Detect the harmful effects of dementia before it's too late

Scientists might have found a method for early detection of some forms of dementia, according to a new study from the University of Arizona and Baycrest Health Sciences Center at the University of Toronto.

According to the study published in the journal neuropsychology Last month, patients with a rare neurodegenerative brain disorder called Primary Progressive Aphasia (APP) show abnormalities of brain function in structurally normal areas on MRI examination.

"We wanted to study the impact of degeneration on brain function," said Aneta Kielar, lead author of the study and assistant professor in the department of speech, language and speech sciences. hearing of the AU.

But what she and her team discovered was that the brain had functional defects in areas that did not yet show structural damage to MRI.

The structural MRI provides a three-dimensional visualization of brain structure, which is useful when studying patients with diseases that literally cause brain dieback, such as PPA.

Magnetoencephalography, or MEG, on the other hand, "gives you a very good spatial accuracy as to the origin of the brain response.We want to know if the decrease in brain function comes from regions already atrophied or declining," said Jed Meltzer, lead author of the study and assistant professor of psychology at the University of Toronto.

Kielar and his colleagues compared brain scans from PPA patients to healthy controls while both groups were performing language tasks. The researchers also imaged the brains of the rest participants. Functional defects were related to poorer performance in tasks because people with APP lose their ability to speak or understand the language while other aspects of cognition are usually preserved.

Identifying the discrepancy between the structural and functional integrity of the brain of a PPA could be used as an early detection method.

This is promising because "many drugs designed to treat dementia do not really look emotional and it's perhaps because we detect brain damage too late," Kielar said. "Often, people do not come for help until their neurons are already dead, we can use compensation treatments to delay the course of the disease, but once the brain cells are dead, we can not recover them. " This technique could allow patients to get ahead of the damage.

Kielar acknowledged that it was a small study, due in part to the fact that the APP is a form of dementia so rare, and that a more in-depth investigation is necessary.

Then she hopes to find out why this structural and functional mismatch occurs in PPA brains.

"It's interesting to note that the affected areas are so far removed from neurodegeneration," said Kielar. "One of the reasons that could explain this phenomenon is that these areas could be connected to white substance bundles," which facilitates communication between different regions of the brain. "When a zone is dead, the connected zone is not getting normal input, it does not know what to do, so it starts to lose its function and atrophy because it does not receive stimulation."