Joe Van Acker

CHICAGO - Results of volumetric scans show that widespread adoption of an active lifestyle could reduce cases of Alzheimer’s disease by half. That would mean more than 1 million fewer cases in the U.S. alone, according to researchers at RSNA 2012 Monday.

By using cross-sectional imaging and volumetric scans, researchers were able to create 3D representations of the patients’ brains. They also incorporated a technique known as “voxel-based morphometry” to quantify the amount of gray matter in each patient.

 used brain scans of 876 patients averaging 78 years of age. The patients ranged from normal to obese, with an average BMI of 27. A BMI of 25 to 30 is considered overweight. About 25 percent of them had either Alzheimer’s disease or mild cognitive impairment (MCI).

The relationship between two data sets lies at the heart of the study, kilocalories burned per week and gray matter volume. The researchers recorded how many kilocalories (the same kind listed on nutrition labels) each patient burned in a week and compared it to gray matter volume. They then used a computer to create a mathematical model, enabling the researchers to analyze the relationship between the two.

Controlling for factors such as head size, gender and BMI, the researchers found that patients who burned more kilocalories burned had larger volumes in three crucial areas of the brain: temporal lobe, cingulate gyrus and the hippocampus, all of which are important for memory and learning. The brain scans revealed that active patients with Alzheimer’s disease also exhibited greater volumes of gray matter than more sedentary patients with the disease.

“The areas of the brain that are benefitting the most from this active lifestyle are also the areas that are affected in Alzheimer’s disease and are also responsible for cognition,” Raji explained.

Exercise helps the brain in a number of ways, stimulating blood flow and neuron growth and reducing the amyloid plaques, which are symptomatic of Alzheimer’s and damage neurons.

It’s not just one behavior or exercise that produced the positive outcome. Participants’ activities included hiking, swimming, walking, dancing and yard work. Raji said this is the first study that allowed for a variety of physical activities.

“That’s important because it allows individuals to customize whatever physical activity regimen they like,” he said. “Lifestyle is more than one factor. It is a combination of factors that is likely to be the most important.”

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CHICAGO - Cross-sectional imaging and volumetric scans reveal that widespread adoption of an active lifestyle could reduce cases of Alzheimer’s disease.

Imaging Shows Active Lifestyle Slows Alzheimer’s

CHICAGO - Brain maps created with multiple MRIs reveal that Alzheimer’s disease affects men and women’s brains differently, according to a study presented Monday at RSNA 2012.

Maria Vittoria Spampinato, MD, associate professor at the Medical University of South Carolina, said the study could change the way the disease is treated and the way that new treatments are developed. The researchers used three MRIs of each patient’s brain to create the brain maps: one taken a year before their Alzheimer’s was identified, one at the time of diagnosis and one a year after the diagnosis.

“These imaging techniques are also used to measure the severity [of the disease] and treatment response in clinical trials, so we want to provide information that is accurate,” she said.

Some sex-based differences in the disease’s effects were already known. Men and women experience effects in terms of risk, cognition and behavior, with women being more prone to depression and men to aggression.

But according to Spampinato, men and women also experience a different pattern of brain atrophy. She and her colleagues analyzed data collected on 109 patients over a five-year period and discovered that men and women undergo different changes in brain structure.

The patients’ data were recorded as they progressed from mild cognitive impairment to Alzheimer’s disease. Spampinato’s study focused on MRIs taken one year prior to diagnosis, at the time of diagnosis and one year after diagnosis. Analysis of these images reveals that the disease tends to strike women earlier, but is more aggressive in men.

One area of the brain particularly important to the study is the hippocampus, a region associated with memory known to shrink as a result of Alzheimer’s disease.

Twelve months before being diagnosed with Alzheimer’s disease, females had smaller hippocampi than men. A year after diagnosis, however, there was no difference, meaning that men lost a greater volume in this part of the brain more quickly than their female counterparts.

Spampinato’s hope is that, by providing more information about how Alzheimer’s affects people differently, the study can lead to more successful methods of treating the disease. She said there are two main questions being asked by the research community.

“Can we predict which individuals are at high risk of developing Alzheimer’s?” she asked. “The next question is, Can we possibly stop this decline? Can we find a cure?”

Figure 1. Shown in blue are areas of relatively greater brain volume in males compared to females 12 months before Alzheimer’s disease diagnosis (Mild Cognitive Impairment) and at the time of Alzheimer’s disease diagnosis (Alzheimer’s disease diagnosis). No areas of greater brain volume were found in females than males.

Figure 2. Shown are areas of brain volume loss found in males (blue) and in females (red) during the 12 months before and during the 12 months after Alzheimer’s disease diagnosis (common areas of volume loss in purple). (Images courtesy RSNA)

CHICAGO - Brain maps created with multiple MRIs reveal that Alzheimer’s disease affects men and women’s brains differently.

Alzheimer’s Differing Effects on Male, Female Brains

CHICAGO - The brain’s ability to compensate for a traumatic injury could result in a new approach to treatment, according to researchers at RSNA 2012. Rather than attempting to reverse damage to the brain, doctors may one day be able to encourage the brain to heal itself.

Michael Lipton, MD, associate director of the Gruss Magnetic Resonance Research Center at the Albert Einstein College of Medicine, revealed Monday the 

 on mild traumatic brain injuries (MTBI). By using a technique called diffusion tensor imaging (DTI), Lipton and other researchers were able to analyze the uniform flow of water in the brain.

This flow of water molecules is called fractional anisotropy, (FA) and its presence in the brain is no surprise. The fact that brain injuries can lead to lower FA has been known for years, and Lipton and his team expected to find it in their study. But they also found something they didn’t expect: areas in the brain that were almost “too normal.” In other words, some patients had parts of the brain with abnormally high FA. These patients experienced fewer post-concussion symptoms and higher cognitive functioning.

Rather than serving as evidence of damage, the development of unusually high FA in areas of the brain may be a sign of neuroplasticity, one of the ways that people are able to recover from a brain injury.

“We’re not talking about new nerves regenerating, but we’re talking about existing nerves connecting and interacting with each other,” Lipton said.

Treating brain injuries isn’t an exact science. According to the CDC, 1.7 million Americans sustain an MTBI each year, and Lipton said that most of them don’t suffer from any long-term effects. However, a sizeable minority (about 30 percent) will experience post-concussion symptoms that may last months or even years. Even the size of the brain injury isn’t a good indicator, according to Lipton.

“Size really doesn’t necessarily matter when you’re talking about brain injuries,” he said. “Saying, ‘Oh, it’s just a small little thing,’ doesn’t necessarily mean that the consequence for function is going to be small.”

As a result, identifying which patients are at risk has proved difficult. Lipton says that DTI and other imaging techniques could help doctors predict the long-term outcome of an MTBI, but stressed that the real breakthrough is what that could mean for treatment. He added that the concept of enhancing the brain’s ability to compensate for injuries is “not very much on the radar” in terms of current techniques.

“I think the most interesting thing about our finding, though, is that it really opens the window to a new idea, a new approach, in terms of therapy,” Lipton said. “There’s a possibility for us to use this… to identify therapies that don’t look at, how do we fix the damage, but look at how do we enhance the brain’s ability to compensate for that effect.” 

Areas of abnormal fractional anisotropy (FA) are shown in three mild traumatic brain injury (MTBI) patients two weeks post-injury. Red indicates areas with abnormally low FA, consistent with axonal injury due to traumatic brain injury (TBI). Blue indicates regions with abnormally high FA, which may represent a compensatory response. Note the difference in spatial distribution of abnormality between the three subjects. Image courtesy RSNA.

CHICAGO - The brain’s ability to compensate for a traumatic injury could result in a new treatment approach, encouraging the brain to heal itself.

Author | Joe Van Acker

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