Parkinson's disease is a progressive disease of the nervous system that primarily affects movement. Symptoms start gradually, sometimes with barely noticeable tremors in just one hand.

Although there is no cure for Parkinson's disease, medication can greatly improve your symptoms. Sometimes, your doctor may recommend surgery to regulate certain areas of the brain and improve symptoms.

Parkinson’s Disease Causes

In Parkinson's disease, certain neurons in the brain gradually die. Many symptoms are caused by the loss of these neurons that produce a chemical called dopamine. When the level of dopamine drops, it can cause abnormal brain activity, which can lead to restricted activity and other symptoms of Parkinson's disease. The cause of Parkinson's disease is unknown, but several factors seem to play a role, including:

• Genetics. Researches have shown specific mutations in certain genes that may play a role, therefore Parkinson’s disease is hereditary. However, these are rare, except in rare cases where many family members suffer from Parkinson's disease.
• Environmental factors. Exposure to certain toxins or environmental triggers will increase the risk of Parkinson's disease in the future, but the risk is relatively small.

Researchers also found that there are many changes in the brains of Parkinson's disease patients, although the reasons for these changes are unclear. These changes include:

• The existence of Lewy bodies. Clumps of certain substances in neurons in the brain are microscopic markers of Parkinson's disease. These are called Lewy bodies, and researchers believe that these Lewy bodies provide important clues to the cause of Parkinson's disease.
• Alpha-synuclein found in Lewy bodies. Although many substances have been found in Lewy bodies, scientists believe that an important substance is a natural and widely available protein called alpha-synuclein (a-synuclein). It appears in all Lewy bodies as clumps that cannot be broken down by cells. This is an important concern of Parkinson's researchers.

Parkinson’s Disease Signs and Symptoms

The signs and symptoms of Parkinson's disease vary from person to person. Early signs may be mild and can even go unnoticed. Symptoms usually start on one side of your body and usually continue to worsen on that side, even if the symptoms begin to affect both sides. Tremors are common, but this disease also causes stiffness or gradual slowness of movement. In the early stages of Parkinson's disease, your face may have little or no expression at all. The arms do not swing when walking anymore. Your speech may become slurred. As the disease progresses, the symptoms will worsen over time.

Parkinson's signs and symptoms may include:

• Tremor. Tremors (shaking) usually start in one limb, usually within the hand or fingers. Your hands may tremble even when resting.
• Bradykinesia (slow movement). Over time, Parkinson's disease can slow down your movement, which makes simple tasks difficult and often time-consuming. When you walk, your steps may become shorter. It may be difficult to get up from the chair. You may even begin to drag your feet when you try to walk.
• Stiff muscles. Rigidity in the muscles can occur anywhere in your body. Stiff muscles can be very painful and may restrict your freedom of movement.
• Writing changes. It may become difficult for you to write normally.
• Loss of automatic movement. Your ability to perform unconscious movements may decrease, including blinking, smiling, or swinging your arms while walking.
• Changes in speech. Before talking, you may speak softly, quickly, vaguely or hesitantly. Your speech may be more monotonous than usual.

Problems with posture and balance. Your posture may change, or you may have balance problems due to Parkinson's disease.

Parkinson’s Disease Diagnosis

Diagnosing Parkinson’s disease is generally based on the symptoms. Diagnosing this disease in the early stages can be challenging, but a skilled practitioner can precisely conclude that it is Parkinson’s disease. For a neurologist to diagnose this disease, you must have at least two of the following symptoms for a period of time:

• Tremors;
• Stiffness or rigidity in your arms, trunk or legs;
• Trouble maintaining your balance and even possible falls;
• Slowing of movements (bradykinesia).

In most cases, Parkinson’s disease is diagnosed by a family doctor or internist, however many people seek help from a neurologist to manage their symptoms and disease.

The Stages of Parkinson’s

• The first stage. In this initial stage, the patient has mild symptoms and they generally do not interfere with daily activities. Tremors and other motor symptoms only occur on one side of the body. There are changes in posture, walking and facial expressions.
• Stage two. Symptoms begin to worsen. Tremors, stiffness, and other motor symptoms can affect both sides of the body now. Walking problems and poor posture may become obvious. People can still live alone, but daily work is more difficult and tedious.
• The third stage. This stage is considered mid-term, characterized by loss of balance and slow movements. Falls are more common. The person is still completely independent, but symptoms can severely interfere with activities such as getting dressed and eating.
• Stage four. At this point, the symptoms are severe and debilitating. The person can stand independently, but may require a walker to move. The person needs help in activities of daily living and cannot live alone.
• Level five. This is the most advanced and limiting level. Stiff legs can make standing or walking impossible. The person needs a wheelchair or is bedridden. All activities need to be taken care of around the clock. The person may experience hallucinations and delusions. The Parkinson community recognizes that there are many important non-motor and motor symptoms.

Parkinson’s disease progression theory

The current theory (part of the Braak hypothesis) is that the earliest signs of Parkinson's disease appear in the enteric nervous system, medulla, and olfactory bulb, responsible for controlling the sense of smell. According to this theory, Parkinson's disease will only progress to the substantia nigra and cortex over time.

What confirms the theory is that non-motor symptoms such as loss of smell (dysosmia), insomnia, and constipation can appear years before the motor features of the disease. Therefore, researchers are paying more and more attention to these non-motor symptoms in order to detect Parkinson’s disease as soon as possible and find ways to stop its progression.

Parkinson’s Disease Treatment

Although there is no standard cure for Parkinson’s disease, the treatment is used for managing some of the symptoms. Treatments include surgery, medications and lifestyle changes, such as getting more rest and exercise regularly.

There are different medications that are used to treat Parkinson’s disease:

• That increase dopamine levels in the brain;
• That affect other brain chemicals in the body;
• That help control non-motor symptoms.

The main treatment for Parkinson’s disease is Levodopa, also called L-dopa. Nerve cells use L-dopa to stimulate dopamine to make up for the depleted reserves of the brain. Patients usually take levodopa with another medicine called carbidopa. Carbidopa can prevent or reduce some of the side effects of levodopa treatment-such as nausea, vomiting, hypotension, irritability and it can also reduce the amount of levodopa needed to improve symptoms. There are many forms in which this medication is found, such as:

• Carbidopa and levodopa. Levodopa is the most effective drug for treating Parkinson's disease. It is a natural chemical substance that can enter the brain and be converted into dopamine. The combination of levodopa and carbidopa (Lodosyn) protects the early conversion of levodopa into dopamine outside the brain. This can prevent or reduce side effects such as nausea. Side effects may include nausea or drowsiness (positional hypotension). Years later, as your disease progresses, the benefits of levodopa may not remain the same, as the effects of this medication tend to decrease after intaking it for longer periods of time. In addition, involuntary movements (dyskinesias) may occur after taking higher doses of levodopa. Your doctor may reduce your dose or adjust the time of administration to control these effects.
• Inhaled Carbidopa and levodopa. When oral medications suddenly stop working during the day, this alternative may help control the symptoms that appear.
• Carbidopa and levodopa infusion. Duopa is a brand-name drug consisting of carbidopa and levodopa. However, it is administered via a feeding tube, which delivers the drug in the form of a gel directly to the small intestine. Duopa is used in patients with advanced Parkinson's disease. These patients still respond to carbidopa and levodopa, but their responses vary widely. Since Duopa is a continuous infusion, the blood concentration of the two drugs remains constant. Catheterization requires minor surgery. Risks associated with catheter use include catheter loss or infection at the infusion site.

Parkinson's disease patients should not stop taking levodopa or any medication without first consulting a doctor. Sudden discontinuation of this medicine can cause serious side effects, such as inability of moving or even breathing difficulties.

Other drugs used to treat Parkinson’s symptoms are:

• Dopamine agonists, which mimic the effects of dopamine in the brain. Unlike levodopa, dopamine agonists do not convert to dopamine. Instead, they mimic the effect of dopamine in your brain.  They are not as effective as levodopa in treating your symptoms. However, they last longer and can be used with levodopa to reduce the adverse effects that levodopa sometimes brings.  Dopamine agonists include pramipexole (Mirapex), ropinirole (Requip) and rotigotine (Neupro, administered as a patch). Apomorphine (Apokyn) is a short-acting injectable dopamine agonist used for rapid relief. Some side effects of dopamine agonists are similar to carbidopa and levodopa. But they may also include hallucinations, lethargy, and compulsive behaviors such as hypersexuality, gambling, and eating. If you are taking these drugs and show abnormalities, please consult your doctor.
• MAO-B inhibitors, which slow down the enzyme that breaks down dopamine in the brain. They help prevent the breakdown of dopamine in the brain by inhibiting the brain enzyme monoamine oxidase B (MAO B). This enzyme metabolizes dopamine in the brain. Taking selegiline (a MAO-B inhibitor) together with levodopa can help prevent it from wearing off too quickly. Side effects of MAO B inhibitors may include headache, nausea, or insomnia. When combined with carbidopa and levodopa, these drugs increase the risk of hallucinations. These drugs are not often used in combination with most antidepressants or certain anesthetics, because serious but rare reactions may occur. Please consult your doctor before taking any other medicines containing MAO-B inhibitors.
• COMT inhibitors, help to break down dopamine.
• Amantadine, an old antiviral drug that reduces involuntary movements.
• Anticholinergic drugs to reduce tremor and muscle stiffness.

Deep Brain Stimulation

For Parkinson's patients who do not respond well to drugs, deep brain stimulation, or DBS, may be appropriate. DBS is a surgical procedure that involves surgically implanting electrodes into a part of the brain and connecting them to small electronic devices implanted in the chest. The device and electrodes stimulate the brain in a painless way and can prevent many of the movement-related symptoms of Parkinson's disease, such as tremor, slow movement, and stiffness.

Other therapies including home remedies

Other therapies can be used to relieve the symptoms of Parkinson's disease. This includes physical therapy, occupational therapy, and speech therapy, which can help treat gait and voice disorders, tremor and stiffness, and decreased mental function. Other supportive therapies include healthy eating and exercise to strengthen muscles and improve balance.

• Healthy Eating. Although no food or food combination has been proven to help treat Parkinson's disease, some foods can relieve certain symptoms. For example, eating fiber-rich foods and drinking plenty of fluids can help prevent constipation, which is common in Parkinson's disease. A balanced diet also provides nutrients such as omega-3 fatty acids, which are beneficial to patients with Parkinson's disease.
• Exercising regularly. Exercise can improve your muscle strength, flexibility and balance. Exercise can also improve your health and reduce depression or anxiety, which are linked to Parkinson’s disease. Your doctor may recommend that you work with a physical therapist to learn an exercise program that is right for you. You can also try walking, swimming, gardening, dancing, water aerobics or stretching exercises. Parkinson's disease can disrupt your sense of balance and make it difficult for you to walk with a normal gait. Exercise can improve your balance. These suggestions may also be helpful with managing balance problems:

1. Try not to move too fast.
2. When walking, make sure that the heel touches the ground first.
3. If you find yourself shuffling, stop and check your posture. It is best to stand upright.
4. When you walk, look forward, not straight down.

• Prevent falls as much as possible. In the later stages of the disease, you are more likely to fall. In fact, a small bump or push will make you lose your balance. The following suggestions may help:

1. Turn your entire body instead of pivoting over your feet.
2. Distribute your weight evenly between your feet, don't lean on them.
3. Avoid carrying things when walking.
4. Avoid walking backwards.

• Daily activities. Daily 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 can make daily life easier.
• Alternative Medicine Supportive therapy can help relieve some of the symptoms of Parkinson's disease, such as pain, fatigue, and depression. Combined with your treatment, these therapies can improve your quality of life:

1. Massage. Massage therapy reduces muscle tension and promotes relaxation. However, this treatment is rarely covered by health insurance companies.
2. Yoga. In yoga, gentle stretches and postures can increase your flexibility and balance. You can adjust most postures to suit your physical capabilities.
3. Alexander Technique. This technique—focusing on muscle posture, balance, and thinking about how you use your muscles—can reduce muscle tension and pain.
4. Meditation. In meditation, calmly reflect and focus on an idea or image. Meditation can reduce stress and pain, and improve your well-being.
5. Pet therapy. Having a dog or cat can increase your flexibility and agility, and improve your emotional health.
6. Tai Chi. Tai Chi is an ancient Chinese form of exercise that uses slow, smooth movements to improve flexibility, balance and muscle strength. Tai Chi can also help prevent falls. Several forms of Tai Chi are suitable for people of all ages and physical conditions. A study showed that Tai Chi can improve the balance of patients with mild to moderate Parkinson's disease better than stretching and strength training.

Risk factors for Parkinson’s Disease

Risk factors for Parkinson's disease include:

• Age. Symptoms of Parkinson’s disease usually start in middle or late life and the risk increases with age. Young people rarely suffer from Parkinson's disease. People usually get sick when they are 60 or older.
• Genetics and Heredity. Having close relatives with Parkinson's disease increases your chances of developing the disease. However, unless many relatives in your family have Parkinson's disease, your risk is still small.
• Sex. Men are more susceptible to Parkinson's disease than women.
• Exposure to toxins. Long-term exposure to herbicides and pesticides slightly increases the risk of Parkinson's disease.

Complications of Parkinson’s Disease

Parkinson's disease is usually accompanied by these additional problems that can be treated:

• Thinking problems. You may have cognitive problems, such as dementia and difficulty thinking. These usually occur in the later stages of Parkinson's disease. This cognitive problem is not very sensitive to drug response.
• Depression and mood changes. You may experience depression, sometimes at a very early stage of this disease., however, treating depression can make it easier to deal with the other challenges of Parkinson's disease. You may experience other emotional changes, such as anxiety, fear or loss of motivation. The doctor can give you medicine to treat these symptoms.
• Swallowing difficulties. As the disease progresses, you may experience difficulty swallowing. As swallowing slows down, saliva will accumulate in your mouth, causing drooling.
• Chewing and eating problems. The latest Parkinson's disease affects the oral muscles, making it difficult to chew. This can lead to suffocation and malnutrition.
• Sleep disorders. People with Parkinson's disease usually have trouble sleeping, including frequent waking at night, waking up early, or falling asleep during the day. People may also suffer from rapid eye movement sleep behavior disorder. Medications can help solve sleep problems.
• Bladder problems. Parkinson's disease can cause bladder problems, including inability to control urine or difficulty urinating.
• Constipation. A lot of people with Parkinson's disease experience constipation, mainly due to a slower digestive tract.

Although these are rarer, people with Parkinson’s disease can also experience:

• Changes in blood pressure. Due to a sudden drop in blood pressure (orthostatic hypotension), you may feel dizzy when you stand up.
• Odor disorders. There may be problems with your sense of smell. You may not be able to tell the difference between certain smells or odors.
• Fatigue. A lot of people with Parkinson's disease lose energy and feel tired, especially later in the evening.
• Pain. Some people with Parkinson's disease experience pain in specific parts of the body or throughout the body.
• Sexual dysfunction. Some people with Parkinson's disease will notice a decrease in libido or sexual performance.

Prevention of Parkinson’s Disease 

Since the cause of Parkinson's disease is unknown, the proven method of preventing the disease is yet to be discovered. Some studies have shown that regular aerobic exercise can reduce the risk of Parkinson's disease.

Other studies have shown that people who consume caffeine (found in coffee, tea, and some sodas) are less likely to develop Parkinson's disease than people who do not drink caffeine. Green tea is also associated with reducing the risk of Parkinson's disease. However, it is not clear whether caffeine can actually prevent Parkinson's disease, or whether there are other links. There is not enough evidence to recommend drinking caffeinated beverages to prevent Parkinson's disease.

Bottom line

Parkinson’s disease comes in many forms, but it is crucial to pay attention to the early signs of this disease. Some symptoms may not be apparently linked to Parkinson’s disease, therefore it is important that you see a doctor if you feel any changes to your body and state of mind. You may write down the symptoms to make sure you do not forget any of when you consult a doctor. Even though there is no cure, treatment for colluding with the symptoms is available.