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Wednesday, July 27, 2016
Credit: Charlotte Eliopoulos
BY FRAN KRITZ
Cases of both parkinsonism and Parkinson's disease increased significantly in the 30 years between 1976 and 2005, especially in men 70 and older. That's according to a study by researchers at the Mayo Clinic in Rochester, MN, published in the June 20 issue of JAMA Neurology. The researchers, who claim their study is the first to show an increase, speculate that the rise may be linked to environmental and lifestyle factors such as pesticides and smoking.
Data from Medical Records
Using data from the Rochester Epidemiology Project (rochesterproject.org/), a collaboration between health care providers in Minnesota and Wisconsin, the researchers looked at medical records from birth to death of more than 1,000 people in Olmsted County, MN, who received at least one diagnosis related to parkinsonism. The researchers defined parkinsonism as an umbrella term that includes Parkinson's disease as well as other disorders that involve slowness of movement and at least one other symptom—a tremor while at rest, muscle rigidity, or a tendency to fall. A movement disorders specialist reviewed the records to confirm the diagnosis and to classify different types of parkinsonism, including Parkinson's disease (defined as having manifestations of parkinsonism but without any other known causes), which is the most common.
Risk Higher for Men
The researchers found that men of all ages had a 17 percent higher risk of developing parkinsonism and a 24 percent higher risk of developing Parkinson's disease for every 10 calendar years. Among men 70 and older, there was a 24 percent higher risk for parkinsonism and 35 percent higher risk for Parkinson's disease for every 10 calendar years. Thus, for men 70 and older, the risk more than doubled in 30 years, says Walter A. Rocca, MD, PHD, professor of neurology and epidemiology at the Mayo Clinic. The researchers also observed an increase in the number of women with parkinsonism, but the rate did not reach statistical significance.
Smoking May Play a Role
The study authors theorize that there may be a link between a decrease in smoking during the last century and the rise in Parkinson's disease, based on earlier studies from a decade ago that Dr. Rocca highlighted that show an association between higher rates of smoking and lower rates of Parkinson's. For example, a 2008 article in the journal Movement Disorders that analyzed several studies on smoking and Parkinson's disease determined that smoking decreased the incidence of Parkinson's disease by 74 percent. In another study published in Neurology in 2007, researchers looked at Parkinson's disease prospectively from 1992 to 2001 among 79,977 women and 63,348 men participating in a national cancer prevention study. Reseachers reviewed participants' responses to questions about smoking status and lifetime smoking history and found that, on average, participants who smoked for more years, smoked more cigarettes per day, were at an older age when they quit smoking, and were part of the study for fewer years since quitting smoking, had a lower risk of Parkinson's. If smoking has a protective effect against Parkinons's disease, then the decline in smoking may be partly responsible for the rise in the incidence of the disorder, they say.
Pesticides May Be Culprits
During the last century there has been a dramatic increase in the use of herbicides and pesticides in agriculture. Dating back to 2007, in a study published in Movement Disorders, Mayo Clinic researchers, including some of the current study authors, identified everyone who developed Parkinson's disease in Olmsted County, MN, from 1976 through 1995, and matched them by age and sex to healthy controls. Through telephone interviews, they asked about exposure to chemicals and found that exposure to pesticides, but not other chemicals, was linked to Parkinson's disease in men. In the study, the researchers speculated that pesticides may interact with factors that are different in men and women.
"The trend cannot be explained by genetic factors because the genetic risk of Parkinson's disease is extremely low in the general population [so] the cause [of the increase] must be environmental or lifestyle," says Dr. Rocca. Exposure to environmental pollutants such as chemical toxins in the air, water, or soil, or infectious agents, such as viruses or bacteria, may be contributing factors. Lifestyle habits such as a poor diet, lack of physical exercise, unhealthy living conditions, or certain medications could be factors as well.
The higher incidence found in men who were born between 1915 and 1924 is important "because the people born in that particular decade may have been exposed to some environmental or other factor during their intrauterine life or soon after birth that increased the risk," says Rodolfo Savica, MD, MPH, a neurologist at the Mayo Clinic and an author of the study. "Changes in exposure to a number of risk factors may have caused [the incidence of] Parkinson's disease to rise."
Drs. Rocca and Savica hope other investigators will confirm this trend. In the meantime, they plan to study smoking and other potential risk factors to determine possible causes.
Monday, July 25, 2016
BY FRAN KRITZ
The US Federal Trade Commission (FTC) recently slapped a $300,000 fine on a company that makes a bracelet soaked in mint oil that claims to protect wearers from the Aedes mosquito, the insect that transmits the Zika virus.
Viatek, the company that makes the bracelet, said the device could protect wearers from mosquito bites for up to 120 hours, but the FTC found no scientific support for that claim. "With mosquito-borne illnesses in the news, consumers might be looking for products that protect them from mosquitoes," says Jessica Rich, director of the FTC's Bureau of Consumer Protection. "The [Viatek Company] took advantage of those concerns."
Fear Spurs Sales
Worries about the Zika virus are justified. Public health experts at the US Centers for Disease Control and Prevention (CDC) say many states in the United States are at risk of an outbreak. As of mid-July, no cases transmitted via a mosquito bite in this country had been reported. But at press time, the CDC was investigating a Zika case in Florida that did not involve travel to another country. The virus can also be transmitted through sex and transfer of other body fluids.
Although Zika is generally a mild illness, it has been linked to serious neurologic conditions including microcephaly, a birth defect that results in babies with very small heads and possible brain damage, and Guillain-Barré syndrome, which can cause temporary paralysis and, in rare cases, death.
"The neurologic threat caused by Zika is real, and people should be aware of it if mosquitoes carrying the virus make their way to their cities and towns," says David Taragin, MD, a neurologist with The Neurology Center in Silver Spring, MD. The consumer protection office in Montgomery County, MD, where Dr. Taragin lives and works recently sent out postcards to residents and posted information on their blog about avoiding Zika-related cons, including a warning from the US Securities and Exchange Commission about an increase in scams as companies rush to develop products or services to combat the Zika virus.
Consider only CDC and EPA-approved Products
Very few of the products that claim to protect against the Zika virus, including ultrasound wave devices and vitamins and supplements that repel mosquitoes, have been shown to be safe and effective, says Joseph Conlon, a technical advisor to the American Mosquito Control Association, a nonprofit information group in Laurel, NJ.
Instead, consumers should consider only products containing ingredients that have been recommended by the CDC and registered by the US Environmental Protection Agency (EPA), says Daniel Pastula, MD, MHS, assistant professor of neurology at the University of Colorado, Denver, and an expert in viruses transmitted by mosquitoes, ticks, and sand flies.
To find those products, visit the EPA's insect repellent site at bit.ly/EPA-InsectRepellent. Active ingredients approved for combatting the Aedes mosquito include DEET, picaridin, IR3535, oil of lemon eucalyptus, or para-menthane-diol. "CDC-recommended ingredients have been proven to repel mosquitoes and prevent mosquito bites," says Dr. Pastula. "Using products not backed by evidence can make people think they're protected, when we're not really sure they are."
All EPA-registered repellents have been evaluated and approved for effectiveness. When used as directed, they are considered safe and effective, even for women who are pregnant or breastfeeding.
Remove Standing Water
Mosquito spraying, which many communities plan to institute to help get rid of any Aedes mosquitos, is only partially effective, says Conlon. What may be more effective, according to the CDC, is to remove standing water, which attracts mosquitoes, both indoors (such as in vases containing flowers past their prime and in water bowls left to stand for pets) and outdoors.
Zika is not the only virus transmitted by mosquitoes, says Dr. Pastula. In the US and its territories, West Nile, dengue, and chikungunya viruses may also be a threat. "Using evidence-backed products is the best protection you can give yourself." To be even safer, follow these recommendations.
1. Wear long-sleeved shirts and long pants when mosquitoes are out and biting.
2. Stay in places that have air conditioning and screens on windows and doors to keep mosquitoes out.
3. Sleep under a mosquito net if you are overseas or outside and unable to protect yourself from mosquito bites.
Thursday, July 21, 2016
BY SARAH OWENS
Certain aspects of physical fitness, including poor balance and a weak grip, are associated with a higher risk of dementia in people over the age of 90, according to new research published in the July 5 issue of the Journal of the American Geriatrics Society.
Testing Physical Health
The population of the so-called "oldest-old" (people older than 90) is projected to quadruple by the year 2050. Given that this group has the highest incidence of dementia, it's important to identify risk factors and ways to treat or prevent the disease. With that in mind, researchers at the University of California at Irvine analyzed 176 men and 402 women participating in The 90+ Study, an ongoing, population-based study of aging and dementia among people aged 90 and older. At the beginning of the study, 54 percent of participants were cognitively normal, while 46 percent had cognitive impairment. None had dementia.
At the start of the study and for at least one follow-up visit, participants performed physical tests, including a 4-minute timed walk; five chair stands; balancing for 10 seconds; and grip strength exercises. Performance on each test was measured on a scale from 0 (unable to perform) to 4 (best performance).
Evaluating Cognitive Function
Researchers also measured cognitive health at the start of the study and every six months afterward for an average of two and a half years. During each evaluation, researchers administered questions from a variety of standardized tests to measure memory, orientation, language, calculation, abstract thinking, and judgment—and to determine if, and when, participants developed dementia.
Identifying the Body-Mind Link
At the end of the follow-up period, 36.7 percent of participants had developed dementia. When looking at the scores on the physical tests, the researchers found that standing balance was associated most strongly with cognitive health, followed by performance on the 4-minute walk and grip strength tests. They also noted that poor physical performance was typically detected two to three years before dementia, which was consistent with previous findings from The 90+ Study, and supported their hypothesis that declining physical performance "may be an early sign of late-age dementia."
Making Physical Testing Routine
The study's results may encourage doctors to use tests of strength and balance to screen their older patients for dementia risk, researchers noted. The simplicity and accessibility of the tests suggest that such screening would be both useful and feasible, they added.
Monday, July 18, 2016
Credit: iSTOCK/Anthony Wing Kosner
BY FRAN KRITZ
People who have had a traumatic brain injury (TBI) may experience sleep problems a year and a half after the injury—and they may not even be aware of it, according to a study in the April 27, 2016 online edition and May 24, 2016 print edition of Neurology. "We found that the majority of those with TBI, no matter how severe, had long-term sleep disturbances but didn't realize it," says Lukas Imbach, MD, MS, a senior physician and neurologist at the University Hospital Zurich in Switzerland and lead author on the study, which was funded by the Swiss National Science Foundation and the University of Zurich.
For 18 months, Dr. Imbach and colleagues followed 31 people who had sustained a TBI, with injuries ranging from mild to severe, as well as a control group of 42 healthy people. In addition to being asked about sleep behavior and daytime sleepiness, participants wore a device on their wrist for two weeks that measured body movement. They also spent a night in a video sleep lab where their brain and muscle activity, eye movements, and heart rhythm were monitored. To test for excessive daytime sleepiness, researchers measured how fast participants fell asleep in a quiet environment during the day.
Sixty-seven percent of those with TBI experienced excessive daytime sleepiness compared with 19 percent of those in the control group, the researchers found. When asked how sleepy they were during the day, those with TBI didn't report feeling any sleepier than people in the control group. The study also demonstrated that people with mild TBI were just as likely to have sleep problems as those with severe TBI, and that these sleep problems persisted even though people with TBI slept an average of eight hours a night, compared to the control group, which slept an average of seven. The researchers didn't find any other health problems that could account for the sleep problems.
Search for Clues
During an acute phase after a TBI, patients sleep more and have deeper sleep, says Dr. Imbach. "We assumed the increased need for sleep was linked to a mechanism in the brain to help recovery. But the persistent sleepiness problem has a different mechanism. If it were only an acute effect it would not continue for a year and a half," he says. One possibility might be permanent damage to the brainstem in sleep-promoting centers of the brain. "If the hypothesis is true, we should see that on magnetic resonance imaging (MRI) scans," he says. "We have collected a lot of MRIs and are about to start analyzing the data."
The Swiss research team conducted a small study on a potential treatment—modafinil (Provigil), a wakefulness medication used for narcolepsy—for excessive sleepiness, and reported a 30 to 40 percent reduction in sleepiness. Modafinil reduced daytime sleepiness in this smaller study, but currently no specific treatment exists that addresses the need for increased sleep after TBI, says Dr. Imbach.
People with TBI who are excessively sleepy during the day may be a greater risk for getting into car accidents or other public safety hazards, so they and their doctors should be monitoring for it," says Dr. Imbach, who considers the sleep-wake disorder a "silent epidemic." Further study is needed before guidelines are changed or new recommendations are made, he says.
Thursday, July 14, 2016
BY FRAN KRITZ
Middle-aged blacks are four times more likely to die of a stroke than whites of the same age, according to a study published in the June issue of Stroke. Researchers wondered if inferior post-stroke care for blacks might account for the disparity, but the study, funded by the National Institute of Neurological Disorders and Stroke (NINDS), found the difference might be attributed more to the increased number of strokes among middle-aged blacks.
Measuring Risk Factors
Researchers analyzed data on almost 30,000 people selected at random from across the United States. Between 2003 and 2007, study participants completed a telephone interview and an in-home physical exam that assessed blood pressure levels and other stroke risk factors. The researchers reviewed the medical records for stroke diagnoses, and contacted participants every six months to ask about stroke symptoms, hospitalizations, and general health.
The researchers followed the participants for an average of nearly seven years. During that time there were 1,168 strokes, 242 of which were fatal.
When the research team looked at stroke incidence by age, they found that between ages 45 and 54, more blacks had a fatal stroke. Blacks also had more stroke risk factors, such as high blood pressure (71 percent versus 51 percent of whites) and diabetes (31 percent versus 16 percent). The risk of dying was four times greater for middle-aged blacks than for whites, but there was no difference in death rates between blacks and whites who survive a stroke.
The way to reduce the disparity in incidence and mortality is to redouble efforts to prevent stroke, especially by controlling and preventing high blood pressure and diabetes, both of which affect blacks disproportionately, said the study authors. "We need to do more to focus on prevention and control of risk factors before they result in a stroke," said George Howard, DrPH, professor of biostatistics at the University of Alabama at Birmingham School of Public Health and lead author of the study.
Prevention is especially important because hypertension can impact blacks more severely than whites, said Walter Koroshetz, MD, FAAN, the director of NINDS. "The prevalence of hypertension is higher in blacks, but its impact is even greater in the black population," he said. "An increase of 10 mm Hg in blood pressure is associated with an 8 percent increase in stroke risk among whites but a 24 percent increase in stroke risk in blacks."
The NINDS is funding several health disparity trials through its Stroke Prevention Intervention Research Program (SPIRP) as well as education and training programs that target high blood pressure control in minority communities, according to Salina Waddy, MD, program director at NINDS.
Other studies are looking at ways to improve blood pressure control, including home blood pressure telemonitoring, patient education, visits to homes from community health workers, and mobile health technology.