by Liz Seegert

Parkinson’s Disease (PD) is a chronic, degenerative neurological disorder that affects about one in 100 people over age 60. Since it is a progressive disease, symptoms worsen over time. There’s no known cause or cure, but medication and surgery can help manage symptoms. Most people’s symptoms take years to develop and can live for years with the disease.

The incidence of Parkinson’s increases with age. However, an estimated 4 percent of people with PD are diagnosed before age 50. Actor Michael J. Fox was only 29 years old when he learned he had the disease. Men are one and a half times more likely to have Parkinson’s than women.

About 50,000 people are diagnosed with PD in the United States each year. At least one million people in the United States and more than five million worldwide are living with Parkinson’s. As the population continues to age, these figures are expected to rise, according to the National Institutes of Health.

The Parkinson’s Association estimates that the combined direct and indirect cost of Parkinson’s, including treatment, social security payments and lost income from inability to work, is nearly $25 billion per year in the United States. Medication costs for an individual with PD average $2,500 a year and therapeutic surgery can cost up to $100,000 per patient.

Parkinson’s occurs when neurons in the brain break down and die, primarily in a region of the brain called the substantia nigra. As PD progresses, the amount of dopamine produced in the brain decreases, leaving a person unable to control movement, balance, or emotions. Swallowing and speaking difficulties are common, as are several non-motor symptoms, including depression and cognitive decline, which severely affect the quality of life. While Parkinson’s disease itself is not fatal, the CDC rates complications from PD as the 14th top cause of death in the United States.

Disease Symptoms

Symptoms vary among patients and can be difficult for even a specialist to diagnose early. They may start with a barely noticeable tremor in just one hand or cause stiffness or slowing of movement. Symptoms often begin on one side of the body and usually remain worse on that side even as the disease begins to affect both sides, according to the Mayo Clinic.

Major symptoms include loss of motor skills:

• Tremors often being in a hand or fingers. One common indication of Parkinson’s is a hand tremor while it is relaxed or at rest. Other people may experience a back-and-forth rubbing of the thumb and forefinger, known as a pill-rolling tremor.

• Bradykinesia is a slowing down and loss of spontaneous and voluntary movement. This makes even simple tasks difficult and time-consuming. Those affected may find their gait becomes shorter or they begin having difficulty getting out of a chair. Foot dragging while walking also is common.

• Unusual stiffness in a limb or other body part as a sign of rigidity. Stiff muscles limit the range of motion and cause pain.

As the disease progresses, other motor symptoms appear:

• Postural instability, as a person’s posture become stooped and they have problems standing and walking. Balance and coordination may become impaired.

• Writing becomes more difficult.

Other physical effects include:

• Cognitive impairment, with a reduced ability to multi-task or concentrate, potentially with a decline in intellectual functioning.

• Mood disorders such as depression and anxiety.

• Problems sleeping, including REM Sleep Disorder, in which individuals act out their dreams.

• Low blood pressure when standing.

• Constipation.

• Speech and swallowing problems may decrease the ability to perform unconscious movements, such as blinking or smiling. Speech patterns may change or become more monotone.

Stages of Disease

The National Parkinson’s Foundation highlights five distinct stages of the disease:

• Stage One: Symptoms are mild, with little to no interference in activities. Tremors usually occur on one side of the body.

• Stage Two: Symptoms worsen, with tremors, rigidity and other movement problems affecting both sides of the body. Walking problems and poor posture become apparent. Daily activities become more difficult.

• Stage Three: Considered the mid-stage progression of the disease, the patient experiences loss of balance, falls and slowness of movement. There is significant difficulty with daily activities such as eating.

• Stage Four: Symptoms are severe and very limiting to carrying out daily activities. It becomes much harder to stand without assistance and waking may require the use of a walker. The person needs help with activities of daily living and is unable to live alone.

• Stage Five: It can become impossible to stand or walk due to leg stiffness, leaving a person confined to a wheelchair or bed. Full-time nursing care is required. Hallucinations or delusions may occur.

Research Efforts

Researchers have identified several genes that can cause rare inherited forms of PD and other genes that influence age of onset and susceptibility to PD. More powerful gene discovery methods, including Genome Wide Association Studies and Deep Sequencing, now are revealing more genetic contributions to PD.

According to the NIH, environmental influences may also play a role. Exposure to certain pesticides may increase risk, while higher intake of vitamin D, caffeine, and tobacco may be associated with lower incidence. For most people with PD, genes and environment may both contribute.

By the time a person is diagnosed, most of the dopamine nerve cells in the brain areas affected by the disease are lost. Efforts are underway to develop biomarkers which will detect PD early before irreversible damage to the brain occurs, speed clinical trials of therapies, and reduce the time to test whether new treatments are slowing degeneration from years to months. Treatments include levodopa and amantadine, which can be effective but have some unpleasant side effects.

The NET-PD program already has facilitated the review of more than 100 drugs, and the NIH will be supporting a large Phase III clinical trial of creatine, the most promising drug examined to date.

Gene therapy for PD has shown promise in animals and now is moving into first stage clinical trials in people. Strategies closest to the clinic, including boosting the capacity of nerve cells to produce neurotransmitters or providing molecules that promote nerve cell survival, may benefit individuals with inherited or non-inherited PD.

Researchers continue to advance brain stimulation therapies through improved technology and studies of how deep brain stimulation affects the brain. For example, optogenetics inserts light-sensitive proteins into nerve cells, which allows precise stimulation of brain cells with light pulses. Scientists currently use optogenetics in animals to understand PD and DBS. In the future, optogenetics, nanotechnology, and other new technologies may treat PD in people.

The National Institute of Neurological Disorders and Stroke (NINDS) is the primary institute supporting PD research. In fiscal 2016, it funded approximately $107 million of a total $161 million in NIH-supported PD basic, translational, and clinical research. The NIH also operates the Parkinson’s Disease Center of Excellence.

Research supported by the Michael J. Fox Foundation for Parkinson’s Research is attempting to identify more clear-cut biomarkers to diagnose people before they start to display symptoms with the disease.

The Parkinson’s Disease Foundation offers this downloadable chart of medications and their side effects.

Sources

• Parkinson’s Disease Foundation: James Beck, Ph.D. vice president, scientific affairs. Media can contact Veronica (Ronnie) Todaro, M.P.H., vice president, national programs: (212) 923-4700 ext. 3.

• The American Parkinson’s Disease Association has an extensive grassroots network across the country that delivers education, support, and patient services to Parkinson’s patients and their families. They may be a good resource for finding patients or caregivers.

• Michael J. Fox Foundation: Todd Sherer, Ph.D., CEO; media inquiries: (212) 509-0995.

• Serge Przedborski, M.D., Ph.D., vice chair of research, Department of Neurology, co-director of the Motor Neuro Center, and director of the Columbia Translational Neuroscience Initiative at Columbia University: sp30@cumc.columbia.edu.

• Stanley Fahn, M.D., professor of neurology and director emeritus of the Center for Parkinson’s Disease and Other Movement Disorders at Columbia University, New York City. Considered one of the world’s preeminent Parkinson’s clinical researchers: 212-305-3716 or sf1@columbia.edu.

• Marian Emr, director of the office of communications and public liaison at the National Institute of Neurological Disorders and Stroke: 301-496-5924 or Me20t@nih.gov.

• Check out this list of researchers at the Scripps Research Institute.

• Check out research that the Department of Veterans Affairs is conducting at their Parkinson’s Disease Research, Education, and Clinical Centers.

• John Q. Trojanowski, M.D., Ph.D., director of the Penn Udall Center for Parkinson’s Research and co–director of the Center for Neurodegenerative Disease Research at Perelman School of Medicine, University of Pennsylvania: 215-662-6399 or Trojanow@mail.med.upenn.edu.

• Ted Dawson, M.D., Ph.D., professor of neurology and director of the Institute for Cell Engineering at the Johns Hopkins University School of Medicine: 410-614-3359 or tdawson@jhmi.edu.

• Martin A. Samuels, M.D., chairman of the department of neurology at Brigham and Women’s Hospital and professor of neurology at Harvard Medicine School. Contact through BWH Communications & Public Affairs, 617-525-6370.

• David Standaert, M.D., Ph.D., professor and chairman of Neurology, University of Alabama, Birmingham, director of the Center for Neurodegeneration and Experimental Therapeutics, director of the UAB Comprehensive Neuroscience Center. Call UAB Public Relations: 205-934-3884. (Note: Standaert is on the Scientific Advisory Council of the Michael J. Fox Foundation for Parkinson’s Research.)

• Check out this study, The Burden of Neurological Disease in the United States: A Summary Report and Call to Action (Annals of Neurology, March 2017).

 Story Ideas

• What programs or supports are available in your community for those with Parkinson’s Disease or their caregivers?

• What research is underway at local/regional academic institutions?

• What will proposed cuts to the NIH budget mean for Parkinson’s research?

• Profile local volunteers through one of the foundations or hospitals that work with people who have Parkinson’s.

• What additional treatments or therapies are available and what’s being done to make the cost of care more affordable?