Clinical identification of fluctuating cognition is challenging. A better understanding of potential etiological mechanisms can allow for optimization of clinical assessment tools and targeted therapeutic approaches.

Former NFL players with symptoms consistent with chronic traumatic encephalopathy had increased tau tracer uptake that was associated with years of playing football but not with cognitive or neuropsychological measures.

A large Finnish case-control study suggests that postmenopausal hormone therapy results in a 9-17% increase in the risk of Alzheimer’s disease. However, the small effect size, and likely confounding of use effect, does not provide strong evidence for a causal relationship.

In a study cohort from the Alzheimer’s Disease Neuroimaging Initiative, cerebrospinal fluid levels of cholecystokinin were associated with better outcomes that may reflect compensatory protection as Alzheimer’s disease pathology progresses. However, because of significant study limitations, these findings need to be validated in additional studies.

Magnetic resonance imaging of the brain in community-dwelling people (average age of 60 years) found that a long-term, high-quality diet was associated with larger hippocampal volumes after an average interval of 11 years.

Apolipoprotein E epsilon 4 (APOE4) genotype, the stronger genetic risk factor for late-onset Alzheimer’s disease, negatively affects cerebrospinal levels of tau protein in a sex-dependent manner, whereby the effect of APOE4 is stronger in women than men.

Magnetic resonance imaging of the brain in community-dwelling people (average age of 60 years) found that a long-term, high-quality diet was associated with larger hippocampal volumes after an average interval of 11 years.

Using a genetic risk score of 23 common genetic variants and apolipoprotein E genotype could help stratify individuals into those very likely to those very unlikely to develop late-onset Alzheimer’s disease and dementia.

tau PET imaging shows progression of brain Alzheimer’s pathology over time and correlates with cognitive impairment better than amyloid PET. In future clinical trials, tau PET can serve as a biomarker for Alzheimer’s disease progression.