When most people think about Parkinson’s disease, they think about actor Michael J. Fox, diagnosed with the disease in 1991 at age 30. But many of us don’t know much more about the progressive disease except its legacy of erratic motor movements.
The disease, which is the second most common neurological disease after Alzheimer’s, affects more than 1 million Americans. It occurs when brain cells in a region of the brain called the substantia nigra begin to die. As they do, the substantia nigra produces less and less dopamine, a neurotransmitter that sends key messages to another part of the brain, the striatum, which coordinates movement and coordination.
But Parkinson’s is much more complex than these basics. Below are facts about Parkinson’s that may surprise you.
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1. Parkinson’s may start with your sense of smell.
One of the earliest symptoms of Parkinson’s may be a loss of smell, which can predate diagnosis by 20 to 30 years, says Jill M. Farmer, DO, MPH, director of the Movement Disorders Program at the Capital Institute for Neurosciences, Capital Health, in Pennington, New Jersey. “It can also cause sleep disorders, depression and anxiety.”
“Parkinson’s involves cognitive problems, constipation, bladder problems and [digestive] absorption problems as well, says Maurizio Facheris, MD, MSc, Associate Director of Research Programs for the Michael J. Fox Foundation for Parkinson’s Research. “Those problems are caused by the degeneration of other systems, which involve other neurotransmitters such as serotonin, glutamate and acetylcholine. It’s not just a dopamine disorder.”
2. Parkinson’s disease is not the same as Parkinsonism.
“Parkinson’s is one form of Parkinsonism,” says Facheris. “But there are a lot of similar disorders, including progressive supranuclear palsy, or palsy; multiple-system atrophy, or MSA; or drug-induced Parkinsonism. These can look like Parkinson’s disease and confuse diagnosis.”
Even Parkinson’s itself has a range of types, says Farmer: “In [the most common type of] Parkinson’s, the patient is usually older with a shuffling gait and shaking arm. But in some people with Parkinson’s, the dominant problem is gait, and in others it may be cramping in the arms and toes. The kind you have guides treatment.”
3. Parkinson’s is not a man’s disease.
About 60 percent of people who have the most typical kind of Parkinson’s are men, says Facheris: “But the other forms of Parkinson’s split 50/50.”
Some researchers suspect that estrogen may be a protective factor, says Farmer: “After menopause, women tend to get Parkinson’s at the same rate as men.”
4. Parkinson’s is not an old person’s disease.
“The average age of diagnosis is in the late 50s,” says Facheris. “But a handful of people are diagnosed in their 40s or earlier.” About 10 percent of people with Parkinson’s are diagnosed under the age of 40, according to the National Parkinson’s Foundation.
5. There’s no test for Parkinson’s.
“There is no standard test,” says Farmer. “A dopamine active transporter (DAT) scan looks at how well dopamine is metabolized in [the brain]. That helps distinguish the condition from other ones such as essential tremor or drug-induced Parkinson’s.” A movement disorder specialist would also look at symptoms such as less arm swing in one arm than another, and will also study whether the patient walks stiffly or loses his balance easily. A doctor would use a blood test to distinguish it from a thyroid problem or Wilson’s disease, both of which can cause tremors.
6. Exercise is critical for people with Parkinson’s.
“Exercise releases dopamine and neurotropic growth factor, which appears to allow more dopamine release,” says Farmer. “It’s possible that 30 minutes of exercise several times a week may lower the needed dose of medication.”
7. Parkinson’s has genetic and environmental components.
No one yet knows the cause of Parkinson’s, but both genetic and environmental factors both play a part, says Facheris.
“You can now test for a panel of genes if you have a family history of Parkinson’s, although finding a genetic link doesn’t change treatment,” says Farmer. Exposure to heavy metals, certain pesticides, and Agent Orange (a herbicide used in the Vietnam war) may increase risk.
8. Doctors may delay prescribing the gold standard of treatment.
After seven to 10 years of taking levodopa (Sinemet), patients often develop dyskinesia, or uncontrolled movements, says Farmer. Although levodopa, used since 1967, is the gold standard treatment, doctors may wait to introduce it to younger patients because of those side effects, she says. Instead, they may offer other classes of drugs have been developed that mimic dopamine but don’t have the movement side effects.
“Dopamine agonists such as the patch Neupro (rotigotine transdermal system) may increase impulses however,” says Farmer. “So you have to be monitored so that you don’t drink or eat excessively or do other compulsive behaviors.”
Another treatment option is MAO-B inhibitors, which recycle the body’s dopamine by blocking its breakdown. “They may also delay progression, but that’s not yet proven,” says Farmer.
9. Surgical options are some of the newest promising treatments for Parkinson’s.
”If tremors are predominant in the disease, one of the most promising treatments is deep brain stimulation surgery [DBS],” says Farmer. Not all patients respond to conventional medical therapy. If they don’t, they can be candidates for DBS.
In the surgery, an electrode is inserted into the part of the brain involved in motor function. Its electrical impulses block signals that may cause some of the Parkinson’s symptoms. It’s a good option for people who are experiencing motor side effects from levodopa,” says Facheris. “But DBS does have surgical risks (such as bleeding and infection), and not everyone qualifies for this therapy.”
Another option that may become available in a year is LCIG/Duodopa. A levodopa/carbidopa gel is delivered through a small tube into the intestine from an external supply on the skin, much like the constant delivery of insulin for diabetics. Constant delivery helps avoid peaks and valleys of medication that cause side effects.
10. Parkinson’s is not fatal.
Although Parkinson’s is a progressive disease, no one dies directly from Parkinson’s, says Facheris. “But there are complications that can lead to death. For instance, a minority of people may have trouble swallowing. If food goes into the lungs, you can get pneumonia.” Falling is also a risk. When older people break bones, they can become bedridden, which can lead to other problems like muscle weakness, and difficulty breathing.
To learn more about Parkinson’s disease, visit the National Parkinson Foundation or The Michael J. Fox Foundation for Parkinson’s Research.