Yale researchers used advanced PET imaging technology to confirm the cause of cognitive decline experienced by patients with Alzheimer’s disease. The results of their study were recently published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.
It has long been believed that the destruction of brain synapses, or connections between brain cells, is the root cause of cognitive decline in patients with AD. However, researchers note that previous studies have been limited in the number of subjects studied and by the extent of their disease progression, with most of them having been conducted on patients with more severe cognitive decline.
“For 30 years, synapse loss has been referred to as the major pathological correlate of cognitive impairment in Alzheimer's disease,” lead author Adam P. Mecca, MD, PhD, with the Alzheimer's Disease Research Unit at Yale University School of Medicine, and coauthors explained. “This statement is based on remarkably few patients studied by autopsy or biopsy in limited brain regions, largely at the moderate to severe stages of disease.”
This led researchers at Yale to develop an advanced PET scan technology that could better evaluate synapse loss. The new glycoprotein 2A (SV2A) PET scan enabled them to get a better view of synaptic abnormalities in brains of the living, even when their symptoms were mild.
To test their technology, a total of 45 participants who had been diagnosed with mild to moderate AD underwent the imaging exam. The results of the scans were then compared to the cognitive function of the participants, which was gauged using five markers: verbal memory, language skills, executive function, processing speed and visual-spatial ability.
Those comparisons revealed a strong association between synaptic density and cognitive performance in individuals with AD. Additionally, synaptic density was a better predictor of cognition than gray matter volume.
“These results confirm neuropathologic studies demonstrating a significant association between synaptic density and cognitive performance and suggest that this correlation extends to the mild and prodromal stages of AD,” the experts suggested. “They further support the use of synaptic imaging as a potential surrogate biomarker outcome for therapeutic trials that is well-correlated with clinical measures.”
Further studies are needed to confirm their results; however, these initial findings could be used to test the effectiveness of new AD drugs, the researchers implied.
You can view the detailed research in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.
In addition to her background in journalism, Hannah also has patient-facing experience in clinical settings, having spent more than 12 years working as a registered rad tech. She joined Innovate Healthcare in 2021 and has since put her unique expertise to use in her editorial role with Health Imaging.