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Objective:Vitamin D (Vit D) regulates calcium and phosphate metabolism and helps to maintain otolith organ function. Residual dizziness (RD) is one of the most common complications after the successful treatment of benign paroxysmal positional vertigo (BPPV). Various theories have been suggested to explain the cause of RD, and otolith organ disorder is the most evident cause of RD. This study aimed to investigate the association between serum levels of Vit D and the occurrence of RD after the successful treatment of BPPV.MethodsA prospective study including patients who were diagnosed with de novo posterior semicircular canal-type BPPV (PC-BPPV) was conducted at our institution from May 2017 to May 2019. All the patients underwent canalith repositioning procedures and were followed up. Univariate and multivariate analyses were performed to investigate the relationship between serum 25-hydroxy vitamin D (25(OH)D) levels and RD occurrence after successful BPPV treatment.ResultsIn total, 123 patients with PC-BPPV were enrolled, and 41.5% (51/123) experienced RD. The serum level of 25(OH)D was significantly lower in PC-BPPV patients with RD [median 16.2 ng/ml (IQR 12.9–22.1)] than in patients without RD [median 20.5 ng/ml (IQR 16.5–26.5)] (P = 0.001). In multivariate models comparing the prevalence of RD in the insufficient group [25(OH)D ≥ 20 to

BackgroundOtolin-1 is an inner ear-specific protein that is exclusively expressed in otoconia and vestibule and cochlea cells. Recent investigations reported that otolin-1 can cross the blood-labyrinthine barrier and that the levels in serum well-reflected otolith status. Serum otolin-1 levels in patients with benign paroxysmal positional vertigo (BPPV) are significantly elevated compared with healthy controls. We aimed to explore whether otolin-1 can also serve as a biomarker for predicting BPPV recurrence.MethodPatients at our institution with new-onset of idiopathic BPPV between May, 2017 and May, 2018 were recruited and followed up for 2 years. All demographic data of the patients were collected, and serum levels of otolin-1 and other laboratory indicators were measured and compared according to the recurrence status.ResultsA total of 74 patients, who met the inclusion criteria were enrolled in this study, of which 27 (36.5%) patients had suffered one or more episodes of recurrence after undergoing canal repositioning treatments during the study. The serum levels of otolin-1 in patients with recurrent BPPV were significantly higher than those in patients without recurrent BPPV (363.9 vs. 309.8 pg/ml, p = 0.001). In multivariate analysis comparing the second to fourth quartiles (Q2–Q4) against the first quartile (Q1) of otolin-1, the level of otolin-1 in Q4 could significantly predict BPPV recurrence, and the odds ratio (OR) was elevated by approximately 812% (OR = 9.12; 95% confidence interval [CI]: 1.44–57.9; p = 0.019).ConclusionHigh serum levels of otolin-1 were associated with an increased risk of BPPV recurrence, and further investigation is required to confirm this association and clarify the exact mechanism.

Abstract Accurate prediction of tropical cyclone (TC) induced rainfall is of great importance to disaster prevention but quite challenging to operational forecasters. This study quantifies the spatial characteristics of the hourly rainfall caused by TCs at several individual weather stations over the south China coast. We use the historical TC datasets from 2004 to 2018 and the hourly rainfall data from six weather stations to investigate the stations' rainfall distribution characteristics induced by TCs within a distance of 700 km to the weather stations. The hourly rainfall data during the study period from six coastal stations: Zhuzilin (ZZL), Shekou Ferry Terminal (SFT), and Wutong Village (WTV) in Shenzhen, and Hong Kong Observatory (HKO), Sha Tin (SHA), and Tai Mo Shan (TMS) in Hong Kong are used to investigate the statistical relationship. Results show that the most hazardous areas for TC‐induced rainfall are TCs within a distance of 200 km relative to the stations. High intensity TCs in the southwest quadrant may bring torrential rainfall to stations within 500 km distance, and low intensity TCs are likely to induce torrential rainfall to stations within 300 km distance when they are in the northeast and northwest quadrants. If TCs are over the region with the azimuth of 60–150° and distance out of 200 km to the six stations, there is almost no rainfall influence on those stations. The findings of this study are valuable to provide information for the local operational forecasters when predicting the potential rainfall along the south China coast due to future TCs.

Objective: Otolin-1, a main specific otoconia matrix protein, passes through the labyrinth-blood barrier and is detectable in peripheral blood. Serum otolin-1 levels differ between patients with benign paroxysmal positional vertigo (BPPV) and healthy controls and are significantly age-related, increasing in healthy controls with age, suggesting that serum otolin-1 levels reflect otolith status. The aim of this study was to determine whether otolin-1 levels change during vertigo episodes in patients with BPPV and whether any change is specific and sensitive enough for BPPV episodes.Method: Patients diagnosed with de novo idiopathic BPPV during an acute episode were included in the study from May 2017 to May 2018. Blood samples were drawn before patients were treated with canalith-repositioning maneuvers. Serum otolin-1 levels were compared between 78 patients and 121 age- and sex-matched healthy individuals.Results: There were no significant differences between the groups in the age distribution, sex ratio, body mass index, clinical history, routine blood parameters, or total protein, albumin, uric acid, creatinine, blood urea nitrogen and lipid profiles (P > 0.05). Serum levels of otolin-1 were significantly higher in BPPV patients than in healthy controls (P < 0.001). Receiver operating characteristic analysis revealed that a serum otolin-1 value of 299.45 pg/ml was the optimal cut-off value to discriminate patients with BPPV from healthy controls (area under the curve 0.757, 95% CI 0.687~0.826) with a sensitivity of 67.9% and a specificity of 72.7%.Conclusion: Serum levels of otolin-1 may be a potential biomarker for BPPV episodes.

Objective: Vestibular neuritis (VN) is characterized by acute onset of vertigo, nausea, and vomiting, without auditory or other neurological symptoms. Although the pathogenesis of VN is not yet clear, many studies have shown that a pro-inflammatory environment can lead to the induction and progression of the disease. Considering the importance of vitamin D in modulating the activation, proliferation, and differentiation of inflammatory physiological processes, we hypothesized that decreased serum vitamin D may be associated with the development of VN. In this study, we evaluated serum levels of 25-hydroxyvitamin D [25(OH)D] in patients presenting acutely with VN and healthy controls and investigated the possible correlation of serum 25(OH)D levels with VN.Methods: A total of 59 consecutive patients diagnosed with VN within 7 days of symptom onset and 112 age- and sex-matched healthy controls referred to Hwa Mei Hospital, University of Chinese Academy of Science, between March 2017 and March 2019 were recruited. Demographic and clinical data, such as age, sex, height, weight, living habits, ongoing health problems, and medication history, for all subjects were recorded, and levels of 25(OH)D were measured and compared.Results: Serum levels of 25(OH)D were lower in patients with VN than in controls (19.01 ± 6.53 vs. 22.94 ± 6.74 ng/ml, p < 0.001). Patients with VN had a higher frequency of vitamin D deficiency (61.0 vs. 34.8%, P = 0.001) than did controls. Regression analyses demonstrated that vitamin D deficiency was associated with VN, with an odds ratio of 4.53 (95% CI = 1.342–15.279, P = 0.015).Conclusion: This prospective study is the first to evaluate serum 25(OH)D levels in patients with VN and found that decreased serum 25(OH)D may be associated with VN occurrence.

Objective: Several studies have suggested a probable association between benign paroxysmal positional vertigo (BPPV) and both reduction of bone mineral density (BMD) and serum vitamin D levels, but none of these studies have explored their findings by examining bone turnover markers (BTM) in male idiopathic BPPV patients. This study aimed to evaluate the relationship between BMD and serum 25-hydroxyvitamin D (25(OH) D), with the occurrence of BPPV along with the characteristics of bone metabolism in male idiopathic BPPV patients.Methods: This retrospective study comprised 60 male idiopathic BPPV patients and 92 age-matched healthy controls referred to Ningbo No.2 Hospital during the period of February 2016 to February 2018. All subjects' serum levels of 25(OH) D, bone formation marker amino-terminal propeptide of type I procollagen (PINP), and bone resorption marker β-isomerized carboxy-terminal telopeptide of type I collagen (β-CTX) were measured. BMD was determined by dual energy X-ray absorption at the lumbar spine and hip.Results: Among male patients with BPPV, the prevalence of BMD reduction was 35.0%, which was similar to that of 27.2% in healthy controls. There were significant differences in the mean serum 25(OH) D level and prevalence of vitamin D deficiency between the two groups, with p-values of 0.049 and 0.009, respectively. The bone turnover markers of PINP and β-CTX in BPPV patients were lower than those in healthy controls. Logistic regression showed that vitamin D deficiency were associated with BPPV with an odds ratio of 3.8 (95% confidence interval = 1.25–11.73).Conclusion: Our study found that decreased serum vitamin D may be a risk factor for BPPV in male patients. The level of bone turnover among male patients with BPPV was lower than that among healthy controls.

The FERM domain containing protein 7 gene (FRMD7) associated with the X-linked disorder idiopathic congenital nystagmus (ICN) is involved in the regulation of neurite elongation during neuronal development. Members of the Rho family of small G-proteins (Rho GTPases) are key regulators of the actin cytoskeleton and are implicated in the control of neuronal morphology. The Rho GDP dissociation inhibitor alpha, RhoGDIα, the main regulator of Rho GTPases, can form a complex with the GDP-bound form of Rho GTPases and inhibit their activation. Here, we demonstrate that the full length of the mouse FRMD7, rather than the N-terminus or the C-terminus alone, directly interacts with RhoGDIα and specifically initiates Rac1 signaling in mouse neuroblastoma cell line (neuro-2a). Moreover, we show that wild-type human FRMD7 protein is able to activate Rac1 signaling by interacting with RhoGDIα and releasing Rac1 from Rac1-RhoGDIα complex. However, two missense mutations (c.781C>G and c.886G>C) of human FRMD7 proteins weaken the ability to interact with RhoGDIα and release less Rac1, that induce the activation of Rac1 to a lesser degree; while an additional mutant, c.1003C>T, which results in a C-terminal truncated protein, almost fails to interact with RhoGDIα and to activate Rac1 signaling. Collectively, these results suggest that FRMD7 interacts with one of the Rho GTPase regulators, RhoGDIα, and activates the Rho subfamily member Rac1, which regulates reorganization of actin filaments and controls neuronal outgrowth. We predict that human mutant FRMD7 thus influences Rac1 signaling activation, which can lead to abnormal neuronal outgrowth and cause the X-linked ICN.

Objective: Several studies have reported the association of benign paroxysmal positional vertigo (BPPV) with vitamin D deficiency. This study aimed to evaluate serum 25-hydroxy vitamin D (25 (OH) D) levels in native Chinese postmenopausal women with de novo idiopathic BPPV and to investigate the possible relationship between the occurrence of BPPV and low 25 (OH) D levels. Methods: This retrospective study comprised of 85 postmenopausal women with de novo idiopathic BPPV and 80 age-matched healthy controls. All subjects had bone mineral density (BMD) and serum 25 (OH) D levels measurements recorded, and the results were compared. Results: The prevalence of reduced BMD (T score <-1.0) was significantly higher in female patients with BPPV than in healthy controls (71.8% vs. 51.2%, p = .004). The mean serum 25 (OH) D levels were also significantly lower in female patients with BPPV than in healthy controls (19.1 ±5.2 vs. 22.5 ±5.8, p < .001). The regression analyses demonstrated that vitamin D deficiency was associated with BPPV with an odds ratio of 2.1 (95% confidence interval = 1.1-3.1, p = .031). Conclusion: Our study suggests that low 25 (OH) D may be a risk factor for BPPV in postmenopausal women. [ABSTRACT FROM AUTHOR]