Parkinsonís disease is a progressive type of movement disorder caused by a loss of certain cells in an area of the brain called the substantia nigra. The affected brain cells produce dopamine, a chemical involved in the transmission of messages associated with smooth movement and coordination. When patients lose 60 to 80 percent of their dopamine-producing cells, symptoms of Parkinsonís disease become more apparent.
There are four main characteristic symptoms of Parkinsonís. Resting tremor is a shaking, usually in the hand or foot, on one side of the body. The tremor occurs while the affected limb is resting and disappears with movement. Resting tremor can also occur in the face or jaw. Bradykinesia is slowed movement. It may also include difficulty initiating movement, incomplete movement and sudden stopping and inability to move (freezing). Rigidity is a stiffness of the muscles, usually those in the limbs and trunk. The affected limb is unable to relax, interfering with full range of motion. Postural instability refers to problems with balance and coordination. This symptom increases risk for falling.
According to the Parkinsonís Disease Foundation, about one million people in the U.S. have Parkinsonís Disease. Roughly 60,000 people are newly diagnosed each year. The condition most commonly occurs after 40, however a small percentage of patients are diagnosed at a younger age. Men are affected slightly more often than women. The total cost of Parkinsonís to the U.S. healthcare system and economy is about $25 billion.
Swallowing Problems in Parkinsonís Patients
Patients with Parkinsonís disease often develop coordination problems with other muscles in the body, including those that coordinate swallowing. In fact, researchers say the majority of patients with Parkinsonís disease eventually develop swallowing problems (dysphagia). That can cause food and liquids to slip into the airways instead of the esophagus (the tube that leads to the stomach). In healthy people, that would trigger a cough reflex to clear out the foreign material. Michelle Troche, Ph.D., Researcher with the University of Florida in Gainesville, says people with Parkinsonís have sensory problems that limit their ability to tell that something is in the airways. Thus, food and liquids can get into the lungs, leading to aspiration pneumonia. Studies show this condition is a leading cause of death for Parkinsonís patients.
Help for Swallowing Problems
University of Florida researchers recently tested a device called the Expiratory Muscle Strength Trainer (EMST) for patients with Parkinsonís. The small, hand-held device looks similar to an air-flow meter. It contains a one-way, spring-loaded valve that opens under a preset range of exhaled air pressure. Troche says this effort exercises the muscles that control swallowing.
In the study, 30 Parkinsonís patients were given the EMST device and 30 were given a sham (non-operating) device. Participants were asked to use their device 20 minutes a day, 5 days a week, for 4 weeks. The researchers found about one-third of patients using the real device had improved swallowing function. In a follow-up study, patients will use the real device at home for five days a week. Participants will be evaluated every three months for two years.
The EMST device is sold online. However, Troche warns it should only be used under guidance of a speech therapist trained in treating swallowing disorders. The device is also being tested for swallowing problems in patients with multiple sclerosis.
American Parkinson Disease Association, http://www.apdaparkinson.org
The Michael J. Fox Foundation for Parkinsonís Research, http://www.michaeljfox.org
National Institute of Neurological Disorders and Stroke, http://www.ninds.nih.gov
National Parkinson Foundation, http://www.parkinson.org
Parkinsonís Disease Foundation, http://www.pdf.org
Pitts, Teresa, et al., ďImpact of Expiratory Muscle Strength Training on Voluntary Cough and Swallow Function in Parkinson Disease,Ē Chest, May 2009, Vol. 135, No. 5, pp. 1301-1308.
Russell, J., et al., ďTargeted Exercise Therapy for Voice and Swallow in Persons with Parkinsonís Disease,Ē Brain Research, June 23, 2010, No. 1341, pp. 3-11.
Sung, H., et al., ďThe Prevalence and Patterns of Pharyngoesophageal Dysmotility in Patients with Early Stage Parkinsonís Disease,Ē Movement Disorders, October 30, 2010, Vol. 25, No. 14, pp. 2361-2368.
Troche, M., et al., ďAspiration and Swallowing in Parkinson Disease and Rehabilitation with EMST,Ē Neurology, November 23, 2010, Vol. 75, No. 21, pp. 1912-1919.
Research compiled and edited by Barbara J. Fister