New and Noteworthy Information—March 2014
The final stage of the normal inflammatory process may be disrupted in patients with Alzheimer’s disease, according to research published online ahead of print February 14 in Alzheimer’s and Dementia. Researchers analyzed specialized proresolving mediators (SPMs), receptors, a biosynthetic enzyme, and downstream effectors involved in inflammation resolution in postmortem hippocampal tissue from patients with and without Alzheimer’s disease. SPMs were analyzed in CSF. Levels of the SPM lipoxin A4 (LXA4) were reduced in patients with Alzheimer’s disease in the CSF and the hippocampus. An enzyme involved in LXA4 synthesis and two SPM receptors were elevated in brains of patients with Alzheimer’s disease. LXA4 and RvD1 levels in CSF correlated with Mini-Mental State Examination scores. Stimulation of inflammation resolution may reduce neuronal death in the brain, said the investigators.
Toxic chemicals may be triggering the recent increases in neurodevelopmental disabilities among children, according to a study published in the March issue of Lancet Neurology. In 2006, researchers identified five industrial chemicals as developmental neurotoxicants. The current study offers updated findings about those chemicals and adds information on six newly recognized ones, including manganese, fluoride, chlorpyrifos and DDT (ie, pesticides), tetrachloroethylene (a solvent), and the polybrominated diphenyl ethers (flame retardants). The study found that manganese is associated with diminished intellectual function and impaired motor skills, solvents are linked to hyperactivity and aggressive behavior, and certain pesticides may cause cognitive delays. More neurotoxicants may remain undiscovered, according to the investigators, who propose a global prevention strategy to control what they call a pandemic of developmental neurotoxicity.
For relatives of patients with multiple sclerosis (MS), the risk of developing the disease may be lower than previously assumed, according to a study published in the March issue of Brain. Researchers from Karolinska Institutet assessed the familial risks for MS using population registers and health care registries. They identified 28,396 patients with MS, along with first- and second-degree relatives and cousins. The investigators used matched population-based controls to calculate relative risks and found lower estimates of familial MS risks than previously reported. Despite a well-established lower prevalence of MS among males, the relative risks were equal among maternal and paternal relations. Using 74,757 twin pairs, the researchers estimated the disease’s heritability to be 0.64 and its shared environmental component to be 0.01.
Football helmets differ in their ability to reduce the risk of concussion, researchers reported online ahead of print January 31 in the Journal of Neurosurgery. The investigators conducted a retrospective analysis of head impact data from 1,833 collegiate football players from 2005 to 2010 who wore helmet-mounted accelerometer arrays for games and practices. The researchers compared concussion rates between players who wore the Riddell VSR4 and Riddell Revolution helmets. A total of 1,281,444 head impacts were recorded, and 64 concussions were diagnosed. The investigators found that the relative risk of sustaining a concussion in a Revolution helmet versus a VSR4 helmet was 46.1%. “Although helmet design may never prevent all concussions from occurring in football, evidence illustrates that it can reduce the incidence of this injury,” the researchers concluded.
Women have a worse quality of life, compared with men, for as long as 12 months after a stroke, even after adjustment for key sociodemographic variables, stroke severity, and disability, according to a study published online ahead of print February 7 in Neurology. Researchers assessed the quality of life in 1,370 patients (53.7% male; median age, 65) with ischemic stroke or transient ischemic attack (TIA) at three and 12 months postdischarge. Women had a significantly lower quality of life at three and 12 months poststroke. After multivariable adjustment for sociodemographic, clinical, and stroke-related factors, the investigators found that women continued to have a lower quality of life at three and 12 months. Women also had a poorer outcome in the dimensions of mobility, pain or discomfort, and anxiety or depression at three and 12 months.
High levels of high-density lipoprotein (HDL) cholesterol and low levels of low-density lipoprotein (LDL) cholesterol may be correlated with lower levels of amyloid plaque deposition in the brain, according to a study published in the February issue of JAMA Neurology. Investigators examined 74 individuals age 70 or older, including three participants with mild dementia, 33 cognitively normal participants, and 38 people with mild cognitive impairment. Cerebral amyloid-beta was measured with carbon C11–labeled Pittsburgh Compound B (PiB) PET. Statistical models that controlled for age and APOE ɛ4 revealed independent associations among the levels of LDL cholesterol, HDL cholesterol, and PiB index. Higher LDL cholesterol and lower HDL cholesterol levels were associated with a higher PiB index. The finding suggests an important role for cholesterol in amyloid-beta processing, said the researchers.
