Tinnitus is the conscious perception of a sound without a corresponding external acoustic stimulus, usually described as a phantom perception. One of the major challenges for tinnitus research is to understand the pathophysiological mechanisms triggering and maintaining the symptoms, especially for subjective chronic tinnitus. Our objective was to synthesize the published literature in order to provide a comprehensive update on theoretical and experimental advances and to identify further research and clinical directions. We performed literature searches in three electronic databases, complemented by scanning reference lists from relevant reviews in our included records, citation searching of the included articles using Web of Science, and manual searching of the last 6 months of principal otology journals. One-hundred and thirty-two records were included in the review and the information related to peripheral and central mechanisms of tinnitus pathophysiology was collected in order to update on theories and models. A narrative synthesis examined the main themes arising from this information. Tinnitus pathophysiology is complex and multifactorial, involving the auditory and non-auditory systems. Recent theories assume the necessary involvement of extra-auditory brain regions for tinnitus to reach consciousness. Tinnitus engages multiple active dynamic and overlapping networks. We conclude that advancing knowledge concerning the origin and maintenance of specific tinnitus subtypes origin and maintenance mechanisms is of paramount importance for identifying adequate treatment.
Early life-stage bioassays have been used as an alternative to short-term adult toxicity tests since they are cost-effective. A single couple can produce hundreds or thousands of embryos and hence can be used as a simple high-throughput approach in toxicity studies. In the present study, zebrafish and sea urchin embryo bioassays were used to test the toxicity of four pharmaceuticals belonging to different therapeutic classes: diclofenac, propranolol, simvastatin and sertraline. Simvastatin was the most toxic tested compound for zebrafish embryo, followed by diclofenac. Sertraline was the most toxic drug to sea urchin embryos, inducing development abnormalities at the ng/L range. Overall, our results highlight the potential of sea urchin embryo bioassay as a promising and sensitive approach for the high-throughput methods to test the toxicity of new chemicals, including pharmaceuticals, and identify several drugs that should go through more detailed toxicity assays.
The scientific literature on GLLR is vast, however controlled and randomized studies comparing different surgical techniques are lacking. At the present moment it is not clear if bioengineered materials are superior to conventional autogeneous tissue as lower eyelid spacers. The effects of GLLR on lower eyelid movements and contour have not been studied.
Primary granular cell tumor of the orbit is a rare type of neoplasm. The tumor is frequently associated with extraocular muscles, and eye motility limitation is an unavoidable complication after its surgical removal. The objective of the present article is to review the literature on primary granular cell tumors of the orbit and to report a case of this uncommon neoplasia. Granular cell tumor is a benign lesion encountered in most cases (58.3%) in the inferior aspect of the orbit. Extraocular muscle involvement occurs in 72.2% of the patients, and diplopia is present in 77.1% of the cases. The inferior and medial recti are the most affected muscles (38.5% and 26.9%, respectively). Surgical excision is the only modality of treatment, but diplopia persists in 73.3% of the cases. In conclusion, granular cell tumor is a benign lesion but involves a high rate of extraocular muscle morbidity.
Objective: Tinnitus is associated with various conditions such as presbycusis, infectious, autoimmune and many other diseases. Our study aims to identify an association between inflammatory markers and the presence of tinnitus or hearing loss (HL).Design: Exploratory study including a structured interview, complete ENT observation, audiological and inflammatory markers evaluation.Study Sample: 60 women and 54 men (55 to 75 years) from the Portuguese population, with or without sensory presbycusis and/or tinnitus.Results: IL10 levels were significantly lower in participants with tinnitus than in those without tinnitus. Moreover, TGF-β was lower in older participants (p=.034), IL1α was higher in participants with tonal tinnitus (p=.033), and IL2 was lower in participants who reported partial or complete residual inhibition (p=.019). Additionally, we observed a negative correlation between tinnitus duration and IL10 levels (r=-.281), and between HSP70 levels and tinnitus loudness (r=-.377). TNF-α and HSP70 levels appears to be sensitive to the time when samples were collected (i.e. morning or afternoon).
Conclusions:The results of our study show fluctuations in inflammatory markers along the hearing loss process, reinforce the idea that inflammatory mechanisms are involved in hearing loss pathogenesis but also in tinnitus. IL10 levels appear significantly altered in tinnitus but not hearing loss.
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