Noninvasive Intracranial Pressure Research Articles

Characterization of intracranial compliance in healthy subjects using a noninvasive method - results from a multicenter prospective observational study.

An FDA-approved non-invasive intracranial pressure (ICP) monitoring system enables the assessment of ICP waveforms by revealing and analyzing their morphological variations and parameters associated with intracranial compliance, such as the P2/P1 ratio and time-to-peak (TTP). The aim of this study is to characterize intracranial compliance in healthy volunteers across different age groups. Healthy participants, both sexes, aged from 9 to 74 years old were monitored for 5min in the supine position at 0º. Age was stratified into 4 groups: children (≤ 7 years); young adults (18 ≤ age ≤ 44 years); middle-aged adults (45 ≤ age ≤ 64 years); older adults (≥ 65 years). The data obtained was the non-invasive ICP waveform, P2/P1 ratio and TTP. From December 2020 to February 2023, 188 volunteers were assessed, of whom 104 were male, with a median (interquartile range) age of 41 (29-51), and a median (interquartile range) body mass index of 25.09 (22.57-28.04). Men exhibited lower values compared to women for both the P2/P1 ratio and TTP (p < 0.001). There was a relative rise in both P2/P1 and TTP as age increased (p < 0.001). The study revealed that the P2/P1 ratio and TTP are influenced by age and sex in healthy individuals, with men displaying lower values than women, and both ratios increasing with age. These findings suggest potential avenues for further research with larger and more diverse samples to establish reference values for comparison in various health conditions. Brazilian Registry of Clinical Trials (RBR-9nv2h42), retrospectively registered 05/24/2022. UTN: U1111-1266-8006.

Probability density and information entropy of machine learning derived intracranial pressure predictions.

Even with the powerful statistical parameters derived from the Extreme Gradient Boost (XGB) algorithm, it would be advantageous to define the predicted accuracy to the level of a specific case, particularly when the model output is used to guide clinical decision-making. The probability density function (PDF) of the derived intracranial pressure predictions enables the computation of a definite integral around a point estimate, representing the event's probability within a range of values. Seven hold-out test cases used for the external validation of an XGB model underwent retinal vascular pulse and intracranial pressure measurement using modified photoplethysmography and lumbar puncture, respectively. The definite integral ±1 cm water from the median (DIICP) demonstrated a negative and highly significant correlation (-0.5213±0.17, p< 0.004) with the absolute difference between the measured and predicted median intracranial pressure (DiffICPmd). The concordance between the arterial and venous probability density functions was estimated using the two-sample Kolmogorov-Smirnov statistic, extending the distribution agreement across all data points. This parameter showed a statistically significant and positive correlation (0.4942±0.18, p< 0.001) with DiffICPmd. Two cautionary subset cases (Case 8 and Case 9), where disagreement was observed between measured and predicted intracranial pressure, were compared to the seven hold-out test cases. Arterial predictions from both cautionary subset cases converged on a uniform distribution in contrast to all other cases where distributions converged on either log-normal or closely related skewed distributions (gamma, logistic, beta). The mean±standard error of the arterial DIICP from cases 8 and 9 (3.83±0.56%) was lower compared to that of the hold-out test cases (14.14±1.07%) the between group difference was statistically significant (p<0.03). Although the sample size in this analysis was limited, these results support a dual and complementary analysis approach from independently derived retinal arterial and venous non-invasive intracranial pressure predictions. Results suggest that plotting the PDF and calculating the lower order moments, arterial DIICP, and the two sample Kolmogorov-Smirnov statistic may provide individualized predictive accuracy parameters.

The Current State of Non-Invasive Measurement of Intracranial Pressure in Patients with Craniosynostosis: A Systematic Review

Introduction: Despite being invasive, direct measurements remain the gold standard to measure intra-cranial pressure (ICP) in patients with craniosynostosis. However, there has been persistent effort to develop non-invasive modalities to measure ICP, possibly avoiding some of the risks of direct measurements. Here, we conduct a systematic review of the evidence behind various non-invasive modalities to monitor ICP in patients with craniosynostosis. Methods: A systematic review was conducted using PubMed, Cochrane, and Web of Science databases to identify studies describing the use of non-invasive ICP measurements in patients with craniosynostosis. Studies were included if they assessed a non-invasive method of ICP monitoring against a direct/invasive ICP monitoring technique in patients with craniosynostosis. Non-English and non-human studies were excluded. Results: A total of 735 studies were screened, of which 52 were included in the study. Nine methods of non-invasive ICP measurement were identified, with varying sensitivities and specificities in detecting elevated ICP. Specifically, optical coherence tomography (OCT), and ocular ultrasonography demonstrated ability to accurately measure ICP when compared to direct measurements. Conclusion: Here, we present the first systemic-review of the current literature surrounding non-invasive modalities to measure ICP in patients with craniosynostosis. While direct measurement remains the gold-standard, multiple reviewed modalities have shown promise in accurately measuring ICP. Of these, OCT has the most rigorous evidence supporting its use. Ocular sonography has also shown promise, albeit without as robust evidence supporting its use. Regardless, further investigation is required before any modality is able to obviate the need for invasive, direct measurements.

Non-invasive intracranial pressure monitoring for high-grade gliomas patients treated with radiotherapy: results of the GMaPIC trial.

Patients with high-grade gliomas are at risk of developing increased intracranial hypertension (ICHT) in relation to the increase in volume of their tumor. ICP change cannot be measured by invasive method but can be estimated by using routine clinical signs, in combination with a standard imaging method, magnetic resonance imaging (MRI). A non-invasive monitoring of ICP could be of interest in high-grade glioma, in particular after radiotherapy treatment with as major side effect a cerebral oedema. This prospective clinical study aimed to compare the ICP changes (estimated by a non-invasive method based upon distortion product otoacoustic emissions (DPOAE) monitoring) with volume changes observed on MRI in patients with high-grade gliomas treated with radiotherapy. DPOAE measurements were performed one month after the end of radiotherapy and then every 3 months for one year. At each visit, the patient also underwent MRI as well as an evaluation of clinical signs. The variation in the estimate of intracranial pressure readout measured at each follow-up visit (in absolute value with respect to the baseline measurements) was significantly associated with the variation of T2/FLAIR volume (n=125; p<0.001) with a cut off value of change ICP readout of 40.2 degrees (e.i. an estimated change of 16 mm Hg). The GMaPIC trial confirm the hypothesis that the ICP change estimated by DPOAEs measurement using a non-invasive medical device is correlated with the change of the tumor or edema in high grade glioma after radiotherapy. The device could thus become an easy-to-use and non-invasive intracranial pressure monitoring tool for these patients. Clinicaltrials.gov, identifier (NCT02520492).

A deep learning approach for generating intracranial pressure waveforms from extracranial signals routinely measured in the intensive care unit

Intracranial pressure (ICP) is commonly monitored to guide treatment in patients with serious brain disorders such as traumatic brain injury and stroke. Established methods to assess ICP are resource intensive and highly invasive. We hypothesized that ICP waveforms can be computed noninvasively from three extracranial physiological waveforms routinely acquired in the Intensive Care Unit (ICU): arterial blood pressure (ABP), photoplethysmography (PPG), and electrocardiography (ECG). We evaluated over 600 h of high-frequency (125 Hz) simultaneously acquired ICP, ABP, ECG, and PPG waveform data in 10 patients admitted to the ICU with critical brain disorders. The data were segmented in non-overlapping 10-s windows, and ABP, ECG, and PPG waveforms were used to train deep learning (DL) models to re-create concurrent ICP. The predictive performance of six different DL models was evaluated in single- and multi-patient iterations. The mean average error (MAE) ± SD of the best-performing models was 1.34 ± 0.59 mmHg in the single-patient and 5.10 ± 0.11 mmHg in the multi-patient analysis. Ablation analysis was conducted to compare contributions from single physiologic sources and demonstrated statistically indistinguishable performances across the top DL models for each waveform (MAE±SD 6.33 ± 0.73, 6.65 ± 0.96, and 7.30 ± 1.28 mmHg, respectively, for ECG, PPG, and ABP; p = 0.42). Results support the preliminary feasibility and accuracy of DL-enabled continuous noninvasive ICP waveform computation using extracranial physiological waveforms. With refinement and further validation, this method could represent a safer and more accessible alternative to invasive ICP, enabling assessment and treatment in low-resource settings.

BLOOD PRESSURE VALUES ACCORDING TO HOME AND CLINIC MEASUREMENTS AND INTRACRANIAL WAVEFORM ASSESSMENT IN HYPERTENSIVE PATIENTS

Objective: Evaluate the Association between Non-Invasive Intracranial Pressure (ICP) Values and Blood Pressure (BP) Values According to Home and Clinic Measurements Design and method: Cross-Sectional Study evaluating the association of variables, including Age, Gender, Office Systolic Blood Pressure (OSBP), Office Diastolic Blood Pressure (ODBP), Home Blood Pressure Measurements (HBPM), Time since Hypertension Diagnosis, P2P1, TTP, Intracranial Hypertension (IC) (P2P1 &gt;1.2), Office Hypertension (Office BP 140/90mmHg), and HBPM Hypertension (HBPM 130/80mmHg). Data collected from participants and medical records. Data analysis conducted using chi-square test, Mann-Whitney U test, and bivariate correlation analyses. Blood pressure values adjusted for hypertension diagnosis time; P2P1 and TTP values adjusted for age. Confidence interval of 95% and p&lt;0.05. Results: 240 patients were evaluated, with average age of 63.4 years (±11.8), 73.3% were female. The average time of diagnosis of arterial hypertension was 19.1 years (±11.9). Uncontrolled blood pressure - 54.2% (n=130) via HBPM and 42.1% (n=101) in the clinic. The proportion of IC was 67.9%, higher in women (71.6%). There was negative correlation between P2P1 and age (r=-0.261; p=0.037). Correlations between P2P1 and systolic blood pressure (HBPM) (-0.152, p=0.019) as well as with morning systolic blood pressure (HBPM) (-0.175, p=0.006). Correlation between P2P1 and morning systolic blood pressure (HBPM) (rho= -0.192, p=0.011), and evening systolic blood pressure (HBPM) (rho= 0.157, p=0.037) was found only among women. Correlation between TTP and systolic blood pressure (HBPM) (rho= -0.194, p=0.003), The correlation between TTP and clinic diastolic blood pressure (rho= 0.313, p=0.012) was found only among men. Correlation between TTP and systolic blood pressure (HBPM) (rho= -0.201, p=0.007), morning systolic blood pressure (HBPM) (rho= -0.237, p=0.002), clinic diastolic blood pressure (rho= 0.157, p=0.038), and nighttime systolic blood pressure (HBPM) (rho= -0.202, p=0.007) was found only among women. Conclusions: The blood pressure control rates were similar when evaluated by different methods. There was no association between blood pressure control rates and IC. P2P1 and TTP values correlated with home blood pressure values, but only with clinic diastolic blood pressure values. The associations of P2P1/TTP values and home blood pressure measurements exhibited different patterns between men and women.

NON-INVASIVE CENTRAL BLOOD PRESSURE AND INTRACRANIAL WAVEFORM ASSESSMENT IN HYPERTENSIVE PATIENTS

Objective: Hypertension (HT) remains as the leading cause of death around the globe and brain diseases, such as cognitive decline. The association between HT and cerebrovascular diseases is strong, mainly with stroke and cognitive impairment, but the mechanistic bases remain to be established. The objective of this study is to observe central blood pressure, arterial stiffness and intracranial pressure in long-term chronic hypertensive patients. Design and method: Patients above 18 years were assessed from November 2022 to August 2023 with non-invasive central blood pressure and intracranial pressure waveform measurements in a cross-sectional analysis. Peripheral and central blood pressure parameters were obtained using a validated oscillometric device (Mobil-O-Graph). Non-invasive intracranial pressure measurement was performed with the validated Brain4Care (B4C) sensor. Using the B4C non-invasive evaluation, the cut-off point identified to define ICHT by the P2/P1 ratio was &gt; 1.2, and the cut-off for time to peak (TTP) was &gt; 0.25 seconds. To compare P2/P1 and TTP values between the categories of quantitative variables, the chi-square test was used; the Mann Whitney or ANOVA tests were used for bivariate analyses; and for correlations, the Spearman test was used. It was adopted as significant at p &lt; 0,05. Results: Non-invasive central blood pressure, arterial stiffness, and intracranial pressure waveform assessment were performed in 145 patients with essential long-term hypertension over a period of ten months. The median age was 69.0 (61.8 – 75.7) years, 77.9% were female, and the median BMI was 29.0 (25.4 – 33.1) kg/m2. The average time since the hypertension diagnosis was 20.0 years. The median value of P2/P1 ratio for all cohort was 1.4 (1.2 – 1.5) and TTP 0.24 (0.21 – 0.29) seconds. A bivariate analysis was performed considering ICHT or not and the parameters of central BP and PWV assessments, with findings of higher central SBP, central DBP, and peripheral DBP among patients with ICHT by the parameter of P2/P1. Conclusions: Central systolic blood pressure levels are more linked to intracranial hypertension, while diastolic blood pressure values are similar, raising questions about the most suitable blood pressure assessment method for brain disorders.

Non-Invasive Methods for Intracranial Pressure Monitoring in Traumatic Brain Injury Using Transcranial Doppler: A Scoping Review.

Intracranial pressure (ICP) monitoring is necessary for managing patients with traumatic brain injury (TBI). Although gold-standard methods include intraventricular or intraparenchymal transducers, these systems cannot be used in patients with coagulopathies or in those who are at high risk of catheter-related infections, nor can they be used in resource-constrained settings. Therefore, a non-invasive modality that is more widely available, cost effective, and safe would have tremendous impact. Among such non-invasive choices, transcranial Doppler (TCD) provides indirect ICP estimates through waveform analysis of cerebral hemodynamic changes. The objective of this scoping review is to describe the existing evidence for the use of TCD-derived methods in estimating ICP in adult TBI patients as compared with gold-standard invasive methods. This review was conducted in accordance with the Joanna Briggs Institute methodology for scoping reviews, with a main search of PubMed and Embase. The search was limited to studies conducted in adult TBI patients published in any language between 2012 and 2022. Twenty-two studies were included for analysis, with most being prospective studies conducted in high-income countries. TCD-derived non-invasive ICP (nICP) methods are either mathematical or non-mathematical, with the former having slightly better correlation with invasive methods, especially when using time-trending ICP dynamics over one-time estimated values. Nevertheless, mathematical methods are associated with greater cost and complexity in their application. Formula-based methods showed promise in excluding elevated ICP, exhibiting a high negative predictive value. Therefore, TCD-derived methods could be useful in assessing ICP changes instead of absolute ICP values for high-risk patients, especially in low-resource settings.

Noninvasive Intracranial Pressure Morphology in Acute Liver Failure: Pre- and Post-orthotopic Liver Transplantation (P7-2.003)

Noninvasive Intracranial Pressure Morphology in Acute Liver Failure: Pre- and Post-orthotopic Liver Transplantation (P7-2.003)

Using EEG total energy as a noninvasively tracking of intracranial (and cerebral perfussion) pressure in an animal model: A pilot study

Purpose: This study aims to describe the total EEG energy during episodes of intracranial hypertension (IH) and evaluate its potential as a classification feature for IH. New methods: We computed the sample correlation coefficient between intracranial pressure (ICP) and the total EEG energy. Additionally, a generalized additive model was employed to assess the relationship between arterial blood pressure (ABP), total EEG energy, and the odds of IH. Results: The median sample cross-correlation between total EEG energy and ICP was 0.7, and for cerebral perfusion pressure (CPP) was 0.55. Moreover, the proposed model exhibited an accuracy of 0.70, sensitivity of 0.53, specificity of 0.79, precision of 0.54, F1-score of 0.54, and an AUC of 0.7. Comparison with existing methods: The only existing comparable methods, up to our knowledge, use 13 variables as predictor of IH, our model uses only 3, our model, as it is an extension of the generalized model is interpretable and it achieves the same performance. Conclusion: These findings hold promise for the advancement of multimodal monitoring systems in neurocritical care and the development of a non-invasive ICP monitoring tool, particularly in resource-constrained environments.

Evaluation of machine learning algorithms for noninvasive intracranial pressure estimation using near infrared spectroscopy as a covariate.

Intracranial pressure (ICP) is a vital parameter that is continuously monitored in patients with severe brain injury and imminent intracranial hypertension. To estimate intracranial pressure without intracranial probes based on transcutaneous near infrared spectroscopy (NIRS). We developed machine learning based approaches for noninvasive intracranial pressure (ICP) estimation using signals from transcutaneous near infrared spectroscopy (NIRS) as well as other cardiovascular and artificial ventilation parameters. In a patient cohort of 25 patients, with 22 used for model development and 3 for model testing, the best performing models were Fourier transform based Transformer ICP waveform estimation which produced a mean absolute error of 4.68 mm Hg (SD = 5.4) in estimation. We did not find a significant improvement in ICP estimation accuracy by including signals measured by transcutaneous NIRS. We expect that with higher quality and greater volume of data, noninvasive estimation of ICP will improve.

The Impact of Intracranial Pressure Telesensors: An Observational Propensity-Matched Control Analysis of Service Demand and Costs.

Implantable telemetric intracranial pressure (ICP) sensors (telesensors) enable routine, noninvasive ICP feedback, aiding clinical decision-making and attribution of pressure-related symptoms in patients with cerebrospinal fluid shunt systems. Here, we aim to explore the impact of these devices on service demand and costs in patients with adult hydrocephalus. We performed an observational propensity-matched control study, comparing patients who had an MScio/Sensor Reservoir (Christoph Miethke, GmbH & Co) against those with a nontelemetric reservoir inserted between March 2016 and March 2018. Patients were matched on demographics, diagnosis, shunt-type, and revision status. Service usage was recorded with frequencies of neurosurgical admissions, outpatient clinics, scans, and further surgical procedures in the 2 years before and after shunt insertion. In total, 136 patients, 73 telesensors, and 63 controls were included in this study (48 matched pairs). Telesensor use led to a significant decrease in neurosurgical inpatient admissions, radiographic encounters, and procedures including ICP monitoring. After multivariate adjustment, the mean cumulative saving after 2 years was £5236 ($6338) in telesensor patients (£5498 on matched pair analysis). On break-even analysis, cost-savings were likely to be achieved within 8 months of clinical use, postimplantation. Telesensor patients also experienced a significant reduction in imaging-associated radiation (4 mSv) over 2 years. The findings of this exploratory study reveal that telesensor implantation is associated with reduced service demand and provides net financial savings from an institutional perspective. Moreover, telesensor patients required fewer appointments, invasive procedures, and had less radiation exposure, indicating an improvement in both their experience and safety.

Management of shunt dysfunction using noninvasive intracranial pressure waveform monitoring: illustrative case.

Normal pressure hydrocephalus (NPH) treatment consists of using valves for drainage, as it is for hydrocephalus in general. Despite this, complications can occur, putting the patient at risk, and neurological monitoring is crucial. A 61-year-old male, who had been diagnosed with NPH 3 years prior and was being treated with a ventriculoperitoneal shunt with a programmable valve, presented to the emergency department because of a traumatic brain injury due to a fall from standing height. No previous complications were reported. He had an altered intracranial pressure (ICP) waveform in the emergency room when monitored with the brain4care device, with a P2/P1 ratio of 1.6. Imaging helped to confirm shunt dysfunction. Revision surgery normalized the ratio to 1.0, and the patient was discharged. Upon return after 14 days, an outpatient analysis revealed a ratio of 0.6, indicating improvement. In selected cases of NPH, noninvasive ICP waveform morphology analysis can be effective as a diagnostic aid, as well as in the pre- and postsurgical follow-up, given the possibility of comparing the values of ICP preoperatively and immediately postoperatively and the outpatient P2/P1 ratio, helping to manage these patients.

A pilot clinical study to estimate intracranial pressure utilising cerebral photoplethysmograms in traumatic brain injury patients

PurposeIn this research, a non-invasive intracranial pressure (nICP) optical sensor was developed and evaluated in a clinical pilot study. The technology relied on infrared light to probe brain tissue, using photodetectors to capture backscattered light modulated by vascular pulsations within the brain’s vascular tissue. The underlying hypothesis was that changes in extramural arterial pressure could affect the morphology of recorded optical signals (photoplethysmograms, or PPGs), and analysing these signals with a custom algorithm could enable the non-invasive calculation of intracranial pressure (nICP).MethodsThis pilot study was the first to evaluate the nICP probe alongside invasive ICP monitoring as a gold standard. nICP monitoring occurred in 40 patients undergoing invasive ICP monitoring, with data randomly split for machine learning. Quality PPG signals were extracted and analysed for time-based features. The study employed Bland–Altman analysis and ROC curve calculations to assess nICP accuracy compared to invasive ICP data.ResultsSuccessful acquisition of cerebral PPG signals from traumatic brain injury (TBI) patients allowed for the development of a bagging tree model to estimate nICP non-invasively. The nICP estimation exhibited 95% limits of agreement of 3.8 mmHg with minimal bias and a correlation of 0.8254 with invasive ICP monitoring. ROC curve analysis showed strong diagnostic capability with 80% sensitivity and 89% specificity.ConclusionThe clinical evaluation of this innovative optical nICP sensor revealed its ability to estimate ICP non-invasively with acceptable and clinically useful accuracy. This breakthrough opens the door to further technological refinement and larger-scale clinical studies in the future.Trial registrationNCT05632302, 11th November 2022, retrospectively registered.

ICP wave morphology as a screening test to exclude intracranial hypertension in brain-injured patients: a non-invasive perspective.

Intracranial hypertension (IH) is a life-threating condition especially for the brain injured patient. In such cases, an external ventricular drain (EVD) or an intraparenchymal bolt are the conventional gold standard for intracranial pressure (ICPi) monitoring. However, these techniques have several limitations. Therefore, identifying an ideal screening method for IH is important to avoid the unnecessary placement of ICPi and expedite its introduction in patients who require it. A potential screening tool is the ICP wave morphology (ICPW) which changes according to the intracranial volume-pressure curve. Specifically, the P2/P1 ratio of the ICPW has shown promise as a triage test to indicate normal ICP. In this study, we propose evaluating the noninvasive ICPW (nICPW-B4C sensor) as a screening method for ICPi monitoring in patients with moderate to high probability of IH. This is a retrospective analysis of a prospective, multicenter study that recruited adult patients requiring ICPi monitoring from both Federal University of São Paulo and University of São Paulo Medical School Hospitals. ICPi values and the nICPW parameters were obtained from both the invasive and the noninvasive methods simultaneously 5 min after the closure of the EVD drainage. ICP assessment was performed using a catheter inserted into the ventricle and connected to a pressure transducer and a drainage system. The B4C sensor was positioned on the patient's scalp without the need for trichotomy, surgical incision or trepanation, and the morphology of the ICP waves acquired through a strain sensor that can detect and monitor skull bone deformations caused by changes in ICP. All patients were monitored using this noninvasive system for at least 10min per session. The area under the curve (AUC) was used to describe discriminatory power of the P2/P1 ratio for IH, with emphasis in the Negative Predictive value (NPV), based on the Youden index, and the negative likelihood ratio [LR-]. Recruitment occurred from August 2017 to March 2020. A total of 69 patients fulfilled inclusion and exclusion criteria in the two centers and a total of 111 monitorizations were performed. The mean P2/P1 ratio value in the sample was 1.12. The mean P2/P1 value in the no IH population was 1.01 meanwhile in the IH population was 1.32 (p < 0.01). The best Youden index for the mean P2/P1 ratio was with a cut-off value of 1.13 showing a sensitivity of 93%, specificity of 60%, and a NPV of 97%, as well as an AUC of 0.83 to predict IH. With the 1.13 cut-off value for P2/P1 ratio, the LR- for IH was 0.11, corresponding to a strong performance in ruling out the condition (IH), with an approximate 45% reduction in condition probability after a negative test (ICPW). To conclude, the P2/P1 ratio of the noninvasive ICP waveform showed in this study a high Negative Predictive Value and Likelihood Ratio in different acute neurological conditions to rule out IH. As a result, this parameter may be beneficial in situations where invasive methods are not feasible or unavailable and to screen high-risk patients for potential invasive ICP monitoring.Trial registration: At clinicaltrials.gov under numbers NCT05121155 (Registered 16 November 2021-retrospectively registered) and NCT03144219 (Registered 30 September 2022-retrospectively registered).

Abstract WP121: Cerebral Hemodynamics in the First Week Postpartum in Healthy Women and Women With Preeclampsia

Objective: Standard adult normative data for transcranial Doppler (TCD)-based cerebral hemodynamic measures, such as mean and peak cerebral blood flow velocity (mCBFV, pCBFV), are used to identify pathological conditions such as postpartum angiopathy. However, little is known about cerebral hemodynamics during the early postpartum period, particularly in patients with preeclampsia (PEC). We characterized cerebral hemodynamics using TCD in the first week postpartum in patients with and without PEC. Methods: We prospectively recruited women with PEC and normotensive pregnant women delivering at an urban academic medical center. We measured CBFV in the bilateral middle cerebral arteries with TCD and calculated systolic mCBFV and pCBFV as well as pulsatility index (PI) and PI-derived noninvasive intracranial pressure (nICP). We compared systolic mCBFV and pCBFV between postpartum women with and without PEC, and historical data from non-pregnant young adult female controls. Results: Subjects were 51 women with PEC, 19 normotensive postpartum women, and 28 non-pregnant historical controls. In the PEC group, median mCBFV was 75.0 cm/s (IQR 65.2-99.1) and median pCBFV was 106.9 cm/s (IQR 92.7-130.8). In the normotensive postpartum group, median mCBFV was 77.1 cm/s (IQR 66.0-92.3) and median pCBFV was 107.9 cm/s (IQR 96.6-127.4). In the non-pregnant female control group, median mCBFV was 62.0 cm/s (IQR 48.5-67.9) and median pCBFV was 83.6 cm/s (IQR 69.3-95.2) (p&lt;0.0001 for mean and peak 3-way comparisons; see Figure). PI and nICP were within normal range in both postpartum groups and did not differ significantly between groups. Conclusion: Postpartum women with and without PEC had mCBFV and pCBFV significantly higher than non-pregnant controls, and many fell outside the standard normal range for healthy adults, but PI and nICP were within normal range. Standard ranges of CBFV for healthy adults may not apply in the postpartum period.

Non-invasive Intracranial Pressure Waveform Analysis in Chiari Malformation Type 1: A Pilot Trial

This pilot study aimed to investigate the role of Posterior Fossa Decompression (PFD) on the intracranial pressure (ICP) waveform in patients with Chiari Malformation type 1 (CM1). It also sought to explore the relationship between symptom improvement and ICP waveform behavior. This exploratory cohort study evaluated adult patients diagnosed with CM1. The patients underwent PFD using a standard technique at our institution, which involved a 3× 3 cm posterior craniectomy and excision of the posterior arch of C1. The ICP waveform was measured using an external strain-gauge device connected to a pin attached to the skull. Measurements were collected pre- and post-PFD, and the P2/P1 ratio was calculated pre- and postoperatively. The pilot study comprised 6 participants, 3 men and 3 women, with ages ranging from 39 to 68years. The primary symptoms were cerebellar ataxia and typical headaches. The study found that most patients who showed clinical improvement, as judged by the Gestalt method, had a postoperative decrease in the P2/P1 ratio. However, 1 patient did not show an improvement in the P2/P1 ratio despite a good clinical outcome. This study suggests that the P2/P1 ratio may decrease after PFD. However, we highlight the need for further research with a larger sample size to confirm these preliminary results.

Secreted proteins in plasma and placenta as novel non-invasive biomarkers for intrahepatic cholestasis of pregnancy: A case-control study

BackgroundIntrahepatic cholestasis of pregnancy (ICP) is likely to lead to unfavorable consequences. Total bile acid (TBA) is thought to be the sole ICP indicator available as of now, but it comes with some kind of restrictions in terms of sensitivity and specificity. We were endeavoring to find potential diagnostic biomarkers for ICP in this investigation. MethodsThis case-control study with a prospective nature included 40 females in the stage of pregnancy who were diagnosed with ICP. It also included another 20 females who were also pregnant but with sound physical condition(control). Placental and plasma samples were collected from all females that were in the stage of pregnancy, except for 20 ICP patients, in which only plasma was collected. We used four-dimensional data-independent acquisition followed by enzyme-linked immunosorbent assay and immunohistochemistry to identify and validate plasma and placental profiles in ICP patients and controls. Bioinformatics was adopted in an effort to demonstrate the relevant biological processes and signalling pathways. Correlation analysis was used to analyse the consistency of tissue and plasma protein expression and the correlation between sequencing and experimental results. ResultsThe expression levels of nectin-1 (NECTIN1), Kunitz-type protease inhibitor 1 (SPINT1), and inter-alpha-trypsin inhibitor heavy chain H3 (ITIH3) were remarkably higher in ICP patients than in controls. However, heparin cofactor 2 (SERPIND1) expression levels in female participants in the stage of pregnancy who were diagnosed with ICP were remarkably lower than those pregnant females with good physical fitness. In addition to the negative correlation between SERPIND1 and TBA, NECTIN1, SPINT1, and ITIH3 expression positively correlated with TBA. Area under the receiver operating characteristic curve (AUC) values of 0.7925, 0.8313, 0.8163, and 0.9025, respectively, were used to assess the diagnostic accuracies of NECTIN1, SPINT1, ITIH3, and SERPIND1. AUC (0.9438) was considerably greater when NECTIN1, SPINT1, and SERPIND1 were integrated, according to binary logistic regression. The AUC of the ROC curve for various combinations of SERPIND1 and other indicators was higher than itself, thus providing a more reliable ICP diagnosis. Furthermore, according to the bioinformatics analysis, the NECTIN1, SPINT1, ITIH3, and SERPIND1 were identified as secreted proteins because they were localized in the extracellular region. ConclusionsThis research discovered new non-invasive ICP indicators. On top of this, it sheds new light on the crucial diagnostic function of secreted proteins in ICP.

Predictive Value of Non-Invasive Intracranial Pressure Monitoring in Profoundly Impaired Traumatic Brain Injury Patients

Introduction: Trauma brain injury is an emergency condition that requires immediate precise first aid to reduce mortality rates and prevent secondary complications. Severe head injuries can lead to intracranial bleeding, thereby affecting hemodynamics. Monitoring the increase in intracranial pressure aims to mitigate the severity of head injury in patients, reducing deaths caused by brain edema. The significance of assessing the Glasgow Coma Scale (GCS) in relation to increased intracranial pressure is to determine conditions that could exacerbate physiological conditions due to head injury. The objective of this study is to determine changes in intracranial pressure among severe head injury patients. Methods: This research employs a descriptive study with a retrospective approach. Patient data were sourced from medical records of individuals treated at RS PKU Muhammadiyah Gombong, diagnosed with severe head injuries during the last year from January to December 2022. A total of 180 severe head injury patients' data were collected. Results: Research findings reveal that patients with head injuries experienced an increase in systolic blood pressure (33.3%), a decrease in pulse rate (30.5%), and a temperature within the normal range (78.9%). Conclusion: However, not all severe head injury patients exhibited elevated blood pressure, reduced pulse rate, or decreased oxygen saturation. All head injury patients experienced a decreased level of consciousness with a GCS score of less than 8.

Automation of ultrasonographic optic nerve sheath diameter measurement using convolutional neural networks.

Ultrasonographic optic nerve sheath (ONS) diameter is a noninvasive intracranial pressure (ICP) surrogate. ICP is monitored invasively in specialized intensive care units. Noninvasive ICP monitoring is important in less specialized settings. However, noninvasive ICP monitoring using ONS diameter (ONSD) is limited by the need for experts to obtain and perform measurements. We aim to automate ONSD measurements using a deep convolutional neural network (CNN) with a novel masking technique. We trained a CNN to reproduce masks that mark the ONS. The edges of the mask are defined by an expert. Eight models were trained with 1000 epochs per model. The Dice-similarity-coefficient-weighted averaged outputs of the eight models yielded the final predicted mask. Eight hundred and seventy-three images were obtained from 52 transorbital cine-ultrasonography sessions, performed on 46 patients with brain injuries. Eight hundred and fourteen images from 48 scanning sessions were used for training and validation and 59 images from four sessions for testing. Bland-Altman and Pearson linear correlation analyses were used to evaluate the agreement between CNN and expert measurements. Expert ONSD measurements and CNN-derived ONSD estimates had strong agreement (r = 0.7, p < .0001). The expert mean ONSD (standard deviation) is 5.27mm (0.43) compared to CNN mean estimate of 5.46mm (0.37). Mean difference (95% confidence interval, p value) is 0.19mm (0.10-0.27mm, p = .0011), and root mean square error is 0.27mm. A CNN can learn ONSD measurement using masking without image segmentation or landmark detection.