New and Noteworthy Information—July 2016
The differences in stroke mortality between African Americans and Caucasians are largely related to differences in stroke incidence, according to a study published online ahead of print June 2 in Stroke. Researchers assessed the difference between African American and Caucasian stroke mortality for 29,681 participants in the Reasons for Geographic and Racial Differences in Stroke cohort. They found that African Americans are four times more likely to die of stroke at age 45 than Caucasians because stroke incidence is greater among African Americans. By age 85, however, the difference in stroke mortality is no longer present. More should be done to reduce the disparity in stroke mortality between African Americans and Caucasians, and interventions should focus on prevention of stroke among African Americans, according to the investigators.
A mutant transmembrane protein of synaptic vesicles in neurons is etiologically linked to Parkinson's disease, according to a study published online ahead of print June 6 in Nature Genetics. Researchers first investigated a family with 15 members who had typical symptoms of Parkinson's disease. They used DNA samples to perform a genome-wide analysis on 65 of the family's members, including 13 with Parkinson's disease, to find a common mutation that could explain the prevalence of Parkinson's disease. The study authors identified TMEM230 as the gene with a disease-causing mutation and found that TMEM230 encodes a protein that extends across the membrane of tiny sacs inside synaptic vesicles. The research team also found mutations in TMEM230 in cases of Parkinson's disease in additional families in North America and China.
People with blast exposure have a pattern of interface astroglial scarring at boundaries between brain parenchyma and fluids, and between gray and white matter, according to a study published online ahead of print June 9 in the Lancet Neurology. Researchers analyzed brain specimens from five military service members with chronic blast exposure, three with acute blast exposure, five with chronic impact traumatic brain injury, five with exposure to opiates, and three control cases with no known neurologic disorders. All five cases with chronic blast exposure showed prominent astroglial scarring involving the subpial glial plate, penetrating cortical blood vessels, gray-white matter junctions, and structures lining the ventricles. Cases of acute blast exposure showed early astroglial scarring in the same brain regions. Cases of chronic blast exposure had an antemortem diagnosis of posttraumatic stress disorder.
A combination of dextromethorphan and quinidine is an effective and well-tolerated treatment for pseudobulbar affect secondary to dementia, stroke, or traumatic brain injury, according to a study published June 9 in BMC Neurology. The study included 367 participants with this disorder. Participants in this open-label, multicenter, 90-day trial received dextromethorphan and quinidine twice daily. The mean Center for Neurologic Study-Lability Scale score improved from 20.4 at baseline to 12.8 at the 90-day final visit. Reduction in pseudobulbar affect episode count was 72.3% at the 90-day final visit, compared with baseline. Scores on Clinical Global Impression of Change and Patient Global Impression of Change indicated that 76.6% and 72.4% of participants, respectively, showed much or very much improvement in symptoms of pseudobulbar affect.
—Kimberly Williams
