Definition: Defining the Meaning of Parkinson's Disease
Parkinson's disease (PD, also known as idiopathic or primary parkinsonism, hypokinetic rigid syndrome (HRS), or paralysis agitans) is a degenerative disorder of the central nervous system. Parkinson's disease is a progressive disorder of the nervous system that affects your 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.
Parkinson's disease affects the movement of the person with the disease through affects in the person's nerve cells in their brain. Usually, the nerve cells in the person's brain produce a chemical called, 'Dopamine,' which sends out a signal to a portion of their brain controlling movement. It allows the person's muscles to move smoothly and perform in the manner they wish them to. In persons who have Parkinson's disease, these nerve cells break down, no longer producing enough Dopamine, and interfere with the person's movement.
Parkinson's disease is progressive, worsening over time. The progression of the disease is usually slow, occurring over a period of many years. There are treatments available to help persons with Parkinson's disease to live full lives.
Causes of Parkinson's Disease
Medical science does not know what causes Parkinson's disease at this time. Scientists are performing a great deal of research, looking for answers. Among the possible causes they are studying are both poisons in the environment and aging. Abnormal genes seem to have led to Parkinson's disease in some people. To date there is simply not enough proof to demonstrate that Parkinson's disease is an inherited one.
Symptoms of Parkinson's Disease
Parkinson's disease involves four main symptoms. These symptoms include tremor that may affect a person's arms, legs, hands, or their head. Person's with Parkinson's disease may experience stiff muscles, or slow movement. Another symptom of Parkinson's disease involves problems with walking or balancing. Tremor may very well be the first symptom a person notices in association with Parkinson's disease; it is the most common of all of the signs of the disease, although not everyone with Parkinson's experiences it. Not everyone who experiences tremor has Parkinson's disease as well. Tremor will many times begin in just one leg or arm, on one side of the person's body, and may be worse when they are awake and not moving the limb affected. The tremor may improve when the person moves the affected limb, or when they are sleeping.
Over time, Parkinson's disease affects muscles throughout the person's body, potentially leading to problems such as difficulty swallowing, or constipation. Persons in later stages of the disease may present a blank or, 'fixed,' expression, have difficulty speaking, or additional problems. Some persons with Parkinson's disease in later stages may experience a decrease in mental skills or dementia. Symptoms of Parkinson's disease usually appear in persons between the ages of fifty and sixty years old, although some people experience symptoms at earlier ages.
Diagnosing Parkinson's Disease
The diagnostic process for Parkinson's disease involves a neurological examination, during which a doctor will ask about the person's symptoms and prior health. A neurological examination includes both tests and questions that help a doctor to understand how well the person's nerves are working. The doctor will examine how the person moves, check their reflexes and muscle strength, as well as their vision. There is the potential for the doctor to try a medicine which will tell them if the person has Parkinson's disease. The doctor may also ask questions related to the person's mood.
Blood and lab testing is not available that can tell a doctor whether or not a person has Parkinson's disease. There are tests that may help the doctor to determine if another disease is responsible for the symptoms the person is experiencing. An example of test that may be performed to rule out other issues include an MRI to look for either a brain tumor, or a stroke.
Treatment of Parkinson's Disease
Currently, there is no known cure for Parkinson's disease. There are a number of forms of medicine that can be used to control the symptoms of Parkinson's disease and make living with it easier for the person affected with it. Levodopa is perhaps the best drug for controlling the symptoms of Parkinson's disease. The medication may cause problems if used for lengthy periods of time, or at high dosages. Because of this, many doctors prefer to use other forms of medication for treatment of persons who are in early stages of Parkinson's disease. Doing so allows them to use Levodopa at a later time, postponing the side effects.
Persons with Parkinson's disease who have mild symptoms may not require treatment; a doctor may wait to prescribe medication until their symptoms begin to interfere with their daily lives. Doctors adjust medications as the symptoms people with Parkinson's disease experience worsen. Sometimes, people with this disease may need to take more than one medication in order to achieve the best results. For some persons with Parkinson's disease, a form of treatment called, 'Deep Brain Stimulation,' may be used. Deep brain stimulation requires a surgeon to place wires in the person's brain. These wires carry tiny electrical signals to portions of the persons brain that control their movement. The signals produced may help the parts of the brain involved perform better.
Coping with Parkinson's Disease
Eating healthy foods, getting appropriate amounts of rest, exercise, and making wise use of energy are good practices for persons with Parkinson's disease. Occupational and physical therapy can help as well. Parkinson's disease usually progresses very slowly, and people live for many years with only minor symptoms, such as a tremor in one hand in many cases. A number of people who have this disease both can and do keep working for many years. As the disease progresses, a change in the way you work may be needed; seek support to learn new ways to adapt. Take an active role in your own health care, learning everything you can about the disease. Establish a relationship with a doctor that you both trust and can work with; attend appointments with this doctor, and follow the treatment plan. Depression is something that a number of persons with Parkinson's disease experience; it is something that needs to be reported to your doctor or counselor, there are antidepressant medications that can help. There are Parkinson's support groups, as well as both online support and message boards for persons affected by Parkinson's disease.
Treating depression in PD patients: New research:
Depression is a common and serious co-morbidity in patients with Parkinson's; studies suggest that approximately 40 percent of PD patients suffer from depression.
A group of scientists from the University of Kentucky College of Medicine and the Sanders-Brown Center on Aging has found interesting new information in a study on depression and neuropsychological function in Parkinson's disease (PD).
Published in the journal Psychiatry Research, the study, which assessed cognitive function in depressed and non-depressed patients with PD, found that the dopamine replacement therapy commonly used to treat motor symptoms of Parkinson's disease was associated with a decline in cognitive performance among depressed Parkinson patients. In contrast, non-depressed Parkinson patients' cognitive function improved on dopamine replacement therapy. The study also found that mood in depressed Parkinson's patients was actually worse while on dopaminergic medications.
"This was a surprise," said Lee Blonder, Ph.D., the study's principal investigator. "It is the opposite of our original hypothesis that both groups of PD patients would improve in cognitive performance on dopaminergic medications, and that mood in the depressed PD group would also improve."
A cohort of 28 patients with PD - 18 non-depressed and 10 depressed - were given a baseline series of tests to assess cognitive function and the incidence and severity of depression. They were then re-tested with and without their dopamine replacement therapy.
Results revealed a statistically significant interaction between depression and medication status on three measures of verbal memory and a facial affect naming task. In all cases, depressed Parkinson's patients performed significantly more poorly while on dopaminergic medication than while off. The opposite pattern emerged for the non-depressed Parkinson's group.
Blonder cautions that these results are to some extent preliminary due to the small cohort of 28 participants. "Additional studies are required before these results should be used to alter treatment plans," Blonder says. But, "future research should ultimately focus on investigating treatment options for patients with Parkinson's and depression to maximize patient function without compromising their mental health."
Blocking Mitochondrial Fission:
The inhibition of a particular mitochondrial fission protein shows promise as a potential treatment for Parkinson's Disease. A study led by a researcher from Plymouth University in the UK, has discovered that the inhibition of a particular mitochondrial fission protein could hold the key to potential treatment for Parkinson's Disease.
The debilitating movement symptoms of the disease are primarily caused by the death of a type of brain cell that produces a chemical called dopamine. This brain chemical (also known as a neurotransmitter) helps nerve cells to send signals to other nerve cells. A reduction in dopamine from cell death results in a lack of communication between nerve cells, which in turn leads to difficulty in movement control. Understanding why these nerve cells die or do not work properly could lead to new therapies for PD.
Mitochondria are small structures within nerve cells that help keep the cells healthy and working properly - they are, in effect, the power generators of the cell. Mitochondria undergo frequent changes in shape, size, number and location either through mitochondrial fission (which leads to multiple, smaller mitochondria) or mitochondrial fusion (resulting in larger mitochondria). These processes are controlled mainly by their respective mitochondrial fission and fusion proteins. A balance of mitochondrial fission/fusion is critical to cell function and viability. The research team found that when a particular mitochondrial fission protein (GTPase dynamin-related protein-1 - Drp1) was blocked using either gene-therapy or a chemical approach in experimental models of PD in mice, it reduced both cell death and the deficits in dopamine release - effectively reversing the PD process. The results suggest that finding a strategy to inhibit Drp1 could be a potential treatment for PD.
Our findings show exciting potential for an effective treatment for PD and pave the way for future in-depth studies in this field. It's worth noting that other researchers are also targeting this mitochondrial fission/fusion pathway as potential treatments for other neurological diseases such as Alzheimer's disease, Huntington's disease and Amyotrophic Lateral Sclerosis.
We've known for decades that problems with mitochondria - the batteries of the cell - play a key role in the death of nerve cells in Parkinson's, but the research in this area hasn't yet led to new treatments. This study, which reveals a potential new drug target to protect mitochondria, is a promising step towards slowing down or stopping the progression of Parkinson's.
Weight and Eating Habits in Parkinson's Disease
Patients affected by Parkinson's disease often show marked changes in body weight: they may gain or lose a lot of weight depending on the stage of the disease, or they may put on up to ten kilos after deep brain stimulation (a treatment to alleviate the symptoms). This situation considerably worsens the quality of life of a person who is already suffering from heavily disabling motor disorders, so it is important to understand what are the factors that cause it.
"The body weight and eating habits of Parkinson's patients change as the disease progresses", explains Marilena Aiello, SISSA researcher and first author of the study published in the journal Appetite. "In our paper, we reviewed studies on Parkinson's that provided data on the association between non-motor symptoms and dietary habits and body weight. This way, we were able to evaluate some factors which, beyond the motor symptoms and drug treatments, might play a role in this problem".
Depression, cognitive impairment, sensory disturbances - chiefly smell and taste -, impaired ability to feel pleasure: all these aspects contribute to incorrect eating habits. "The possible role of the ability to feel pleasure and motivation towards food consumption is particularly interesting. Parkinson's patients may be somewhat lacking in this respect and therefore eat less and lose weight, whereas the weight gain exhibited after deep brain stimulation seems to point to an increase in pleasure and motivation associated with food. Specific studies are required to confirm or refute this finding emerging from the literature review". The study was conducted in collaboration with the "Santa Maria della Misericordia" Hospital in Udine, and coordinated by Raffella Rumiati, head of the Neuroscience and Society Lab at SISSA.
Parkinson's Disease Awareness
The silver awareness ribbon is the color for Parkinson's disease (also gray ribbon). The month of April is Parkinson's disease Awareness Month and April 11th is Parkinson Disease International Awareness Day.
Quick Facts: Symptoms of Parkinson's Disease
The main symptoms of Parkinson's disease are:
- Slow movement
- Stiff and inflexible muscles
- Tremor (involuntary shaking of particular parts of the body)
- Other physical and psychological symptoms include depression, constipation, problems sleeping (insomnia), loss of sense of smell (anosmia) and memory problems.
Statistics: Parkinson's Disease Facts &
- The average age of onset is 60
- Parkinson's affects up to 1 million people in the U.S.
- Parkinson's strikes 50 percent more men than women
- Doctors diagnose as many as 60,000 new cases each year
- 15-25 percent of people with Parkinson's have a relative with the disease
- Risk for people related to someone with Parkinson's increases 2-5 percent
- Symptoms of Parkinson's may progress over a period longer than 20 years
- Early onset PD, beginning before age 50 accounts for 5-10 percent of cases
- According to available statistics, 1.2 million people in Europe have Parkinson's disease.
- It is estimated that 6.3 million people have Parkinson's disease worldwide, affecting all races and cultures.