Measurement Of Optic Nerve Sheath Diameter Research Articles

Diagnostic Accuracy of Optic Nerve Sheath Diameter Measurement by Ultrasonography for Noninvasive Estimation of Intracranial Hypertension in Traumatic Brain Injury: A Systematic Review and Meta-Analysis.

Intracranial hypertension (IH) is associated with an unfavorable outcome in traumatic brain injury (TBI), and management strategies guided by intracranial pressure monitoring improve prognosis. Owing to the limitations of using invasive devices, measurement of optic nerve sheath diameter (ONSD) by ultrasonography is an alternative noninvasive method. However, its accuracy has not been validated in patients with TBI, so we aim to determine the diagnostic accuracy of measuring ONSD by ultrasonography in patients with TBI to estimate IH, compared with invasive monitoring. Systematic review of electronic databases and manual literature review from inception to June 2023. The analysis included diagnostic accuracy studies of ultrasonographic measurement of ONSD compared with invasive monitoring published in any language and with patients of any age. A qualitative synthesis was performed describing the clinical and methodological characteristics, strengths, limitations, and quality of evidence. In addition, a bivariate random effects model meta-analysis and a hierarchical summary receiver operating characteristics model were performed for the pediatric and adult population separately. Five hundred and forty eight patients of 688 in 16 eligible studies were adults and 120 were children. Pooled sensitivity and specificity of ONSD measurement by ultrasonography were 84% (95% CI, 76%-89%) and 83% (95% CI, 73%-90%), respectively. During the sensitivity analysis, these parameters exhibited consistent values. Pooled area under the curve was 0.91 for adults and 0.76 for children. Optimal threshold for estimating IH was 5.76 mm for adults and 5.78 mm for children. Measurement of ONSD by ultrasonography is a reliable, low-cost, and safe alternative for the estimation of IH with TBI in adults. More robust studies are needed to overcome the high risk of bias and heterogeneity for this analysis.

The association of early passive mobilization with intracranial pressure in the adult intensive care unit: A prospective, cohort study.

Early mobilization are key components of the ABCDEF Care Bundle and critical treatments to reduce acquired muscle weakness, delirium and prolonged intensive care unit (ICU) stay. This study aimed to determine whether routine early mobilization related to intracranial pressure in intensive care patients on mechanical ventilation, using optic nerve sheath diameter measurement (ONSD). This study was planned as a prospective, cohort study in the third-step adult ICU of a faculty hospital. The study included only patients who were intubated and followed up on a mechanical ventilator and were clinically stable. Passive range of motion (PROM) exercises were performed daily by the physiotherapists as part of routine care from the day of hospitalization. ONSD was assessed before, during and 10 min after PROM exercises. The study included 20 eligible patients out of the 142 who were evaluated upon admission to the ICU. The median age of the patients was 65 years, and nine (45%) of them were female. The analyses showed that there was no statistically significant change in ONSD during and at the end of the PROM (ONSD right eye p:.621, Partial η2: 0.025, ONSD left eye p:.935, Partial η2: 0.004). Similarly, there was no statistically significant change in haemodynamic parameters in during and at the end of the PROM (Heart beat p:.849, Partial η2: 0.009, Systolic Pressure p:.435, Partial η2: 0.043, Diastolic Pressure p:.128, Partial η2:0.103, Saturation p:.103, Partial η2: 0.113 and Respiratory rate p:.071, Partial η2:0.130). This study suggests that daily extremity physiotherapy exercises can be safely applied without causing increased intracranial pressure or haemodynamic instability in intensive care patients followed up on mechanical ventilation, including patients with vasopressor therapy. Early mobilization, including PROM, is considered safe in terms of intracranial pressure for intubated patients in the ICU.

Optic nerve sheath diameters predict mortality and severity in hepatic encephalopathy.

The aim of this study was to compare the predictive power of optic nerve sheath diameter (ONSD) measured by brain computed tomography (CT) in patients diagnosed with hepatic encephalopathy (HE) in the emergency department, with other factors for mortality and disease severity. A total of 217 patients aged 18 years and older with acute decompensation of cirrhosis diagnosed with HE in the emergency department were included in the study. To compare with patients diagnosed with HE, a total of 217 individuals were included in the study as the healthy control group. ONSD measurements were performed on both the HE patients and the healthy control group in the brain CT. The mortality rate of HE patients was 32.7%. Regarding the severity of the disease, 53% of the patients had late-stage HE. The presence of acute-on-chronic liver failure was detected in 51.4% of patients. The mortality rate among acute-on-chronic liver failure patients was 56.6%. According to the study data, ONSD, creatinine, lactate, and procalcitonin were independent predictors of mortality. Meanwhile, Child-Pugh score, direct bilirubin, ONSD, ammonia, and total bilirubin were independent predictors of disease severity. In the receiver operating characteristic curve analysis, the ONSD had the highest predictive power for mortality and disease severity among the determined predictive values. The data from the study suggests that assessing the ONSD through brain CT scans in individuals diagnosed with HE in the emergency department may provide valuable insights for clinicians, aiding in the prediction of both mortality rates and the severity of the disease.

Ultrasonographic Measurement of Optic Nerve Sheath Diameter in Patients with Traumatic Head Injury: A Prospective Observational Study

Introduction: The early detection of elevated intracranial pressure is crucial for guiding interventions and improving patient outcomes in head injury patients. The intracranial pressure assessment with invasive intracranial devices is the gold standard. These devices however has a risk of infection, bleeding and dislodgement. Optic nerve sheath diameter measurement using ultrasonography has emerged as a promising method for indirect intracranial pressure estimation. Aims: To observe the changes in optic nerve sheath diameter over period of time, and to correlate the optic nerve sheath diameter with computed tomography findings of raised intracranial pressure in traumatic head injury. Methods: A prospective cross-sectional time series study was conducted at Nepalgunj Medical College to assess the utility of ultrasonography measurement of optic nerve sheath diameter in patients with head injuries from August 2023 to January 2024. Forty-nine patients with head injuries were included in the study. The ultrasonographic optic nerve sheath diameter measurements were obtained at admission, 48 hours post-admission, and 1 month post-head injury. The clinical parameters including Glasgow Coma Scale and radiological findings from Computed Tomography head were recorded. Results: Forty nine patients were enrolled in the study. Among them, 44.90% (27) were male and 55.10% (22) were female. Age ranged from 5 to 66 years, with a mean of 33.94 ± 15.27 years. The mean optic nerve sheath diameter was 5.24±0.86 mm at admission which decreased to 4.31±0.62 mm at 48 hours and 4.02±0.47 mm at 1 month. Our study showed significant reduction in optic nerve sheath diameter after conservative or surgical treatment in patients with head injury (F = 27.017; P =0.002) Conclusion: The ultrasonographic measurement of optic nerve sheath diameter proved to be a valuable tool in monitoring intracranial pressure in patients with head injuries.

Evaluation of optic nerve sheath diameter in patients undergoing laparoscopic surgery in the Trendelenburg position: a prospective observational study.

The Trendelenburg position and pneumoperitoneum may cause cerebral edema and increased intracranial pressure. Non-invasive measurement of the diameter of the optic nerve sheath by ultrasonography can provide early recognition of intracranial pressure. Evaluate the optic nerve sheath diameter (ONSD) changes in patients who undergo laparoscopic surgery in the Trendelenburg position and make indirect conclusions about changes in intracranial pressure. Prospective, observational. Laparoscopic surgeries. Patients aged 18-75 years who underwent laparoscopic surgery in the Trendelenburg position under general anesthesia were included in our study. The ONSD was measured four times: Immediately after tracheal intubation, in the neutral position (baseline value) (T0), 10 minutes after pneumoperitoneum and Trendelenburg position (T1), 60 minutes after pneumoperitoneum and Trendelenburg position (T2), and 10 minutes after the pneumoperitoneum is terminated and placed in the neutral position (T3). Compare ONSD measured by ultrasonography at different times of surgery. 40. Arterial carbon dioxide pressure increased with laparoscopy and Trendelenburg position in parallel with ONSD measurements and decreased again after returning to the neutral position. It was still higher than the baseline value at the T3. There was also a significant difference[a] between the measurement made at the T2 and the measurement made at T1. This difference showed that the prolongation of the Trendelenburg time was associated with an increase in ONSD. At the end of the operation it was observed that the decreased statistically significantly (T3) 10 minutes after the pneumoperitoneum was terminated and the position was corrected. However, the ONSD was still higher at the end of the operation (T3) compared to the baseline value measured at the beginning of the operation (T0). The ONSD increased in relation to Trendelenburg position and pneumoperitoneum. With these results, we think the ultrasonographic measurement of ONSD, a non-invasive method, can be used for clinical follow-up when performing laparoscopic surgery in the Trendelenburg position in cases requiring intracranial pressure monitoring. There may be variations in the measurement of ONSD, even in the measurements of the same practitioner, as in all imaging with an ultrasonography device.

Optic Nerve Sheath Diameter on Computed Tomography Scans Reflects Elevated Intracranial Pressure in Patients with Craniosynostosis.

Assessment for elevated intracranial pressure (ICP) helps guide interventional decision-making to treat craniosynostosis. However, non-invasive techniques for measuring ICP are limited. This study assesses whether optic nerve sheath diameter (ONSD) on low-dose computed tomography (CT) scans is associated with ICP in patients with craniosynostosis. Pediatric patients treated between 2014 and 2023 with craniosynostosis, intraoperative ICP measurements by direct subdural catheterization, and spectral domain-optical coherent tomography (SD-OCT) data were included. ONSD was retrospectively assessed on pre-operative CT scans by a masked neuroradiologist and compared to measures and proxies of ICP. Among 132 patients included, median age was 6.9 years (IQR 4.7-9.5) and 41 (31.1%) had a syndromic diagnosis. Maximum ONSD (ONSDmax) was increased in patients with ICP≥15mmHg (6.1mm vs. 5.5mm, p<0.01) and ICP≥20mmHg (6.3mm vs. 5.6mm, p<0.01). Maximum (r=0.32, p<0.001), minimum (r=0.26, p=0.003), and average (r=0.29, p<0.001) ONSD correlated with direct ICP measurements. ONSD and SD-OCT measurements were also correlated (RNFLmax: r=0.21, p=0.04; RTmax: r=0.24, p=0.02). An ONSDmax threshold of 5.75mm demonstrated 65% sensitivity and 64% specificity for detecting ICP≥15mmHg on optimized receiver operating characteristic curve analysis. Multivariable logistic regression generated an algorithm incorporating ONSDmax and age to detect ICP≥20mmHg with 64% sensitivity and 80% specificity. Optic nerve sheath diameter measured in low-dose CT scans detects elevated intracranial pressure with moderate accuracy, and precision increases when patient age is taken into consideration. Given the ease of accessing CT scan data, this may be a helpful ICP proxy for clinical decision-making.

Non-invasive estimation of cerebrospinal fluid pressure in idiopathic intracranial hypertension: magnetic resonance imaging analysis of optic nerve and eyeball.

Invasive methods such as lumbar puncture and intraventricular catheters are commonly used to measure intracranial pressure (ICP). This study aims to develop quantitative and non-invasive techniques to measure ICP in patients with Idiopathic Intracranial Hypertension (IIH) using magnetic resonance imaging (MRI) findings. MRI data obtained from 50 patients with IIH and 30 age- and sex- matched controls were analyzed and optic nerve sheath diameter (ONSD), eyeball transverse diameter (ETD) and optic nerve diameter (OND) were measured. ONSD, ONSD/ETD and OND/ONSD indexes were calculated according to different ONSD measurement distances. Correlations of MRI findings with ICP were calculated. Sensitivity and specificity of all methods were analyzed. ONSD and ONSD/ETD index at 3mm and 10mm behind the eyeball were significantly higher (p < 0.001) and OND/ONSD index at 3mm behind the eyeball was significantly lower (p < 0.001) in the IIH group. The ONSD/ETD index at 3mm had the highest area under the curve (AUC) value (0.898) with a cut-off of 0.27mm (82% sensitivity and 91.67% specificity) for predicting high cerebrospinal fluid (CSF) pressure, followed by ONSD measurements at 3mm (AUC = 0.886) with a cut-off of 6.17mm (83% sensitivity and 86.67% specificity). The OND/ONSD index at 3mm posterior to the eyeball decreased significantly as ICP increased, and the strength of the relationship was moderate (p < 0.001; r = -0.358). ONSD and ONSD/ETD index measured on MRI sequences are potentially useful in detecting elevated ICP. The OND/ONSD index correlates with CSF pressure and these techniques may be helpful in diagnosing IIH.

Diagnostic Accuracy of Optic Nerve Sheath Diameter Using Ultrasonography for Raised Intracranial Pressure in Pediatric Patients - A Systematic Review and Meta-Analysis

PurposeDetecting increased intracranial pressure early in pediatric patients is essential, as early initiation of therapy prevents morbidity and mortality. The objective of this study was to determine the diagnostic accuracy of the ONSD measured via ultrasound for the prediction of increased intracranial pressure. MethodsFour databases, namely, PubMed, EMBASE, Scopus & CINAHL, were searched for this systematic review and meta-analysis. The study's predefined inclusion criteria considered diagnostic accuracy, cross-sectional, prospective observational, and retrospective studies with a focus on children with elevated intracranial pressure from causes such as traumatic brain injury and cerebral edema, the diagnostic accuracy of the optic nerve sheath diameter measured using ultrasound was assessed. The primary outcome measures included sensitivity, specificity. The study included invasive monitoring (EVD) and noninvasive measures as the gold standards for increased intracranial pressure. Two authors extracted and reviewed the data. Baseline data, outcome measures, and diagnostic accuracy data were extracted. ResultsTwenty-five studies with 1,591 patients and 3,143 ONSD measurements via ultrasound were analyzed. The pooled sensitivity and specificity of the ONSD measured via ultrasound for the prediction of increased intracranial pressure were 92% (86–96%) and 89% (77–96%), respectively. The pooled positive and negative likelihood ratios were 8.6 and 0.08, respectively. Conclusion and RelevanceOptic nerve ultrasonography stands out as a precise and valuable diagnostic tool applicable across diverse patient populations and clinical scenarios. We recommend routine ocular ultrasound for optic nerve sheath diameter measurement in pediatric patients to increase the accuracy of diagnosing increased intracranial pressure.

Prognostic Value of Optic Nerve Sheath Diameters after Acute Ischemic Stroke According to Slice Thickness on Computed Tomography.

The optic nerve sheath diameter (ONSD) can predict intracranial pressure and outcomes in neurological disease, but it remains unclear whether a small ONSD can be accurately measured on routine CT images with a slice thickness of approximately 4-5 mm. We measured the ONSD and ONSD/eyeball transverse diameter (ETD) ratio on routine-slice (4 mm) and thin-slice (0.6-0.75 mm) brain CT images from initial scans of acute ischemic stroke (AIS) patients. ONSD-related variables, National Institutes of Health Stroke Scale (NIHSS) scores, and age were compared between good (modified Rankin Scale [mRS] ≤ 2) and poor (mRS > 2) outcomes at discharge. Among 155 patients, 38 had poor outcomes. The thin-slice ONSD was different between outcome groups (p = 0.047), while the routine-slice ONSD showed no difference. The area under the curve (AUC) values for the ONSD and ONSD/ETD were 0.58 (95% CI, 0.49-0.66) and 0.58 (95% CI, 0.50-0.66) on the routine-slice CT, and 0.60 (95% CI, 0.52-0.68) and 0.62 (95% CI, 0.54-0.69) on the thin-slice CT. The thin-slice ONSD/ETD ratio correlated with initial NIHSS scores (r = 0.225, p = 0.005). After adjusting for NIHSS scores and age, ONSD-related variables were not associated with outcomes, and adding them to a model with NIHSS scores and age did not improve performance (all p-values > 0.05). Although ONSD measurements were not an independent outcome predictor, they correlated with stroke severity, and the thin-slice ONSD provided a slightly better prognostic performance than the routine-slice ONSD.

Optic nerve sheath diameter measurement using ultrasonography: associations with in-hospital mortality in COVID-19 intensive care unit admissions.

Optic nerve sheath diameter measurement using ultrasonography: associations with in-hospital mortality in COVID-19 intensive care unit admissions.

Changes in optic nerve sheath diameter and its correlation with degree of consciousness, pupil diameter, and light reflex in children with central nervous system infection after osmotherapy.

High intracranial pressure (ICP) is one of the most common complications of central nervous system (CNS) infection. Failure to control high intracranial pressure results in brain herniation and death. One of the treatments for high ICP involves the administration of osmotherapy in the form of 3% NaCl or 20% mannitol with observation during administration. Observation of ICP during administration of osmotherapy is possible through measurement of optic nerve sheath diameter (ONSD), which could be correlated with degree of consciousness, pupil diameter, and light reflex. Previous studies have not correlated ONSD with degree of consciousness, pupil diameter, and light reflex during the administration of osmotherapy. To provide insights of incorporating ONSD measurement as a form of non-invasive bedside method for ICP monitoring by correlating it with degree of consciousness, pupil diameter, and light reflex at several time points. This study is a prospective cohort study, performed at Dr. Hasan Sadikin General Central Hospital Bandung, Cibabat General Regional Hospital, and General Regional Hospital Bandung Kiwari on children aged 2-18 years with decreased consciousness and CNS infection, from June 2023. Inter-rater reliability was performed with a correlation coefficient of 0.90. Measurement of ONSD, degree of consciousness, pupil diameter, and light reflex simultaneously up to 48 h after initiation of osmotherapy to 30 patients. Correlational analyses were performed using Spearman's rank. Observation for 48 h after administration of osmotherapy showed changes in ONSD. A significant positive correlation was found between ONSD and degree of consciousness (r = 0.621 for the right eye and r = 0.602 for the left eye, p < 0.001). A significant positive correlation was found between ONSD and light reflex (r = 0.801 for the right eye and r = 0.812 for the left eye, p < 0.001). No significant correlation was found with changes of pupil diameter (r = -0.136 for the right eye and r = -0.141 for the left eye, p > 0.05). A significant correlation was found between ONSD and degree of consciousness and light reflex in children aged 2-18 years with CNS infection during administration of osmotherapy.

Optic nerve sheath diameter as a non-invasive tool to detect clinically relevant raised intracranial pressure in children: an observational analytical study

BackgroundRaised intracranial pressure (ICP) contributes to approximately 20% of the admissions in the paediatric intensive care unit (PICU) in our setting. Timely identification and treatment of raised ICP is important...

Optic Nerve Sheath Diameter Point-of-Care Ultrasonography Quality Criteria Checklist: An International Consensus Statement on Optic Nerve Sheath Diameter Imaging and Measurement.

To standardize optic nerve sheath diameter (ONSD) point-of-care ultrasonography (POCUS) and improve its research and clinical utility by developing the ONSD POCUS Quality Criteria Checklist (ONSD POCUS QCC). Three rounds of modified Delphi consensus process and three rounds of asynchronous discussions. Online surveys and anonymous asynchronous discussion. Expert panelists were identified according to their expertise in ONSD research, publication records, education, and clinical use. A total of 52 panelists participated in the Delphi process. None. Three Delphi rounds and three asynchronous discussion rounds generated consensus on quality criteria (QC). This started with 29 QC in addition to other QC proposed by expert panelists. The QC items were categorized into probe selection, safety, body position, imaging, measurement, and research considerations. At the conclusion of the study, 28 QC reached consensus to include in the final ONSD POCUS QCC. These QC were then reorganized, edited, and consolidated into 23 QC that were reviewed and approved by the panelists. ONSD POCUS QCC standardizes ONSD ultrasound imaging and measurement based on international consensus. This can establish ONSD ultrasound in clinical research and improve its utility in clinical practice.

Comparison of Optic Nerve Sheath Diameter (ONSD) Measurements Obtained from USG Before and After Placement of Ventriculoperitoneal Shunt in Obstructive Hydrocephalus as a Surrogate Marker for Adequacy of Shunt Function: A Prospective Observational Study.

Introduction Optic nerve sheath diameter (ONSD) measured using ultrasonography has been widely used as a surrogate marker of elevated intracranial pressure. However, literature is sparse on the correlation between ONSD and ventriculoperitoneal (VP) shunt function, especially in adults with hydrocephalus. Our study was designed to assess the correlation between ONSD measured using ultrasonography before and 12 hours after VP shunt placement and the success of VP shunt placement assessed using computed tomography (CT) of the brain. Materials and Methods Fifty-one patients between 16 and 60 years of age, with obstructive hydrocephalus scheduled for VP shunt surgery were included in this prospective, observational study. ONSD measurements were obtained from both eyes prior to induction of anesthesia, immediately after the surgery, and at 6, 12, and 24 hours after the surgery. An average of three readings was obtained from each eye. Cerebrospinal fluid (CSF) opening pressure was noted after entry into the lateral ventricle. Noncontrast CT (NCCT) brain was obtained 12 hours after the surgery and was interpreted by the same neurosurgeon for signs of successful VP shunt placement. Results There was a significant reduction in ONSD in the postoperative period compared to ONSD measured preoperatively. The average ONSD (mean ± standard deviation) measured prior to induction of anesthesia, immediately after the surgery, and at 6, 12, and 24 hours after the surgery was 5.71 ± 0.95, 5.20 ± 0.84, 5.06 ± 0.79, 4.90 ± 0.79, and 4.76 ± 0.75 mm, respectively. The mean CSF opening pressure was 19.6 ± 6.9 mm Hg. Postoperative NCCT brain revealed misplacement of the shunt tip in only one patient. Conclusion ONSD measured using ultrasonography may be used as a reliable indicator of VP shunt function in adults with obstructive hydrocephalus.

Optic nerve sheath diameter correlates with both success and failure of hydrocephalus treatment in pediatric patients with pineal region lesions.

Pineal region lesions in children are heterogenous pathologies often symptomatic due to occlusive hydrocephalus and thus elevated intracranial pressure (ICP). MRI-derived parameters to assess hydrocephalus are the optic nerve sheath diameter (ONSD) as a surrogate for ICP and the frontal occipital horn ratio (FOHR), representing ventricle volume. As elevated ICP may not always be associated with clinical signs, the adjunct of ONSD could help decision making in patients undergoing treatment. The goal of this study is to assess the available magnetic resonance imaging (MRI) of patients with pineal region lesions undergoing surgical treatment with respect to pre- and postoperative ONSD and FOHR as an indicator for hydrocephalus. Retrospective data analysis was performed in all patients operated for pineal region lesions at a tertiary care center between 2010 and 2023. Only patients with pre- and postoperative MRI were selected for inclusion. Clinical data and ONSD at multiple time points, as well as FOHR were analyzed. Imaging parameter changes were correlated with clinical signs of hydrocephalus before and after surgical treatment. Thirty-three patients with forty operative cases met the inclusion criteria. Age at diagnosis was 10.9 ± 4.6years (1-17years). Hydrocephalus was seen in 80% of operative cases preoperatively (n = 32/40). Presence of hydrocephalus was associated with significantly elevated preoperative ONSD (p = 0.006). There was a significant decrease in ONSD immediately (p < 0.001) and at 3months (p < 0.001) postoperatively. FOHR showed a slightly less pronounced decrease (immediately p = 0.006, 3months p = 0.003). In patients without hydrocephalus, no significant changes in ONSD were observed (p = 0.369). In 6/6 patients with clinical hydrocephalus treatment failure, ONSD increased, but in 3/6 ONSD was the only discernible MRI change with unchanged FOHR. ONSD measurements may have utility in evaluating intracranial hypertension due to hydrocephalus in patients with pineal region tumors. ONSD changes appear to have value in assessing hydrocephalus treatment failure.

P.106 Using optic nerve sheath diameter over ventricular size to assess elevated intracranial pressure in pediatric patients with pineal region tumors

Background: Pineal region tumors are a heterogenous group of pathologies often symptomatic due to occlusive hydrocephalus leading to elevated intracranial pressure (ICP). High ICP may not always be associated with clinical signs. A non-invasive technique for assessment of ICP is measuring the optic nerve sheath diameter (ONSD). The goal of this study was to determine the utility of preoperative and postoperative ONSD measurements for assessment of elevated ICP in children with pineal region tumors. Methods: Retrospective data analysis was performed in patients operated for pineal region tumors at our tertiary care center between 2003 and 2022. Preoperative and postoperative MRI scans were reviewed. Clinical data and ONSD at multiple time points were analyzed and correlated. Results: Thirty-four patients with forty operative cases met the inclusion criteria. Hydrocephalus was seen in 80% of patients preoperatively (n=32/40). Presence of hydrocephalus was associated with significantly elevated ONSD preoperatively (p=0.006) and postoperatively (p=0.017). There was significant decrease in ONSD immediately postoperatively (p&lt;0.001), at 3 months (p&lt;0.001) and 12 months (p&lt;0.001). In patients without hydrocephalus, no significant changes in ONSD were observed (p=0.369). Conclusions: ONSD is a useful adjunct for the identification of high ICP preoperatively and evaluation of treatment response postoperatively in patients presenting with pineal region tumors.

Cerebral hemodynamics and optic nerve sheath diameter acquired via neurosonology in critical patients with severe coronavirus disease: experience of a national referral hospital in Peru.

We aimed to describe the neurosonological findings related to cerebral hemodynamics acquired using transcranial Doppler and to determine the frequency of elevated ICP by optic nerve sheath diameter (ONSD) measurement in patients with severe coronavirus disease (COVID-19) hospitalized in the intensive care unit of a national referral hospital in Peru. We included a retrospective cohort of adult patients hospitalized with severe COVID-19 and acute respiratory failure within the first 7 days of mechanical ventilation under deep sedoanalgesia, with or without neuromuscular blockade who underwent ocular ultrasound and transcranial Doppler. We determine the frequency of elevated ICP by measuring the diameter of the optic nerve sheath, choosing as best cut-off value a diameter equal to or >5.8 mm. We also determine the frequency of sonographic patterns obtained by transcranial Doppler. Through insonation of the middle cerebral artery. Likewise, we evaluated the associations of clinical, mechanical ventilator, and arterial blood gas variables with ONSD ≥5.8 mm and pulsatility index (PI) ≥1.1. We also evaluated the associations of hemodynamic findings and ONSD with mortality the effect size was estimated using Poisson regression models with robust variance. This study included 142 patients. The mean age was 51.39 ± 13.3 years, and 78.9% of patients were male. Vasopressors were used in 45.1% of patients, and mean arterial pressure was 81.87 ± 10.64 mmHg. The mean partial pressure of carbon dioxide (PaCO2) was elevated (54.08 ± 16.01 mmHg). Elevated intracranial pressure was seen in 83.1% of patients, as estimated based on ONSD ≥5.8 mm. A mortality rate of 16.2% was reported. In the multivariate analysis, age was associated with elevated ONSD (risk ratio [RR] = 1.07). PaCO2 was a protective factor (RR = 0.64) in the cases of PI ≥ 1.1. In the mortality analysis, the mean velocity was a risk factor for mortality (RR = 1.15). A high rate of intracranial hypertension was reported, with ONSD measurement being the most reliable method for estimation. The increase in ICP measured by ONSD in patients with severe COVID-19 on mechanical ventilation is not associated to hypercapnia or elevated intrathoracic pressures derived from protective mechanical ventilation.

The Effect of Hydrocephalus on the Optic Nerve in the Presence of Intracranial Mass

The measurement of optic nerve sheath diameter is a noninvasive, practical, and economical method used to identify increased intracranial pressure. The purpose of this study is to detect the preoperative and postoperative changes in optic nerve sheath diameter in patients with intracranial mass, to correlate these changes with optic nerve diameter variations, and to evaluate the impact of hydrocephalus on these alterations. This study was conducted with patients who presented to our clinic with complaints of intracranial mass, were decided for surgery, and underwent surgical procedures. The optic nerve and optic nerve sheath diameter measurement values were different preoperatively and postoperatively, with a significant decrease in the optic nerve sheath diameter in all groups in postoperative measurements, while the optic nerve diameter significantly increased. Although there was no significant difference between the effects of hydrocephalus and intracranial mass-related increase in intracranial pressure on the optic nerve and optic nerve sheath, it was observed that hydrocephalus increased intracranial pressure when considering the Evans ratio. It has been determined that as ventricular dilatation increases, so does intracranial pressure, which leads to an increase in the diameter of the optic nerve sheath, resulting in papilledema and thinning of the optic nerve. These findings indicate the importance of early cerebrospinal fluid diversion and monitoring optic nerve sheath diameter in the management.

An Acute Bout of Subconcussive Head Impacts Does Not Change Intracranial Pressure

Purpose: Subconcussive head impacts (SHI) are known to cause a variety of negative sequelae including increased plasma concentrations of neuronal structural and glial proteins, attenuated neurovascular coupling, and impaired vestibular function. Traumatic brain injuries are associated with an increase in intracranial pressure (ICP). However, it is unknown whether an acute bout of SHI increases ICP. We tested the hypothesis that estimates of ICP via ultrasound assessments of optic nerve sheath diameter (ONSD) would be greater following a single session of repetitive SHI versus a control condition. Methods: 14 healthy participants (age: 19±2 y; BMI: 21±4 kg/m2, 3 women) with at least 3 y of soccer heading experience completed two experimental conditions in a randomized crossover design. 20 soccer headings were used to induce repetitive SHI and 20 soccer kicks were used as the control condition. A soccer ball was projected from a soccer JUGS machine (40 km/h, 12.2 m away) every 30 s for both conditions. ONSD assessed via ultrasound is associated with direct measures of ICP. Subjects were in the supine position during ONSD (transverse plane, each eye; B-mode linear array ultrasound), heart rate (HR; 3-lead ECG), and mean arterial blood pressure (MAP; photoplethysmography) measurements conducted at baseline prior to heading/kicking and at 2 h, 24 h, and 72 h post. ONSDs were measured 3 mm under the bulb in triplicate for each eye and the mean values were used for analyses. Inter-eye ONSD values were also averaged for analyses. Clinical intervention to alleviate elevated ICP is indicated when ONSD is &gt; 5.0 mm. Data were analyzed using a mixed-effects model with repeated measures with time and condition as within subject factors. Data are presented as mean ± SD if statistically significant. Results: No subjects had an ONSD &gt; 5.0 mm in either eye following heading or kicking. Left ONSD was greater than baseline at 2 h post heading (2.89 ± 0.25 mm vs. 2.99 ± 0.27 mm; p = 0.0157) and greater than baseline at 2 h (2.92 ± 0.37 mm vs. 2.98 ± 0.31 mm; p = 0.0352) and 72 h (3.08 ± 0.26 mm; p = 0.0067) post kicking. Left ONSD at 72 h post kicking was greater than heading (3.08 ± 0.26 mm vs. 2.93 ± 0.25 mm; p = 0.0022). There were no interaction effects for right ONSD (p = 0.4686), average ONSD (p = 0.1178), HR (p = 0.1039) or MAP (p = 0.3889). Conclusion: Neither the heading nor kicking intervention elicited a clinically relevant ONSD that would require medical attention. Contrary to our hypothesis, an acute bout of 20 soccer headers did not evoke greater ONSD in healthy subjects versus kicking. Therefore, our data indicate that a single session of SHI does not increase ICP. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Effect of Target Temperature Management on Optic Nerve Sheath Diameter in Post-Cardiac Arrest Patients.

Target Temperature Management (TTM) is a procedure used in post-cardiac arrest (CA) patients to reduce mortality and morbidity. The goal of this study was to investigate the link between intracranial pressure (ICP) and optic nerve sheath diameter (ONSD) in this patient group, which has a high mortality rate, despite TTM, and to see if ONSD may be used to predict mortality. The research was designed to be a retrospective observational study. The study comprised patients who were followed up on in a tertiary intensive care unit, had post-CA TTM, and had brain computed tomography (BCT) before and 0-6 hours after TTM. ONSD measurements were acquired from patients' BCT images recorded before and after TTM. The difference in pre-TTM ONSD and post-TTM ONSD measurements in all post-CA patients, as well as the difference in pre-TTM ONSD and post-TTM ONSD measurements in surviving and deceased patients, was compared. The study involved 33 participants. The patients' average age was 60.58-12.39 years, and 75.8% were male. Around 51.5% of the patients died. When the pre-TTM and post-TTM ONSDs of all patients were compared, there was no statistically significant difference (p = 0.856). When the percentage change (Δ) values between the post-TTM ONSD and pre-TTM ONSD and post-TTM ONSD measures of the surviving patients and the deceased patients were compared, a difference was observed (p < 0.01). Increased ICP in post-CA patients is a significant clinical issue associated with mortality and poor neurological prognosis. ONSD measurement may be useful in monitoring ICP, which may rise, despite TTM, and higher ONSD measurements may be used as an indicator for mortality in post-CA patients, who have received TTM.