Noninvasive detection of elevated ICP using spontaneous tympanic membrane pulsation

Abstract

Neurological conditions such as traumatic brain injury (TBI) and hydrocephalus may lead to intracranial pressure (ICP) elevation. Current diagnosis methods rely on direct pressure measurement, while CT, MRI and other expensive imaging may be used. However, these invasive or expensive testing methods are often delayed because symptoms of elevated ICP are non-specific. Invasive methods, such as intraventricular catheter, subdural screw, epidural sensor, lumbar puncture, are associated with an increased risk of infection and hemorrhage. On the other hand, noninvasive, low-cost, accurate methods of ICP monitoring can help avoid risks and reduce costs while expediting diagnosis and treatment. The current study proposes and evaluates a novel method for noninvasive ICP monitoring using tympanic membrane pulsation (TMp). These signals are believed to be transmitted from ICP to the auditory system through the cochlear aqueduct. Fifteen healthy subjects were recruited and TMp signals were acquired noninvasively while the subjects performed maneuvers that are known to change ICP. A custom made system utilizing a stethoscope headset and a pressure transducer was used to perform these measurements. Maneuvers included head-up-tilt, head-down-tilt and hyperventilation. When elevated ICP was induced, significant TMp waveform morphological changes were observed in each subject (p < 0.01). These changes include certain waveform slopes and high frequency wave features. The observed changes were reversed by the maneuvers that decreased ICP (p < .01). The study results suggest that TMp waveform measurement and analysis may offer an inexpensive, noninvasive, accurate tool for detection and monitoring of ICP elevations. Further studies are warranted to validate this technique in patients with pathologically elevated ICP.

The application value of CT radiomics features in predicting pressure amplitude correlation index in patients with severe traumatic brain injury

“…In the past, the analysis of CT images was limited to the interpretation of structural information, despite the widespread use of CT, their diagnostic accuracy for detection of elevated ICP and their correlation with ICP measurement are unknown. The analysis of CT texture features provides a perspective for establishing relevant assessment criteria and monitoring techniques ( 20 ). The morphological structural information alone is interpreted with a serious subjective bias ( 21 ).…”

“…are unknown. The analysis of CT texture features provides a perspective for establishing relevant assessment criteria and monitoring techniques (20). The morphological structural information alone is interpreted with a serious subjective bias (21).…”

Analysis of intracranial pressure pulse waveform in studies on cerebrospinal compliance: a narrative review

“…However, a later study by Evensen et al (2018b) reported that the cochlear aqueduct appears to act as a low-pass filter, resulting in substantial differences in time domain metrics. Similarly, Dhar et al (2021) showed a substantial discrepancy between the TM pulsation and expected ICP pulse shape in illustrative examples.…”

Accuracy of Intracranial Pressure Monitoring—Single Centre Observational Study and Literature Review

“…While they cannot drain CSF, they are easier to implant and carry a lower risk of infection than EVDs [ 1 ]. It is worth noting that because of the inherent risks and costs associated with invasive ICP monitoring, there have been many attempts to replicate it non-invasively using methods such as transcranial doppler ultrasound (including machine learning) or correlation with tympanic membrane displacement, (amongst others) [ 2 , 3 , 4 ]. While there have been advancements in this subject, it is a different challenge and beyond the scope of this review.…”