Non-invasive Measurement Of Intracranial Pressure Research Articles

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 > 1.2, and the cut-off for time to peak (TTP) was > 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 < 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.

1314 Prediction of Raised Intracranial Pressure in Traumatic Brain Injury Patient by Non-Invasive Methods in Lower-Middle Income Countries: Systematic Review and Meta-Analysis

Abstract Background The prediction of raised Intracranial Pressure (ICP) with accuracy in Traumatic Brain Injury (TBI) patients is a clinical important decision and therapeutic tool. This study aimed to evaluate the existing methods used for non-invasive ICP monitoring in TBI patients in LMICs. Method Systematic searches of PubMed, Google Scholar, and ScienceDirect were performed from database inception to November 2021. Studies reporting the prediction of raised ICP in TBI patients by non-invasive means in LMICs were included. Pooled estimates of sensitivity, specificity, positive likelihood ratios, and negative likelihood ratios with 95%CI were calculated for each index test in JAMOVI 2.2.5. We carried out a “Medical Decision”, “Plots”, “Fagan Normogram” and the ROC curve to find the perfect discrimination point of all the five tests used for the non-invasive measurement of ICP in the TBI patients in LMICs. Results A total of 1032 studies were identified, of which, 15 included 3316 patients with male predominance (n = 2458, 74.13%). Patients' ages range from 15-96 years with 40-80 (n = 1205, 36.34%), being the most represented population. The ICP measured by Transcranial Doppler (TCD) had a sensitivity of 92.3%, and a specificity of 70%. The positive predictive value was 66.67%, with a negative predictive value of 93.33%. Furthermore, the positive Likelihood Ratio (+LR) was 3.69; 2<+LR<5, and the negative Likelihood Ratio (-LR) was 0.103; 0.1<-LR<0.2. Conclusions The TCD had shown high performance in its sensitivity and specificity, placing it on top of the other four different tests used in LMICs for the management of patients with TBI.

Anesthesia for preoperative non-invasive intracranial pressure measurement in a child with Apert syndrome: a case report

Introduction: The presence of craniofacial alterations such as craniosynostosis and midface hypoplasia are some features of Apert syndrome. Those characteristics may lead to intracranial hypertension. For clinical evaluation, a non-invasive intracranial pressure measurement can be performed both as a preoperative examination and to evaluate surgical treatment. Several methods have been used to measure intracranial pressure non-invasively, such as optic nerve sheath ultrasound, optical coherence tomography, and intracranial pressure waveform (ICPw) monitoring with the sensor Brain4Care®. Some methods like ICPw, require that the patient remains standstill. Because the patient wasn’t cooperative, it was decided to register the ICPw under hypnosis. A specific anesthetic planning was done to minimize the impact on the ICPw. Case presentation: We present a 6 years old child with Apert Syndrome with ICPw registered by Brain4Care® device before and after monobloc craniofacial advancement with internal distraction. The chosen anesthetic was Sevoflurane at a dose ≤ 0.9% of inspired gases and air/oxygen proportion of 50/50%, with a laryngeal mask, under spontaneous ventilation, with normal end-tidal CO2 range. The preoperative ICPw suggested low cranial compliance, with a mean P2/P1 index above 1,2. The postoperative showed a mean P2/P1 index under 1.2, demonstrating improved cranial compliance. The same anesthetic planning was done on both occasions. Conclusion: Likely, an appropriate way to obtain a reliable non-invasive ICPw measurement under hypnosis includes positioning the patient at neutral decubitus, choosing hypnotics with minimal impact on ICP, and maintaining spontaneous ventilation during the exam.

Contrast-enhanced subharmonic aided pressure estimation for assessment of intracranial pressure in vivo.

Intracranial pressure (ICP) monitoring in children currently requires invasive techniques. Subharmonic aided pressure estimation (SHAPE) uses contrast-enhanced ultrasound (CEUS) to measure intravascular and interstitial pressure, but utility in ICP measurements has yet to be explored. The objective of this study was to investigate SHAPE as a novel tool for noninvasive ICP measurements in fetal lambs. Eighteen fetal lambs at 107-139days gestational age (term = 145days) underwent subdural ICP catheter placement. The brain was imaged in the coronal plane in CEUS mode optimized for SHAPE, while infusing an US contrast agent into the fetal circulation. After SHAPE calibration, saline was infused via the subdural catheter to increase ICP. Five-second SHAPE cine clips were obtained at various ICPs. Subharmonic intensity values of the whole brain and thalami were correlated with ICP values using mixed effects linear regression analyses and the strength of the relationship was evaluated by Spearman's rank-order correlation. Forty-nine experiments produced 723 datapoints, including SHAPE intensity values and mean ICP measurements. There was a statistically significant inverse relationship between SHAPE intensity values and ICP measurements in the whole brain and thalami (median rho value - 0.58 and - 0.56, respectively). SHAPE intensity values of the brain demonstrate an inverse and statistically significant correlation with in vivo ICP measurements in an animal model.

Non-Invasive Intracranial Pressure Monitoring.

(1) Background: Intracranial pressure (ICP) monitoring plays a key role in the treatment of patients in intensive care units, as well as during long-term surgeries and interventions. The gold standard is invasive measurement and monitoring via ventricular drainage or a parenchymal probe. In recent decades, numerous methods for non-invasive measurement have been evaluated but none have become established in routine clinical practice. The aim of this study was to reflect on the current state of research and shed light on relevant techniques for future clinical application. (2) Methods: We performed a PubMed search for "non-invasive AND ICP AND (measurement OR monitoring)" and identified 306 results. On the basis of these search results, we conducted an in-depth source analysis to identify additional methods. Studies were analyzed for design, patient type (e.g., infants, adults, and shunt patients), statistical evaluation (correlation, accuracy, and reliability), number of included measurements, and statistical assessment of accuracy and reliability. (3) Results: MRI-ICP and two-depth Doppler showed the most potential (and were the most complex methods). Tympanic membrane temperature, diffuse correlation spectroscopy, natural resonance frequency, and retinal vein approaches were also promising. (4) Conclusions: To date, no convincing evidence supports the use of a particular method for non-invasive intracranial pressure measurement. However, many new approaches are under development.

Prediction of Increased Intracranial Pressure in Traumatic Brain Injury Using Quantitative Electroencephalogram in a Porcine Experimental Model.

Continuous and non-invasive measurement of intracranial pressure (ICP) in traumatic brain injury (TBI) is important to recognize increased ICP (IICP), which can reduce treatment delays. The purpose of this study was to develop an electroencephalogram (EEG)-based prediction model for IICP in a porcine TBI model. Thirty swine were anaesthetized and underwent IICP by inflating a Foley catheter in the intracranial space. Single-channel EEG data were collected every 6 min in 10 mmHg increments in the ICP from baseline to 50 mmHg. We developed EEG-based models to predict the IICP (equal or over 25 mmHg) using four algorithms: logistic regression (LR), naive Bayes (NB), support vector machine (SVM), and random forest (RF). We assessed the performance of each model based on the accuracy, sensitivity, specificity, and AUC values. The accuracy of each prediction model for IICP was 0.773 for SVM, 0.749 for NB, 0.746 for RF, and 0.706 for LR. The AUC of each model was 0.860 for SVM, 0.824 for NB, 0.802 for RF, and 0.748 for LR. We developed a machine learning prediction model for IICP using single-channel EEG signals in a swine TBI experimental model. The SVM model showed good predictive power with the highest AUC value.

A Review of the Methods of Non-Invasive Assessment of Intracranial Pressure through Ocular Measurement.

The monitoring of intracranial pressure (ICP) is essential for the detection and treatment of most craniocerebral diseases. Invasive methods are the most accurate approach to measure ICP; however, these methods are prone to complications and have a limited range of applications. Therefore, non-invasive ICP measurement is preferable in a range of scenarios. The current non-invasive ICP measurement methods comprise fluid dynamics, and ophthalmic, otic, electrophysiological, and other methods. This article reviews eight methods of non-invasive estimation of ICP from ocular measurements, namely optic nerve sheath diameter, flash visual evoked potentials, two-depth transorbital Doppler ultrasonography, central retinal venous pressure, optical coherence tomography, pupillometry, intraocular pressure measurement, and retinal arteriole and venule diameter ratio. We evaluated and presented the indications and main advantages and disadvantages of these methods. Although these methods cannot completely replace invasive measurement, for some specific situations and patients, non-invasive measurement of ICP still has great potential.

Zero retinal vein pulsation amplitude extrapolated model in non-invasive intracranial pressure estimation

Intracranial pressure (ICP) includes the brain, optic nerve, and spinal cord pressures; it influences blood flow to those structures. Pathological elevation in ICP results in structural damage through various mechanisms, which adversely affects outcomes in traumatic brain injury and stroke. Currently, invasive procedures which tap directly into the cerebrospinal fluid are required to measure this pressure. Recent fluidic engineering modelling analogous to the ocular vascular flow suggests that retinal venous pulse amplitudes are predictably influenced by downstream pressures, suggesting that ICP could be estimated by analysing this pulse signal. We used this modelling theory and our photoplethysmographic (PPG) retinal venous pulse amplitude measurement system to measure amplitudes in 30 subjects undergoing invasive ICP measurements by lumbar puncture (LP) or external ventricular drain (EVD). We estimated ICP from these amplitudes using this modelling and found it to be accurate with a mean absolute error of 3.0 mmHg and a slope of 1.00 (r = 0.91). Ninety-four percent of differences between the PPG and invasive method were between − 5.5 and + 4.0 mmHg, which compares favourably to comparisons between LP and EVD. This type of modelling may be useful for understanding retinal vessel pulsatile fluid dynamics and may provide a method for non-invasive ICP measurement.

Noninvasive intracranial pressure monitoring in women with migraine

This cross-sectional study aimed to compare the waveform morphology through noninvasive intracranial pressure (ICP-NI) measurement between patients with migraine and controls, and to analyze the association with clinical variables. Twenty-nine women with migraine, age 32.4 (11.2) years and headache frequency of 12.6 (7.5) days per month and twenty-nine women without headache, age 32.1 (9.0) years, were evaluated. Pain intensity, migraine disability, allodynia, pain catastrophizing, central sensitization and depression were evaluated. The ICP-NI monitoring was performed by a valid method consisting of an extracranial deformation sensor positioned in the patients’ scalp, which allowed registration of intracranial pressure waveforms. Heart rate and blood pressure measurements were simultaneously recorded during 20 min in the supine position. The analyzed parameter was the P2/P1 ratio based on mean pulse per minute which P1 represents the percussion wave related to the arterial blood pression maximum and P2 the tidal wave, middle point between the P1 maximum and the dicrotic notch. There was no between-groups difference in the P2/P1 ratio (mean difference: 0.04, IC95%: -0.07 to 0.16, p = 0.352, F (1,1) = 0.881) adjusted by body mass index covariable. The Multiple Linear Regression showed non-statistical significance [F (5,44) = 1.104; p = 0.372; R2 = 0.11)] between the P2/P1 ratio and body mass index, presence of migraine, central sensitization, pain catastrophizing and depression. We found no correlation (p > 0.05) between P2/P1 ratio and migraine frequency, migraine onset, pain intensity, pain intensity at day of examination, disability, allodynia. Migraine patients did not present alterations in the waveform morphology through ICP-NI compared to women without headache and no association with clinical variables was found.

Non-Invasive Measurement of Intracranial Pressure Through Application of Venous Ophthalmodynamometry.

Non-invasive intracranial pressure (ICP) monitoring is possible using venous ophthalmodynamometry to observe a pulsation in retinal blood vessels when intraocular pressure (IOP) exceeds ICP. Here, we identify features in the eye - optic disc and retinal blood vessel locations - and identify pulsation in large retinal blood vessels. The relationship between force and the magnitude of pulsation is used to estimate ICP when force is applied to the eye to gradually increase IOP over time. This approach yields 77% accuracy in automatically observing vessel pulsation.Clinical Relevance - Non-invasive ICP monitoring is desirable to improve patient outcome by reducing potential trauma and complications associated with invasive assessment with intracranial sensors or lumbar puncture.

Wideband tympanometry patterns in relation to intracranial pressure

Wideband tympanometry performs a more thorough analysis of middle-ear mechanics than the conventional single-frequency method with a 226-Hz probe tone. The present work examines the sensitivity of wideband tympanometry to the stiffness of the stapes-annular ligament system in relation to intracranial pressure (ICP) and labyrinthine fluid pressure. Here, body tilt allowed ICP to be set at different values. Sixty-eight ears of volunteers were tested sequentially in upright, supine, head-down (-30°) and upright postures. Energy absorbance of the ear was measured in these postures with a commercially available wideband-tympanometry device between 0.25 and 3 kHz, at ear-canal pressures between -600 and 300 daPa. In each posture, it was possible to find a single (posture-dependent) pressure in the ear canal at which a tympanometric peak occurred at all frequencies below about 1.1 kHz. The average across ears of tympanometric-peak pressure (TPP), close to 0 in upright posture, got increasingly positive, +19 daPa in supine and +27 daPa in head-down positions. The three-dimensional plot of energy absorbance against frequency and pressure displayed an invariant shape, merely shifting with TPP along the pressure axis. Thus, a properly adjusted ear-canal pressure neutralized the effects of ICP on the ear's energy absorbance. Comparisons to published invasive assessments of ICP in the different tested body positions led to the proposed relationship ICP ≈ 15 TPP, likely describing the transformer effect between tympanic membrane and stapes-annular ligament system at quasi-static pressures. With wideband tympanometry, the middle ear may serve as a precision scales for noninvasive ICP measurements.

Optical Detection of Intracranial Pressure and Perfusion Changes in Neonates With Hydrocephalus

To demonstrate that a novel noninvasive index of intracranial pressure (ICP) derived from diffuse optics-based techniques is associated with intracranial hypertension. We compared noninvasive and invasive ICP measurements in infants with hydrocephalus. Infants born term and preterm were eligible for inclusion if clinically determined to require cerebrospinal fluid (CSF) diversion. Ventricular size was assessed preoperatively via ultrasound measurement of the fronto-occipital (FOR) and frontotemporal (FTHR) horn ratios. Invasive ICP was obtained at the time of surgical intervention with a manometer. Intracranial hypertension was defined as invasive ICP ≥15mmHg. Diffuse optical measurements of cerebral perfusion, oxygen extraction, and noninvasive ICP were performed preoperatively, intraoperatively, and postoperatively. Optical and ultrasound measures were compared with invasive ICP measurements, and their change in values after CSF diversion were obtained. We included 39 infants, 23 with intracranial hypertension. No group difference in ventricular size was found by FOR (P=.93) or FTHR (P=.76). Infants with intracranial hypertension had significantly higher noninvasive ICP (P=.02) and oxygen extraction fraction (OEF) (P=.01) compared with infants without intracranial hypertension. Increased cerebral blood flow (P=.005) and improved OEF (P<.001) after CSF diversion were observed only in infants with intracranial hypertension. Noninvasive diffuse optical measures (including a noninvasive ICP index) were associated withintracranial hypertension. The findings suggest that impaired perfusion from intracranial hypertension was independentof ventricular size. Hemodynamic evidence of the benefits of CSF diversion was seen in infants with intracranial hypertension. Noninvasive optical techniques hold promise for aiding the assessment of CSF diversion timing.

Prospective Clinical Study of Non-Invasive Intracranial Pressure Measurements in Open-Angle Glaucoma Patients and Healthy Subjects.

Background and Objective: Glaucoma is a progressive optic neuropathy in which the optic nerve is damaged. The optic nerve is exposed not only to intraocular pressure (IOP) in the eye, but also to intracranial pressure (ICP), as it is surrounded by cerebrospinal fluid in the subarachnoid space. Here, we analyse ICP differences between patients with glaucoma and healthy subjects (HSs). Materials and Methods: Ninety-five patients with normal-tension glaucoma (NTG), 60 patients with high-tension glaucoma (HTG), and 62 HSs were included in the prospective clinical study, and ICP was measured non-invasively by two-depth transcranial Doppler (TCD). Results: The mean ICP of NTG patients (9.42 ± 2.83 mmHg) was significantly lower than that of HSs (10.73 ± 2.16 mmHg) (p = 0.007). The mean ICP of HTG patients (8.11 ± 2.68 mmHg) was significantly lower than that of NTG patients (9.42 ± 2.83 mmHg) (p = 0.008) and significantly lower than that of HSs (10.73 ± 2.16 mmHg) (p < 0.001). Conclusions: An abnormal ICP value could be one of the many influential factors in the optic nerve degeneration of NTG patients and should be considered as such instead of just being regarded as a “low ICP”.

High-resolution MRI assessment of optic nerve sheath diameter in adults: optic nerve sheath variation and a new diagnostic tool for intracranial hypertension.

Assessment of optic nerve sheath diameter (ONSD) is a non-invasive measure of intracranial pressure (ICP). However, it is not clear whether healthy individuals exhibit ONSD variation or whether factors other than ICP affect the ONSD. To investigate whether ONSD was correlated with age, sex, height, weight, eyeball transverse diameter (ETD), or body mass index (BMI), and to develop a new diagnostic model to increase the diagnostic accuracy of intracranial hypertension (IH). A total of 145 relatively healthy adults and 40 patients with acute IH who underwent high-resolution magnetic resonance imaging (MRI) were enrolled in this study. Linear regression analyses were used to determine the relationship between ONSD and these variables. If correlations were identified, an index ONSDΔ removing variables effects was calculated. ROC analysis was used to assess the IH predictive value of ONSDΔ in terms of sensitivity and specificity. In relatively healthy adults, there was a correlation between ONSD and BMI (P = 0.002), which can be presented as an index ONSDΔ. The ONSDΔ model better predicted IH than the ONSD model (P = 0.035), with a sensitivity of 70.00%, a specificity of 71.72%, and an AUC of 0.755. A correlation between ONSD and body mass index (BMI) was found using high-resolution MRI. This result indicates that the effects of BMI should be considered along with the ONSD during ICP monitoring. Meanwhile, the index ONSDΔ was better than the ONSD in predicting IH and could be used to obtain a more precise estimation of ICP.

The Relationship Between Bariatric Surgery, Weight Loss, and Non-Invasive Intracranial Pressure Measurement via the Optic Nerve Sheath Diameter

The Relationship Between Bariatric Surgery, Weight Loss, and Non-Invasive Intracranial Pressure Measurement via the Optic Nerve Sheath Diameter

Non-Invasive Techniques for Multimodal Monitoring in Traumatic Brain Injury: Systematic Review and Meta-Analysis.

Monitoring brain oxygenation and intracranial pressure non-invasively and continuously is of paramount importance in traumatic brain injury (TBI). The primary motivation of this study was to identify and provide robust evidence of the most effective techniques for the non-invasive multimodal monitoring for traumatic brain injury. Two reviewers independently searched PubMed, Embase, Scopus, the Cochrane Library, and the Web of Science between January 15, 2010, and January 22, 2020. Cohort studies assessing correlation or accuracy of non-invasive techniques for intracranial pressure (ICP) and/or brain oxygenation monitoring in TBI patients were included. The Newcastle-Ottawa Scale was used to assess the methodological quality of the studies. PROSPERO registration ID is CRD42020164739. Eight out of the 12 studies selected focused on the non-invasive measurement of ICP. Near-Infrared spectroscopy was the main technology for brain oxygenation, whereas ultrasound-based techniques were also used for ICP monitoring. PbtO2 monitoring through near-infrared spectroscopy showed low correlation and limited accuracy in detecting hypoxic events. A meta-analysis on non-invasive ICP monitoring revealed a strong pooled correlation coefficient of 0.725 (95 % confidence interval [CI]: 0.450-0.874; I2 91.31%) between transcranial Doppler and the gold standard ICP monitoring. The current meta-analysis has shown that the two most prominent and widely used technologies for non-invasive monitoring in TBI are near-infrared spectroscopy and transcranial Doppler. Both techniques could be considered for the future development of a single non-invasive and continuous multimodal monitoring device for TBI.

Detection of intracranial hypertension in children using optical coherence tomography: a systematic review protocol.

IntroductionIntracranial hypertension (ICH) in children can have deleterious effects on the brain and vision. It is notoriously difficult to estimate intracranial pressure (ICP) in children and existing methods deliver suboptimal diagnostic accuracy to be used as screening tools. Optical coherence tomography (OCT) may represent a valuable, non-invasive surrogate measure of ICP, as has been demonstrated in a number of associated conditions affecting adults. More recently, OCT has been employed within the paediatric age group. However, the role of OCT in detecting ICH in children has not been rigorously assessed in a systematic review for all relevant conditions. Here, we propose a systematic review protocol to examine the role of OCT in the detection of ICH in children.Methods and analysisElectronic searches in the Cochrane Central Register of Controlled Trials, Medline, Embase, Web of Science and PubMed will identify studies featuring OCT in detecting ICH in children. Two independent screeners will identify studies for inclusion using a screening questionnaire. The systematic search and screening will take place between 2 April 2020 and 1 June 2020, while we aim to complete data analysis by 1 September 2020. Quality assessment will be performed using the National Institutes of Health Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. The primary outcome measure is the sensitivity and specificity of OCT in detecting ICH in children. Secondary outcomes measures include conditions associated with ICH per study, direct ICP monitoring, sensitivity and specificity of other measures for ICP and OCT parameters used.Ethics and disseminationEthical approval is not required for the proposed systematic review as no primary data will be collected. The findings will be disseminated through presentations at scientific meetings and peer-reviewed journal publication.PROSPERO registration numberCRD42019154254.

Translaminar Pressure Gradient in Glaucoma and Non-invasive Methods for Intracranial Pressure Evaluation: A Review

Studies have shown that intracranial pressure is correlated with some ocular diseases including glaucoma, where low intracranial pressure has been found to be correlated with disease progression and high intracranial pressure may play a protective role. Multiple hypothesis have been proposed for the role of intracranial pressure in ocular disease, including that it can act as a stabilizing force to protect the optic nerve from intraocular pressure by balancing forces across the lamina cribrosa. While currently there is no non-invasive measure of intracranial pressure that has consistently performed well across multiple large studies, there are several methods under development which have shown promising results. This paper reviews current understanding of the role of intracranial pressure in ocular diseases, non-invasive methods for measuring intracranial pressure, as well as related topics where current research will likely inform findings on the effect of intracranial pressure on the eye.

How to use cerebral ultrasound in the ICU.

Cerebral ultrasound is a developing point of care tool for intensivists and emergency physicians, with an important role in the diagnosis of acute intracranial pathology, such as the assessment of cerebrovascular diseases and in the noninvasive intracranial pressure measurement both in the acute clinical settings and in intensive care unit (ICU). The traditional application of transcranial doppler (TCD) by assessing blood flow velocities in the main cerebral arteries, allows the evaluation and follow up of cerebral vasospasm, cerebral perfusion pressure, cerebral autoregulation and intracranial hypertension. The use of TCD, traditionally limited to the neurosonology laboratories settings, has expanded over the last years following the introduction of B-mode ultrasound and color Doppler, the transcranial color-coded duplex ultrasonography (TCCS), opening a new window to the assessment of cerebral anatomy not only in the neurocritical patients, but also in general ICU and emergency room patients. Here we report a brief review with the intent to up-to-date and describe the main applications and use of TCD/TCCS in the setting of Neurointensive Care.

Letter: Validation of Noninvasive Absolute Intracranial Pressure Measurements in Traumatic Brain Injury and Intracranial Hemorrhage

Letter: Validation of Noninvasive Absolute Intracranial Pressure Measurements in Traumatic Brain Injury and Intracranial Hemorrhage