Noninvasive intracranial pressure measurement using infrasonic emissions from the tympanic membrane

Stettin, Eduard; Paulat, Klaus; Schulz, C.; Kunz, Ulrich; Mauer, Uwe Max

doi:10.1007/s10877-011-9297-x

Cited by 19 publications

(14 citation statements)

References 21 publications

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“…[79] investigated whether measuring infrasonic emissions from the tympanic membrane could monitor ICP in 31 individuals (17 patients, 14 healthy). Invasive ICP monitoring was indicated in all patients and was done so with implanted pressure sensors.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Noninvasive monitoring intracranial pressure – A review of available modalities

Khan¹,

Shallwani²,

Khan³

et al. 2017

Surg Neurol Int

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Background:Intracranial pressure (ICP) monitoring is important in many neurosurgical and neurological patients. The gold standard for monitoring ICP, however, is via an invasive procedure resulting in the placement of an intraventricular catheter, which is associated with many risks. Several noninvasive ICP monitoring techniques have been examined with the hope to replace the invasive techniques. The goal of this paper is to provide an overview of all modalities that have been used for noninvasive ICP monitoring to date.Methods:A thorough literature search was conducted on PubMed, selected articles were reviewed in completion, and pertinent data was included in the review.Results:A total of 94 publications were reviewed, and we found that over the past few decades clinicians have attempted to use a number of modalities to monitor ICP noninvasively.Conclusion:Although the intraventricular catheter remains the gold standard for monitoring ICP, several noninvasive modalities that can be used in settings when invasive monitoring is not possible are also available. In our opinion, measurement of optic nerve sheath diameter and pupillometry are the two modalities which may prove to be valid options for centers not performing invasive ICP monitoring.

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Section: Methodsmentioning

confidence: 99%

“…An increase in ICP was stimulated by postural changes using a tilting table. [79] The infrasonic emissions were measured by recording the TMD using a probe placed in the external auditory meatus in an airtight manner. [30] It was observed that the stimulated changes in ICP were detected in waveforms both noninvasively and invasively.…”

Section: Methodsmentioning

confidence: 99%

Noninvasive monitoring intracranial pressure – A review of available modalities

Khan¹,

Shallwani²,

Khan³

et al. 2017

Surg Neurol Int

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“…Intracranial pressure measurement using tympanic membrane displacement (TMD) and infrasonic emissions: by measuring infrasonic emissions from the tympanic membrane researchers have be able to estimate in vivo and non-invasively whether the intracranial pressure is high or low. 4 Low intracranial pressure is associated with an initial high peak followed by peaks with smaller amplitudes whereas elevated intracranial pressure is associated with a significant decrease in the number of peaks and in the amplitude difference between initial and last measured peaks. This method, nevertheless, does not provide objective, numeric measurements of intracranial pressure levels, even though it could potentially be used as a screening tool and for the continuous intracranial pressure monitoring.…”

Section: How Can We Measure Intracranial Cerebrospinal Fluid (Csf) Prmentioning

confidence: 98%

Discussion

Moraes

2013

Journal of Glaucoma

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T he previous chapters -and lectures they refer to -provided an update on what is new in the relationship between the brain and glaucoma and yielded information needed to plan future studies capable of translating this knowledge into clinical practice. During the second day of the Think Tank, our panel of scientists spent the time synthesizing and interpreting the material presented, examining new conceptual relationships, developing concepts for future directions and collaborations, discovering new areas for research, and elaborating on experiments that could be performed in the coming years to address unanswered questions and generate translational information. The following topics were merited special focus and a summary of their content is present below. HOW CAN WE MEASURE INTRACRANIAL CEREBROSPINAL FLUID (CSF) PRESSURE NONINVASIVELY?Given the strong arguments that the pressure gradient between the prelaminar optic nerve tissue and the subarachnoid CSF space may be more relevant than the 'estimated' intraocular pressure (IOP), the development of non-invasive methods to measure intracranial CSF pressure is warranted. Lumbar puncture is unsuitable as a routine procedure, particularly as an office procedure by ophthalmologists, given the risks of discomfort, infection and cerebral herniation. It is also possible that CSF pressure in the lumbar region may differ substantially from that in the subarachnoid space around the orbital portion of the optic nerve. Thus a technique for measurement of CSF pressure at the cranial level would be a valuable addition to our research and clinical armamentarium. Some of the proposed techniques are:Ophthalmodynamometry: since the central retinal venous pressure correlates with the subarachnoid space CSF pressure, the pressure exerted to the eye to cause cessation of venous pulsations seen during ophthalmoscopy could be a surrogate measure of the pressure in that compartiment. 1,2 One limitation is the lack of information on venous resistance, how it correlates with the pressure need to cease pulsation, and more importantly, what systemic variables (eg: systemic hypertension, use of medications) can interfere with venous resistance and its correlation with CSF pressure.Magnetic resonance imaging (MRI): recent studies have shown that the cross-sectional width of the optic nerveincluding its meningeal sheets -can provide information on the pressure level in the subarachnoid space. 3 Some of its disadvantages are cost and the fact that this technique does not provide numeric, objective measurements of CSF pressure, but rather a subjective dichotomized conclusion to be correlated with IOP measurements. Intracranial pressure measurement using tympanic membrane displacement (TMD) and infrasonic emissions: by measuring infrasonic emissions from the tympanic membrane researchers have be able to estimate in vivo and non-invasively whether the intracranial pressure is high or low. 4 Low intracranial pressure is associated with an initial high peak followed by peaks with smaller amplitudes ...

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“…The CAP and ECP spectra also include the interactions between the two latter components, which are located at f C À f R , f C À 2f R , f C þ f R , and so on. Figures 3(a) and 3(b) suggest that the assessment of infrasonic emissions (ECP) will someday be suitable both as a screening tool and for the continuous monitoring of ICP in an intensive care environment (Stettin et al, 2011).…”

Section: Transfer Function Between Cap and Ecpmentioning

confidence: 99%

“…Low-frequency power reflectance appears to increase systematically with increased ICP, while the corresponding transmittance decreases systematically. Paulat et al (1999) and Stettin et al (2011) investigated whether ICP can be assessed by measuring infrasonic emissions from the TM. In a total of 83 measurements, the changes in ICP that were observed in response to different types of stimulation were detected in noninvasively and invasively acquired waveforms.…”

Section: Introductionmentioning

confidence: 99%

Transfer function for vital infrasound pressures between the carotid artery and the tympanic membrane

Kenji

Yamashita

2013

The Journal of the Acoustical Society of America

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While occupational injury is associated with numerous individual and work-related risk factors, including long working hours and short sleep duration, the complex mechanisms causing such injuries are not yet fully understood. The relationship between the infrasound pressures of the tympanic membrane [ear canal pressure (ECP)], detected using an earplug embedded with a low-frequency microphone, and the carotid artery [carotid artery pressure (CAP)], detected using a stethoscope fitted with the same microphone, can be quantitatively characterized using systems analysis. The transfer functions of 40 normal workers (19 to 57 years old) were characterized, involving the analysis of 446 data points. The ECP waveform exhibits a pulsatile character with a slow respiratory component, which is superimposed on a biphasic recording that is synchronous with the cardiac cycle. The respiratory ECP waveform correlates with the instantaneous heart rate. The results also revealed that various fatigue-related risk factors may affect the mean magnitudes of the measured pressures and the delay transfer functions between CAP and ECP in the study population; these factors include systolic blood pressure, salivary amylase activity, age, sleep duration, postural changes, chronic fatigue, and pulse rate.

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Noninvasive intracranial pressure measurement using infrasonic emissions from the tympanic membrane

Abstract: It is conceivable that the assessment of infrasonic emissions will become suitable both as a screening tool and for the continuous monitoring of ICP in an intensive care environment.

Cited by 19 publications

References 21 publications

Noninvasive monitoring intracranial pressure – A review of available modalities

Noninvasive monitoring intracranial pressure – A review of available modalities

Discussion

Transfer function for vital infrasound pressures between the carotid artery and the tympanic membrane

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