Alzheimer’s Differing Effects on Male, Female Brains

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)