BACKGROUND: Neuromonitoring in medical intensive care units is challenging as most patients are unfit for invasive intracranial pressure (ICP) modalities or unstable to transport for imaging. Ultrasonography-based optic nerve sheath diameter (ONSD) is an attractive option as it is reliable, repeatable and easily performed at the bedside. It has been sufficiently validated in traumatic brain injury (TBI) to be incorporated into the guidelines. However, currently the data for non-TBI patients is inconsistent for a scientific recommendation to be made.
OBJECTIVE: To compile the existing evidence for understanding the scope of ONSD in measuring ICP in adult non-traumatic neuro-critical patients.
METHODS: PubMed, Google Scholar and research citation analysis databases were searched for studies in adult patients with non-traumatic causes of raised ICP. Studies from 2010 to 2024 in English languages were included.
RESULTS: We found 37 articles relevant to our search. The cutoff for ONSD in predicting ICP varied from 4.1 to 6.3 mm. Most of the articles used cerebrospinal fluid opening pressure followed by raised ICP on computed tomography/magnetic resonance imaging as the comparator parameter. ONSD was also found to be a reliable outcome measure in cases of acute ischaemic stroke, intracerebral bleeding and intracranial infection. However, ONSD is of doubtful utility in septic metabolic encephalopathy, dysnatremias and aneurysmal subarachnoid haemorrhage.
CONCLUSIONS: ONSD is a useful tool for the diagnosis of raised ICP in non-traumatic neuro-critically ill patients and may also have a role in the prognostication of a subset of patients.

This review presents an in-depth examination of implantable antennas for various biomedical purposes. The development of implantable antennas, including their designs, materials, and operating principles, are introduced at the beginning of the discussion. An overview of the many kinds of implantable antennas utilized in implantable medical devices (IMDs) are presented in this study. The article then discusses the important factors to consider when developing implantable antennas for biomedical purposes, including implant placement, frequency range, and power needs. This investigation additionally examines the challenges and limitations encountered with implantable antennas, including the limited space available within the human body, the requirement for biocompatible materials, the impact of surrounding tissue on antenna performance, tissue attenuation, and signal interference. This review also emphasizes the most recent advances in implanted antenna technology, such as wireless power transmission, multiband operation, and miniaturization. Furthermore, it offers illustrations of several biomedical uses for implantable antennas, including pacemaker, capsule endoscopy, intracranial pressure monitoring, retinal prostheses, and bone implants. This paper concludes with a discussion of the future of implantable antennas and their possible use in bioelectronic medicine and novel medical implants. Overall, this survey offers a thorough analysis of implantable antennas in biomedical applications, emphasizing their importance in the development of implantable medical technology.

OBJECTIVE: Hydrocephalus is a challenging neurosurgical condition due to nonspecific symptoms and complex brain-fluid pressure dynamics. Typically, the assessment of hydrocephalus in children requires radiographic or invasive pressure monitoring. There is usually a qualitative focus on the ventricular spaces even though stress and shear forces extend across the brain. Here, the authors present an MRI-based vector approach for voxelwise brain and ventricular deformation visualization and analysis.
METHODS: Twenty pediatric patients (mean age 7.7 years, range 6 months-18 years; 14 males) with acute, newly diagnosed hydrocephalus requiring surgical intervention for symptomatic relief were randomly identified after retrospective chart review. Selection criteria included acquisition of both pre- and posttherapy paired 3D T1-weighted volumetric MRI (3D T1-MRI) performed on 3T MRI systems. Both pre- and posttherapy 3D T1-MRI pairs were aligned using image registration, and subsequently, voxelwise nonlinear transformations were performed to derive two exemplary visualizations of compliance: 1) a whole-brain vector map projecting the resulting deformation field on baseline axial imaging; and 2) a 3D heat map projecting the volumetric changes along ventricular boundaries and the brain periphery.
RESULTS: The patients underwent the following interventions for treatment of hydrocephalus: endoscopic third ventriculostomy (n = 6); external ventricular drain placement and/or tumor resection (n = 10); or ventriculoperitoneal shunt placement (n = 4). The mean time between pre- and postoperative imaging was 36.5 days. Following intervention, the ventricular volumes decreased significantly (mean pre- and posttherapy volumes of 151.9 cm3 and 82.0 cm3, respectively; p < 0.001, paired t-test). The largest degree of deformation vector changes occurred along the lateral ventricular spaces, relative to the genu and splenium. There was a significant correlation between change in deformation vector magnitudes within the cortical layer and age (p = 0.011, Pearson), as well as between the ventricle size and age (p = 0.014, Pearson), suggesting higher compliance among infants and younger children.
CONCLUSIONS: This study highlights an approach for deformation analysis and vector mapping that may serve as a topographic visualizer for therapeutic interventions in patients with hydrocephalus. A future study that correlates the degree of cerebroventricular deformation or compliance with intracranial pressures could clarify the potential role of this technique in noninvasive pressure monitoring or in cases of noncompliant ventricles.

UNASSIGNED: Intracranial pressure (ICP) monitoring is a very commonly performed neurosurgical procedure but there is a wide variation in how it is reported, hindering analysis of it. The current study sought to generate consensus on the reporting of ICP monitoring recording data.
UNASSIGNED: \"What should be included in an ICP monitoring report?\"
UNASSIGNED: The exercise was completed via a modified eDelphi survey. An expert panel discussion was held from which themes were identified and used to produce a code to annotate the transcript of the discussion. Statements were generated for a further two rounds of electronic questionnaires distributed via the REDcap platform. A Likert scale was used to grade agreement with each statement in the survey. A statement was accepted if more than 70% agreement was achieved between respondents. Data was collated using Microsoft Excel and analysed using R.
UNASSIGNED: 149 relevant statements were identified from the transcript and categorised into recording parameters, waveform characteristics or reporting. A total of 22 statements were generated for the first round of the survey which was answered by 39 respondents. Following the electronic round of surveys consensus was achieved for all but one statement regarding the acceptability of automating ICP reporting. This was put forward to a second round after which 79% agreement was reached.
UNASSIGNED: The themes and statements from this eDelphi can be used as a framework to allow the standardisation of the reporting of intracranial pressure monitoring data.

UNASSIGNED: Intracranial pressure (ICP) monitoring is commonly used in investigating the aetiology of chronic paediatric neurological conditions. A series of high-amplitude spikes has been observed in overnight ICP recordings of some children, many of whom have hydrocephalus or craniosynostosis.
UNASSIGNED: This clinical evaluation aimed to define the spike pattern, describe the patient group in which it is most likely to occur, and conduct high-resolution waveform analysis.
UNASSIGNED: ICP waveforms from 40 patients aged 0-5 years (inclusive), recorded between 2017 and 2021 at the Royal Hospital for Children Glasgow, were retrospectively analysed. The pattern was defined through visual inspection of regions of interest by two reviewers. Patients were stratified using demographic and clinical data. R software was used to perform regression and high-resolution waveform analyses.
UNASSIGNED: The spike pattern was defined as the presence of 2 consecutive spikes with an amplitude of at least 8 mmHg, with a gap of at least 30 min between spikes. In the adjusted Poisson regression, age was significantly associated with the number of spikes (IRR 0.8, 95% CI 0.70 to 0.92, p-value 0.001).
UNASSIGNED: Younger age was significantly associated with an increased number of spikes in this cohort. Investigation of clinical consequences of the spikes is warranted.

BACKGROUND: Extracranial complications occur commonly in patients with traumatic brain injury (TBI) and can have implications for patient outcome. Patient-specific risk factors for developing these complications are not well studied, particularly in low and middle-income countries (LMIC). The study objective was to determine patient-specific risk factors for development of extracranial complications in TBI.
METHODS: We assessed the relationship between patient demographic and injury factors and incidence of extracranial complications using data collected September 2008-October 2011 from the BEST TRIP trial, a randomized controlled trial assessing TBI management protocolized on intracranial pressure (ICP) monitoring versus imaging and clinical exam, and a companion observational patient cohort.
RESULTS: Extracranial infections (55%), respiratory complications (19%), hyponatremia (27%), hypernatremia (27%), hospital acquired pressure ulcers (6%), coagulopathy (9%), cardiac arrest (10%), and shock (5%) occurred at a rate of ≥5% in our study population; overall combined rate of these complications was 82.3%. Tracheostomy in the intensive care unit (P < 0.001), tracheostomy timing (P = 0.025), mannitol and hypertonic saline doses (P < 0.001), brain-specific therapy days and brain-specific therapy intensity (P < 0.001), extracranial surgery (P < 0.001), and neuroworsening with pupil asymmetry (P = 0.038) were all significantly related to the development of one of these complications by univariable analysis. Multivariable analysis revealed ICP monitor use and brain-specific therapy intensity to be the most common factors associated with individual complications.
CONCLUSIONS: Extracranial complications are common following TBI. ICP monitoring and treatment are related to extra-cranial complications. This supports the need for reassessing the risk-benefit balance of our current management approaches in the interest of improving outcome.

BACKGROUND: Early mobilization benefits critically ill patients, but concerns persist, especially in neurologic intensive care unit patients with acute brain injuries. This study assesses early mobility\'s impact on cerebrovascular autoregulation (CA) and systemic hemodynamics.
METHODS: This single-center retrospective study focused on adult neurologic intensive care unit patients undergoing passive cycle ergometry. Data were collected from December 2020 to April 2022. Physical therapists conducted sessions using a standardized protocol, monitoring mean arterial blood pressure (MAP) and intracranial pressure (ICP). The Pressure Reactivity Index (PRx) was calculated as a measure of CA. Statistical analysis included mixed models and repeated measures ANOVA.
RESULTS: Eleven patients undergoing continuous physiologic monitoring and early mobility were included, primarily with subarachnoid hemorrhage or intracranial hemorrhage. Median time to protocol initiation was 4 days, with two patients discontinuing due to hemodynamic disturbances. Over a total of 11-hours of neuromonitoring data, passive cycling demonstrated a significant reduction in heart rate (HR), MAP, and ICP across different rotations per minute (RPM) settings compared to baseline. No significant alterations in PRx or cerebral perfusion pressure (CPP) were noted at various RPM levels. However, a significant difference in PRx emerged between patients who completed the protocol and those who did not, particularly at 10 RPM.
CONCLUSIONS: This study offers preliminary insights into the impact of early mobility on CA in acute brain injured patients. While passive cycling demonstrates promise in preserving cerebral hemodynamics, its tolerability may not be uniform across all brain-injured patients. These findings highlight the need to determine optimal early mobilization timing and intensity in this population, emphasizing the necessity for larger prospective studies to validate these findings and inform clinical practice.
UNASSIGNED: This manuscript complies with all instructions to the authors. All coauthors meet the authorship requirements and have reviewed and approved the contents of the manuscript. The manuscript has not been published totally or partly, accepted for publication, or under editorial review for publication elsewhere. We have no conflicts of interest to disclose. STROBE checklist was reviewed prior to the submission of this paper. The manuscript adheres to ethical guidelines and was approved by Cleveland Clinic\'s institutional research board for retrospective study. There is no funding to disclose for this study.

UNASSIGNED: Intracranial pressure (ICP) monitoring is essential in severe traumatic brain injury (sTBI) cases; yet, the frequency of high ICP occurrences remains debated. This study presents a 9-year analysis of ICP monitoring using intraventricular catheters among sTBI patients.
UNASSIGNED: A retrospective review of 1760 sTBI patients (Glasgow Coma Score <9) admitted between January 2011 and December 2019 was conducted. Of these, 280 patients meeting monitoring criteria were included based on Brain Trauma Foundation (BTF) Guidelines. ICP was monitored using intraventricular catheters through right frontal burr holes. Initial ICP readings were recorded intraoperatively, followed by continuous monitoring. Patients with ICP >20 mmHg for 10-15 min during 72 h were categorized with high ICP. Data collected included demographics, computed tomography (CT) findings, intra- and post-operative ICP, and complications.
UNASSIGNED: Of 273 patients, 228 were male and 45 females, aged 18-80 (71.30% aged 18-45). Traffic accidents were the primary cause (90.48%). Fifty-two-point seventy-five percent experienced high ICP, correlating significantly with subdural hematoma (P < 0.001), intraventricular hemorrhage (P < 0.013), and compressed basal cisterns (P = 0.046) on initial CT. Twenty patients (7.3%) developed meningitis. Lower mortality rates and improved outcomes were observed in the low ICP group across discharge 3-and 6-month follow-ups.
UNASSIGNED: Adherence to BTF guidelines yielded a 52.75% high ICP rate. Significant correlations were found between high ICP and specific CT abnormalities. This study underscores the benefits of ICP monitoring in selected sTBI cases, suggesting a need to review criteria for initiating monitoring protocols.

OBJECTIVE: To describe the potential effects of Intracranial pressure monitoring on the outcome of patients with spontaneous intracerebral hemorrhage (ICH).
METHODS: This study is a systematic review with meta-analysis. Patients with spontaneous ICH treated with intracranial pressure monitoring were included. The primary outcome was mortality at 6 months and in-hospital mortality. The secondary outcome was poor neurological function outcome at 6 months.
RESULTS: This analysis compares in-hospital and 6-month mortality rates between patients with intracranial pressure monitoring (ICPm) and those without (no ICPm). Although the ICPm group had a lower in-hospital mortality rate, it was not statistically significant (24.9% vs. 34.1%; OR 0.51, 95% CI 0.20 to 1.31, P = 0.16). Excluding patients with intraventricular hemorrhage revealed a significant reduction in in-hospital mortality for the ICPm group (23.5% vs. 43%; OR 0.39, 95% CI 0.29 to 0.53, P < 0.00001). For 6-month mortality, the ICPm group showed a significant reduction (32% vs. 39.6%; OR 0.76, 95% CI 0.61 to 0.94, P = 0.01), with the effect being more pronounced after excluding intraventricular hemorrhage patients (29.1% vs. 47.2%; OR 0.45, 95% CI 0.34 to 0.60, P < 0.0001). However, there were no statistically significant differences in 6-month functional outcomes between the groups. Increased ICP was associated with higher 3-month mortality (OR 1.12, 95% CI 1.07 to 1.18, P < 0.00001) and lower likelihood of good functional outcomes (OR 1.11, 95% CI 1.04 to 1.18, P < 0.00001).
CONCLUSIONS: Elevated ICP is associated with increased mortality and poor prognosis in ICH patients. Although continuous intracranial pressure monitoring may reduce short-term mortality rates in specific subgroups of ICH patients, it does not improve neurological functional outcomes. While potential patient populations may benefit from ICP monitoring, more research is needed to screen suitable populations for ICP monitoring.

BACKGROUND: Intracranial pressure (ICP) monitoring plays a key role in patients with traumatic brain injury (TBI), however, cerebral hypoxia can occur without intracranial hypertension. Aiming to improve neuroprotection in these patients, a possible alternative is the association of Brain Tissue Oxygen Pressure (PbtO2) monitoring, used to detect PbtO2 tension.
METHODS: We systematically searched PubMed, Embase and Cochrane Central for RCTs comparing combined PbtO2 + ICP monitoring with ICP monitoring alone in patients with severe or moderate TBI. The outcomes analyzed were mortality at 6 months, favorable outcome (GOS ≥ 4 or GOSE ≥ 5) at 6 months, pulmonary events, cardiovascular events and sepsis rate.
RESULTS: We included 4 RCTs in the analysis, totaling 505 patients. Combined PbtO2 + ICP monitoring was used in 241 (47.72%) patients. There was no significant difference between the groups in relation to favorable outcome at 6 months (RR 1.17; 95% CI 0.95-1.43; p = 0.134; I2 = 0%), mortality at 6 months (RR 0.82; 95% CI 0.57-1.18; p = 0.281; I2 = 34%), cardiovascular events (RR 1.75; 95% CI 0.86-3.52; p = 0.120; I2 = 0%) or sepsis (RR 0.75; 95% CI 0.25-2.22; p = 0.604; I2 = 0%). The risk of pulmonary events was significantly higher in the group with combined PbtO2 + ICP monitoring (RR 1.44; 95% CI 1.11-1.87; p = 0.006; I2 = 0%).
CONCLUSIONS: Our findings suggest that combined PbtO2 + ICP monitoring does not change outcomes such as mortality, functional recovery, cardiovascular events or sepsis. Furthermore, we found a higher risk of pulmonary events in patients undergoing combined monitoring.