Evaluation de la pression intracrânienne absolue par une technologie non invasive auditive

Abstract : There is no validated non-invasive method for determining the absolute value of intracranial pressure (ICP). Ear connect cerebrospinal fluid (CSF) and cochlear fluid via cochlear aqueduct. The goal of this project is to use ear absorbance, optimal when the vibrating structures are in resting position, so the stapes when the pressure outside the ear (in the external ear canal -Peec) counteracts the ICP through the middle ear ossicles. Subjects are testing in different tilt body position, which increase ICP, using a tympanometer Wideband. 78 ears of control subjects between 20 and 30 years have shown that the absorbance is maximum at all frequencies at Peec = 0 mmH2O in standing posture, decreases in a complex way at zero Peec, but again identical to the maximum absorbance at Peec = 13 mm H2O ± 7 in supine, and 23 mm H2O ± 14 in Trendelenburg posture (-30 °), this in 68 ears out of 78. The remaining 10 ears had an anatomical dysfunction. A physical model was established from a classical electromechanical ear model, which reproduces the observed behavior by attributing to the ICP the cause of changes in absorbance and predicting the ability for Peec to offset the absorbance changes due to ICP. Furthermore, 3 patients treated with a perfusion test were tested as well as 2 patients treated by a lumbar puncture. These patients showed the effect of positives and negatives pressure in absorbance curves. Literature make possible a correlation between absolute ICP (in every tilt body position) and absorbance, we can conclude that due to the geometry of the middle ear, the equilibrium relationship between absolute values is ICP = 15 x Peec, where 15 is the ratio of the areas between the tympanic membrane and the stape plate. Subjects tested by invasive measurement of ICP will be required for the continuation of this study.
Complete list of metadatas

Cited literature [132 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-02426256
Contributor : Abes Star <>
Submitted on : Thursday, January 2, 2020 - 1:49:08 AM
Last modification on : Friday, January 3, 2020 - 1:25:35 AM

File

2019CLFAS004_GONZALEZ_TORECILL...
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-02426256, version 1

Collections

Citation

Sandra Gonzalez Torrecilla. Evaluation de la pression intracrânienne absolue par une technologie non invasive auditive. Neurobiologie. Université Clermont Auvergne, 2019. Français. ⟨NNT : 2019CLFAS004⟩. ⟨tel-02426256⟩

Share

Metrics

Record views

69

Files downloads

27