A process for prioritising systematic reviews in tinnitus

Objective: To develop an innovative prioritisation process to identify topics for new or updated systematic reviews of tinnitus research.Design: A two-stage prioritisation process was devised. First, a scoping review assessed the amount of randomized controlled trial-level evidence available. This enabled development of selection criteria for future reviews, aided the design of template protocol and suggested the scale of work that would be required to conduct these reviews. Second, using the pre-defined primary and secondary criteria, interventions were prioritised for systematic review.Study sample: Searches identified 1080 records. After removal of duplicates and out of scope works, 437 records remained for full data charting.Results: The process was tested, using subjective tinnitus as the clinical condition and using Cochrane as the systematic review platform. The criteria produced by this process identified three high priority reviews: (1) Sound therapy using amplification devices and/or sound generators; (2) Betahistine and (3) Cognitive behaviour therapy. Further secondary priorities were: (4) Gingko biloba, (5) Anxiolytics, (6) Hypnotics, (7) Antiepileptics and (8) Neuromodulation.Conclusions: A process was developed which successfully identified priority areas for Cochrane systematic reviews of interventions for subjective tinnitus. This technique could easily be transferred to other conditions and other types of systematic reviews.

Effect of Ginkgo Biloba Extract on N-Methyl-D-Aspartic Acid Receptor Subunit 2B Expression in a Salicylate-Induced Ototoxicity Model

Objectives.

Sodium salicylate (SS) is well known for its ototoxic properties that induce functional and morphological changes in the cochlea and brain. Ginkgo biloba extract (GBE) has been widely used for treatment of various neurodegenerative diseases; however, its effects on salicylate-induced ototoxicity remain unclear. Herein, we examined the effects of EGb 761 (EGb), a standard form of GBE, on the plasticity of the N-methyl-D-aspartate receptor subunit 2B (GluN2B) in the inferior colliculus (IC) following SS administration.

Methods.

Seven-week-old Sprague Dawley rats (n=24) were randomly allocated to control, SS, EGb, and EGb+SS groups. The SS group received a single intraperitoneal SS injection (350 mg/kg), the EGb group received EGb orally for 5 consecutive days (40 mg/kg), and the EGb+SS group received EGb for 5 consecutive days, followed by an SS injection. The auditory brainstem responses (ABRs) were assessed at baseline and 2 hours after SS administration. GluN2B expression was examined by Western blot and immunohistochemistry.

Results.

There were no significant differences in ABR threshold shifts among the groups. The expression of the GluN2B protein normalized by which of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) was significantly lower in the EGb+SS group, as compared to the SS group (P=0.012). Weak and diffused GluN2B immunoreactivity was detected in the IC neural cells of the EGb+SS group, while those of the SS group exhibited strong and diffused GluN2B positivity.

Conclusion.

EGb may play a role in regulating the GluN2B expression in the IC of salicylate-induced ototoxicity model.