New and Noteworthy Information—November 2014
Researchers have found Class II evidence that serum metabolite profiles accurately distinguish patients with different subtypes and stages of multiple sclerosis (MS), according to a study published October 21 in Neurology. Investigators obtained serum samples from patients with primary progressive MS, secondary-progressive MS, and relapsing-remitting MS, patients with other neurodegenerative conditions, and from age-matched controls. Samples were analyzed by nuclear magnetic resonance, and partial least squares discriminant analysis models were derived to separate disease groups. The partial least squares discriminant analysis models for serum samples from patients with MS enabled reliable differentiation between relapsing-remitting MS and secondary-progressive MS. This approach identified significant differences between the metabolite profiles of each of the MS groups and the healthy controls, as well as predicting disease group membership with high sensitivity and specificity.
Parkinson’s disease pathogenic mutations have an age-dependent penetrance that could be ameliorated or exacerbated by modifier genes or environmental factors in different populations, according to a study published online ahead of print October 20 in JAMA Neurology. The investigators examined 49 previously published studies that included 709 participants and were found in ISI Web of Science and PubMed. They also analyzed extracted information about the number of mutation carriers within families and sporadic cases worldwide for pathogenic mutations in SNCA, LRRK2, VPS35, EIF4G1, and DNAJC13. The end-of-search date was January 31, 2014. In particular, penetrance of SNCA duplications were comparable to point mutations and driven by inclusion of SNCA p.A53T (mean age at onset, 45.9). Each penetrance estimate was given separately with 95% confidence intervals.
Spreading depolarizations can be measured after traumatic brain injury (TBI) by the placement of EEG electrodes on the scalp, according to a study published online ahead of print August 25 in Annals of Neurology. Eighteen patients requiring surgical treatment for TBI were monitored by invasive electrocorticography (ECoG) and noninvasive scalp EEG during intensive care. Spreading depolarizations were first identified in subdural recordings, and EEGs were then examined visually and quantitatively to identify correlates. A total of 455 spreading depolarizations occurred during 65.9 days of simultaneous ECoG and EEG monitoring. For 179 of 455 events (39%), depolarizations caused temporally isolated, transient depressions of spontaneous EEG amplitudes to 57% (median) of baseline power. For 62 of 179 (35%) events, isolated depressions showed a clear spread of depression between EEG channels with delays of 17 minutes (median).
A diet that includes walnuts may have a beneficial effect on reducing the risk, delaying the onset, and slowing the progression of, or preventing, Alzheimer’s disease, according to a study published October 21 in the Journal of Alzheimer’s Disease. The research group examined the effects of dietary supplementation on mice with 6% or 9% walnuts, which is equivalent to 1 ounce and 1.5 ounces per day, respectively, of walnuts in humans. The investigators found significant improvement in learning skills, memory, reducing anxiety, and motor development in mice fed a walnut-enriched diet. “These findings are very promising and help lay the groundwork for future human studies on walnuts and Alzheimer’s disease,” the investigators said.
Dopamine receptor agonist drugs are associated with impulse control disorders, such as pathologic gambling, hypersexuality, and compulsive shopping, according to a study that was published online ahead of print October 20 in JAMA Internal Medicine. Researchers conducted a retrospective disproportionality analysis that was based on the 2.7 million serious domestic and foreign adverse drug event reports between 2003 and 2012 that were extracted from the FDA Adverse Event Reporting System. The investigators identified 1,580 events indicating impulse control disorders from the United States and 21 other countries (710 for dopamine receptor agonist drugs and 870 for other drugs). The dopamine receptor agonist drugs had a strong signal associated with these impulse control disorders. The association was strongest for the dopamine agonists pramipexole and ropinirole, with preferential affinity for the dopamine D3 receptor. A signal was also seen for aripiprazole.
—Kimberly D. Williams
