New and Noteworthy Information—July 2018
Gomes-Osman J, Cabral DF, Morris TP, et al. Exercise for cognitive brain health in aging. Neurology. 2018 May 30 [Epub ahead of print].
Blood Biomarkers Detect Subconcussive Head Trauma
Blood biomarkers can detect the neurologic injury associated with repetitive subconcussive head trauma, according to a study published online ahead of print May 29 in the Journal of Neurosurgery. A total of 35 National Collegiate Athletic Association football players underwent blood sampling throughout the 2016 football season. Samples were analyzed for plasma concentrations of tau and serum concentrations of neurofilament light. Athletes were categorized as starters or nonstarters, and the investigators assessed between-group differences and time-course differences. In nonstarters, plasma concentrations of tau decreased over the season. Starters had lower plasma concentrations of tau. Plasma concentrations of tau could not be used to distinguish between starters and nonstarters. Serum concentrations of neurofilament light increased as head impacts increased, specifically in starters. Serum neurofilament light distinguished starters from nonstarters.
Oliver JM, Anzalone AJ, Stone JD, et al. Fluctuations in blood biomarkers of head trauma in NCAA football athletes over the course of a season. J Neurosurg. 2018 May 29 [Epub ahead of print].
Model Estimates Risk of Alzheimer’s Disease Dementia
Most people with preclinical Alzheimer’s disease will not develop dementia during their lifetimes, according to a study published online ahead of print May 7 in Alzheimer’s & Dementia. Researchers used a multistate model for Alzheimer’s disease along with US death rates to estimate lifetime and 10-year risks of Alzheimer’s disease dementia. Lifetime risks of Alzheimer’s disease dementia vary by age, gender, and preclinical or clinical disease state. A 70-year-old male with amyloid but no signs of neurodegeneration and no memory loss has a lifetime risk of 19.9%. The lifetime risks for a female with amyloidosis are 8.4% at age 90 and 29.3% at age 65. People younger than 85 with mild cognitive impairment, amyloidosis, and neurodegeneration have lifetime risks of Alzheimer’s disease dementia greater than 50%.
Brookmeyer R, Abdalla N. Estimation of lifetime risks of Alzheimer’s disease dementia using biomarkers for preclinical disease. Alzheimers Dement. 2018 May 7 [Epub ahead of print].
Depression Is Associated With Brain and Memory Outcomes
In a sample of mostly Caribbean Hispanic, stroke-free older adults, greater depressive symptoms were associated with worse episodic memory, smaller cerebral volume, and silent infarcts, according to a study published online ahead of print May 9 in Neurology. Researchers analyzed data from the Northern Manhattan Study. A total of 1,111 participants underwent baseline evaluations of depressive symptoms, MRI markers, and cognitive function. At baseline, 22% of participants had greater depressive symptoms. Greater depressive symptoms were significantly associated with worse baseline episodic memory in models adjusted for sociodemographics, vascular risk factors, behavioral factors, and antidepressant medications. Furthermore, greater depressive symptoms were associated with smaller cerebral parenchymal fraction and increased odds of subclinical brain infarcts, after adjustment for sociodemographics, behavioral factors, and vascular risk factors.
Al Hazzouri AZ, Caunca MR, Nobrega JC. Greater depressive symptoms, cognition, and markers of brain aging. Neurology. 2018 May 9 [Epub ahead of print].
—Kimberly Williams
