News Roundup

News Roundup: New and Noteworthy Information


 

Vascular conditions, including atherosclerosis, may play an important role in the development of cognitive impairment and dementia, according to a report published online in the July 21 Stroke. The authors used previously published guidelines and literature, as well as personal experience, to summarize existing evidence, indicate gaps in current knowledge, and formulate recommendations regarding vascular contributions to cognitive decline late in life. Observed vascular risk factors included atrial fibrillation, hypertension, diabetes mellitus, and hypercholesterolemia, all of which, the researchers noted, were also risk factors for stroke and Alzheimer’s disease. “The neuropathology of cognitive impairment later in life is often a mixture of Alzheimer’s disease and microvascular brain damage,” the authors wrote. “Detection and control of the traditional risk factors for stroke and cardiovascular disease may be effective in the prevention of vascular cognitive impairment, even in older people.”
Women with epilepsy experience greater seizure frequency during anovulatory cycles than during cycles when ovulation occurs, according to results of a study published July 14 online ahead of print in Epilepsia. Almost 300 women with epilepsy were enrolled in the study; 92 had completed both cycles during the study period. Their average daily seizure frequency, seizure type, and progesterone/estradiol serum level ratios were recorded. “Average daily seizure frequency was 29.5% greater for secondary generalized tonic-clonic seizures during anovulatory than during ovulatory cycles,” the researchers wrote. Frequency did not differ significantly for complex or simple partial seizures, or for all seizure types combined. “Because the proportional increases in secondary generalized tonic-clonic seizure frequency during anovulatory cycles correlate with the proportional increases in estradiol/progesterone serum level ratios, these findings support a possible role for reproductive steroids in [seizure] occurrence.”
Researchers have identified a new genetic risk factor for restless legs syndrome (RLS), as reported in the July 14 PLoS Genetics. The authors conducted a genome-wide association study of 922 patients with RLS, and compared the results with 1,526 controls. The researchers included 301,406 single nucleotide polymorphisms (SNPs) in the study, followed by a replication of 76 candidate SNPs in 3,935 patients and 5,754 controls. “We identified six RLS susceptibility loci of genome-wide significance, two of them novel: an intergenic region on chromosome 2p14 (rs6747972) and a locus on 16q12.1 (rs3104767) in a linkage disequilibrium block of 40 kb containing the 5´-end of TOX3 and the adjacent noncoding RNA BC034767,” the investigators reported. They concluded, “The physiologic role of TOX3 and BC034767 in the CNS and a possible involvement of these two genes in RLS pathogenesis remain to be established.”
Breastfeeding does not significantly provide protection against postpartum relapses in women with multiple sclerosis (MS), a finding that contradicts results from previous studies, researchers reported in the July 12 Neurology. The investigators prospectively followed up pregnancies in 298 women with MS and gathered data on breastfeeding; they monitored relapse rates for up to one year after delivery. “The time-dependent profile of the relapse rate before, during, and after pregnancy did not differ between patients who breastfed and patients who did not,” the authors reported. The only significant predictors of postpartum relapses were relapses before and during pregnancy. “Therefore, the reported association between breastfeeding and a lower risk of postpartum relapses may simply reflect different patient behavior, biased by the disease activity,” the investigators concluded.
Low bone density and osteoporosis commonly appear in the early stages of multiple sclerosis (MS), according to a study published in the July 12 Neurology. “If vitamin D exerts a major effect on MS risk,” the investigators hypothesized, “skeletal consequences of hypovitaminosis D could be apparent shortly after the onset of MS.” To test their hypothesis, the researchers measured the bone mineral density of 99 patients in the early stages of the disease with no or minor disability; these results were compared with the densities of 159 healthy controls. Half of the patients had either osteopenia or osteoporosis, compared with 37.1% of the controls. “[This finding is] compatible with shared etiologic or pathogenic factors in MS and osteoporosis, and calls for an active approach to optimize bone health in early stages of MS,” the authors concluded.
According to a study published in the July 12 online BMJ, there is no significant link between adjuvanted vaccines used during the 2009 swine flu pandemic and Guillain-Barré syndrome. The investigators performed a case-control study in five European countries of 104 patients with the syndrome and age-, sex-, and location-matched controls. The initial, unadjusted pooled risk estimate for all countries was 2.8, and case recruitment and vaccine coverage varied considerably between countries. “After adjustment for influenza-like illness/upper respiratory tract infection and seasonal influenza vaccination, receipt of pandemic influenza vaccine was not associated with an increased risk of Guillain-Barré syndrome,” the investigators reported. They did note, however, “the upper limit does not exclude a potential increase in risk up to 2.7-fold or three excess cases per one million vaccinated people.”
A team of researchers has found a genetic determinant of late-onset Parkinson’s disease, according to a study published in the July 9 issue of American Journal of Human Genetics. “To identify rare causal variants in late-onset Parkinson’s disease, we investigated an Austrian family with 16 affected individuals by exome sequencing,” the investigators explained. “We found a missense mutation, c.1858G>A, in the VPS35 gene in all seven affected family members who are alive.” Screening the entire VPS35 coding sequence in additional Parkinson’s disease cases and controls revealed six other missense variants; three were only present in patients, two were only present in controls, and one was present in both groups. The investigators also noted, “VPS35 is a component of the retromer complex and mediates retrograde transport between endosomes and the trans-Golgi network, and it has recently been found to be involved in Alzheimer’s disease.”
Researchers have found that African-American patients with ischemic stroke are significantly less likely to be treated with IV t-PA, due to delayed presentation and stroke severity, according to a study published in the June 30 online Stroke. The investigators performed a systematic chart review on patients admitted to seven Washington, DC–area hospitals; of 1,044 patients with ischemic stroke, 74% were black and 5% received t-PA. African-American patients were one-third less likely than white patients to receive IV t-PA, were less likely to present at the hospital within three hours of symptom onset, and were less likely to be eligible for t-PA treatment. African-American patients also had a greater rate of contraindications to t-PA treatment, including hypertension, recent stroke, or use of blood thinners.
People with a history of traumatic brain injury (TBI) are more likely to develop long-term neurodegeneration than those who have never experienced a brain injury, according to research appearing in the June 29 online Brain Pathology. Investigators examined postmortem brains from 39 survivors of a single TBI and 47 brains of uninjured, age-matched controls using immunochemistry and thioflavin-S staining. “Neurofibrillary tangles were exceptionally rare in young, uninjured controls, yet were abundant and widely distributed in approximately one-third of TBI cases,” the researchers reported. In addition, patients with TBI had a greater density of amyloid-beta plaques than controls. “These data demonstrate widespread neurofibrillary tangles and amyloid-beta plaque pathologies are present in a proportion of patients following a single TBI, suggesting that some individuals who experience a single TBI may develop long-term neuropathological changes akin to those found in neurodegenerative disease,” the authors concluded.
A group of researchers presented a new set of practice guidelines regarding genetic counseling, as reported in the June Genetics in Medicine. The guidelines, developed through a joint effort by the American College of Medical Genetics and the National Society of Genetic Counselors, seek to provide medical professionals with guidance in the complex area of genetic testing. “Despite its limited utility, patients express concern over their risk and, in some instances, request testing,” the authors wrote. “This practice guideline provides clinicians with a framework for assessing their patients’ genetic risk for Alzheimer’s disease, identifying which individuals may benefit from genetic testing, and providing the key elements of genetic counseling for Alzheimer’s disease,” they concluded.
Regions important for cognitive and motor control are smaller in the brains of children with attention-deficit hyperactivity disorder (ADHD) than in typically developing children, researchers reported in the June 9 online Clinical Neuropsychologist. To understand the neurobiologic development of ADHD, the investigators examined high-resolution anatomic images of 13 children with ADHD and 13 controls (ages 4 to 5). “Children with ADHD showed significantly reduced caudate volumes bilaterally; in contrast there were no significant group differences in cortical volume or thickness in this range,” the authors observed. Left caudate volume was a significant predictor of hyperactive and impulsive symptom severity, but not inattention. “Anomalous basal ganglia, particularly caudate, development appears to play an important role among children presenting with early onset symptoms of ADHD,” the researchers concluded.
A diet low in saturated fat and simple carbohydrates may modulate the risk of developing dementia that precedes Alzheimer’s disease, researchers reported in the June Archives of Neurology. To compare the effects of different diets on insulin and lipid metabolism, CSF markers of Alzheimer’s disease, and cognition, the investigators randomized 20 healthy adults and 29 adults with amnestic mild cognitive impairment to either a high- or low-fat and glycemic index diet. In the cognitively impaired group, the “low” diet increased CSF amyloid-beta 42 concentrations; the opposite was true for healthy patients on this diet. For both groups, the “low” diet improved visual memory. “Diet may be a powerful environmental factor that modulates Alzheimer’s disease risk through its effects on CNS concentrations of amyloid-beta 42, lipoproteins, oxidative stress, and insulin,” the investigators concluded.
A study in the June Headache found that prophylactic medications and behavioral interventions for migraine are cost-competitive and cost-efficient options during the early phases of treatment. Researchers distributed surveys to physicians and behavioral specialists to gather data about costs of prototypical regimens for preventive pharmacologic treatment, clinic-based behavioral treatment, minimal contact behavioral treatment, and group behavioral treatment. During the initial months of treatment, pharmacologic treatment with inexpensive medications was the least costly option (

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