No abstract

BackgroundThe video head impulse test (vHIT) is a valuable clinical tool that can help identify dysfunction of the semicircular canals. While in cases with semicircular canal dysfunction, both decreased vestibulo-ocular reflex (VOR) gain and corrective saccades (CS) are usually observed, there are cases which show CS despite normal VOR gain in vHIT.ObjectiveThis study aimed to investigate the clinical characteristics of patients who showed CS with normal VOR gain in vHIT.Materials and methodsAmong 390 patients who underwent vHIT, 51 patients (20 males and 31 females, age 31–87 years, average 61.3 years old) who showed CS with normal VOR gain unilaterally during horizontal vHIT were included. All patients had normal vHIT (normal VOR gain and absent CS) on the contralateral side.The VOR gain of vHIT, the maximum slow phase velocity in the caloric test, and the amplitude of cervical and ocular vestibular evoked myogenic potentials (cVEMPs and oVEMPs) were analyzed.ResultsThe VOR gain on the affected side (0.95 ± 0.08) was significantly smaller than that on the contralateral side (1.03 ± 0.13) in horizontal vHIT (p < 0.001). The maximum slow phase velocity in the caloric test on the affected side (17.9 ± 17.8 degrees/s) was significantly smaller than that on the contralateral side (21.3 ± 16.6 degrees/s, p = 0.020). There were no significant differences in the amplitude of cVEMPs or oVEMPs between the affected side and the contralateral side (p = 0.096 for cVEMP; p = 0.770 for oVEMP).ConclusionThe side that showed CS with normal VOR gain in horizontal vHIT showed significantly smaller VOR gain as well as smaller caloric responses compared to the contralateral side. Having CS with normal VOR gain could be a sensitive indicator of mild dysfunction of the semicircular canals.

We prepared oil-in-water emulsions with a phosphorylcholine-type gemini amphiphile (abbreviated as 18P-2-18N). The key emulsification process was found to be control of temperature; i.e., relatively stable emulsions were obtained when 18P-2-18N, hexadecane, and water were homogenized at 80 °C. We suggest that a liquid-crystalline 18P-2-18N phase stabilizes the oil/water interface at 80 °C, and then the transition to the gel phase at low temperature achieves further stabilization in a manner similar to the Pickering emulsion.

No abstract