Differences in bone conduction ocular vestibular evoked myogenic potentials to 500 Hz narrow band chirp stimulus and 500 Hz tone burst.

OBJECTIVE: This study aims to investigate the differences of N1 latency, P1 latency and N1P1 amplitude in response to bone conducted 500 Hz tone burst and narrowband CE chirp stimulus in ocular vestibular evoked myogenic potentials (oVEMPs). METHODS: Forty-two healthy volunteers were included in this prospective study. Subjects with abnormal otological examinations and otological diseases were excluded. oVEMPs were randomly recorded in response to BC 500 Hz narrowband (NB) chirp stimulus and BC 500 Hz tone burst. The stimulus intensity was 50 dB nHL for both 500 Hz tone burst and 500 Hz NB CE chirp stimulus. P1 latency, N1 latency, and N1P1 amplitude were measured, and these measurements were compared between these two types of stimuli. RESULTS: Both types of stimuli elicited oVEMP in all subjects. N1 latency and P1 latency were significantly shorter (6.41 ms vs 10.84 ms; 10.64 ms vs 15.56 ms, respectively) for chirp stimulus (p < 0.05). N1P1 amplitude was significantly higher (11.64 vs 7.18 µV) for NB chirp stimulus (p < 0.05). CONCLUSION: It is reasonable to conclude that the NB CE chirp stimulus is effective to elicit robust BC oVEMP in healthy subjects.

Normative Data of Ocular Vestibular Evoked Myogenic Potentials in Response to Chirp Stimulus.

OBJECTIVES: This study aims at comparing the tone-burst (TB) and narrow-band (NB) CE-chirp stimuli in terms of amplitude, latency, and interaural asymmetry ratio (IAR) in ocular vestibular evoked myogenic potentials (oVEMP). MATERIALS AND METHODS: In this prospective study, we enrolled 60 healthy subjects (27 men, 33 women) with a mean age of 25.83 (range, 18-48) years. Otological examination was normal in all the subjects. The subjects did not have any otological disease. All the subjects underwent oVEMP testing. We used 500 Hz TB stimulus and 500 Hz NB CE-chirp stimulus in random order. oVEMP test was performed at 100 dB normalized hearing level. P1 latency, N1 latency, and P1N1 amplitude were measured for each ear and stimulus, and IAR was calculated. RESULTS: Ocular VEMPs were obtained from all the subjects for both the stimuli. P1 and N1 latencies were significantly shorter in chirp stimulus than in TB stimulus for both the sides (p<0.0001). P1 and N1 amplitudes were significantly higher for chirp stimulus than for TB stimulus for both the sides (p<0.0001). There was no significant difference between the ears in IAR between the 2 types of stimuli. CONCLUSION: Narrow-band CE-chirp stimulus is an effective stimulus to evoke oVEMP with higher amplitudes and shortened latencies.

Is the C-reactive protein/albumin ratio a prognostic and predictive factor in sudden hearing loss?

INTRODUCTION: Sudden hearing loss is a significant otologic emergency. Previous studies have revealed a coexistence of sudden hearing loss with chronic inflammation. The predictive importance of C-reactive protein/albumin values as a prognostic factor has been shown in various inflammatory and tumoral conditions. OBJECTIVES: The aim of this study was to determine whether the C-reactive protein/albumin ratio in sudden hearing loss can be used for prognostic purposes and whether there is a relationship between the neutrophil/lymphocyte ratio and the C-reactive protein/albumin ratio. METHODS: A retrospective examination was made of 40 patients diagnosed with idiopathic sudden hearing loss and a control group of 45 healthy subjects. The pure tone averages of all the patients were determined on first presentation and repeated at 3 months after the treatment. The patients were separated into 2 groups according to the response to treatment. The neutrophil/lynphocyte ratio and the C-reactive protein/albumin ratios were calculated from the laboratory tests. RESULTS: The patients included 16 females and 24 males with a mean age of 44.1±14.2 years and the control group was composed of 23 females and 22 males with a mean age of 42.2±13.8 years. The mean C-reactive protein/albumin ratio was 0.95±0.47 in the patient group and 0.74±0.13 in the control group. The difference was statistically significant (p=0.009). The mean C-reactive protein/albumin ratio was 0.79±0.12 in the response to treatment group and 1.27±0.72 in the non-response group, with no significant difference determined between the groups (p=0.418). The mean neutrophil/lymphocyte ratio was 3.52±3.00 in the response to treatment group and 4.90±4.60 in the non-response group, with no statistically significant difference determined between the groups (p=0.261). CONCLUSION: C-reactive/albumin ratio was significantly higher in patients with sudden hearing loss than in the control group. Although C-reactive protein/albumin ratio was found to be lower in sudden hearing loss patients who responded to treatment compared to those who did not, the difference between two groups was not statistically significant.