A new Alzheimer’s treatment side effect that results in brain swelling may have an upside, according to a new study from Houston Methodist Research Institute. The research finds that beta amyloid – a protein that accumulates as plaques in the brain – may be cleared more in brain regions that had this side effect, signaling a stronger treatment response.
Led by Joseph Masdeu, M.D., Ph.D., director of the Nantz National Alzheimer Center and Neuroimaging and recently published in the American Journal of Neuroradiology, the research examined Alzheimer’s patients who had moderate or severe amyloid-related imaging abnormality edema (ARIA-E), a side effect of treatment that causes leakage of plasma from the blood into some regions of the brain and results in swelling. The researchers compared scans taken before and after the swelling had receded. Among most patients, areas that had swelling showed larger drops in brain plaques than areas that never swelled.
“This study shows that not all parts of the brain respond equally to anti‑amyloid therapy,” Masdeu, professor of Neurology in the Department of Neurology at Houston Methodist Research Institute said. “For the first time, results show that the brain regions that swell during treatment have a greater decrease in the amyloid signal on Positron emission tomography (PET) Scan, possibly because more amyloid is removed or because amyloid is hidden on PET. That reframes ARIA‑E from being only a side effect to a possible sign of strong local treatment activity.”
Clinically, this side effect is managed in a straightforward way: when swelling appears, clinicians typically slow or briefly pause treatment and monitor the patient closely. In most cases, the swelling then recedes and disappears, after which treatment can be resumed as appropriate. These new findings offer doctors and families a more nuanced way to interpret this side effect, balancing safety with the possibility that it may coincide with a stronger local treatment response.
About 6.9 million Americans are living with Alzheimer’s and the number is set to double to 14 million by 2060, according to the Centers for Disease Control and Prevention.
The investigators are expanding the patient sample and will collaborate with other institutions, including the Longitudinal Early Onset Alzheimer’s Disease Study (LEADS) consortium, to validate the results in larger, more diverse cohorts.
Other collaborators on the study are Quentin Finn and Belen Pascual from Houston Methodist and Paul Schulz from UTHealth Houston.
This study was funded by the Cho, Farish Graham, Harrison and Nantz Funds from the Houston Methodist Foundation. The florbetaben PET scans for Patient 1 were funded by the National Institutes of Health through the LEADS Consortium, funded by the National Institute on Aging.
American Journal of Neuroradiology