Segmental Analysis of the Vestibular Nerve and the Efferents of the Vestibular Complex

2018 ◽  
Vol 302 (3) ◽  
pp. 472-484 ◽  
Author(s):  
Carmen Díaz ◽  
Luis Puelles
Keyword(s):  
Vestibular Nerve ◽  
Segmental Analysis ◽  
Vestibular Complex

Combined retrosigmoid retrolabyrinthine vestibular nerve section: Results of our experience over 10 years. Otol Neurotol 2005;26:481-483

Skull Base ◽  
2005 ◽  
Vol 15 (04) ◽  
pp. 292-292
Author(s):  
Nebil Goksu ◽  
Metin Yilmaz ◽  
Ismet Bayramoglu ◽  
Yildirim A Bayazit
Keyword(s):  
Vestibular Nerve ◽  
Nerve Section

Combined retrosigmoid retrolabyrinthine vestibular nerve section: Results of our experience over 10 years. Otol Neurotol 2005;26:481-483

Skull Base ◽  
2005 ◽  
Vol 15 (04) ◽  
pp. 292-292
Author(s):  
Nebil Goksu ◽  
Metin Yilmaz ◽  
Ismet Bayramoglu ◽  
Yildirim A Bayazit
Keyword(s):  
Vestibular Nerve ◽  
Nerve Section

Segmental Analysis of Color Kinesis Images

Circulation ◽  
1997 ◽  
Vol 95 (8) ◽  
pp. 2082-2097 ◽  
Author(s):  
Victor Mor-Avi ◽  
Philippe Vignon ◽  
Rick Koch ◽  
Lynn Weinert ◽  
Maria J. Garcia ◽  
...  
Keyword(s):  
Segmental Analysis ◽  
Color Kinesis

Differences in the brain stem terminations of large- and small-diameter vestibular primary afferents

1995 ◽  
Vol 74 (3) ◽  
pp. 1362-1366 ◽  
Author(s):  
J. A. Huwe ◽  
E. H. Peterson
Keyword(s):  
Brain Stem ◽  
Large Diameter ◽  
Small Diameter ◽  
Movement Control ◽  
Three Dimensions ◽  
Significant Shift ◽  
Axon Diameter ◽  
Vestibular Complex ◽  
The Brain ◽  
Adjacent Brain

1. We visualized the central axons of 32 vestibular afferents from the posterior canal by extracellular application of horseradish peroxidase, reconstructed them in three dimensions, and quantified their morphology. Here we compare the descending limbs of central axons that differ in parent axon diameter. 2. The brain stem distribution of descending limb terminals (collaterals and associated varicosities) varies systematically with parent axon diameter. Large-diameter afferents concentrate their terminals in rostral regions of the medial/descending nuclei. As axon diameter decreases, there is a significant shift of terminal concentration toward the caudal vestibular complex and adjacent brain stem. 3. Rostral and caudal regions of the medial/descending nuclei have different labyrinthine, cerebellar, intrinsic, commissural, and spinal connections; they are believed to play different roles in head movement control. Our data help clarify the functions of large- and small-diameter afferents by showing that they contribute differentially to rostral and caudal vestibular complex.

scholarly journals Potential relationship between high wall shear stress and plaque rupture that cause acute coronary syndrome: insights from optical coherence tomography based computational fluid dynamic simulation

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
Y Fukuyama ◽  
H Otake ◽  
F Seike ◽  
H Kawamori ◽  
T Toba ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Shear Stress ◽  
Acute Coronary Syndrome ◽  
Wall Shear Stress ◽  
Plaque Rupture ◽  
Optical Coherence ◽  
Lumen Area ◽  
Segmental Analysis ◽  
Coronary Syndrome ◽  
Fibrous Cap

Abstract Background The direct relationship between plaque rupture (PR) that cause acute coronary syndrome (ACS) and wall shear stress (WSS) remains uncertain. Methods From the Kobe University ACS-OCT registry, one hundred ACS patients whose culprit lesions had PR documented by optical coherence tomography (OCT) were enrolled. Lesion-specific 3D coronary artery models were created using OCT data. Specifically, at the ruptured portion, the tracing of the luminal edge of the residual fibrous cap was smoothly extrapolated to reconstruct the luminal contour before PR. Then, WSS was computed from computational fluid dynamics (CFD) analysis by a single core laboratory. Relationships between WSS and the location of PR were assessed with 1) longitudinal 3-mm segmental analysis and 2) circumferential analysis. In the longitudinal segmental analysis, each culprit lesion was subdivided into five 3-mm segments with respect to the minimum lumen area (MLA) location at the centered segment (Figure. 1). In the circumferential analysis, we measured WSS values at five points from PR site and non-PR site on the cross-sections with PR. Also, each ruptured plaque was categorized into the lateral type PR (L-PR), central type PR (C-PR), and others according to the relation between the site of tearing and the cavity (Figure. 2). Results In the longitudinal 3-mm segmental analysis, the incidences of PR at upstream (UP1 and 2), MLA, and downstream (DN1 and 2) were 45%, 40%, and 15%, respectively. The highest average WSS was located in UP1 in the upstream PR (UP1: 15.5 (10.4–26.3) vs. others: 6.8 (3.3–14.7) Pa, p<0.001) and MLA segment in the MLA PR (MLA: 18.8 (6.0–34.3) vs. others: 6.5 (3.1–11.8) Pa, p<0.001), and the second highest WSS was located at DN1 in the downstream PR (DN1: 5.8 (3.7–11.5) vs. others: 5.5 (3.7–16.5) Pa, p=0.035). In the circumferential analysis, the average WSS at PR site was significantly higher than that of non-PR site (18.7 (7.2–35.1) vs. 13.9 (5.2–30.3) Pa, p<0.001). The incidence of L-PR, C-PR, and others were 51%, 42%, and 7%, respectively. In the L-PR, the peak WSS was most frequently observed in the lateral site (66.7%), whereas that in the C-PR was most frequently observed in the center site (70%) (Figure. 3). In the L-PR, the peak WSS value was significantly lower (44.6 (19.6–65.2) vs. 84.7 (36.6–177.5) Pa, p<0.001), and the thickness of broken fibrous cap was significantly thinner (40 (30–50) vs. 80 (67.5–100) μm, p<0.001), and the lumen area at peak WSS site was significantly larger than those of C-PR (1.5 (1.3–2.0) vs. 1.4 (1.1–1.6) mm2, p=0.008). Multivariate analysis demonstrated that the presence of peak WSS at lateral site, thinner broken fibrous cap thickness, and larger lumen area at peak WSS site were independently associated with the development of the L-PR. Conclusions A combined approach with CFD simulation and morphological plaque evaluation by using OCT might be helpful to predict future ACS events induced by PR. Funding Acknowledgement Type of funding source: None

Relationship of Semicircular Canal Size to Vestibular-Nerve Afferent Sensitivity in Mammals

2007 ◽  
Vol 98 (6) ◽  
pp. 3197-3205 ◽  
Author(s):  
Aizhen Yang ◽  
Timothy E. Hullar
Keyword(s):  
Semicircular Canal ◽  
High Frequency ◽  
High Gain ◽  
Vestibular Nerve ◽  
Radius Of Curvature ◽  
Horizontal Canal ◽  
Vestibular Nerve Afferents ◽  
The Relationship ◽  
Irregular Afferents ◽  
Anterior Canal

The relationship between semicircular canal radius of curvature and afferent sensitivity has not been experimentally determined. We characterized mouse semicircular canal afferent responses to sinusoidal head rotations to facilitate interspecies and intraspecies comparisons of canal size to sensitivity. The interspecies experiment compared the horizontal canal afferent responses among animals ranging in size from mouse to rhesus monkey. The intraspecies experiment compared afferent responses from the larger anterior canal to those from the smaller horizontal canal of mice. The responses of mouse vestibular-nerve afferents showed a low- and high-frequency phase lead and high-frequency gain enhancement. Regular horizontal-canal afferents showed a sensitivity to 0.5-Hz sinusoidal rotations of 0.10 ± 0.03 (SD) spike · s−1/deg · s−1 and high-gain irregular afferents showed a sensitivity of 0.25 ± 0.11 spike · s−1/deg · s−1. The interspecies comparison showed that the sensitivity of regular afferents was related to the radius of curvature R according to the formula Gr = 0.23R − 0.09 ( r2 = 0.86) and the sensitivity of irregular afferents was related to radius according to the formula Gi = 0.32R + 0.01 ( r2 = 0.67). The intraspecies comparison showed that regularly firing anterior canal afferents were significantly more sensitive than those from the relatively smaller horizontal canal, with Gr = 0.25R. This suggests that canal radius of curvature is closely related to afferent sensitivity both among and within species. If the relationship in humans is similar to that demonstrated here, the sensitivity of their regular vestibular-nerve afferents to 0.5-Hz rotations is likely to be about 0.67 spike · s−1/deg · s−1 and of their high-gain irregular afferents about 1.06 spikes · s−1/deg · s−1.

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