Researchers have identified three susceptibility loci for common migraine in the general population, according to a study published in the June 12 online Nature Genetics. In a population-based genome-wide analysis that included 5,122 patients with migraine and 18,108 patients without migraine, investigators found seven single nucleotide polymorphisms (SNPs) associated with migraine. Subsequent testing and meta-analysis confirmed that three replicating SNPs (re2651899, rs10166942, and rs11172113) were significantly associated with migraine. “The associations at r2651899 and rs10166942 were specific for migraine compared with nonmigraine headache,” the researchers reported. In addition, none of the three SNP associations was preferential for migraine with aura or without aura; there were also no associations specific for migraine features, suggesting that there is a shared pathophysiology among common types of migraine. “The three new loci identified in the present work provide hypotheses for immediate further exploration,” the authors concluded.
People who have had a herpes zoster attack may be at a higher risk for developing multiple sclerosis (MS) than people who have not had an occurrence of the virus, researchers reported in the June 7 online Journal of Infectious Diseases. “Varicella zoster virus has been proposed to be involved in the pathogenesis of MS,” the investigators wrote. In the study, they followed 315,550 patients with herpes zoster and 946,650 subjects without the virus for one year; they then calculated the one-year MS–free survival rate. “Of 1,262,200 sampled patients, 29 from the study group (.009%) and 24 from the control group (.003%) had MS during the one-year follow-up period,” the authors reported. The odds ratio of developing MS was 3.96 times greater for the study group than for the control group, supporting the notion that occurrence of the disease could be associated with herpes zoster attack.
A study published in the June 7 issue of Neurology found that patients with Parkinson’s disease have a significantly higher risk of having melanoma than do healthy controls. The researchers conducted a meta-analysis of 12 publications on melanoma and Parkinson’s disease; eight of the publications had fewer than 10 cases with both Parkinson’s disease and melanoma. The pooled odds ratio was 2.11 overall, 2.04 for men, and 1.52 for women. Melanoma occurrence was significantly higher after the diagnosis of Parkinson’s disease, but not before Parkinson’s disease was diagnosed. After analyzing the data for nonmelanoma skin cancers, the researchers found no significant relationship. “Collective epidemiologic evidence supports an association of Parkinson’s disease with melanoma,” the authors concluded. “Further research is needed to examine the nature and mechanisms of this relationship.”
At-home physical training may be just as effective as locomotor training for improving the ability to walk in patients who have had a stroke, researchers reported in the May 26 New England Journal of Medicine. The investigators randomly assigned 408 participants with stroke to one of three training groups; one group received early locomotor training on a body weight–supported treadmill two months after stroke occurred, one group received the same training six months after stroke, and the third group completed an at-home exercise program guided by a physical therapist two months after stroke. At one year of training, 52% of all participants had increased functional walking ability. The researchers observed no significant differences in improvement between early or late locomotor training and home exercise. “All groups had similar improvements in walking speed, motor recovery, balance, functional status, and quality of life,” the authors noted.
High consumption of olive oil and high plasma oleic acid are associated with lower risk for stroke in older adults, according to the results of a study published in the June 15 online Neurology. To examine this relationship, the researchers looked at 7,625 older adults; in this sample, 148 incident strokes occurred. After adjusting for demographic and dietary variables and stroke risk factors, the investigators found that “compared to those who never used olive oil, those with intensive use had a 41% lower risk of stroke.” In a secondary sample, the researchers investigated the plasma oleic acid levels of 1,245 individuals (27 had incident stroke) and found that participants in the third tertile had a 73% reduction of stroke risk. “These results suggest a protective role for high olive oil consumption on the risk of stroke in older subjects,” the authors concluded.