News Roundup

New and Noteworthy Information


Deep brain stimulation (DBS) for Parkinson’s disease provides beneficial effects on motor function for at least three years, according to a study in the online June 20 Neurology. Patients in the multicenter, randomized trial were assigned to receive DBS of either the globus pallidus interna (89 patients) or the subthalmic nucleus (70 patients). Both groups were assessed at baseline and at 3, 6, 18, 24, and 36 months, and motor function in both groups improved between baseline and 36 months and was stable over time. However, gradual declines in neurocognitive function were observed. According to the investigators, these declines “likely reflect underlying disease progression and highlight the importance of nonmotor symptoms in determining quality of life.”

Patients with multiple sclerosis (MS), especially those taking antidepressants or hypnotics/anxiolytics, may have an increased risk of hip fracture, researchers reported in the June 12 Neurology. In a population-based cohort study, 2,415 patients with MS were matched by birth, sex, and practice to up to six control patients without MS. The investigators used Cox proportional hazards models to estimate the hazard ratio of fracture in patients with MS, finding that 59 fractures (2.4%) occurred among patients with MS, while 227 fractures (1.8%) occurred among controls. Patients with MS also had a fourfold increased risk of hip fracture, and patients with MS who had been prescribed antidepressants or hypnotics/anxiolytics in the previous six months had a significantly higher risk of osteopathic fracture. “Increased awareness of the risk of hip fracture is warranted in patients with MS,” the study authors concluded.

Women with Alzheimer’s disease are more likely to have the apolipoprotein E (APOE) e4 allele, and the interaction between APOE genotype and gender is evident in the preclinical period, researchers reported in the June 13 issue of the Journal of Neuroscience. Using fcMRI, the investigators analyzed the default mode network in the brains of 131 healthy participants with a median age of 70. Carriers of the e4 allele showed reduced default mode connectivity compared with carriers of e3 homozygotes, and additional testing indicated that female carriers of e4 showed significantly decreased connectivity in the default mode, compared with either female e3 homozygotes or male e4 carriers. However, male carriers of e4 did not show substantial difference from male e3 homozygotes. The researchers confirmed the finding through an additional analysis of a cohort of cognitively healthy participants.

Healthy older persons taking omega-3 supplements performed no better on cognitive performance tests than persons taking placebo, according to a June 13 review in the Cochrane Database of Systematic Reviews. The review included three randomized, controlled trials that involved 3,536 participants—two trials assigned participants to receive gel capsules of omega-3 long-chain polyunsaturated fatty acids (PUFA) or placebo for six or 24 months, and a third study assigned participants to receive margarine fortified or unfortified with omega-3 PUFA. The investigators’ results showed that participants receiving omega-3 performed no better than those who received placebo, but long-term studies are needed to determine whether omega-3 supplementation has cognitive benefits, the authors commented. “Longer-term studies may identify greater change in cognitive function in study participants, which may enhance the ability to detect the possible effects of omega-3 PUFA supplementation in preventing cognitive decline in older people.”

CAD106, a novel active amyloid-beta immunotherapy for patients with Alzheimer’s disease, has a favorable safety profile and acceptable antibody response, researchers reported in the online June 6 Lancet Neurology. In this phase I, double-blind study, patients were randomly assigned to two cohorts and then randomized within those cohorts. Those in the first cohort received CAD106 50 µg or placebo, and those in the second cohort received CAD106 150 µg or placebo. Although 56 of 58 patients reported adverse events, none of the events was thought to result from CAD106. Furthermore, 67% of the first cohort of patients and 82% of the second cohort of patients treated with CAD106 developed an amyloid-beta response that met the study’s pre-established responder thresholds. “Our findings suggest that CAD106 has a favorable safety profile and acceptable antibody response,” the researchers concluded.

The FDA has approved Horizant (gabapentin enacarbil) extended-release tablets for the management of postherpetic neuralgia in adults. Gabapentin enacarbil met the primary end point in a 12-week principal efficacy trial, as well as in two supportive studies—collectively the studies involved 574 adult patients. The drug should be initiated with a morning dose of 600 mg for three days followed by 600 mg twice daily beginning on day four. The most common side effects of gabapentin enacarbil were somnolence, which was reported in 10% of patients treated with gabapentin enacarbil, compared with 8% of those receiving placebo, and dizziness, which was reported in 17% of patients receiving gabapentin enacarbil, compared with 15% of those receiving placebo. Gabapentin enacarbil is marketed by GlaxoSmithKline, of Research Triangle Park, North Carolina, and XenoPort Inc, of Santa Clara, California.

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