Multisensory Exercise Improves Balance in People with Balance Disorders: A Systematic Review.

OBJECTIVE: To examine the effect of multisensory exercise on balance disorders. METHODS: PubMed, Scopus and Web of Science were searched to identify eligible studies published before January 1, 2020. Eligible studies included randomized control trials (RCTs), non-randomized studies, case-control studies, and cohort studies. The methodological quality of the included studies was evaluated using JBI Critical Appraisal Checklists for RCTs and for Quasi-Experimental Studies by two researchers independently. A narrative synthesis of intervention characteristics and health-related outcomes was performed. RESULTS: A total of 11 non-randomized studies and 9 RCTs were eligible, including 667 participants. The results supported our assumption that multisensory exercise improved balance in people with balance disorders. All of the 20 studies were believed to be of high or moderate quality. CONCLUSION: Our study confirmed that multisensory exercise was effective in improving balance in people with balance disorders. Multisensory exercises could lower the risk of fall and enhance confidence level to improve the quality of life. Further research is needed to investigate the optimal strategy of multisensory exercises and explore the underlying neural and molecular mechanisms of balance improvement brought by multisensory exercises.

Removal of biofilm is essential for long-term ventilation tube retention.

BACKGROUND: Although long-term retention of a ventilation tube is required in many ear diseases, spontaneous removal of conventional ventilation tube is observed in patients within 3 to 12 mo. To address this issue, we aimed to determine a new method for long-term retention of the ventilation tube. AIM: To explore the value of removing the biofilm for long-term retention of tympanostomy ventilation tubes. METHODS: A case-control study design was used to evaluate the safety and effectiveness of long-term tube retention by directly removing the biofilm (via surgical exfoliation) in patients who underwent myringotomy with ventilation tube placement. The patients were randomly divided into two groups: Control group and treatment group. Patients in the treatment group underwent regular biofilm exfoliation surgery in the clinic, whereas those in the control group did not have their biofilm removed. Only conventional ventilation tubes were placed in this study. Outcome measures were tube position and patency. Tube retention time and any complications were documented. RESULTS: Eight patients with biofilm removal and eight patients without biofilm removal as a control group were enrolled in the study. The tympanostomy tube retention time was significantly longer in the treatment group (43.5 ± 26.4 mo) than in the control group (9.5 ± 6.9 mo) (P = 0.003). More tympanostomy tubes were found to be patent and in correct position in the treatment group during the follow-up intervals than in the control group (P = 0.01). CONCLUSION: Despite the use of short-term ventilation tubes, direct biofilm removal can be a well-tolerated and effective treatment for long-term tube retention of tympanostomy ventilation tubes in patients who underwent myringotomy.

Bilirubin induces auditory neuropathy in neonatal guinea pigs via auditory nerve fiber damage.

Bilirubin can cause temporary or permanent sensorineural deafness in newborn babies with hyperbilirubinemia. However, the underlying targets and physiological effects of bilirubin-induced damage in the peripheral auditory system are unclear. Using cochlear functional assays and electron microscopy imaging of the inner ear in neonatal guinea pigs, we show here that bilirubin exposure resulted in threshold elevation in both compound action potential (CAP) and auditory brainstem response (ABR), which was apparent at 1 hr and peaked 8 hr after drug administration. The threshold elevation was associated with delayed wave latencies and elongated interwave intervals in ABR and CAP. At 72 hr postinjection, these measures returned to control levels, except for the CAP amplitude. Cochlear microphonics remained unchanged during the experiment. Morphological abnormalities were consistent with the electrophysiological dysfunction, revealing fewer auditory nerve fibers (ANFs) in the basal turn, myelin sheath lesions of spiral ganglion neurons (SGNs) and ANFs, and loss of type 1 afferent endings beneath inner hair cells (IHCs) without loss of hair cells at 8 hr posttreatment. Similar to the electrophysiological findings, morphological changes were mostly reversed 10 days after treatment, except for the ANF reduction in the basal turn. These results suggest that hyperbilirubinemia in neonatal guinea pigs impaired auditory peripheral neuromechanisms that targeted mainly the IHC synapses and the myelin sheath of SGNs and their fibers. Our observations indicate a potential connection between hyperbilirubinemia and auditory neuropathy.

[Streptomycin-induced apoptosis of rat cochlear hair cell cultured in vitro].

OBJECTIVE: To evaluate if caspase pathway was involved in streptomycin-induced cell apoptosis in cochlear hair cells. METHODS: F344 rats at postnatal day 3 or 4 were used for the study in cochlear organotypic cultures. The cochlear basilar membrane was micro-dissected out and cultured overnight, and then treated with 1 mmol/L streptomycin for 24 hours. Before the termination, the activity of caspase-8, 9 or 6 were detected with FAM-peptide-FMK labeled caspase-8, 9 or 6, respectively. The stereocilia and cuticular plate of hair cells were stained with TRITC conjugated phalloidin, and the nuclei were stained with Topro-3 DNA probe. The specimens were observed and photographed under confocal fluorescent microscope. RESULTS: Streptomycin with 1 mmol/L causes about 80% cochlear hair cells missing in the basal turn and 10% hair cell loss in the apex. After streptomycin treatment, the nuclear shrinkage and fragmentation were found in most cochlear hair cells, and the caspase-8, caspase-9 and caspase-6 were greatly activated. CONCLUSIONS: Apoptosis is involved in the cochlear hair cells death induced by Streptomycin in vitro. The caspase activities in upstream and downstream are maybe the major apoptotic pathway.

[Ototoxic effects of streptomycin in vestibular organotypic cultures].

OBJECTIVE: To investigate the ototoxic effects of streptomycin in vestibular organotypic cultures. METHODS: F344 rats with age at postnatal day three or four were used for this study. The maculae of saccule and utricle were routinely dissected out and cultured with serum-free medium containing various dose of streptomycin for 24 hours. The ciliary turf of vestibular hair cells was stained with fluorescent phalloidin, and its nucleus was stained with to pro-3 DNA probe. The vestibular hair cells were quantitatively counted and photographed under confocal fluorescent microscope. RESULTS: Morphological feature of vestibular hair cells were good in normal control cultures. However, the density of hair cells was decreased in evidence with increase of streptomycin sulfate concentrations. Twenty-four hours after streptomycin cultures, 0.25 mmol/L streptomycin caused a 10% hair cell missing, 50% hair cell loss from 1 mmol/L streptomycin treatment, and more than 75% hair cells gone post-3 mmol/L streptomycin cultures. After streptomycin treatment, the nuclear shrinkage and fragmentation were found in vestibular hair cells, whereas the vestibular supporting cells were normal. CONCLUSION: Streptomycin induced-vestibular hair cells lesion was in a dose dependent manner with nuclear shrinkage and fragmentation. This may suggest that streptomycin leads vestibular hair cell die through apoptosis.

[Correlation between reduction of distortion product otoacoustic emission and percentage of outer hair cell missing in chinchillas].

OBJECTIVE: To explore the quantitative relationship between the reduction of distortion product otoacoustic emission (DPOAE) and the percentage of outer hair cell loss. METHODS: Coadministration of cisplatin (0.2 mg/kg) and ethacrynic acid (40 mg/kg) were used to establish a cochlear lesion model in chinchillas. DPOAE was measured before and 1 week, 2 weeks, and 3 weeks later respectively after cisplatin and ethacrynic acid treatment. Animals were terminated 3 weeks after the treatment. Cochlear surface preparations were performed, and the cochlear hair cells were counted through entire length of the cochlea. The correlation between DPOAE reduction and outer hair cell missing was analyzed using Pearson correlation analysis. RESULTS: Cisplatin and ethacrynic acid treatment induced cochlear hair cell lesion that the outer hair cell loss in the cochlea developed in a stereotypic pattern; damage began in the base of the cochlea and progressed towards the apex. Reduction of DPOAE was relatively consistent with outer hair cells loss. On the average, 1% outer hair cells loss may result in 0.24 dB reduction in DPOAE levels. Pearson analysis showed a positive correlation between the reduction in DPOAE and missing of outer hair cells (r = 0.796, P < 0.05). CONCLUSIONS: It may be helpful to evaluate missing percentage of outer hair cells from reduction in DPOAE levels.

Anatomic and spiral computed tomographic study of the genial tubercles for genioglossus advancement.

OBJECTIVE: To measure and compare Chinese mandibular genial tubercles measured anatomically and with computed tomography (CT). STUDY DESIGN AND SETTING: Spiral CT scans were taken of 40 adult human skulls; the superior genial spines were measured using anatomic and CT methods. RESULTS: The height and width of the superior genial spines, mandible thickness, and distance from the menton to the inferior and superior margins of the superior genial spines were 5.82 +/- 0.71, 6.98 +/- 1.35, 11.95 +/- 1.59, 11.08 +/- 2.05, and 16.91 +/- 2.30 mm from anatomic measurements and 6.17 +/- 0.71, 7.01 +/- 1.13, 12.19 +/- 1.64, 10.41 +/- 1.55, and 15.73 +/- 2.12 mm using spiral CT, respectively. The anatomic and CT measurements were correlated. CONCLUSION: Spiral CT of the genial tubercles can help locate the osteotomy in genioglossus advancement. SIGNIFICANCE: This study acquired reference data on Chinese genial tubercles demonstrating that CT measurements of the genial tubercles reflect their anatomy, which should allow accurately locate the osteotomy.

[Duration-tuning of the neurons in the inferior colliculus of guinea pigs and the role of gamma-aminobutyric acid mediated inhibition].

OBJECTIVE: To evaluate duration tuning in the inferior colliculus (IC) of guinea pigs and the role of GABA-mediated inhibition on this tuning. METHODS: Totally 23 healthy albino guinea pigs of either sex were employed in this study. After anesthesia, spikes of neurons in inferior colliculus were recorded using five-barrel glass-pipettes. The characteristic frequency was determined by recording iso-intensity response curves at moderate intensity level (40-70 dB SPL) and duration tuning was measured with signals of fixed intensity and varied durations. GABA-A receptor antagonist, bicuculline, was applied to neurons by means of in vivo micro-iontophoresis through one channel in the five-barrel glass-pipettes. RESULTS: IC neurons of guinea pigs, especially for those who showed sustained temporal response pattern, showed stronger duration tuning in their transient response peak to signal onset. Among 207 neurons recorded, totally 93 neurons were found to show clear duration selectivity. The duration selectivity was eliminated or turned to be weaker in most of the neurons in which the effect of bicuculline was observed successfully. CONCLUSIONS: Unlike what was reported in bats, duration selectivity may be a transient process for most of IC neurons in guinea pigs. Duration selectively of IC neurons in the guinea pig was also largely dependent on the GABAergic inhibition.

[Anatomic and spiral computed tomographic study of the genial tubercles for genioglossus advancement].

OBJECTIVE: To study anatomic and computed tomographic measurements of Chinese mandibular genial tubercles and to evaluate the correlations between them. METHODS: The axial images were taken by spiral CT in 40 adult human skulls with 1 mm thick section from infraorbital margin to menton. Sagittal plane reconstruction was produced through mandibular central line. Then the height and width of superior genial tubercles, the distance between menton and inferior margin of genial tubercles, the distance between mandibular incisor apex and superior margin of superior genial tubercles, the thickness of mandible were measured respectively. Thereafter anatomic measurements were taken by the same methods as computed tomographic images. The measured value were showed as means +/- standard deviation, then paired-t test and correlation analysis was made by SPSS 10.0. RESULTS: The genioglossus almost origins from superior genial tubercles, geniohyoideus from inferior genial tubercles. The height of superior genial tubercles which were measured by anatomy and spiral CT were (5.82 +/- 0.71) mm and (6.17 +/- 0.71) mm respectively. The width of superior genial tubercles were (6.98 +/- 1.35) mm and (7.01 +/- 1.13) mm. The distance between menton and inferior margin of superior genial tubercles were (11.08 +/- 2.05) mm and (10.41 +/- 1.55) mm. The distance between mandibular incisor apex and superior margin of superior genial tubercles for male were (15.57 +/- 1.82) mm and (14.34 +/- 2.06)mm, and for female were (9.36 +/- 2.79) mm (8.78 +/- 2.53) mm. The thickness of mandibles at genial tubercles were (11.95 +/- 1.59) mm and (12.19 +/- 1.64) mm. The distance from menton to superior margin of superior genial tubercles were (16.1 +/- 2.30) mm and (15.73 +/- 2.12) mm. The correlations between anatomic measurements and spiral CT measurements of the above mentioned parameters were significant except for height of superior genial tubercles (r = 0.59 - 0.92). CONCLUSION: The anatomic and spiral CT measurements of genial tubercles appear to have significant correlations. Preoperative spiral CT measurements of genial tubercles could be help for the design of osteotomy in genioglossus advancement.

Relationship between three inner ear antigens with different molecular weights and autoimmune inner ear disease.

Crude inner ear antigen (CIEAg) can induce autoimmune inner ear disease (AIED) although it is not known which subcomponent of CIEAg is involved. In this study, we investigated the relationship between 3 purified inner ear antigens (31, 42-45 and 60 kD proteins) and AIED, and determined their distribution in normal guinea pig cochlea. Three groups of guinea pigs were immunized with the three inner ear antigens and one group served as a control. The hearing thresholds, serum IgG level and morphological changes in the inner ear were observed. The expression of the three antigens in the cochlea was detected using immunohistochemical techniques. No obvious changes in hearing thresholds or inner ear morphology were observed between the control and 42-45 kD groups. Animals immunized with the 31 or 60 kD proteins showed a significant increase in hearing thresholds (p < 0.05 vs control), accompanied by morphological changes in the inner ear. The serum IgG level was increased significantly (p < 0.05) in all immunized animals. The 31 kD protein was distributed in the cochlear nerve and spiral ganglion, while the 42-45 and 60 kD proteins were distributed widely, being found in the spiral ganglion, organ of Corti, stria vascularis and spiral ligament. These results suggest that two subcomponents of CIEAg (the 31 and 60 kD proteins) may induce AIED independently, that several inner ear antigens may contribute to the pathogenesis of AIED and that the 31 kD protein is of high tissue specificity and may be used as a marker protein for the clinical diagnosis of AIED.