When someone suffers a stroke, there is poor blood flow to the brain, and this results in the death of brain cells. Dead fragments of the brain donโ€™t heal like normal muscle or body tissue โ€” they liquify, and this liquid brain stays in the skull, right next to the healthy brain, for a long time.

Scientists at the UAโ€™s College of Medicine found this liquefied brain tissue is toxic and can leak into the remaining healthy portion of the brain over time, potentially causing harm.

โ€œMost people probably assume that the brain heals in the same way as other tissues,โ€ said Kristian Doyle, PhD, assistant professor of Immunobiology at UA. โ€œBut it doesnโ€™t; dead brain tissue doesnโ€™t just heal and go away like other bodily injuries. Instead it liquefies and remains in this liquefactive state for a long time.โ€

These new findings may open the door for developing new treatments to fight dementia after a stroke. Roughly 10 million people survive a stroke annually. About one-third of which will develop dementia for unclear reasons. It is hypothesized that if the brain is injured near the hippocampus (the portion of the brain responsible for memory) this slow leak of toxic fluid can cause neuron loss in the brain and lead to memory problems.

โ€œThis work really challenges the old paradigms and breaks new ground critical for our understanding of stroke and its consequences,โ€ said doctor Janko Nikolich-Zugich, chair of the UA Department of Immunobiology. โ€œThanks to this research, we now will be able to consider new and different stroke therapies.โ€