Disease indicators noted in studies of those stricken
By Carla McClain
Arizona Daily Star
Tucson, Arizona | Published: 09.10.2006
Are you shy? Do you avoid taking risks? Are you always on time and often anxious? Are you a teetotaler, a nonsmoker and don't drink much coffee?
Then, believe it or not, you may be at risk for one of the dreaded scourges of aging today — Parkinson's disease.
That's the conclusion of a series of studies of people with Parkinson's — a progressive brain disease that gradually destroys muscle movement, causing tremors, weakness, loss of facial expression and finally immobility and dementia.
Though most neurological diseases experts in Tucson say the science pointing to an at-risk "Parkinsonian personality" is valid, the issue remains controversial, especially among Parkinson's sufferers themselves. Many protest their portrayal as meek and mild.
"When I first heard of Parkinsonian personality, I remember thinking this did not describe Dad in my experience," said Anne Udall, daughter of Arizona's most famous Parkinson's patient, Morris K. Udall, the longtime U.S. congressman from Southern Arizona who died in 1998 after a lengthy struggle with the disease.
Noting that running for president — as her father did in 1976 — is not exactly the behavior of the shy and timid, Anne Udall said: "But this does describe a number of folks I know with Parkinson's. There are so many different kinds, and so many different interactions and complexities of this damn disease."
At least 1 million Americans are battling the relentless degeneration of Parkinson's and about 50,000 new cases are diagnosed each year — a number that's steadily growing as the population ages.
Medical science long has searched for the cause of Parkinson's and many studies point to toxic chemical exposure — mainly pesticides, but also some herbicides — as a likely factor. Many experts believe Parkinson's can result from such exposures in those genetically vulnerable to the disease. And about 10 percent of all cases appear to be genetic.
But especially intriguing in this complex picture is the growing evidence that certain personality traits also signal a risk for the disease.
Shyness, aversion to risk, social withdrawal, anxiety, depression, subordination and rigidity — meaning a person who is inflexible, punctual, law-abiding and conscientious — are traits of the Parkinsonian personality that may emerge years, even decades, before the onset of the disease itself.
By the same token, people with opposite traits — risk-takers, sensation-seekers, extroverts, smokers and drinkers, even to the point of addiction — appear to be protected against Parkinson's, studies show.
The theory centers on a brain chemical — the neurotransmitter dopamine — that's destroyed as Parkinson's progresses. Dopamine affects muscle function as well as impulse control and reactions to stimulation.
"It is possible that long before people develop Parkinson's disease, they have low dopamine levels, which might make them disinclined to take risks and less likely to enjoy smoking or drinking coffee," concluded experts at Johns Hopkins School of Medicine in Baltimore.
They were analyzing the most recent study of Parkinsonian personality, which explored the history of personal characteristics, also smoking and drinking habits, in more than 100 people with Parkinson's disease.
When compared to 100 healthy people, the study found the Parkinson's patients "had lower sensation-seeking and higher depression and anxiety scores. … They were also less likely to have ever smoked, and had lower caffeine and alcohol intakes."
The results likely explain why smoking and drinking coffee appeared in earlier studies to protect against Parkinson's. Instead, people who develop the disease simply have the risk-averse personalities that shun smoking, caffeine and alcohol, the study concluded.
"This is definitely a valid concept, no question about it," said Dr. Charles Adler, a neurologist who specializes in Parkinson's at the Mayo Clinic in Scottsdale.
"I do think there is evidence for a pre-symptomatic personality in people who go on to Parkinson's. But what we cannot say is if you don't smoke and you don't parasail, you're going to get Parkinson's. This personality does not actually predict Parkinson's. It only means you may have an increased risk."
Some of the earliest studies of Parkinsonian personality were done at the University of Arizona in the 1990s. One study found significantly higher rates of Parkinson's in the families of shy, elderly people than in families of those who were not shy.
A second UA study found that among young people, the shy types were much more likely to get sick from drinking a small amount of alcohol or from pesticides and other chemically toxic odors than their bolder peers.
"There probably is a Parkinson-prone personality," said Dr. Iris Bell, UA professor of family and community medicine, psychiatry, psychology and public health, who led these studies.
"But the take-home message for people is if you have this kind of personality, it means only a very small increased risk. The environmental risk factors, such as exposure to toxic chemicals, are likely much more important in the development of disease."
Parkinson's victims such as Udall, Billy Graham, Michael J. Fox and Pope John Paul II — who performed before millions — seem to defy the typical Parkinsonian type, Bell noted.
"When you see people out there who have done these huge public things, it's obviously not the whole story," she said. "We need to do much larger epidemiological studies to determine just how much of a role personality plays in this disease."
No shrinking violet either is Tucsonan Tiena Fiske, 68, who was diagnosed with Parkinson's seven years ago, not long after she noticed her hand shaking as she tried to grip a golf club.
Not only did she start smoking at age 15, she kept it up until 10 years ago, finally quitting for her grandchildren. Three or four cups of coffee a day also have been part of her lifestyle.
"She is not a risk-averse person," said her husband, Mac. "She's done a lot of unconventional things through her life."
Fiske describes herself as "conscientious," saying, "I like to have things done right. But people need to know that not all Parkinson's patients are submissive," she said.
The whole subject of "Parkinsonian personality" is sensitive in the patient community.
"I could imagine if I were a Parkinson's patient, I would not really want to be described as dull and uninteresting," said Cynthia Holmes, a health psychologist and Parkinson's educator at the Arizona Chapter of the American Parkinson Disease Association.
To the contrary, many tend to be high achievers, often functioning at top professional levels before their symptoms become disabling, said Adler, the Mayo Clinic doctor.
"These are not couch potatoes, even if they may tend to be shy. You see a lot of tremendously driven people," he said.
Admitting she probably does fit the "personality" in many ways, Tucsonan Eve Pender, 82, says she's never smoked, drinks very little coffee and maybe sips a cocktail once a month.
Still, she hiked the Grand Canyon 15 years ago and has enjoyed playing casino slot machines — both risky activities.
"I noticed I really started avoiding doing anything risky somewhat later in life," said Pender, who learned she had the disease about three years ago. "I am pretty introverted and rather quiet. I always have been that way."
It may surprise many to find out Pam Ronstadt — wife of former City Councilman Fred Ronstadt — has always battled painful shyness, despite the demands of political life and work dealing with the public. Hit with early-onset Parkinson's seven years ago, Ronstadt, now 40, only recently decided to stop working and spend her time with her children.
"I've jumped out of airplanes, and I plan to do that again, so I don't consider myself a non-risk-taker," she said. "But I am pretty introverted, really pretty shy. I have to force myself to approach large groups or go to large parties. That's always been true, but it has gotten worse with the Parkinson's.
"My friends know that my speech is slurred by the disease and not by knocking back five scotches, but other people don't," she added. "Maybe it's fear of exposure now."
? Contact reporter Carla McClain at 806-7754 or at cmcclain@azstarnet.com. |
