Background In the past few decades, it has been demonstrated with animal models and clinical studies that a chronic inflammatory process significantly contributes to Alzheimer's disease (AD) pathogenesis. Methods We systematically searched on PubMed and Web of Science for studies associated with peripheral inflammatory biomarkers in AD and mild cognitive impairment (MCI) before July 2018. Meta‐analysis was conducted to summarise results of studies relative to peripheral cytokines and chemokines in AD and MCI. Results Mean (± SD) concentrations of peripheral inflammatory biomarkers for AD, MCI and healthy controls were extracted from these studies. Our meta‐analysis revealed consistently elevated concentrations of inflammatory biomarkers such as C‐reactive protein, interleukin‐1β (IL‐1β), IL‐2, IL‐6, IL‐12, IL‐18, monocyte chemotactic protein‐1 (MCP‐1), MCP‐3, IL‐8 and interferon‐γ‐inducible protein 10 in AD patients, whereas no consistent results were obtained for elevated concentrations of cytokines or chemokines except MCP‐1 in MCI patients. Conclusions In conclusion, these results provided evidence to support that systematic inflammation might be a biomarker for AD diagnosis, whereas it might be a later event during AD disease progression.

<b><i>Background:</i></b> Previous studies have shown inconsistent results for associations between vitamin D and risk of stroke. We gathered the existing published articles and conducted this meta-analysis with the aim to explore the association between vitamin D and risk of stroke. <b><i>Methods:</i></b> We searched for articles exploring the association between vitamin D and risk of stroke and published before April 2021 in the following databases: PubMed, Web of Science, MEDLINE, EMBASE, and Google Scholar. All statistical analyses were made using STATA 12.0 software. Q test and <i>I</i>^<i>2</i> were applied to examine heterogeneities between studies. <b><i>Results:</i></b> For the association between serum levels of 25(OH) vitamin D and risks of stroke, the present analysis included 20 cohort studies (including 213,276 participants) and a case-control analysis (including 13,642 participants). Additionally, the analysis included 15 studies (including 41,146 participants given vitamin D supplementation and 41,163 participants given placebo) to evaluate the influence of vitamin D supplementation on risk of stroke. Higher circulating levels of 25(OH) vitamin D were associated with a reduced risk of stroke (odds ratio/relative risk = 0.78, 95% confidence interval [CI]: 0.70–0.86, <i>I</i>^<i>2</i> = 41.5%, <i>p</i> = 0.025). However, the present analysis showed that vitamin D supplementation did not influence the risk of stroke (hazard ratio = 1.05, 95% CI: 0.96–1.14, <i>I</i>² = 2.3%, <i>p</i> = 0.425). <b><i>Conclusions:</i></b> Our analysis indicated that lower circulating level of vitamin D was associated with an elevated risk of stroke, but extra supplement of vitamin D failed to show benefit in decreasing the risk of stroke. Further research and study are also needed to show the role of vitamin D in relation to stroke.

To evaluate the diagnostic value of combination of D-dimer and Doppler Intima-Media Thickness (IMT) based on clinical data for vascular dementia (VaD). In this study, 100 cases of initial VaD were diagnosed by Zhenjiang Fourth People Hospital as VaD group, and 100 healthy were engaged as control group, medical history and test results were collected for evaluation. IMT and D-dimer were highly correlated with the onset of VaD. The sensitivity of combination diagnosis for early VaD: 90.2%, the specificity: 87.9%, the area under the curve (AUC) is 0.872, which were superior to IMT or D-dimer alone. D-dimer and IMT are significantly increased in the initial onset of cerebrovascular diseases, and combined detection of them is conducive to early diagnosis and evaluation of the disease. Given the limitations of D-dimer and IMT, combined detection is more conducive to early diagnosis and prognosis, and can be used as screening and routine examination items, even evaluate the severity of cognitive decline.Abbreviations: AD = Alzheimer disease, AUC = area under the curve, IMT = intima-media thickness, NCI = neurocognitive index, VaD = vascular dementia.

Background and Objective: Mitochondrial encephalomyopathies represent a clinically heterogeneous group of disorders resulting from abnormal mitochondrial function. This study investigates the clinical and genetic characteristics of families with mitochondrial encephalomyopathy. Methods: The clinical manifestations, biopsy and gene detection were retrospectively analyzed for four probands with definitively diagnosed mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) from three families with MELAS and/or maternally inherited diabetes and deafness (MIDD). Results: The initial symptoms of probands were convulsive headache and/or epilepsy. The members of the three families also had diabetes, deafness, muscle weakness and short statures. Typical characteristics were indicated by muscle biopsy and gene detection in all. Conclusion: We reveal that the same family can have MIDD and MELAS cases, which clearly show that the unique mutation may cause different syndromes in one family. Neurologists should take into account more possibilities and phenotypes in screening and genetic counselling for the families of probands.