What is Parkinson's Disease?
Parkinson's disease belongs to a group of conditions called movement disorders. It is both chronic, meaning it persists over a long period of time, and progressive, meaning its symptoms grow worse over time.
Parkinson's disease occurs when a group of cells, in an area of the brain called the substantia nigra, that produce a chemical called dopamine begin to malfunction and eventually die. Dopamine is a neurotransmitter, or chemical messenger, that transports signals to the parts of the brain that control movement initiation and coordination. When Parkinson's disease occurs, for unexplained reasons, these cells begin to die at a faster rate and the amount of dopamine produced in the brain decreases. The four primary symptoms are:
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Visit our "Publications & Videos" section to review a list of print and audio patient materials from the Parkinson's Disease Foundation that are available free of charge, or sign up to receive regular news and updates by mail and email. Click here to sign up.As many as one million Americans suffer from Parkinson's disease. While approximately 15% of Parkinson's patients are diagnosed before the age of 40, incidence increases with age. The cause is unknown, and although there is presently no cure, there are many treatment options such as medication and surgery to manage the symptoms.
Tremor: In the early stages of the disease, about 70% of people experience a slight tremor in the hand or foot on one side of the body, or less commonly in the jaw or face. It appears as a 'beating' or oscillating movement and is regular (4-6 beats per second). Because tremor usually appears when the muscles are relaxed, it is called "resting tremor." This means that the affected body part trembles when it is at rest and not doing work and often subsides with action. The tremor often spreads to the other side of the body as the disease progresses, but remains most apparent on the original side of occurrence.
Rigidity: Rigidity or increased muscle tone means stiffness or inflexibility of the muscles. Normally muscles contract when they move, and then relax when they are at rest. In rigidity, the muscle tone of an affected limb is stiff. Rigidity can result in a decreased range of motion. For example a patient may not swing his or her arms when walking. Rigidity can also cause pain and cramps at the muscle site.
Bradykinesia: Bradykinesia is a slowing of voluntary movement. In addition to slow movements, a person with bradykinesia will likely also have incompleteness of movement, difficulty in initiating movements, and arrests of ongoing movement. Patients may begin to walk with short, shuffling steps (festination), which, combined with other symptoms such as loss of balance, increases the incidence of falls. They may also experience difficulty making turns or abrupt movements. They may go through periods of "freezing," which is when the patient is stuck and finds it difficult to stop or start walking. Bradykinesia and rigidity can occur in the facial muscles, causing a "mask-like" expression with little or no movement of the face. The slowness and incompleteness of movement can also affect speaking and swallowing.
There are many secondary symptoms of Parkinson's disease. These include stooped posture, a tendency to lean forward or backward, and speech problems, such as softness of voice or slurred speech caused by lack of muscle control. Non-motor symptoms also impact the life of a person with Parkinson's. A survey published in October 2003, "The Impact of Parkinson's Disease on Quality of Life" revealed that two of the top three most disabling symptoms for people with Parkinson's are non-motor symptoms, including loss of energy and pain. To review the results of this survey go to: http://www.amarinpharma.com/.
The following is a list of secondary symptoms of Parkinson's disease:
What Causes Parkinson's Disease?
While the debate concerning environmental factors and genetics as causative factors in PD continues, there has been extensive investigation of the mechanisms involved in the cell death process. A number of cell death concepts have been put forward including, oxidative stress, mitochondrial dysfunction and excitotoxicity.
Medications for Parkinson's Disease
Levodopa is a dopamine precursor, a substance that is converted into dopamine by an enzyme in the brain. The use of levodopa was a breakthrough in the treatment of PD. Unfortunately, patients experienced debilitating side effects, including severe nausea and vomiting. With increased dosing and prolonged use of levodopa, patients experienced other side effects including dyskinesias (spontaneous, involuntary movements) and "on-off" periods when the medication will suddenly start or stop working.
Check with a doctor before taking any of the following to avoid possible interactions: antacids, anti-seizure drugs, anti-hypertensives, anti-depressants and high protein food.
Combining Levodopa with Carbidopa (Sinemet) represented a significant improvement in the treatment of Parkinson's disease. The addition of carbidopa prevents levodopa from being metabolized in the gut, liver and other tissues, and allows more of it to get to the brain. Therefore, a smaller dose of levodopa is needed to treat symptoms. In addition, the severe nausea and vomiting often associated with levodopa treatment was greatly reduced.
Consult a doctor before taking any medications to avoid possible interactions. In particular, antacids, anti-seizure drugs, anti-hypertensives, anti-depressants and high protein food may adversely affect the function of Levodopa/carbidopa.
Stalevo (carbidopa, levodopa and entacapone) is a new (September 2003) combination tablet for patients who experience signs and symptoms of end-of-dose "wearing-off." The tablet combines carbidopa/levodopa (the most widely used agent for PD), with entacapone. While carbidopa reduces the side effects of levodopa, entacapone extends the time levodopa is active in the brain (up to 10 percent longer). The same drugs that interact with carbidopa/levodopa and entacapone interact with Stalevo.
Symmetrel (amantadine hydrochloride) is thought to work in PD because it has several actions. It activates both the release of dopamine from storage sites and possibly blocks the re-uptake of dopamine into nerve terminals. It also has a glutamate receptor blocking activity. Its dopaminergic actions result in its usefulness in reducing dyskinesia induced by levodopa. It is thus called an indirect-acting dopamine agonist, and is widely used as an early monotherapy (treatment of a condition by means of a single drug), with the more powerful Sinemet added when needed. Unfortunately, its benefit in more advanced PD is often short-lived, with patients reporting a fall-off effect.d
Symmetrel may interact with Cogentin (benztropine), Disipal (orphenadrine), Sinemet (levodopa), Artane (trihexyphenidyl), amphetamines and alcohol.
Anticholinergics (trihexyphenidyl, benztropine mesylate, procyclidine, etc.) do not act directly on the dopaminergic system. Instead they act to decrease the activity of another neurotransmitter, acetylcholine. There is a complex interaction between levels of acetylcholine in the brain and levels of dopamine. Many clinicians find that if an agonist or levodopa does not relieve tremor, then the addition of an anticholinergic drug is often effective. Adverse effects include blurred vision, dry mouth and urinary retention. These drugs may be contraindicated in older patients since they can cause confusion and hallucination.d
Check with a doctor before using anticholinergics with anti-histamines, Haldol, Thorazine, Symmetrel, Clozaril and alcohol.
Selegiline or deprenyl (Eldepryl) has been shown to delay the need for Sinemet when prescribed in the earliest stage of PD, and has also been approved for use in later stages to boost the effects of Sinemet. Eldepryl may interact with anti-depressants, narcotic pain killers and decongestants. Check with a doctor before taking any new medications.
Dopamine agonists are drugs that activate dopamine receptors directly, and can be taken alone or in combination with Sinemet. Agonists available in the United States include bromocriptine (Parlodel), pergolide (Permax), pramipexole (Mirapex) and ropinirole (Requip).
Consult a doctor before taking any of the following to avoid possible interactions: alcohol, anti-psychotics, medications that lower blood pressure, Navane (thiothixene), Taractan (chlorprothixene), Haldol (haloperidol), Reglan (metoclopramide), phenothiazines, thiozanthenes, cimetidine, phenothiazines, butyrophenones, Cipro and benzodiazepines.
COMT inhibitors such as tolcapone (Tasmar) and entacapone (Comtan) represent a different class of Parkinson's medications. These drugs must be taken with levodopa. They prolong the duration of symptom relief by blocking the action of an enzyme which breaks down levodopa.
*** Side Effects from Medications - Like the symptoms of PD themselves, the side effects caused by Parkinson's medications vary from patient to patient. They may include dry mouth, nausea, dizziness, confusion, hallucinations, drowsiness, insomnia, and other unwelcome symptoms. Some patients experience no side effects from a drug, while others may have to discontinue its use because of them.
Two older, and somewhat outdated, lesioning procedures that provide relief from Parkinson's symptoms are pallidotomy and thalamotomy. Pallidotomy can alleviate rigidity and bradykinesia symptoms, and thalamotomy helps to control tremors. Doctors rarely perform either procedure because both permanently destroy parts of the brain and have serious side effects. The damage could make it impossible to perform surgeries that may become available in the future, such as brain tissue transplants.
Deep brain stimulation (DBS) , a safer and more effective surgery, has replaced these methods. It is a preferred surgical option because it has the same, if not better results than pallidotomy and thalamotomy. DBS also leaves open the possibility of other therapies, should they become available in the future. As with any surgical procedure, there are risks and side effects. The main benefit of DBS surgery is to reduce motor fluctuations i.e. the ups and downs caused by a decreasing effectiveness of Sinemet.
The electrode is usually placed on one side of the brain. The DBS electrode implanted in the left side of the brain will control the symptoms on the right side of the body and vice versa. In some cases, patients will need to have stimulators on both sides of the brain.
During surgery, a device is implanted to provide an electrical impulse to a part of the brain involved in motor function. This is often the subthalamic nucleus, in a deep part of the brain called the thalamus. During the procedure, electrodes are inserted into the targeted brain region using MRI and neurophysiological mapping to ensure that they are implanted in the right place. The electrodes are connected to wires that lead to an impulse generator or IPG (similar to a pacemaker) that is placed under the collarbone and beneath the skin. Patients have a controller, which allows them to verify whether the DBS is 'on' or 'off'. They can use this device to check the battery and to turn the device 'on' or 'off'. An IPG battery lasts for about 3 to 5 years and is relatively easy to replace under local anesthesia.
Patients considering one or another surgical procedure should discuss the options first with their movement disorder specialists and then with their families and/or caregivers.For more information on DBS, order from PDF our comprehensive booklet "Surgery for Parkinson's Disease", written by our medical advisor Dr. Blair Ford. To order your free copy, send a request by email to firstname.lastname@example.org. Or you can get information on the web by visiting these sites:
Role of the Patient
Exercise: For people with Parkinson's, regular exercise and/or physical therapy are essential for maintaining and improving mobility, flexibility, balance, and a range of motion, and for warding off many of the secondary symptoms mentioned above. Exercise is as important as medication for the management of PD.
Support groups: For many people, these groups play an important role in the emotional well-being of patients and families. They provide a caring environment for asking questions about Parkinson's, for laughing and crying and sharing stories and getting advice from other sufferers, and for forging friendships with people who understand each other's problems.
Diet: There is no specific diet to prevent or slow Parkinson's but there are several suggestions to help manage the disease. A vegetable-rich diet may aid digestion and prevent constipation. Parkinson's patients should also take a balanced approach to protein intake because protein inhibits the absorption of levodopa in the gut. Avoiding high protein meals when taking levodopa helps prevent this potential problem. However, a patient should not make dietary changes without discussing this first with their doctor. Parkinson's disease nutrition author, Kathrynne Holden, offers several books, including "Eat Well, Stay Well" and "Cook Well, Stay Well" that provide beneficial eating and cooking tips. Copies can be ordered from Five Star Living, on (877) 565-2665 or at www.nutritionucanlivewith.com.
A Healthy Patient/Doctor Relationship: A neurologist can most effectively help a patient manage his or her Parkinson's if the neurologist and the patient have a good working relationship. Doctors need the patient to be honest, forthright, and inquisitive in order to give the best medical attention possible. Patients should also require that a doctor treat them in the same honest, open manner, engaging them in dialogue about the patient's experiences. Doctors can provide a wealth of information and suggestions for improving quality of life.
Physical, Speech and/or Occupational Therapy: These therapies can help Parkinson's patients control their symptoms and make daily life easier. Physical therapy may increase muscle strength and flexibility and decrease the incidence of falls. Speech therapy is available to increase voice volume and assist with word pronunciation. The Lee Silverman technique is a special speech therapy that can be very beneficial to people with Parkinson's - for further information see www.lsvt.org.
Occupational therapy affords patients alternative methods of doing tasks that they can no longer perform with ease. These options may give patients a stronger sense of control when living with Parkinson's disease, which seems to take control from them. The patient should ask a physician for recommendations if he or she does not provide them. These therapies may or may not be covered by insurance.
Clinical Trials: Getting involved in a clinical trial may be a way for a patient to feel empowered and help researchers understand more about Parkinson's disease in order to improve treatment options for this disorder. Increased clinical trial participation will result in a better understanding of the disease and will also help treatments that are in the research and developmental phases reach patients more quickly. A patient should understand what the trial entails and be educated about the patient's responsibilities and obligations. To find more information on the patient's role in clinical trials, visit www.ninds.nih.gov/parkinsonsweb/clinical_trials_info.htm.
To participate in an important survey about clinical trials, please click here.
What can friends and family of a person with Parkinson's do?
3 Score of 16 or higher on the CES-D demonstrates evidence of clinically significant depressive symptoms. caregivers reporting other functional needs. Additionally, PD caregivers who reported their loved ones were either forgetting what day it was or were being argumentative or irritable, were significantly more likely to score high on the CES-D respectively than PD caregivers whose care recipient did not report these behaviors.
PD Caregiver Strain
Perception of role
Identified PD Caregiver Problems at Assessment