MicroRNAs Related to Cognitive Impairment After Hearing Loss.

OBJECTIVES: Our research group has previously demonstrated that hearing loss might be a risk factor for synaptic loss within the hippocampus and impairment of cognition using an animal model of Alzheimer disease. In this study, after inducing hearing loss in a rat model of Alzheimer disease, the associations of various microRNAs (miRNAs) with cognitive impairment were investigated. METHODS: Rats were divided randomly into two experimental groups: the control group, which underwent sham surgery and subthreshold amyloid-ß infusion and the deaf group, which underwent bilateral cochlear ablation and subthreshold amyloid-ß infusion. All rats completed several cognitive function assessments 11 weeks after surgery, including the object-in-place task (OPT), the novel object recognition task (NOR), the object location task (OLT), and the Y-maze test. After the rats completed these tests, hippocampus tissue samples were assessed using miRNA microarrays. Candidate miRNAs were selected based on the results and then validated with quantitative reverse transcriptionpolymerase chain reaction (qRT-PCR) analyses. RESULTS: The deaf group showed considerably lower scores on the OPT, OLT, and Y-maze test than the control group. The microarray analysis revealed that miR-29b-3p, -30e-5p, -153-3p, -376a-3p, -598-3p, -652-5p, and -873-3p were candidate miRNAs, and qRT-PCR showed significantly higher levels of miR-376a-3p and miR-598-3p in the deaf group. CONCLUSION: These results indicate that miR-376a-3p and miR-598-3p were related to cognitive impairment after hearing loss.

Can Osteopenia Induce Residual Dizziness After Treatment of Benign Paroxysmal Positional Vertigo?

OBJECTIVE: This study aimed to determine whether there is an association between osteopenia and residual dizziness after successful treatment of benign paroxysmal positional vertigo (BPPV). METHODS: In all, 62 patients with canalolithiasis-type BPPV were included in the study. Patients were divided into two groups according to the presence of residual dizziness after resolution of BPPV. Univariate and multivariate analyses were performed to determine the factors associated with residual dizziness. Patients were analyzed based on age, sex, affected semicircular canal, affected side, BPPV duration, and presence of hypertension, diabetes mellitus, hyperlipidemia, and osteopenia. RESULTS: In univariate analysis, BPPV duration and osteopenia showed a relatively significant association (p < 0.20) with the development of residual dizziness. On subsequent multivariate analysis using these factors, osteopenia remained a statistically significant factor in association with residual dizziness (p = 0.012, odds ratio, 9.916). CONCLUSION: Osteopenia is associated with the development of residual dizziness. BPPV patients with osteopenia more frequently suffer from residual dizziness after successful treatment of BPPV than those without osteopenia.