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Membrane Stress in the Human Labyrinth and Meniere Disease: A Model Analysis.

Pender DJ - Int Arch Otorhinolaryngol (2015)

Bottom Line: These results reflect macrostructural variations in membrane shape, size, and thickness among the several chambers of the labyrinth.Conclusions This model analysis of a human membranous labyrinth indicates that substantial disparities in stress exist among the several vestibular chambers due to macrostructural membrane configuration.Low stress levels in the canals are the result of thick highly curved membranes, and the high levels computed for the saccule reflect its thin and relatively flat membranes.

View Article: PubMed Central - PubMed

Affiliation: Department of Otolaryngology, Columbia University, New York City, New York, United States.

ABSTRACT
Introduction The nature and extent of membrane damage encountered in Meniere disease remains unexplained. Pressure-induced membrane stress may underlie the characteristic hydropic distention. Analysis of stress in the several vestibular chambers may offer insight into the nature and progression of Meniere disease. Objective Membrane stress levels will be assessed by constructing a specific model of the human membranous labyrinth through the application of human dimensions to an existing generic model of the mammalian labyrinth. Methods Nominal dimensions for a model of the human membranous labyrinth were obtained from fixed human tissue. Stress proclivities were calculated and normalized based on shell theory applied to the various geometric figures comprising the model. Results Normalized peak stress levels were projected to be highest in the saccule (38.8), followed by the utricle (5.4), then ampulla (2.4), and lowest in the canal system (1.0). These results reflect macrostructural variations in membrane shape, size, and thickness among the several chambers of the labyrinth. These decreasing stress proclivities parallel the decreasing frequency of histologic lesions found in documented cases of Meniere disease. Conclusions This model analysis of a human membranous labyrinth indicates that substantial disparities in stress exist among the several vestibular chambers due to macrostructural membrane configuration. Low stress levels in the canals are the result of thick highly curved membranes, and the high levels computed for the saccule reflect its thin and relatively flat membranes. These findings suggest that chamber configuration may be a factor controlling the progression of endolymphatic hydrops in Meniere disease.

No MeSH data available.


Related in: MedlinePlus

A model of the human membranous labyrinth using geometrical elements. Heavy lines represent thick membrane in the pars superior and Perlman membrane in the saccule. Light lines represent thin membranes in the saccule and the vestibular membrane (Reissner) of the cochlea spiral.
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FI0265or-1: A model of the human membranous labyrinth using geometrical elements. Heavy lines represent thick membrane in the pars superior and Perlman membrane in the saccule. Light lines represent thin membranes in the saccule and the vestibular membrane (Reissner) of the cochlea spiral.

Mentions: A geometric model of the macrostructure of membranous labyrinth in mammals has been described that uses axially symmetric shapes to emulate the several chambers.12 In this model, a semicircular canal is treated as a torus, an ampulla as a sphere, the utricle as a cylinder, and the saccule as a discus (i.e., a flattened spheroid). These features are illustrated in Fig. 1. Stress proclivity (the peak level of stress per unit of transmural pressure) in each chamber of the model has been shown to depend on chamber macrostructure (i.e., shape, size, and thickness of its membranes).13


Membrane Stress in the Human Labyrinth and Meniere Disease: A Model Analysis.

Pender DJ - Int Arch Otorhinolaryngol (2015)

A model of the human membranous labyrinth using geometrical elements. Heavy lines represent thick membrane in the pars superior and Perlman membrane in the saccule. Light lines represent thin membranes in the saccule and the vestibular membrane (Reissner) of the cochlea spiral.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4593924&req=5

FI0265or-1: A model of the human membranous labyrinth using geometrical elements. Heavy lines represent thick membrane in the pars superior and Perlman membrane in the saccule. Light lines represent thin membranes in the saccule and the vestibular membrane (Reissner) of the cochlea spiral.
Mentions: A geometric model of the macrostructure of membranous labyrinth in mammals has been described that uses axially symmetric shapes to emulate the several chambers.12 In this model, a semicircular canal is treated as a torus, an ampulla as a sphere, the utricle as a cylinder, and the saccule as a discus (i.e., a flattened spheroid). These features are illustrated in Fig. 1. Stress proclivity (the peak level of stress per unit of transmural pressure) in each chamber of the model has been shown to depend on chamber macrostructure (i.e., shape, size, and thickness of its membranes).13

Bottom Line: These results reflect macrostructural variations in membrane shape, size, and thickness among the several chambers of the labyrinth.Conclusions This model analysis of a human membranous labyrinth indicates that substantial disparities in stress exist among the several vestibular chambers due to macrostructural membrane configuration.Low stress levels in the canals are the result of thick highly curved membranes, and the high levels computed for the saccule reflect its thin and relatively flat membranes.

View Article: PubMed Central - PubMed

Affiliation: Department of Otolaryngology, Columbia University, New York City, New York, United States.

ABSTRACT
Introduction The nature and extent of membrane damage encountered in Meniere disease remains unexplained. Pressure-induced membrane stress may underlie the characteristic hydropic distention. Analysis of stress in the several vestibular chambers may offer insight into the nature and progression of Meniere disease. Objective Membrane stress levels will be assessed by constructing a specific model of the human membranous labyrinth through the application of human dimensions to an existing generic model of the mammalian labyrinth. Methods Nominal dimensions for a model of the human membranous labyrinth were obtained from fixed human tissue. Stress proclivities were calculated and normalized based on shell theory applied to the various geometric figures comprising the model. Results Normalized peak stress levels were projected to be highest in the saccule (38.8), followed by the utricle (5.4), then ampulla (2.4), and lowest in the canal system (1.0). These results reflect macrostructural variations in membrane shape, size, and thickness among the several chambers of the labyrinth. These decreasing stress proclivities parallel the decreasing frequency of histologic lesions found in documented cases of Meniere disease. Conclusions This model analysis of a human membranous labyrinth indicates that substantial disparities in stress exist among the several vestibular chambers due to macrostructural membrane configuration. Low stress levels in the canals are the result of thick highly curved membranes, and the high levels computed for the saccule reflect its thin and relatively flat membranes. These findings suggest that chamber configuration may be a factor controlling the progression of endolymphatic hydrops in Meniere disease.

No MeSH data available.


Related in: MedlinePlus