Although cerebral blood flow reductions have been observed in Alzheimer's disease and linked to impaired cognition, the precise mechanism is unclear. We know that circulating cells, such as neutrophils, can block brain capillaries and reduce blood flow in the cortex. Cruz Hernández et al. used in vivo microscopy in an Alzheimer's disease mouse model to investigate this phenomenon. They injected mice with a neutrophil-specific antibody and observed a direct reduction in the amount of neutrophils that stuck to and blocked the capillaries in the brain. This, in turn, increased cerebral blood flow and enhanced memory performance in these mice.
In a study, published earlier this month, researchers developed a machine-learning algorithm to detect Alzheimer's in brain scans 86 percent of the time. Even more impressively, it identified changes in the brain that showed mild cognitive impairment (MCI) 84 percent of the time. It might be able to identify these changes even earlier, but the researcher's only tested it on individual's who developed Alzheimer symptoms within nine years.
The most in-depth analysis of human brain tissue ever done in Alzheimer's disease has found evidence for the controversial theory that viruses play a role in the condition. If true, it could mean that some instances of Alzheimer's might be treated with anti-viral drugs. Alzheimer's is the most common cause of dementia, affecting some 47 million people worldwide.
Alzheimer's disease has no cure, but getting a diagnosis as quickly as possible can allow patients to start symptom-delaying drugs. The problem with getting that diagnosis, though, is that the early stages of Alzheimer's can look a lot like mild cognitive impairment, which may or may not progress into Alzheimer's.