Frequent cognitive activity can reduce a person’s risk of developing Alzheimer’s disease, reported researchers in the online June 27 Neurology. Ninety of more than 700 study participants who underwent up to five years of annual clinical evaluations developed Alzheimer’s disease. Frequent participation in cognitive activity was associated with a reduced incidence of Alzheimer’s disease (hazard ratio, 0.58), and those participants in the bottom 10th percentile of cognitive activity were 2.6 times more likely to develop Alzheimer’s disease than those in the 90th percentile, said the authors. The association remained after the researchers controlled for past cognitive activity, lifespan socioeconomic status, current social and physical activity, and low baseline cognitive function. Brain autopsies of 102 participants revealed no global or region-specific measures of neuropathy related to level of cognitive activity before the study, at study onset, or during the course of the study.

The pattern of regional toxicity observed in the brains of people with Huntington’s disease may be caused by the breakdown of myelin and changes in ferritin iron distribution, according to a study published May 5 in the online Neurochemical Research. The investigators compared measurements of iron content and myelin breakdown in 11 participants with Huntington’s disease and 27 control participants using two MRI instruments operating at different field strengths. Both the significantly increased breakdown of tissue integrity and accumulation of ferritin in participants with Huntington’s disease, compared with those in the control group, matched the typical progression of the disease, from early to late myelinating regions. The pattern was largely preserved when a small set of participants in the early stages of Huntington’s disease was examined, said the researchers.

The FDA has approved Lyrica® (pregabalin) capsules for the management of fibromyalgia, the first FDA-approved treatment option for these patients. In clinical trials, participants taking pregabalin experienced rapid and sustained improvements in pain compared with placebo; the most commonly reported adverse events included dizziness, somnolence, dry mouth, edema, blurred vision, weight gain, constipation, euphoric mood, balance disorder, increased appetite, and difficulty with concentration. Researchers believe that pregabalin binds to a specific protein within overexcited nerve cells and calms damaged nerve cells to reduce patients’ pain levels, though the exact mechanism is not known. Pregabalin is also approved for the management of neuropathic pain associated with diabetic peripheral neuropathy and post-herpetic neuralgia, and as an adjunctive therapy in adults with partial onset seizures.

A study of 3,088 Canadian nuclear families with one parent with multiple sclerosis (MS) indicated that men and women equally transmit the genetic risk of the disease to their offspring. As reported online June 27 in Neurology, 9.41% of affected fathers transmitted MS to their children, compared with 9.76% of affected mothers. After stratifying by gender of the affected parent, the investigators found no significant differences in the female:male sex ratio of affected (2.46% vs 2.41%) or unaffected (0.91% vs 0.95%) offspring. The authors noted that their findings show no evidence for the Carter effect, which predicts that men, as the sex lesser affected by MS, are more genetically loaded for risk alleles and would thus transmit the disease more often to their offspring.

Combined environmental exposure to paraquat and iron, two toxic substances implicated individually in the development of sporadic Parkinson’s disease, may result in accelerated age-related neuronal degeneration, reported researchers in the June 27 Journal of Neuroscience. Mice exposed to both toxins began to exhibit symptoms of Parkinson’s disease at the human equivalent of middle age, with a progression of increased oxidative stress followed by decreased neuronal function and neuronal cell loss. However, mice also treated with the antioxidant EUK-189 had significantly less nerve death in the area of the brain frequently affected by Parkinson’s disease. “These findings support the notion that environmental Parkinson’s disease risk factors may act synergistically … and that iron and paraquat may act via common oxidative stress-mediated mechanisms,” concluded the authors.

The FDA has approved Nuvigil™ (armodafinil) tablets for treatment of excessive sleepiness associated with obstructive sleep apnea–hypopnea syndrome, narcolepsy, and shift work sleep disorder. The drug was generally well tolerated in randomized placebo-controlled studies, with the most commonly reported adverse events being nausea, head­aches, dizziness, diarrhea, decreased appetite, and upset stomach. Additional clinical programs will evaluate the use of armodafinil as a treatment for bipolar depression, cognitive difficulties associated with schizophrenia, excessive sleepiness in patients with Parkinson’s disease, and fatigue in patients being treated for cancer. Armodafinil is a nonamphetamine agent that is a single-isomer formulation of modafinil, which was approved by the FDA in 1998 to improve wakefulness.

Researchers have clarified the role of PTEN-induced putative kinase 1 (PINK1) protein as protecting against oxidative stress-induced cell death by suppressing cytochrome c release from the mitochondria, as reported in the online June 19 PLoS Biology. The investigators demonstrated that PINK1 phosphorylates the mitochondrial chaperone tumor necrosis factor receptor-associated protein 1 and suppresses cytochrome c release from the mitochondria.

A higher prevalence of stroke was observed in women ages 45 to 54 than in similarly aged men in a study published online June 20 in Neurology. Investigators examined data from 1999 to 2004 from a nationally representative sample of 17,061 US adults and found that women in that age group had an odds ratio (OR) for stroke of 2.39, compared with men of the same age. “No other significant midlife stroke differences between sexes were noted,” they reported; however, a higher stroke trend was seen in women ages 45 to 54 versus women ages 35 to 44. Independent predictors of stroke for women 45 to 54 included coronary artery disease and waist circumference. Vascular risk factors such as systolic blood pressure and total cholesterol levels increased at higher rates among women, compared with men, in each successively older cohort from 24 to 64 years, noted the authors.     

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