Parkinson's disease

We have selected the following expert medical opinion based on its clarity, reliability and accuracy. Credits: Sourced from the Mayo Clinic, Minnesota. Please refer to your own medical practitioner for a final perspective, assessment or evaluation.

Overview

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

In the early stages of Parkinson's disease, your face may show little or no expression, or your arms may not swing when you walk. Your speech may become soft or slurred. Parkinson's disease symptoms worsen as your condition progresses over time.

Although Parkinson's disease can't be cured, medications may markedly improve your symptoms. In occasional cases, your doctor may suggest surgery to regulate certain regions of your brain and improve your symptoms.

Symptoms

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

Parkinson's signs and symptoms may include:

• Tremor: A tremor, or shaking, usually begins 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. One characteristic of Parkinson's disease is a tremor of your hand when it is relaxed (at rest).
• Slowed movement (bradykinesia): Over time, Parkinson's disease may reduce your ability to move and slow your movement, making simple tasks difficult and time-consuming. Your steps may become shorter when you walk, or you may find it difficult to get out of a chair. Also, you may drag your feet as you try to walk, making it difficult to move.
• Rigid muscles: Muscle stiffness may occur in any part of your body. The stiff muscles can limit your range of motion and cause you pain.
• Impaired posture and balance: Your posture may become stooped, or you may have balance problems as a result of Parkinson's disease.
• Loss of automatic movements: In Parkinson's disease, you may have a decreased ability to perform unconscious movements, including blinking, smiling or swinging your arms when you walk.
• Speech changes: You may have speech problems as a result of Parkinson's disease. 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: It may become hard to write, and your writing may appear small.

When to see a doctor

See your doctor if you have any of the symptoms associated with Parkinson's disease — not only to diagnose your condition but also to rule out other causes for your symptoms.

Causes

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 signs of Parkinson's disease.


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

• Your 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 disease. However, certain gene variations appear to increase the risk of Parkinson's disease but with a relatively small risk of Parkinson's disease for each of these genetic markers.
• Environmental triggers: Exposure to certain toxins or environmental factors may increase the risk of later Parkinson's disease, but the risk is relatively small.

Researchers have also noted that many changes occur in the brains of people with Parkinson's disease, although it's not clear why these changes occur.

These changes include:

• The presence of 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 is found within Lewy bodies: Although many substances are found within Lewy bodies, scientists believe an important one is the natural and widespread protein called alpha-synuclein (A-synuclein). It's found in all Lewy bodies in a clumped form that cells can't break down. This is currently an important focus among Parkinson's disease researchers.

Risk factors

Risk factors for Parkinson's disease include:

• 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 are women.
• Exposure to toxins: Ongoing exposure to herbicides and pesticides may put you at a slightly increased risk of Parkinson's disease.

Complications

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

• Thinking difficulties: You may experience cognitive problems (dementia) and thinking difficulties, which usually occur in the later stages of Parkinson's disease. Such cognitive problems aren't very responsive to medications.
• Depression and emotional changes: People with Parkinson's disease may experience depression. 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.
• 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. People may also experience rapid eye movement sleep behaviour 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.

You may also experience:

• 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 odours or the difference between odours.
• Fatigue: Many people with Parkinson's disease lose energy and experience fatigue, and the cause isn't always known.
• Pain: Many 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.

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.

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 you manage problems with walking, movement and tremor. These medications increase or substitute for dopamine, a specific signalling chemical (neurotransmitter) in your brain.

People with Parkinson's disease have low brain dopamine concentrations. 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, although symptoms usually can continue to be fairly well-controlled.

Medications your doctor may prescribe include:

Carbidopa-levodopa: Levodopa, the most effective Parkinson's disease medication, is a natural chemical that passes into your brain and is converted to dopamine. Levodopa is combined with carbidopa, which protects levodopa from premature conversion to dopamine outside your brain, which prevents or lessens side effects such as nausea.

Side effects may include nausea or light-headedness (orthostatic hypotension).

After years, as your disease progresses, the benefit from levodopa may become less stable, with a tendency to wax and wane ("wearing off"). Also, you may experience involuntary movements (dyskinesia) after taking higher doses of levodopa. Your doctor may lessen your dose or adjust the times of your doses to control these effects.

Dopamine agonists include pramipexole, ropinirole and rotigotine (given as a patch). A short-acting injectable dopamine agonist, apomorphine, is used for quick relief.

Some of the side effects of dopamine agonists are similar to the side effects of carbidopa-levodopa, but also include hallucinations, sleepiness and compulsive behaviours such as hypersexuality, gambling and eating. If you're taking these medications and you behave in a way that's out of character for you, talk to your doctor.

MAO-B inhibitors: These medications include selegiline and rasagiline. They help prevent the breakdown of brain dopamine by inhibiting the brain enzyme monoamine oxidase B (MAO-B). This enzyme metabolizes brain dopamine. Side effects may include nausea or insomnia.

When added to carbidopa-levodopa, these medications increase the risk of hallucinations. These medications are not often used in combination with most antidepressants or certain narcotics due to potentially serious but rare reactions. Check with your doctor before taking any additional medications with a MAO-B inhibitor.

Catechol-O-methyltransferase (COMT) inhibitors:

• Entacapone is the primary medication from this class. This medication mildly prolongs the effect of levodopa therapy by blocking an enzyme that breaks down dopamine. Side effects, including an increased risk of involuntary movements (dyskinesias), mainly result from an enhanced levodopa effect. Other side effects include diarrhoea or other enhanced levodopa side effects.
• Tolcapone is another COMT inhibitor that is rarely prescribed due to a risk of serious liver damage and liver failure.

Anticholinergics: These medications were used for many years to help control the tremor associated with Parkinson's disease. Several anticholinergic medications are available, including benztropine or trihexyphenidyl.

However, their modest benefits are often offset by side effects such as impaired memory, confusion, hallucinations, constipation, dry mouth and impaired urination.

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 (dyskinesias) induced by carbidopa-levodopa.

Side effects may include a purple mottling of the skin, ankle swelling or hallucinations.

Surgical procedures

Deep brain stimulation: In deep brain stimulation (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 haemorrhage. 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 (dyskinesias), reduce tremor, reduce rigidity, and improve slowing of movement.

DBS is effective in controlling erratic and fluctuating responses to levodopa or for controlling dyskinesias that don't improve with medication adjustments.

However, DBS isn't helpful for problems that don't respond to levodopa therapy apart from tremor. A tremor may be controlled by DBS even if the tremor isn't very responsive to levodopa.

Although DBS may provide sustained benefit for Parkinson's symptoms, it doesn't keep Parkinson's disease from progressing.

Lifestyle and home remedies

If you've received a diagnosis of Parkinson's disease, you'll need to work closely with your doctor to find a treatment plan that offers you the greatest relief from symptoms with the fewest side effects. Certain lifestyle changes may also help make living with Parkinson's disease easier.

Healthy eating: 

While there's no food or combination of foods proven to help in Parkinson's disease, some foods may help ease some of the symptoms. For example, eating foods high in fibre and drinking an adequate amount of fluids can help prevent constipation that is common in Parkinson's disease.

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 suggest 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 also help:

• Try not to move too quickly.
• Aim for your heel to strike the floor first when you're walking.
• If you notice yourself shuffling, stop and check your posture. It's best to stand up straight.
• Look in front of you, not directly down, while walking.
• 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 you walk.
• 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.

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