Parkinson’s Disease DIAGNOSIS AND TESTS

admin July 6, 2020

Parkinson’s disease is a neurological movement disorder. Common symptoms include tremor, slowness of movement, stiff muscles, and unsteady walk and balance and coordination problems. There is no cure for the disease. Most patients can maintain a good quality of life with medications. In some patients, surgery can help improve symptoms.

What is Parkinson’s disease?

Parkinson’s disease is a nervous system disease that affects your ability to control movement. The disease usually starts out slowly and worsens over time. If you have Parkinson’s disease, you may shake, have muscle stiffness, and have trouble walking and maintaining your balance and coordination. As the disease worsens, you may have trouble talking, sleeping, have mental and memory problems, experience behavioural changes and have other symptoms.

Who gets Parkinson’s disease?

About 50% more men than women get Parkinson’s disease. It is most commonly seen in persons 60 years of age and older. However, up to 10% of patients are diagnosed before age 50.

About 60,000 new cases of Parkinson’s disease are diagnosed in the United States each year.

Is Parkinson’s disease inherited?

Scientists have discovered gene mutations that are associated with Parkinson’s disease.

There is some belief that some cases of early-onset Parkinson’s disease – disease starting before age 50 – may be inherited. Scientists identified a gene mutation in people with Parkinson’s disease whose brains contain Lewy bodies, which are clumps of the protein alpha-synuclein. Scientists are trying to understand the function of this protein and its relationship to genetic mutations that are sometimes seen in Parkinson’s disease and in people with a type of dementia called Lewy body dementia.

Several other gene mutations have been found to play a role in Parkinson’s disease. Mutations in these genes cause abnormal cell functioning, which affects the nerve cells’ ability to release dopamine and causes nerve cell death. Researchers are still trying to discover what causes these genes to mutate in order to understand how gene mutations influence the development of Parkinson’s disease.

Scientists think that about 10% to 15% of person’s with Parkinson’s disease may have a genetic mutation that predisposes them to development of the disease. There are also environmental factors involved that are not fully understood.

What causes Parkinson’s disease?

Parkinson’s disease occurs when nerve cells (neurons) in an area of the brain called the substantianigra become impaired or die. These cells normally produce dopamine, a chemical (neurotransmitter) that helps the cells of the brain communicate (transmits signals, “messages,” between areas in the brain). When these nerve cells become impaired or die, they produce less dopamine. Dopamine is especially important for the operation of another area of the brain called the basal ganglia. This area of the brain is responsible for organizing the brain’s commands for body movement. The loss of dopamine causes the movement symptoms seen in people with Parkinson’s disease.

People with Parkinson’s disease also lose another neurotransmitter called norepinephrine. This chemical is needed for proper functioning of the sympathetic nervous system. This system controls some of the body’s autonomic functions such as digestion, heart rate, blood pressure and breathing. Loss of norepinephrine causes some of the non-movement-related symptoms of Parkinson’s disease.

Scientists aren’t sure what causes the neurons that produce these neurotransmitter chemicals to die.

What are the symptoms of Parkinson’s disease?

Symptoms of Parkinson’s disease and the rate of decline vary widely from person to person. The most common symptoms include:

• Tremor – Shaking begins in your hands and arms. It can also occur in your jaw or foot. In the early stages of the disease, usually only one side of your body or one limb is affected. As the disease progresses, tremor may become more wide spread. It worsens with stress. Tremor often disappears during sleep and when your arm or leg is being moved.
• Slowness of movement (bradykinesia) – This is the slowing down of movement and is caused by your brain’s slowness in transmitting the necessary instructions to the appropriate parts of the body. This symptom is unpredictable and can be quickly disabling. One moment you may be moving easily, the next you may need help moving at all and finishing tasks such as getting dressed, bathing or getting out of a chair. You may even drag your feet as you walk.
• Muscle spasms – Spasms can be the result of varying factors and can occur at any time during the day.
• Rigid muscles/stiff limbs – Rigidity is the inability of your muscles to relax normally. This rigidity is caused by uncontrolled tensing of your muscles and results in you not being able to move about freely. You may experience aches or pains in the affected muscles and your range of motion may be limited.
• Unsteady walk and balance and coordination problems – You may develop a forward lean that makes you more likely to fall when bumped. You may take short shuffling steps, have difficulty starting to walk and difficulty stopping and not swing your arms naturally as you walk. You may feel like your feet are stuck to the floor when trying to take a step.
• Muscle twisting, spasms or cramps (DYSTONIA) – You may experience a painful cramp in your foot or curled and clenched toes. Dystonia can occur in other body parts.
• Stooped posture – You have a “hunched over” posture.

Other symptoms include:

• Decreased facial expressions: You may not smile or blink as often as the disease worsens; your face lacks expression.
• Speech/vocal changes: Speech may be quick, become slurred or be soft in tone. You may hesitate before speaking. The pitch of your voice may become unchanged (monotone).
• Handwriting changes: You handwriting may become smaller and more difficult to read.
• Depression and anxiety.
• Chewing and swallowing problems, drooling.
• Urinary problems.
• Mental “thinking” difficulties/memory problems.
• Hallucinations/delusions.
• Constipation.
• Skin problems, such as dandruff.
• Loss of smell.
• Sleeping disturbances including disrupted sleep, acting out your dreams, and restless leg syndrome.
• Pain, lack of interest (apathy), fatigue, change in weight, vision changes.
• Low blood pressure.

What are the different stages of Parkinson’s disease?

Each person with Parkinson’s disease experiences symptoms in in their own unique way. Not everyone experiences all symptoms of Parkinson’s disease. You may not experience symptoms in the same order as others. Some people may have mild symptoms; others may have intense symptoms. How quickly symptoms worsen also varies from individual to individual and is difficult to impossible to predict at the outset.

In general, the disease progresses from early stage to mid-stage to mid-late-stage to advanced stage. This is what typically occurs during each of these stages:

Early stage

Early symptoms of Parkinson’s disease are usually mild and typically occur slowly and do not interfere with daily activities. Sometimes early symptoms are not easy to detect or you may think early symptoms are simply normal signs of aging. You may have fatigue or a general sense of uneasiness. You may feel a slight tremor or have difficulty standing.

Often, a family member or friend notices some of the subtle signs before you do. They may notice things like body stiffness or lack of normal movement (no arm swing when walking) slow or small handwriting, lack of expression in your face, or difficulty getting out of a chair.

Mid stage

Symptoms start getting worse. Tremor, muscle stiffness and movement problems may now affect both sides of the body. Balance problems and falls are becoming more common. You may still be fully independent but daily tasks of everyday living, such as bathing and dressing, are becoming more difficult to do and take longer to complete.

Mid-late stage

Standing and walking are becoming more difficult and may require assistance with a walker. You may need full time help to continue to live at home.

Advanced stage

You now require a wheelchair to get around or are bedridden. You may experience hallucinations or delusions. You now require full-time nursing care.

How is Parkinson’s disease diagnosed?

Diagnosing Parkinson’s disease is sometimes difficult, since early symptoms can mimic other disorders and there are no specific blood or other laboratory tests to diagnose the disease. Imaging tests, such as CT (computed tomography) or MRI (magnetic resonance imaging) scans, may be used to rule out other disorders that cause similar symptoms.

To diagnose Parkinson’s disease, you will be asked about your medical history and family history of neurologic disorders as well as your current symptoms, medications and possible exposure to toxins. Your doctor will look for signs of tremor and muscle rigidity, watch you walk, check your posture and coordination and look for slowness of movement.

If you think you may have Parkinson’s disease, you should probably see a neurologist, preferably a movement disorders-trained neurologist. The treatment decisions made early in the illness can affect the long-term success of the treatment

MANAGEMENT AND TREATMENT

How is Parkinson’s disease treated?

There is no cure for Parkinson’s disease. However, medications and other treatments can help relieve some of your symptoms. Exercise can help your Parkinson’s symptoms significantly. In addition, physical therapy, occupational therapy and speech-therapy can help with walking and balance problems, eating and swallowing challenges and speech problems. Surgery is an option for some patients.

What medications are used to treat Parkinson’s disease?

Medications are the main treatment method for patients with Parkinson’s disease. Your doctor will work closely with you to develop a treatment plan best suited for you based on the severity of your disease at the time of diagnosis, side effects of the drug class and success or failure of symptom control of the medications you try.

Medications combat Parkinson’s disease by:

• Helping nerve cells in the brain make dopamine.
• Mimicking the effects of dopamine in the brain.
• Blocking an enzyme that breaks down dopamine in the brain.
• Reducing some specific symptoms of Parkinson’s disease.

Levodopa: Levodopa is a main treatment for the slowness of movement, tremor, and stiffness symptoms of Parkinson’s disease. Nerve cells use levodopa to make dopamine, which replenishes the low amount found in the brain of persons with Parkinson’s disease. Levodopa is usually taken with carbidopa (Sinemet®) to allow more levodopa to reach the brain and to prevent or reduce the nausea and vomiting, low blood pressure and other side effects of levodopa. Sinemet® is available in an immediate release formula and a long-acting, controlled release formula. Rytary® is a newer version of levodopa/carbidopa that is a longer-acting capsule. The newest addition is Inbrija®, which is inhaled levodopa. It is used by people already taking regular carbidopa/levodopa for when they have off episodes (discussed below).

As people have Parkinson’s for a longer amount of time, the effects of their levodopa doses don’t last as long as they did before, resulting in their symptoms (tremor, muscle rigidity, slowness) worsening before they are due to take their next dose. This is called ‘wearing off.’ They may also notice involuntary, fluid, dancing or fidgeting-like movements of their body called dyskinesias. These movements can indicate the levodopa dose is too high. These ups and downs of the effects of levodopa are called motor fluctuations and are often improve with adjustment of the medication by the neurologist.

Dopamine agonists: These drugs mimic the effects of dopamine in your brain. They are not as effective as levodopa in controlling slow muscle movement and muscle rigidity. Your doctor may try these medications first and add levodopa if your symptoms are not well controlled depending on severity of your symptoms and your age.

Newer dopamine medications include ropinirole (Requip®) and pramipexole (Mirapex®). Rotigotine (Neupro®) is given as a patch. Apomorphine (Apokyn®) is a short-acting injectable medication.

Side effects of dopamine agonists include nausea, vomiting, dizziness, lightheadedness, sleeping problems, leg swelling, confusion, hallucinations and compulsive behavior (such as excessive gambling, buying, eating, or sex). Some of these side effects are more likely to occur in people over 70 years old.

Catechol O-methyltransferase (COMT) inhibitors: These drugs block an enzyme that breaks down dopamine in your brain. These drugs are taken with levodopa and slow your body’s ability to get rid of levodopa, so it lasts longer and is more reliable. Entacapone (Comtan®) and tolcapone (Tasmar®) are examples of COMT inhibitors. Opicapone (Ongentys®) is the newest medication in this class, receiving FDA approval in April 2020. Because these drugs increase the effectiveness of levodopa, they may also increase its side effects, including involuntary movements (dyskinesia). Tolcapone is rarely prescribed because it can damage the liver and requires close monitoring to prevent liver failure.

MAO B inhibitors: These drugs block a particular brain enzyme – monoamine oxidase B (MAO B) – that breaks down dopamine in your brain. This allows dopamine to have longer lasting effects on the brain. Examples of MAO B inhibitors include selegiline (Eldepryl®, Zelapar®), rasagiline (Azilect®) and safinamide (Xadago®). Side effects of these drugs include nausea and insomnia. Giving carbidopa-levodopa with an MAO B inhibitor increases the chance of hallucinations and dyskinesia. MAO B inhibitors are not prescribed if you are taking certain antidepressants or narcotic medications. Your doctor will review all your current medications and make the best treatment choice for you.

Anticholinergics: These drugs help reduce tremor and muscle stiffness. Examples include benztropine (Cogentin®) and trihexyphenidyl (Artane®). These are the oldest class of drugs to treat Parkinson’s disease. Side effects include blurred vision, constipation, dry mouth and urine retention. Persons over age 70 who are prone to confusion and hallucinations or have memory impairment should not take anticholinergics. Because of the high rate of side effects these medications are less commonly used.

Amantadine: Amantadine (Symmetrel®), first developed as an antiviral agent, is useful in reducing the involuntary movements (dyskinesia) caused by levodopa medication. There are two extended-release forms of the drug, Gocovri®, and Osmolex ER®. Side effects include confusion and memory problems.

Istradefylline: Istradefylline (Nourianz®) is an adenosine A2A receptor antagonist. It is used for people taking carbidopa-levodopa but experiencing off symptoms. Like the other drugs that act to increase the effectiveness of levodopa, they may also increase its side effects, including involuntary movements (dyskinesia) and hallucinations.

What are the surgical treatments for Parkinson’s disease?

Most patients with Parkinson’s disease can maintain a good quality of life with medications. However, as the disease worsens, medications may no longer be effective in some patients. In these patients, the effectiveness of medications becomes unpredictable – reducing symptoms during “on” periods and no longer controlling symptoms during “off” periods, which usually occur when the medication is wearing off and just before the next dose is to be taken. Sometimes these variations can be managed with changes in medications. However, sometimes they can’t. Based on the type and severity of your symptoms, the failure of adjustments in your medications, the decline in your quality of life and your overall health, your doctor may discuss some of the available surgical options.

• Deep brain stimulation (DBS) involves implanting electrodes in the brain, which deliver electrical impulses that block or change the abnormal activity that cause symptoms. DBS can treat most of the major movement symptoms of Parkinson’s disease such as tremor, slowness of movement (bradykinesia) and stiffness (rigidity). It does not improve memory, hallucinations, depression, and the other non-movement symptoms of Parkinson’s disease. Only patients whose symptoms are not controlled despite medication trials and who meet other strict criteria may be candidates for DBS. Your doctor will discuss if this is the right treatment for you.
• Carbidopa-levodopa infusion involves the surgical placement of a feeding tube into the small intestine. A gel form of the medication carbidopa-levodopa (Duopa®) is delivered through this tube. This method of continuous infusion of the drug keeps a stable dosage in the body. This helps patients who have had variation in their response to the oral form of carbidopa-levodopa but are still benefitting from the combination drug.
• Pallidotomy involves destroying a small portion of a part of the brain that controls movement (the globus pallidus). Pallidotomy help reduce involuntary movements (dyskinesias), muscle stiffness and tremor.
• Thalamotomy involves destroying a small part of the thalamus. This may help a small number of patients who have severe tremors of their arm or hand.

PREVENTION

Can Parkinson’s disease be prevented?

Unfortunately, no. Parkinson’s disease is long-term disease that worsens over time. Although there is no way to prevent or cure the disease (at this current moment in time), medications may significantly relieve your symptoms. In some patients – especially those with later-stage disease, surgery to improve symptoms may be an option.

OUTLOOK OR PROGNOSIS

What is the outlook for persons with Parkinson’s disease?

Although there is no cure or absolute evidence of ways to prevent Parkinson’s disease, scientists are working hard to learn more about the disease and find innovative ways to better manage it, prevent it from progressing and ultimately curing it.

Currently, you and your healthcare team’s efforts are focused on medical management of your symptoms along with general health and lifestyle improvement recommendations (exercise, healthy eating, improved sleep). By identifying individual symptoms and adjusting the course of action based on changes in symptoms, most people with Parkinson’s disease can live fulfilling lives.

The future is hopeful. Some of the research underway includes:

• Using stem cells (from either bone marrow or embryos) to produce new neurons, which would produce dopamine.
• Producing a dopamine-producing enzyme that is delivered to a gene in the brain that controls movement.
• Using a naturally occurring human protein – glial cell-line derived neurotrophic factor, GDNF – to protect dopamine-releasing nerve cells.

Many other investigations are underway too. Much has been learned, much progress has been made and additional discoveries are likely to come.

PHYSIOTHERAPY

What lifestyle changes can I make to ease Parkinson’s symptoms?

Exercise: Exercise helps improve muscle strength, balance, coordination, flexibility, and tremor. It is also strongly believed to improve memory, thinking and reduce the risk of falls and decrease anxiety and depression. One study in persons with Parkinson’s disease showed that 2.5 hours of exercise per week resulted in improved ability to move and a slower decline in quality of life compared to those who didn’t exercise or didn’t start until later in the course of their disease. Some exercises to consider include strengthening or resistance training, stretching exercises or aerobics (running, walking, dancing). All types of exercise are helpful.

Eat a healthy, balanced diet: This is not only good for your general health but can ease some of the non-movement related symptoms of Parkinson’s, such as constipation. Eating foods high in fiber in particular can relieve constipation. The Mediterranean diet is one example of a healthy diet.

Improve the quality of your sleep.

Living with Parkinson’s disease can be a frustrating experience. It’s normal to feel angry, depressed and anxious. You and your family members might find it helpful to reach out to others who have this disease – to share your knowledge and insights, experiences and tips for living. You may check out local support groups of Parkinson’s organizations.

NEXT ARTICLE
Causes of Neck Pain, Headaches and Shoulder Blade Pain