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Abstract Background/Objectives Several studies have shown a relationship between vitamin D and migraine, including the association between decreased serum 25‐hydroxyvitamin D in patients with migraine and the positive effects of vitamin D supplementations in the therapy of this disease. Two single‐nucleotide variants (SNVs) vitamin D receptor (VDR) gene, VDR rs2228570, and VDR rs731236 have shown an association with migraine risk in a previous case–control association study, while an exome sequencing study identified a rare variant in GC vitamin D binding protein gene. This study aims to look for the association between several common variants in these two genes and the risk for migraine. Methods We genotyped 290 patients diagnosed with migraine and 300 age‐matched controls using specific TaqMan assays for VDR rs2228570, VDR rs731236, VDR rs7975232, VDR rs739837, VDR rs78783628, GC rs7041, and GC rs4588 SNVs. Results We did not find an association between these SNVs and the risk for migraine. None of these SNVs were related to the positivity of a family history of migraine or with the presence of aura. The VDR rs731236A allele showed a significant association with the triggering of migraine attacks by ethanol (Pc = 0.007). Conclusions In summary, the results of the current study suggest a lack of association between common SNVs in the VDR and GC gene and the risk of developing migraine. The possible relationship between VDR rs731236 and the triggering of migraine episodes with ethanol deserves future studies.

Introduction In recent years, multiple studies have aimed to develop and validate portable technological devices capable of monitoring the motor complications of Parkinson’s disease patients (Parkinson’s Holter). The effectiveness of these monitoring devices for improving clinical control is not known.Methods and analysis This is a single-blind, cluster-randomised controlled clinical trial. Neurologists from Spanish health centres will be randomly assigned to one of three study arms (1:1:1): (a) therapeutic adjustment using information from a Parkinson’s Holter that will be worn by their patients for 7 days, (b) therapeutic adjustment using information from a diary of motor fluctuations that will be completed by their patients for 7 days and (c) therapeutic adjustment using clinical information collected during consultation. It is expected that 162 consecutive patients will be included over a period of 6 months.The primary outcome is the efficiency of the Parkinson’s Holter compared with traditional clinical practice in terms of Off time reduction with respect to the baseline (recorded through a diary of motor fluctuations, which will be completed by all patients). As secondary outcomes, changes in variables related to other motor complications (dyskinesia and freezing of gait), quality of life, autonomy in activities of daily living, adherence to the monitoring system and number of doctor–patient contacts will be analysed. The noninferiority of the Parkinson’s Holter against the diary of motor fluctuations in terms of Off time reduction will be studied as the exploratory objective.Ethics and dissemination approval for this study has been obtained from the Hospital Universitari de Bellvitge Ethics Committee. The results of this study will inform the practical utility of the objective information provided by a Parkinson’s Holter and, therefore, the convenience of adopting this technology in clinical practice and in future clinical trials. We expect public dissemination of the results in 2022.Trial registration NCT04176302; https://clinicaltrials.gov/show/NCT04176302

Because nitric oxide and endothelial dysfunction could play a role in the pathogenesis of idiopathic restless legs syndrome (RLS), as was suggested by some preliminary data, we investigated the possible association between the rs2070744 variants in the endothelial nitric oxide synthase (eNOS or NOS3) gene (chromosome 7q36.1) and the risk for RLS in a Caucasian Spanish population. We assessed the frequencies of NOS3 single nucleotide polymorphisms (SNPs) rs2070744, rs1799983, and rs79467411 genotypes and allelic variants in 273 patients with idiopathic RLS and 325 healthy controls using a TaqMan-based qPCR assay. We also analyzed the possible influence of genotype frequency on age at onset of RLS symptoms, gender, family history of RLS, and response to drugs commonly used in the treatment of RLS such as dopaminergic drugs, clonazepam, and GABAergic drugs. The frequencies of genotypes and allelic variants were not associated with the risk for RLS and were not influenced by gender, age, and positive family history of RLS. We identified weak statistical associations of the SNP rs1799983 with the response to dopamine agonists (Pc = 0.018 for the rs1799983 G/T genotype) and of the SNP rs79467411 with the response to clonazepam (Pc = 0.018 for the rs79467411 G allele), although these findings should be cautiously interpreted and require further confirmation. These associations aside, our findings suggest that common NOS3 SNPs are not associated with the risk for idiopathic RLS in Caucasian Spanish people.

Increased brain and serum zinc levels in patients with idiopathic restless legs syndrome (idiopathic RLS or iRLS) were described when compared with controls, suggesting a possible role of zinc in the pathogenesis of this disease. However, serum magnesium, calcium, manganese, iron, and copper levels of RLS patients were similar to controls, suggesting a specific impairment of zinc-dependent metabolism in RLS. The aim of this study is to assess the serum concentrations of trace elements involved in oxidative stress or causing peripheral nerve toxicity in a large series of patients with iRLS and controls. We determined serum levels of iron, copper, manganese, zinc, magnesium, selenium, calcium, aluminium, lead, cadmium, arsenic and mercury in 100 patients diagnosed with iRLS and in 110 age- and sex-matched controls using Inductively Coupled Plasma Mass Spectrometry. Serum copper, magnesium, selenium, and calcium concentrations were significantly higher in RLS patients than in controls. These differences were observed both in men and women. There were no major correlations between serum trace metal concentrations and age at onset of RLS or RLS severity, nor was there any association with a family history of RLS or drug response. This study shows an association between increased serum concentrations of copper, magnesium, selenium, and calcium with RLS in a Spanish Caucasian population and does not confirm the previously reported increase in serum zinc concentrations in patients suffering from this disease, suggesting that the different accuracy of the analytical methods used could have influenced the inconsistent results found in the literature.