Introduction Diabetes mellitus is a metabolic disease associated with a rise in the level of blood glucose. Individuals with diabetes mellitus are more likely to develop hearing loss, tinnitus, and dizziness due to macro- and microvascular complications. The extent to which auditory and vestibular functions are impaired in individuals with type-2 diabetes mellitus is still under debate. Objective To systematically review studies focusing on auditory and vestibular functions in individuals with type-2 diabetes mellitus. Data Synthesis A search was conducted in the PubMed, MedlinePlus, Ingenta Connect and Google Scholar databases for articles published until June 2019. A total of 15,980 articles were primarily retrieved, 33 of which were shortlisted based on the inclusion criteria set by the investigators for the systematic review. Out of 33 full-length articles, 26 evaluated the functioning of the auditory system, while 7 evaluated the functioning of the vestibular system. Most studies related to auditory functioning reported a significant effect of type-2 diabetes mellitus on the peripheral auditory system, whereas studies on vestibular functioning reported no significant effect of diabetes mellitus on the functioning of the peripheral vestibular end-organ. Conclusion Overall, the results of various audiological and peripheral vestibular tests reveal distinctive peripheral and/or central auditory and vestibular end-organ impairments in individuals with type-2 diabetes mellitus.

Objectives: Benign paroxysmal positional vertigo (BPPV) is a unilateral peripheral vestibular pathology, mostly involving the semicircular canals and the otolith organs. Although equivocal findings exist on the utility of cervical vestibular-evoked myogenic potential in identifying BPPV-associated changes in saccule, ocular vestibular-evoked myogenic potential (oVEMP), which is primarily a utricular response, has sparingly been explored in this population. Hence, the present study aimed at examining oVEMP in individuals with BPPV and comparing them with healthy individuals to illustrate its efficacy in identifying BPPV-associated changes in the utricle. Design: Using a case-control design, oVEMPs were elicited by 500 Hz tone bursts at 125 dB peak sound pressure level and recorded bilaterally from 30 individuals with unilateral posterior canal BPPV and 30 age- and gender-matched healthy controls. Results: There were no inter- or intragroup differences in latency aspects (p > 0.05); however, amplitudes were significantly smaller in BPPV ears compared with the non-BPPV ears of individuals with BPPV as well as ears of healthy controls (p < 0.05). Exceptions to this were five participants with BPPV in whom the affected ears demonstrated larger response amplitude (augmentation) than the unaffected ears. Furthermore, there was significantly larger interaural amplitude ratio in individuals with BPPV compared with the healthy controls (p < 0.05). Interaural amplitude ratio produced the largest effect size among the oVEMP parameters for differentiating BPPV from healthy controls. Conclusions: Large asymmetry ratio of oVEMP, usually exceeding 26.8%, is the most potent characteristic of oVEMP in BPPV. Abnormal oVEMP results confirm utricular pathology in ears with BPPV, and therefore, oVEMP can be used as an objective tool with asymmetry ratio as the parameter of choice for the evaluation of utricular function in persons with posterior canal BPPV.

Background:Video head impulse test (vHIT) is widely accepted as a test for the assessment of functional integrity of semicircular canals (SCCs). It allows for the evaluation of the functioning of all six SCCs independent of each other. It works on the principle of the vestibulo-ocular reflex (VOR). In individuals with vestibular pathologies, the VOR is impaired, and hence, the use of vHIT may provide vital information about the functional status of SCCs and the VOR pathway originating from them.Purpose:In the recent past, studies reported excellent test‐retest reliability of vHIT in healthy individuals. However, these studies used analysis of variance or the nonparametric counterpart Wilcoxon signed-rank test, which are insufficient statistical methods for conclusions about test‐retest reliability. Further, because vHIT assesses VOR function in individuals with vestibular pathologies, it is important to assess test‐retest reliability in the pathological group as well. Therefore, the present study aimed to evaluate test‐retest reliability of vHIT in healthy individuals and individuals with vestibular pathology.Research Design:Repeated measures.Study Sample:Twenty healthy individuals with no history of vestibular pathology and 20 individuals with known vestibular pathology were included.Data Collection and Analysis:Each participant underwent vHIT testing for all three SCCs of both sides on four different occasions. VOR gain and the presence of pathological saccades were noted and analyzed for each recording.Results:Intraclass correlation coefficient (ICC) revealed excellent test‐retest reliability for VOR gain in both groups (ICC ≥ 0.76). Kappa coefficient analysis for the presence of refixation saccades demonstrated moderate to excellent agreement between test sessions (K ≥ 0.63) for the lateral canal. For the anterior and posterior SCC, there was large variability between sessions for refixation saccades.Conclusions:This study provides evidence about test‐retest reliability of VOR gain and refixation saccades assessed using vHIT in healthy individuals and individuals with vestibulopathies. These findings suggest that both measures are highly reliable and replicable across test sessions, except refixation saccades in vertical canals which varied between sessions in some individuals.

Objective: Several parameters of ocular vestibular-evoked myogenic potential (oVEMP) have been used to identify Meniere’s disease. Nonetheless frequency–amplitude ratio (FAR), which is the ratio of amplitude between two frequencies, is one among the parameters that has failed to attract researchers’ attention despite proving its worth in diagnosis of Meniere’s disease when used in conjunction with cervical VEMP. Thus, the present study aimed at investigating the utility of FAR of oVEMP in identifying Meniere’s disease and finding out an optimum frequency pair for its diagnosis.Design: Using a case–control design, oVEMPs were recorded for tone bursts of 500, 750, 1000, and 1500 Hz from 36 individuals with unilateral definite Meniere’s disease in the age range of 15 to 50 years. For comparison purposes, oVEMP at the above frequencies were also obtained from an equal number of age- and gender-matched healthy individuals. The amplitudes of 750, 1000, 1500 Hz and tuned frequency, which was the frequency with the largest peak to peak amplitude among the above-mentioned frequencies, were divided by the amplitude of 500 Hz to obtain FARs for 750/500, 1000/500, 1500/500, and tuned frequency/500 frequency pairs.Results: The results revealed significantly higher FAR in the Meniere’s disease group than the healthy controls for all the frequency pairs (p< 0.05). The sensitivity of almost 90% and the specificity 100% was obtained for 1000/500 and 750/500, whereas the other frequency pairs produced a sensitivity of about 56% while still showing a specificity of 100%.Conclusions: High sensitivity and specificity, coupled with considerably lowered test duration when using only two frequencies, makes the use of FAR a more attractive prerogative, with 1000/500 as the frequency pair of choice.