Transmission of infrasonic pressure waves from cerebrospinal to intralabyrinthine fluids through the human cochlear aqueduct: Non-invasive measurements with otoacoustic emissions

Traboulsi, Raghida; Avan, Paul

doi:10.1016/j.heares.2007.06.012

Cited by 22 publications

(18 citation statements)

References 25 publications

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“…1B and C). 19 When OAEs travel through the stapes to the recording microphone in the external auditory meatus, their phase shifts reflect these biomechanical changes accordingly (Fig. 1D).…”

Section: Objective Testmentioning

confidence: 99%

Validation of a noninvasive test routinely used in otology for the diagnosis of cerebrospinal fluid shunt malfunction in patients with normal pressure hydrocephalus

Sakka

Chomicki²,

Gabrillargues

et al. 2016

JNS

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V entriculoperitoneal shunting remains the firstline treatment for normal pressure hydrocephalus (NPH), despite a high rate of malfunctions that reaches 31% within the 2 years following surgery. 9,12 Its detection is challenging since neuroimaging does not systematically correlate with clinical outcome. Notably, CT scanning often discloses the persistent distension of the cerebral ventricles in clinically improved patients. 13,14 In addition, the cerebrospinal fluid (CSF) dynamic tests recommended by specialized neurosurgical teams 6,17,21 OBJectiVe Ventriculoperitoneal shunting is the first-line treatment for normal pressure hydrocephalus. Noninvasive auditory tests based on recorded otoacoustic emissions were assessed, as currently used for universal neonatal hearing screenings, for the diagnosis of cerebrospinal fluid shunt malfunction. The test was designed based on previous works, which demonstrated that an intracranial pressure change induces a proportional, characteristic, otoacoustic-emission phase shift. methOdS Forty-four patients with normal pressure hydrocephalus (23 idiopathic and 21 secondary cases) were included in this prospective observational study. The male:female sex ratio was 1.44, the age range was 21-87 years (mean age 64.3 years), and the range of the follow-up period was 1-3 years (mean 20 months). Patients were implanted with a Sophy SU8 adjustable-pressure valve as the ventriculoperitoneal shunt. The phase shifts of otoacoustic emissions in response to body tilt were measured preoperatively, immediately postoperatively, and at 3-6 months, 7-15 months, 16-24 months, and more than 24 months postoperatively. Three groups were enrolled: Group 1, 19 patients who required no valve opening-pressure adjustment; Group 2, 18 patients who required valve opening-pressure adjustments; and Group 3, 7 patients who required valve replacement. reSultS In Group 1, phase shift, which was positive before surgery, became steadily negative after surgery and during the follow-up. In Group 2, phase shift, which was positive before surgery, became negative immediately after surgery and increasingly negative after a decrease in the valve-opening pressure. In Group 3, phase shift was positive in 6 cases and slightly negative in 1 case before revision, but after revision phase shift became significantly negative in all cases. cONcluSiONS Otoacoustic emissions noninvasively reflect cerebrospinal fluid shunt function and are impacted by valve-opening pressure adjustments. Otoacoustic emissions consistently diagnosed shunt malfunction and predicted the need for surgical revision. The authors' diagnostic test, which can be repeated without risk or discomfort by an unskilled operator, may address the crucial need of detecting valve dysfunction in patients with poor clinical outcome after shunt surgery.

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Section: Objective Testmentioning

confidence: 99%

Validation of a noninvasive test routinely used in otology for the diagnosis of cerebrospinal fluid shunt malfunction in patients with normal pressure hydrocephalus

Sakka

Chomicki²,

Gabrillargues

et al. 2016

JNS

Self Cite

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“…To estimate the time constant R A C of the inner ear, DPOAE, and thoracic signals, 250 to 450 points were recorded over 2-3 minutes with a sampling frequency equal to 6.25 Hz, as already previously described [26]. Briefly, DPOAEs are recorded at about 1 kHz after stimulation of two tones of frequency f 1 and f 2 where f 2 / f 1 ratio is equal to 1.2.…”

Section: Data Acquisitionmentioning

confidence: 99%

“…These methods have been shown to be effective in removing noise and artifacts from DPOAE without blurring eventual physiological modulations. Thereafter, the normalized ICP [26] gives more details about the filter system. and ILP infrasonic waves were used as the input and output signals, respectively, for the model system.…”

Section: Data Acquisitionmentioning

confidence: 99%

“…This model describes the connections and interconnections between the three different compartments of the human body: the respiratory (C 1 ), the head (C 2 ), and the auditory systems (C 3 ). Thereafter, the equivalent electrical parameters to this model (Figure 2(b)): CSF characteristics are represented by the lumpedelement Rcsf, Lcsf, and Cc [26], the cochlear aqueduct connecting the cochlea to these spaces acts as a resistance R A . The cochlear pressure signal transmitted from the CSF spaces is applied both at the round window and stapes but their large impedance difference implies that only the round window and its compliance C can play a significant part.…”

Section: Modelmentioning

confidence: 99%

“…Our technique is based on the transmission of infrasonic pressure waves from cerebrospinal to intralabyrinthine fluids through the human cochlear aqueduct [26], by utilizing the recording of the DPOAE stimulus. The estimated R A C values were characterized as a function of the dynamic modulation between intralabyrinthine and intracranial pressures, and then their mean values as a function of the posture body were deduced.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The Estimation of the Time Constant of the Human Inner Ear Pressure Change by Noninvasive Technique

Traboulsi

Poumarat

Chazal

et al. 2009

Modelling and Simulation in Engineering

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We propose a noninvasive method to estimate the time constant. The calculation of this factor permits us to understand the pressure variations of the inner ear and also predict the behavior of the flow resistance of the cochlear aqueduct. A set of mathematical relationships incorporating the intralabyrinthine pressure, the intracranial pressure, and the time constant was applied. The modeling process describes the hydrodynamic effects of the cerebrospinal fluid in the intralabyrinthine fluid space, where the input and output of the created model are, respectively, the sinusoidal variation of the respiration signal and the distortion product of otoacoustic emissions. The obtained results were compared with those obtained by different invasive techniques. A long time constant was detected each time when the intracranial pressure increased; this phenomenon is related to the role of the cochlear aqueduct described elsewhere. The interpretation of this model has revealed the ability of these predictions to provide a greater precision for hydrodynamic variation of the inner ear, consequently the variation of the dynamic process of the cerebrospinal fluid.

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Electrophysiological Monitoring of Cochlear Function as a Non-invasive Method to Assess Intracranial Pressure Variations

Sakka¹,

Thalamy

Giraudet

et al. 2012

Acta Neurochirurgica Supplementum

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The "cochlear" aqueduct is a narrow channel connecting the subarachnoid and intralabyrinthine spaces. Through this communication, cerebrospinal fluid (CSF) pressure variations are transmitted to the intralabyrinthine space and modify the impedance of the ear. Distortion-product otoacoustic emissions (DPOAE) are sounds emitted by cochlear sensory cells in response to sonic stimulation. Cochlear microphonic potentials (CMP) express the electrophysiological activity of cochlear sensory cells. At 1 kHz, the phase of DPOAE and CMP varies according to the impedance of the ear and thus to intracranial pressure (ICP) variations. DPOAE and CMP have been shown to strictly follow ICP variations produced during infusion tests performed in the diagnosis of chronic hydrocephalus. DPOAE and CMP recordings appear to be valuable tools for monitoring ICP non-invasively.

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Transmission of infrasonic pressure waves from cerebrospinal to intralabyrinthine fluids through the human cochlear aqueduct: Non-invasive measurements with otoacoustic emissions

Cited by 22 publications

References 25 publications

Validation of a noninvasive test routinely used in otology for the diagnosis of cerebrospinal fluid shunt malfunction in patients with normal pressure hydrocephalus

Validation of a noninvasive test routinely used in otology for the diagnosis of cerebrospinal fluid shunt malfunction in patients with normal pressure hydrocephalus

The Estimation of the Time Constant of the Human Inner Ear Pressure Change by Noninvasive Technique

Electrophysiological Monitoring of Cochlear Function as a Non-invasive Method to Assess Intracranial Pressure Variations

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