New and Noteworthy Information—July 2017

Hughes KC, Gao X, Kim IY, et al. Intake of dairy foods and risk of Parkinson disease. Neurology. 2017 Jun 8 [Epub ahead of print].

Elevated Brain Amyloid Increases Likelihood of Cognitive Decline

Elevated baseline brain amyloid level, compared with normal brain amyloid level, is associated with higher likelihood of cognitive decline, according to a study published June 13 in JAMA. Exploratory analyses were conducted with longitudinal cognitive and biomarker data from 445 cognitively normal people. Participants were classified at baseline as having normal or elevated brain amyloid using PET amyloid imaging or a CSF assay of amyloid β. Outcomes included scores on the Preclinical Alzheimer Cognitive Composite (PACC), Mini-Mental State Examination (MMSE), Clinical Dementia Rating Sum of Boxes (CDR-SOB), and Logical Memory Delayed Recall. Compared with the group with normal amyloid, people with elevated amyloid had worse mean scores at four years on the PACC, MMSE, and CDR-SOB. For Logical Memory Delayed Recall, between-group scores were not significantly different at four years.

Donohue MC, Sperling RA, Petersen R, et al. Association between elevated brain amyloid and subsequent cognitive decline among cognitively normal persons. JAMA. 2017;317(22):2305-2316.

Seven Risk Genes for Insomnia Found

Researchers have found seven risk genes for insomnia, according to a study published online ahead of print June 12 in Nature Genetics. To identify genetic factors for insomnia complaints, investigators performed a genome-wide association study and a genome-wide gene-based association study in 113,006 participants. The authors identified three loci and seven genes, including MEIS1, associated with insomnia complaints, with the associations for one locus and five genes supported by joint analysis with an independent sample. Sex-specific analyses suggest that the sexes have different genetic architectures, in addition to shared genetic factors. The researchers also found a substantial positive genetic correlation between insomnia complaints and internalizing personality traits and metabolic traits. There was a negative correlation with subjective well-being and educational attainment.

Hammerschlag AR, Stringer S, de Leeuw CA, et al. Genome-wide association analysis of insomnia complaints identifies risk genes and genetic overlap with psychiatric and metabolic traits. Nat Genet. 2017 Jun 12 [Epub ahead of print].

Is Telemedicine for Headache as Effective as In-Person Visit?

In people with headache, a video consultation with a neurologist for treatment may be as effective as an in-person visit, according to a study published online ahead of print June 14 in Neurology. Researchers randomized, allocated, and consulted patients with nonacute headache via telemedicine or in a traditional manner in a noninferiority trial. Efficacy end points assessed by questionnaires at three and 12 months included change from baseline in Headache Impact Test-6 (HIT-6) and pain intensity. The primary safety end point was presence of secondary headache within 12 months after consultation. There were no differences between telemedicine and traditional consultations in HIT-6 or pain intensity over three periods. The absolute difference in HIT-6 from baseline was 0.3 at three months and 0.2 at 12 months.

Müller KI, Alstadhaug KB, Bekkelund SI. A randomized trial of telemedicine efficacy and safety for nonacute headaches. Neurology. 2017 Jun 14 [Epub ahead of print].

Minocycline Reduces Risk of Conversion From CIS to MS

The risk of conversion from clinically isolated syndrome (CIS) to multiple sclerosis (MS) is significantly lower with minocycline than with placebo over six months, but not over 24 months, according to a study published June 1 in the New England Journal of Medicine. This study included 142 participants who had had their first demyelinating symptoms within the previous 180 days. At 12 Canadian MS clinics, researchers randomly assigned participants to receive either 100 mg of minocycline, administered orally twice daily, or placebo. Administration of minocycline or placebo was continued until a diagnosis of MS was established or until 24 months after randomization. The unadjusted risk of conversion to MS within six months after randomization was 61.0% in the placebo group and 33.4% in the minocycline group.

Metz LM, Li DKB, Traboulsee AL, et al. Trial of minocycline in a clinically isolated syndrome of multiple sclerosis. N Engl J Med. 2017;376(22):2122-2133.

Can Gene Mutation Speed Memory Loss in Alzheimer’s Disease?

In a middle-aged cohort with Alzheimer’s disease risk, the BDNF Met allele is associated with steeper decline in episodic memory and executive function, according to a study published online ahead of print May 3 in Neurology. One thousand twenty-three adults enrolled in the Wisconsin Registry for Alzheimer’s Prevention underwent BDNF genotyping and cognitive assessment at as many as five time points. A subset of participants underwent Pittsburgh compound B scanning. Compared with BDNF Val/Val homozygotes, Met carriers had steeper decline in verbal learning and memory, and in speed and flexibility. In addition, amyloid β burden moderated the relationship between BDNF and verbal learning and memory, such that Met carriers with greater amyloid β burden showed even steeper cognitive decline.