyltransferase (COMT) inhibitors: Entacapone (Comtan) is the primary medication from this class. This medication mildly prolongs the effect of levodopa therapy by blocking an enzyme that breaks down dopamine.
• Anticholinergics: These medications were used for many years to help control the tremor associated with Parkinson's disease. Several anticholinergic medications are available, such as benztropine (Cogentin) or trihexyphenidyl.
• Amantadine: Doctors may prescribe amantadine alone to provide short-term relief of symptoms of mild, early-stage Parkinson's disease. It may also be given with carbidopa-levodopa therapy during the later stages of Parkinson's disease to control involuntary movements (dyskinesia) induced by carbidopa-levodopa.

Surgical Procedures

Deep brain stimulation (DBS): In DBS, surgeons implant electrodes into a specific part of your brain. The electrodes are connected to a generator implanted in your chest near your collarbone that sends electrical pulses to your brain and may reduce your Parkinson's disease symptoms. Your doctor may adjust your settings as necessary to treat your condition. Surgery involves risks, including infections, stroke, or brain hemorrhage. Some people experience problems with the DBS system or have complications due to stimulation, and your doctor may need to adjust or replace some parts of the system. Deep brain stimulation is most often offered to people with advanced Parkinson's disease who have unstable medication (levodopa) responses. DBS can stabilize medication fluctuations, reduce or halt involuntary movements (dyskinesia), reduce tremor, reduce rigidity, and improve slowing of movement.

Lifestyle and Home Remedies

Certain lifestyle changes may also help make living with Parkinson's disease easier.

• Healthy eating: While no food or combination of foods has been proved to help in Parkinson's disease, some foods may help ease some symptoms. For example, eating foods high in fiber and drinking adequate fluids can help prevent constipation. A balanced diet also provides nutrients, such as omega-3 fatty acids, that may be beneficial for people with Parkinson's disease.
• Exercise: Exercising may increase your muscle strength, flexibility, and balance. Exercise can also improve your well-being and reduce depression or anxiety. Your doctor may recommend that you work with a physical therapist to learn an exercise program that works for you. You may also try exercises such as walking, swimming, gardening, dancing, water aerobics, or stretching. Parkinson's disease can disturb your sense of balance, making it difficult to walk with a normal gait. Exercise may improve your balance. These suggestions may help:
• Try not to move too quickly.
• Hold on to a rail when going up or down stairs.
• Avoid carrying things while walking.
• Avoid walking backward.
• Avoiding falls: In the later stages of the disease, you may fall more easily. In fact, you may be thrown off balance by just a small push or bump. The following suggestions may help:
• Make a U-turn instead of pivoting your body over your feet.
• Distribute your weight evenly between both feet, and don't lean.
• Avoid carrying things while walking.
• Avoid walking backward.
• Daily living activities: Daily living activities — such as dressing, eating, bathing, and writing — can be difficult for people with Parkinson's disease. An occupational therapist can show you techniques that make daily life easier.

Living with Parkinson's Disease

Receiving a diagnosis of Parkinson's disease can be overwhelming and frightening. While there is currently no cure for Parkinson's, there are many ways to manage the disease and maintain a good quality of life. Here are some tips for living with Parkinson's disease:

• Educate yourself: Learn as much as you can about Parkinson's disease. The more you know, the more active you can be in your own care. In addition to talking with your doctor, you may find it helpful to talk to a counselor or social worker. Or you may find encouragement and understanding in a support group, whether in-person or online. Group members often know about the latest treatments and tend to share their own experiences. However, remember that Parkinson's affects everyone differently. What works for someone else may not work for you.
• Stay active: Exercise is essential for everyone, but it's especially important if you have Parkinson's disease. Regular exercise can help you maintain mobility, flexibility, and balance. It can also improve your mood and overall well-being. Choose activities you enjoy, such as walking, swimming, or dancing. Work with your doctor or a physical therapist to design an exercise program that's right for you.
• Eat a healthy diet: A balanced diet is crucial for maintaining overall health and managing Parkinson's symptoms. Focus on eating plenty of fruits, vegetables, whole grains, lean proteins, and healthy fats. Stay hydrated by drinking plenty of water throughout the day. If you experience constipation, a common issue in Parkinson's, increase your fiber intake and talk to your doctor about other strategies to manage this symptom.
• Manage medications: Taking your medications as prescribed is essential for managing Parkinson's symptoms. Work closely with your doctor to find the right medication regimen for you. Keep a medication diary to track your doses, symptoms, and any side effects. This information can help your doctor make adjustments to your treatment plan as needed.
• Prioritize sleep: Sleep disturbances are common in Parkinson's disease. To improve your sleep, establish a regular sleep schedule, create a relaxing bedtime routine, and make your sleep environment comfortable. Avoid caffeine, alcohol, and large meals close to bedtime. If sleep problems persist, talk to your doctor about possible treatments or strategies to improve sleep quality.
• Stay socially engaged: Maintaining social connections is important for emotional well-being. Stay in touch with friends and family, and consider joining a support group for people with Parkinson's disease. Sharing your experiences and learning from others can be incredibly helpful and comforting.
• Plan for the future: As Parkinson's disease progresses, you may need to make adjustments to your home, work, and daily routines. Talk to your doctor, family, and friends about your needs and preferences. Consider consulting with an occupational therapist to help you adapt your home and work environment to better suit your abilities. You may also want to discuss advance care planning with your doctor and loved ones to ensure your wishes are respected as the disease progresses.

Prevention

Because the cause of Parkinson's is unknown, proven ways to prevent the disease also remain a mystery. However, some research has shown that caffeine — which is found in coffee, tea, and cola — may reduce the risk of developing Parkinson's disease. Green tea also may reduce the risk of developing Parkinson's disease. Some research has shown that regular aerobic exercise may reduce the risk of Parkinson's disease. Some other research has shown that people who consume fish may have a lower risk of developing Parkinson's disease, and fatty acids, such as omega-3, may be beneficial for people with Parkinson's disease. More research is needed to determine whether these factors can help prevent Parkinson's disease.

Complications

Parkinson's disease is often accompanied by these additional problems, which may be treatable:

• Cognitive difficulties: Cognitive problems (dementia) usually occur in the later stages of Parkinson's disease. Such cognitive problems aren't very responsive to medications.
• Depression and emotional changes: You may experience depression, sometimes in the very early stages. Receiving treatment for depression can make it easier to handle the other challenges of Parkinson's disease. You may also experience other emotional changes, such as fear, anxiety, or loss of motivation. Doctors may give you medications to treat these symptoms.
• Swallowing problems: You may develop difficulties with swallowing as your condition progresses. Saliva may accumulate in your mouth due to slowed swallowing, leading to drooling.
• Chewing and eating problems: Late-stage Parkinson's disease affects the muscles in your mouth, making chewing difficult. This can lead to choking and poor nutrition.
• Sleep problems and sleep disorders: People with Parkinson's disease often have sleep problems, including waking up frequently throughout the night, waking up early, or falling asleep during the day. You may also experience rapid eye movement sleep behavior disorder, which involves acting out your dreams. Medications may help your sleep problems.
• Bladder problems: Parkinson's disease may cause bladder problems, including being unable to control urine or having difficulty urinating.
• Constipation: Many people with Parkinson's disease develop constipation, mainly due to a slower digestive tract.
• Blood pressure changes: You may feel dizzy or lightheaded when you stand due to a sudden drop in blood pressure (orthostatic hypotension).
• Smell dysfunction: You may experience problems with your sense of smell. You may have difficulty identifying certain odors or the difference between odors.
• Fatigue: Many people with Parkinson's disease lose energy and experience fatigue, especially later in the day. The cause isn't always known.
• Pain: Some people with Parkinson's disease experience pain, either in specific areas of their bodies or throughout their bodies.
• Sexual dysfunction: Some people with Parkinson's disease notice a decrease in sexual desire or performance.

When to Seek Emergency Care

Sources and Further Reading

• Mayo Clinic - Parkinson's Disease
• Parkinson's Foundation
• National Institute on Aging - Parkinson's Disease
• Johns Hopkins Medicine - Parkinson's Disease
• Cleveland Clinic - Parkinson's Disease