Neurosciences - June 2012 Archives

SCOTTSDALE, Ariz. — June 28, 2012.  More than 40,000 student athletes in Arizona have taken advantage of computerized baseline concussion evaluations offered by Mayo Clinic, in the program's first year. That amounts to nearly 40 percent of the state's roughly 100,000 high school athletes. Baseline concussion evaluations measure how the brain is working before injury, and are mandatory tests for professional and college athletes. Mayo covers the cost of the cognitive evaluations for all high school and junior high school-aged interscholastic and club athletes in the state. The program was made possible through the support of benefactors and Mayo Clinic. The test takes 8–15 minutes to complete, and athletes or their parents can share the results with health care providers of their choice. After a concussion, the test can be repeated to determine if there has been a change in the cognitive capabilities of the athlete and, once symptoms have resolved, the test can be repeated to determine whether the athlete has returned to pre-injury baseline. The results of this test, combined with a thorough neurological evaluation, ensure that the health care provider can make an informed and objective determination on when and whether the athlete can safely resume normal activities — and in the case of student athletes, when they can return to their sport. "The diagnosis of concussion, assessment of its severity and knowing when an athlete can return to physical activity, competition, work or school is not always clear," says Mayo neurologist David Dodick, M.D., at Mayo Clinic in Arizona and president of the American Headache Society. "Having a baseline concussion assessment for each athlete will assist in a physician's ability to identify and quantify a change in brain function, and determine if and when the athlete has returned to his or her baseline." After a concussion, if an athlete continues to play or returns to play too early, there is a significant risk of experiencing another concussion. Dr. Dodick adds. "Repeat concussions may take longer to resolve and come with a risk of permanent neurological damage or, rarely, death," he says. Children, adolescents and female athletes appear to be at a higher risk for concussions, and may also take longer to recover. While the importance of baseline testing is clear, the results should be used with a comprehensive neurological evaluation. Although the majority of concussions resolve relatively quickly, some athletes may experience symptoms that may persist for months or longer. The medical care and rehabilitation of these athletes is best achieved by a multidisciplinary team of health professionals with expertise in the evaluation and management of concussions. Providing this baseline assessment also highlights the importance of safeguarding the brain health of young athletes.

Researchers at Mayo Clinic in Florida are building a case that says neurodegenerative disorders like Alzheimer’s disease are primarily caused by genes that are too active or ...

JACKSONVILLE, Fla. — June 6, 2012.  Using a new and powerful approach to understand the origins of neurodegenerative disorders such as Alzheimer's disease, researchers at Mayo Clinic in Florida are building the case that these diseases are primarily caused by genes that are too active or not active enough, rather than by harmful gene mutations. VIDEO ALERT: Video resources of Nilufer Ertekin-Taner, M.D., Ph.D., discussing the study are available here. In the June 7 online issue of PLoS Genetics, they report that several hundred genes within almost 800 brain samples of patients with Alzheimer's disease or other disorders had altered expression levels that did not result from neurodegeneration. Many of those variants were likely the cause. "We now understand that disease likely develops from gene variants that have modest effects on gene expression, and which are also found in healthy people. But some of the variants — elevating expression of some genes, reducing levels of others — combine to produce a perfect storm that leads to dysfunction," says lead investigator Nilufer Ertekin-Taner, M.D., Ph.D., a Mayo Clinic neurologist and neuroscientist. "If we can identify the genes linked to a disease that are too active or too dormant, we might be able to define new drug targets and therapies," she says. "That could be the case for both neurodegenerative disease as well as disease in general." Dr. Ertekin-Taner says no other lab has performed the extent of brain gene expression study conducted at Mayo Clinic's Florida campus. "The novelty, and the usefulness, of our study is the sheer number of brain samples that we looked at and the way in which we analyzed them. These results demonstrate the significant contribution of genetic factors that alter brain gene expression and increase risk of disease," she says. This form of data analysis measures gene expression levels by quantifying the amount of RNA produced in tissue and scans the genome of patients to identify genetic variants that associate with these levels. Mayo researchers measured the level of 24,526 transcripts (messenger RNA) for 18,401 genes using cerebellar autopsy tissue from 197 Alzheimer's disease patients and from 177 patients with other forms of neurodegeneration. The researchers then validated the results by examining the temporal cortex from 202 Alzheimer's disease patients and from 197 with other pathologies. The difference between these samples is that while the temporal cortex is affected by Alzheimer's disease, the cerebellum is relatively spared. From these analyses, the researchers identified more than 2,000 markers of altered expression in both groups of patients that were common between the cerebellum and temporal cortex. Some of these markers also influenced risk of human diseases, suggesting their contribution to development of neurodegenerative and other diseases regardless of their location in the brain. They identified novel expression "hits" for genetic risk markers of diseases that included progressive supranuclear palsy, Parkinson's disease, and Paget's disease, and confirmed other known associations for lupus, ulcerative colitis, and type 1 diabetes. "Altered expression of brain genes can be linked to a number of diseases that affect the entire body," Dr. Ertekin-Taner says.