Pulsatile tinnitus (PT) is often an initial presenting symptom of dural arteriovenous fistula (dAVF), but it may be overlooked or diagnosed late if not suspected on initial diagnostic work-up. Here, we assess anatomical features, treatment outcomes, and clinical implications of patients with PT due to dAVF. Of 220 patients who were diagnosed with dAVF between 2003 and 2014, 30 (13.6%) presented with only PT as their initial symptom. The transverse-sigmoid sinus (70.0%) was the most common site, followed by the hypoglossal canal (10.0%) and the middle cranial fossa (6.7%) on radiologic evaluation. Regarding venous drainage patterns, sinus or meningeal venous drainage pattern was the most common type (73.3%), followed by sinus drainage with a cortical venous reflux (26.7%). PT disappeared completely in 21 (80.8%) of 26 patients who underwent therapeutic intervention with transarterial embolization of the fistula, improved markedly in 3 (11.5%), and remained the same in 2 (7.7%). In conclusion, considering that PT may be the only initial symptom in more than 10% of dAVF, not only otolaryngologists but also neurologists and neurosurgeons should meticulously evaluate patients with PT. In most cases, PT originating from dAVF can be cured with transarterial embolization regardless of location and venous drainage pattern.

Prevalence of Allergic Rhinitis(AR) is increasing year by year. It has been proved that environmental factors and epigenetic regulation are involved in the differentiation and development of immunocytes in AR. We aim to clarify whether fine particulate air pollution (for example, PM2.5) affects ten-eleven-translocation 1 (TET1) 5-mC dioxygenase enzymes in the differentiation of dentritic cells(DC) in AR. METHODS: Thirty-four HDM-sensitized patients with AR and twenty healthy controls were enrolled to compare the expression of TET1 in the peripheral blood mononuclear cells(PBMCs) and DC using quantitative reverse transcription polymerase chain reaction(qRT-PCR), Western blot and flow cytometry. In vitro, monocyte-derived DCs(moDCs) exposed to PM2.5 were detected by flow cytometry to evaluate the expression costimulatory molecules. Further to co-culture DC with CD4 + T cell and evaluate the number and immunosuppressive function of activated regulatory T cell(aTreg, CD4 + CD25 + CD45RA low Foxp3 high) by CFSE. In vivo, BALB/c mice were OVA-sensitized and challenged with or without PM2.5 exposed. HE and PAS staining in lung tissue, cytokines in bronchoalveolar lavage fluid, serum OVA-specific IgG1 and IgE were observed. TET1 expression in lung was evaluated by qRT-PCR and flow cytometry. RESULTS: TET1 expression decreases in PBMC of AR patients, especially in DC. MoDCs exposed to PM2.5 highly express CD86 and downregulate the number and immunosuppressive function of aTreg, increasing Th2 polarization and decreasing TET1 expression. Exacerbating effect of PM2.5 in OVA-sensitized and challenged mice decreases the expression of TET1. CONCLUSIONS: Exposing to fine particulate air pollution epigenetically downregulates TET1 expression in dendritic cells and exacerbates the inflammation of Allergic Rhinitis.