“The results show that forced-rate bicycle exercise is an effective, low-cost therapy for Parkinson’s disease,” Mr. Shah said.
Dr. Alberts noted that that while faster pedaling led to more significant results, not all patients with Parkinson’s disease need to do forced-rate exercise to see improvement. “We’re now looking at this phenomenon in patients with exercise bikes in their home, and other exercises like swimming and rowing on tandem machines may provide similar benefits,” he said.
Gender-Based Differences Observed in Alzheimer’s Disease
All patients with Alzheimer’s disease lose brain cells, which leads to atrophy of the brain. However, the pattern of gray matter loss is significantly different between men and women, according to investigators.
“We found that the extent and distribution of regional gray matter volume loss in the brain was strongly influenced by gender,” said lead researcher Maria Vittoria Spampinato, MD, Associate Professor of Radiology at the Medical University of South Carolina in Charleston.
“There is a strong interest in using MRI to assess brain atrophy with the purpose of monitoring dementia progression noninvasively and to aid in understanding which factors can influence brain atrophy progression and distribution in the Alzheimer’s brain,” said Dr. Spampinato.
Dr. Spampinato and colleagues analyzed data on 109 patients, including 60 men and 49 women (mean age, 77), who participated in the Alzheimer’s Disease Neuroimaging Initiative, a major study that followed hundreds of cognitively healthy individuals and patients with mild cognitive impairment (MCI) and Alzheimer’s disease for five years.
During the five-year period, each of the 109 patients progressed from amnestic MCI to Alzheimer’s disease. Using MRI scans of the patients’ brains taken when they were diagnosed with Alzheimer’s disease and 12 months before and after the diagnosis, the researchers created brain maps that illustrated gray matter changes.
The brain maps revealed that, compared with male patients, women had greater atrophy in gray matter 12 months before their Alzheimer’s disease diagnosis and at the time of their diagnosis. The brain maps also showed that men and women in the study lost gray matter volume in different areas of the brain as their disease progressed from MCI to Alzheimer’s disease.
“The female patients in our study initially had more gray matter atrophy than the male patients, but over time, the men caught up,” said Dr. Spampinato. “In the men, the disease developed more aggressively in a shorter period of time.”
The gender differences in atrophy patterns may have important implications for the development of therapies for MCI and Alzheimer’s disease. “These differences should be taken into consideration when testing new drugs in clinical trials,” said Dr. Spampinato. “Knowing the difference between the male and female patterns of atrophy will help researchers better decipher a patient’s response to drug therapy.”
Active Lifestyle May Boost Brain Structure and Slow Alzheimer’s Disease
An active lifestyle may help preserve gray matter in the brains of older adults and could reduce the burden of dementia and Alzheimer’s disease.
To study how an active lifestyle can influence brain structure, Cyrus Raji, MD, PhD, radiology resident at the University of California in Los Angeles, and colleagues examined 876 adults (average age, 78), drawn from the multisite Cardiovascular Health Study. The patients’ condition ranged from normal cognition to Alzheimer’s dementia.
“We had 20 years of clinical data on this group, including BMI and lifestyle habits,” said Dr. Raji. “We drew our patients from four sites across the country, and we were able to assess energy output in the form of kilocalories per week.” The lifestyle factors examined included recreational sports, gardening and yard work, bicycling, dancing, and riding an exercise bicycle.
The researchers used MRI and voxel-based morphometry to model the relationships between energy output and gray matter volume. “Voxel-based morphometry is an advanced method that allows a computer to analyze an MR image and build a mathematical model that helps us to understand the relationship between active lifestyle and gray matter volume,” said Dr. Raji. “Gray matter volume is a key marker of brain health. Larger gray matter volume means a healthier brain. Shrinking volume is seen in Alzheimer’s disease.”
After controlling for age, head size, cognitive impairment, gender, BMI, education, study site location, and white matter disease, the researchers found a strong association between energy output and gray matter volumes in areas of the brain crucial for cognitive function. Greater caloric expenditure was related to larger gray matter volumes in the frontal, temporal, and parietal lobes, including the hippocampus, posterior cingulate, and basal ganglia. There was a strong association between high-energy output and greater gray matter volume in patients with mild cognitive impairment and Alzheimer’s disease.