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Abstract Background An increase in epidural pressure around the stenosis has been observed in patients with lumbar spinal stenosis (LSS) with positive signs of sedimentation or redundant nerve roots. Further analysis of the pressure conditions in the stenotic area would be of great interest. We hypothesized that it would be possible to determine the physiological parameters of the epidural pulse wave and its course in pathological stenosis as a basis for objective identification of LSS based on pressure using a new measuring method with continuous spatial and temporal resolution. Methods We performed a single‐case proof‐of‐principle in vivo animal trial and used a newly developed hybrid pressure‐measurement probe with a fiber‐tip Fabry–Pérot interferometer and several fiber Bragg gratings (FBG). Results With reproducible precision, we determined the mean epidural pressure to be 7.5 mmHg and the peak‐to‐peak value to be 4–5 mmHg. When analyzing the pressure measured by an FBG array, both the heart and respiratory rates can be precisely determined. This study was the first to measure the pulse wave velocity of the cerebrospinal fluid pressure wave as 0.97 m/s using the newly developed pressure probe. A simulated LSS was detected in real time and located exactly. Conclusions The developed fiber‐optic pressure sensor probe enables a new objective measurement of epidural pressure. We confirmed our hypothesis that physiological parameters of the epidural pulse wave can be determined and that it is possible to identify an LSS.

Abstract Background Childhood obesity has become a major global health problem. Obesity is associated with major health problems, such as diabetes, hypertension, dyslipidemia, cardiovascular disease. Obesity is also considered a risk factor for Pseudotumor cerebri (PTC). The present study aimed to investigate the relationship between body mass index (BMI), and cerebrospinal fluid (CSF) pressure in patients with pseudotumor cerebri. Methods A total of 48 children diagnosed with PTC, who were aged

Background: Childhood obesity has become a major global health problem. Obesity is associated with major health problems, such as diabetes, hypertension, dyslipidemia, cardiovascular disease. Obesity is also considered a risk factor for Pseudotumor cerebri (PTC). The present study aimed to investigate the relationship between body mass index (BMI), and cerebrospinal fluid (CSF) pressure in patients with pseudotumor cerebri. Methods: A total of 48 children diagnosed with PTC, who were aged < 18 years and followed up in the pediatric clinic were included in the retrospective study. National BMI percentile curves were used for reference. We investigated statistically the relationship between BMI, clinical and laboratory results, and CSF pressure in patients. Results: Of total patients 27 were female (56.25%) and 21 were male (43.75%). With regard to the BMI percentile, 20 (41.67%) were overweight or obese. CSF pressure was higher in overweight and obese patients compared to children with BMI in normal ranges (p < 0.05). A statistically significant positive correlation was also observed between BMI and CSF pressure values and between monocyte and CSF values (p < 0.05). Conclusions: The results of the present study indicate a direct relationship between CSF pressure and BMI in children with PTC. Appropriate diet, exercise, and medical treatment in overweight and obese children can make a significant contribution to the treatment of PTC. Additionally, a significant correlation was observed between CSF pressure and monocyte levels. [ABSTRACT FROM AUTHOR]

Objective: To explore the correlation between magnetic resonance（MR）findings[optic nerve sheath diameter（ONSD） and peripheral cerebrospinal fluid volume/intracranial volume ratio（PCSFV/ICV）]and cerebrospinal fluid pressure（CSFP）in patients with leptomeningeal metastases（LM）from non - small cell lung cancer（NSCLC). And to assess the diagnostic accuracy of combined ONSD and PCSFV/ICV in diagnosing elevated CSFP. Methods: A total of 63 patients with NSCLC-LM were enrolled. Both optic nerve and cranial MR scans were performed to measure bilateral ONSD, cranial PCSFV and ICV. Subsequently, CSFP was measured in all patients through lumbar puncture, and intrathecal chemotherapy was administered regularly. Pearson correlation analysis was used to analyze the correlation between CSFP and MR findings. The accuracy of combined ONSD and PCSFV/ICV in diagnosing elevated CSFP was evaluated through receiver operating characteristic（ROC）curve analysis. Results: In patients with NSCLC-LM, the average ONSD of bilateral eyes was positively correlated with CSFP（r=0.567, P ＜ 0.001). PCSFV/ICV was negatively correlated with CSFP （r=-0.365, P=0.003). ROC curve analysis showed that the performance of ONSD, PCSFV/ICV, and combined ONSD with PCSFV/ICV in diagnosing intracranial hypertension（CSFP＞15 mmHg）were 0.81（95%CI: 0.71-0.91). 0.76（95%CI: 0.64-0.89). and 0.91（95%CI: 0.84-0.99). respectively. The performance of ONSD, PCSFV/ICV, and combined ONSD with PCSFV/ICV in diagnosing intracranial hypertension（CSFP＞20 mmHg）were 0.70（95%CI: 0.58-0.82). 0.72（95%CI: 0.57-0.88). and 0.81（95%CI: 0.70-0.93). respectively. Conclusion: The utilization of MR for measuring ONSD and PCSFV/ICV provides a valuable means to assess variations in CSFP among patients diagnosed with NSCLC -LM. Additionally, the combination of these two measurements enhances the diagnostic accuracy for evaluating CSFP, demonstrating its potential clinical significance. [ABSTRACT FROM AUTHOR]

Objectives: To review the current literature related to the correlation between translaminar pressure difference (TLPD) and glaucoma. Materials and Methods: In this article, we conducted a literature review using MEDLINE via PubMed, Cochrane Eyes and Vision, and Google Scholar from 01/01/2010 to 31/12/2022. Search terms included “glaucoma”, “intraocular pressure”, “translaminar cribrosa pressure gradient/difference”, “intracranial pressure”, and “cerebrospinal fluid pressure”. Of 471 results, 8 articles were selected for the meta-analysis. Results: Our meta-analysis demonstrated significantly higher intraocular pressure, lower cerebrospinal fluid pressure (CSFp), and greater TLPD in high-tension and normal-tension glaucoma groups compared to healthy groups. Conclusion: The differences in CSFp and TLPD between glaucoma and healthy people detected in current studies suggests a potential relationship between TLPD and glaucoma.

Abstract Background The relationship between cerebrospinal fluid pressure (CSFP) and cognition has received little research attention. The purpose of this study was to explore the relationship between CSFP and cognition in patients with Alzheimer’s disease (AD) and patients with Lewy body dementia (LBD). Method We included 178 participants, including 137 patients with AD and 41 patients with LBD (including dementia with Lewy bodies (DLBs) and Parkinson’s disease dementia (PDD)). CSFP was measured by lumbar puncture, and a patient-reported history and laboratory test data were collected. Logistic and linear regression analyses were used to evaluate the associations between CSFP and cognition, the cerebrospinal fluid (CSF) / serum albumin ratio (Qalb), and CSF biomarkers of AD. Results The mean age of the included patients was 63.58 ± 8.77 years old, and the mean CSFP was 121 ± 33.72 mmH2O. A total of 76.9% of the patients had a CSFP distribution of [90–170) mmH2O, 46 patients (25.8%) had severe dementia, 83 patients (46.6%) had moderate dementia, 28 patients (15.7%) had mild dementia, and 21 patients (11.8%) had mild cognitive impairment (MCI) (including 16 patients with MCI due to AD and 5 patients with MCI due to LBD). In all patients (p value

Background: The relationship between cerebrospinal fluid pressure (CSFP) and cognition has received little research attention. The purpose of this study was to explore the relationship between CSFP and cognition in patients with Alzheimer's disease (AD) and patients with Lewy body dementia (LBD). Method: We included 178 participants, including 137 patients with AD and 41 patients with LBD (including dementia with Lewy bodies (DLBs) and Parkinson's disease dementia (PDD)). CSFP was measured by lumbar puncture, and a patient-reported history and laboratory test data were collected. Logistic and linear regression analyses were used to evaluate the associations between CSFP and cognition, the cerebrospinal fluid (CSF) / serum albumin ratio (Qalb), and CSF biomarkers of AD. Results: The mean age of the included patients was 63.58 ± 8.77 years old, and the mean CSFP was 121 ± 33.72 mmH2O. A total of 76.9% of the patients had a CSFP distribution of [90–170) mmH2O, 46 patients (25.8%) had severe dementia, 83 patients (46.6%) had moderate dementia, 28 patients (15.7%) had mild dementia, and 21 patients (11.8%) had mild cognitive impairment (MCI) (including 16 patients with MCI due to AD and 5 patients with MCI due to LBD). In all patients (p value < 0.001) and in patients with AD (p value = 0.01), the mean cerebrospinal fluid pressure (CSFP) was higher in patients with MCI than in patients with dementia. In multivariate analysis, in all patients (OR: 6.37, 95% confidential interval (CI): 1.76–23.04, p = 0.005) and patients with AD (odds ratio (OR): 5.43, 95% CI: 1.41–20.87, p = 0.005), a CSFP in the lowest quartile ([50–90) mmH2O) was associated with a higher level of severe dementia than a CSFP in the highest quartile ([170–210) mmH2O). In addition, there was a significant linear correlation between CSFP and the Mini-Mental State Examination (MMSE) score in all patients with dementia (r = 0.43, p = 0.04, Durbin-Watson test (D-W test) = 0.75). Conclusion: In patients with AD, the mean cerebrospinal fluid pressure was higher in patients with MCI than in patients with dementia, and the decrease in CSFP was related to a more serious dementia level. However, no such relationship was found in patients with LBD. [ABSTRACT FROM AUTHOR]

Purpose: Idiopathic intracranial hypertension (IIH) is a clinical syndrome that mimics brain tumors with increased intracranial pressure. The present study is designed to investigate the diagnostic criteria of magnetic resonance imaging (MRI) and the severity of cerebrospinal fluid (CSF) pressure to understand the relationship and frequency of these criteria with the level of CSF pressure. Methods: The present cross-sectional study was conducted on children diagnosed with IIH between the years 2011 and 2020, who were admitted to the pediatric neurology department of Ghaem Hospital, Mashhad, Iran. Clinical manifestations and imaging findings of the patients were recorded through a checklist. Results: Forty-nine patients were included in the study; 27 (55.1%) were male, and 22 (44.9%) were female. The average CSF pressure was 40.64±20.63 cmH2O. The mean diameter distension of the perioptic subarachnoid space was 6.02±1.21 mm. Six (10.8%) patients had unilateral transverse sinus stenosis with an average CSF pressure of 20.47±36.80 cmH2O and 11 (21.4%) patients had bilateral transverse sinus stenosis with an average pressure of 48.22±21.04 cmH2O. In 22 (44.89%) patients, flattening of the posterior globe with the CSF pressure of 48.80±17.94 cmH2O was reported. Twenty-four (49%) patients had optic nerve tortuosity, with an average CSF pressure of 46.52±20.33 cmH2O. Among the diagnostic criteria, the pressure had a significant relationship with the flattening of the posterior globe (P<0.022). Conclusion: Since MRI is a non-invasive method for examining IIH, the findings of this study may aid in diagnosing and monitoring these patients. [ABSTRACT FROM AUTHOR]

BACKGROUND: Few data on the management of acute phase of traumatic spinal cord injury (tSCI) in patients suffering polytrauma are available. As the therapeutic choices in the first hours may have a deep impact on outcome of tSCI patients, we conducted an international survey investigating this topic. METHODS: The survey was composed of 29 items. The main endpoints of the survey were to examine: (1) the hemodynamic and respiratory management, (2) the coagulation management, (3) the timing of magnetic resonance imaging (MRI) and spinal surgery, (4) the use of corticosteroid therapy, (5) the role of intraspinal pressure (ISP)/spinal cord perfusion pressure (SCPP) monitoring and (6) the utilization of therapeutic hypothermia. RESULTS: There were 171 respondents from 139 centers worldwide. A target mean arterial pressure (MAP) target of 80-90 mmHg was chosen in almost half of the cases [n = 84 (49.1%)]. A temporary reduction in the target MAP, for the time strictly necessary to achieve bleeding control in polytrauma, was accepted by most respondents [n = 100 (58.5%)]. Sixty-one respondents (35.7%) considered acceptable a hemoglobin (Hb) level of 7 g/dl in tSCI polytraumatized patients. An arterial partial pressure of oxygen (PaO2) of 80-100 mmHg [n = 94 (55%)] and an arterial partial pressure of carbon dioxide (PaCO2) of 35-40 mmHg [n = 130 (76%)] were chosen in most cases. A little more than half of respondents considered safe a platelet (PLT) count > 100.000/mm3 [n = 99 (57.9%)] and prothrombin time (PT)/activated partial thromboplastin time (aPTT)

Introduction: In-office use of the Trendelenburg position has been shown to be a beneficial clinical tool to help decipher if a CSF pressure/volume component is part of the underlying etiologic process for a patient’s persistent headache. Utilizing the Trendelenburg position at home could potentially be an additional diagnostic tool for the treating headache physician. Case Series: Our headache practice has been using at-home self-Trendelenburg for the past 2 years and will present the clinical scenarios in which it seems to be the most helpful utilizing a case series of patients. These include (1) in those who just had a lumbar puncture and call for worsening headaches and do not have an obvious orthostatic component; (2) in those who had a spinal epidural blood patch for a presumed CSF leak and state there was no improvement; (3) in those who are on daily preventive CSF volume-lowering medications and call in with worsening headaches; (4) in those with known CSF pressure-dependent headaches high or low but who are not on daily preventive CSF volume modulatory medications; (5) in those with a history of migraine or other primary headache disorder to see if a new type of headache is possibly from a CSF leak or an abnormal reset of CSF pressure to an elevated state; (6) in those with triggered only headaches like cough or exertional headache. Conclusion: Utilizing at-home self-Trendelenburg can provide valuable information for the treating headache physician on possible underlying headache etiology and can guide specific treatment strategies. Its simplicity and quick declaration of results are very patient pleasing.

Abstract Intracranial pressure (ICP) is an important parameter in clinical management and diagnosis of several neurological diseases which is indirectly measured via lumbar puncture (LP). In routine measurements of cerebrospinal fluid pressure (P CSF ) from lumbar region, a spinal needle and a spinal manometer are used. P CSF measurement via LP with the use of a spinal manometer may not yield correct P CSF results due to prolonged times required to obtain an accurate pressure value. Equilibrium pressure may be underestimated in circumstances where spinal manometry procedure is terminated prematurely, with the wrong assumption that equilibrium pressure is reached. Elevated P CSF levels can lead to visual loss and brain damage when go undiagnosed. In this study, the spinal needle-spinal manometer combination was modelled with a first-order differential equation and a time constant (τ) was defined as the product of the resistance to flow of the needle with the bore area of the manometer divided by the dynamic viscosity of CSF, i.e. τ= RA/ρ CSF . Each needle/manometer combination had a unique constant as a predictor of the equilibrium pressure. The fluid pressure in the manometer rose in an exponential manner which was tested in a simulated environment using 22G spinal needles namely Braun-Spinocan, Pajunk-Sprotte and M.Schilling. Curve fitting of the manometer readings were obtained with regression coefficients of R2 ≥ 0.99 to determine measurement time constants. The residual differences between predicted and true values were less than 1.18 cmH2O. For a given needle/manometer combination, time required to reach equilibrium pressure was identical for all pressure levels. P CSF measured at reduced times can easily be interpolated to their equilibrium level allowing clinicians to obtain P CSF values with high accuracy within seconds. This method can be used as an indirect estimation of ICP in routine clinical practice.

Purpose: To explore intraocular pressure (IOP) and its associated parameters in an aged population. Methods: The epidemiologic Ural Very Old Study (UVOS) conducted in Bashkortostan/Russia included 1526 participants with an age of ≥85 years. Besides a whole series of ocular and systemic examinations, IOP was determined applying non-contact tonometry. Body mass index, diastolic blood pressure and age were the factors used to estimate the cerebrospinal fluid pressure (CSFP). Results: The study consisted of 904 participants (age: 88.6 ± 2.7 years) with available IOP readings and without anti-glaucomatous therapy. Mean IOP was 14.5 ± 5.1 mmHg (median: 14 mm Hg; Q1:11; Q3:16; 95%CI:8,25) and 14.8 ± 4.6 mmHg (median: 14 mm Hg; Q1:12; Q3:17; 95%CI:8,28) in the right and left eyes, respectively. Higher IOP correlated (multivariable analysis; correlation coefficient r2:0.32) with female sex (P

Background and purposeCraniospinal space compliance reflects the distensibility of the spinal and intracranial CSF spaces as a system. Craniospinal space compliance has been studied in intracranial pathologies, but data are limited in assessing it in spinal CSF leak. This study describes a method to estimate craniospinal space compliance using saline infusion during CT myelography and explores the use of craniospinal space compliance and pressure-volume curves in patients with suspected cerebrospinal-venous fistula.Materials and methodsPatients with suspected cerebrospinal-venous fistula underwent dynamic CT myelography. During the procedure, 1- to 5-mL boluses of saline were infused, and incremental changes in CSF pressure were recorded. These data were used to plot craniospinal space compliance curves. We calculated 3 quantitative craniospinal space compliance parameters: overall compliance, compliance at opening pressure, and the pressure volume index. These variables were compared between patients with confirmed cerebrospinal-venous fistula and those with no confirmed source of CSF leak.ResultsThirty-four CT myelograms in 22 patients were analyzed. Eight of 22 (36.4%) patients had confirmed cerebrospinal-venous fistulas. Bolus infusion was well-tolerated with no complications and transient headache in 2/34 (5.8%). Patients with confirmed cerebrospinal-venous fistulas had higher compliance at opening pressure and overall compliance (2.6 versus 1.8 mL/cm H20, P < .01). There was no difference in the pressure volume index (77.5 versus 54.3 mL, P = .13) between groups.ConclusionsA method of deriving craniospinal space compliance curves using saline intrathecal infusion is described. Preliminary analysis of craniospinal space compliance curves provides qualitative and quantitative information about pressure-volume dynamics and may serve as a diagnostic tool in patients with known or suspected cerebrospinal-venous fistulas.

Abstract Objectives To explore the diagnostic accuracy of ultrasound measurement of optic nerve sheath diameter (ONSD) and optic disc height (ODH) in detecting intracranial hypertension in non‐small‐cell lung cancer (NSCLC) patients with leptomeningeal metastases (LM). Methods Seventy‐two patients with NSCLC‐LM and 65 patients with NSCLC were enrolled. The ONSD, ODH, eyeball transverse diameter (ETD), and eyeball vertical diameter (EVD) were measured by ultrasound. Subsequently, lumbar puncture was performed in NSCLC‐LM patients to measure cerebrospinal fluid pressure (CSFP), and intrathecal chemotherapy was regularly implemented. Pearson's correlation analysis was used to analyze the relationship between CSFP and ultrasound findings. The diagnostic accuracy of ONSD, ODH, and combined ONSD and ODH was evaluated by receiver operating characteristic (ROC) curve analysis and the corresponding area under the ROC curve (AUC). Results The ONSD, ODH, ONSD/ETD, and ONSD/EVD values were higher in the NSCLC‐LM group (all p 280 mmH2O were 0.787 (95% CI: 0.64–0.93, sensitivity 68.75%, specificity 91.07%), 0.885 (95% CI: 0.81–0.96, sensitivity 100%, specificity 69.64%), 0.765 (95% CI: 0.64–0.89, sensitivity 81.25%, specificity 64.29%), and 0.788 (95% CI: 0.64–0.93, sensitivity 56.25%, specificity 91.07%), respectively. When ONSD was combined with ODH, the AUC was 0.913 (95% CI: 0.83–0.99, sensitivity 87.85%, specificity 85.70%). Furthermore, intrathecal chemotherapy was associated with a downtrend in CSFP and ultrasound findings. Conclusion There are important advantages of using bedside ultrasonography for detecting elevated CSFP in NSCLC‐LM patients. Further research should be performed to evaluate the clinical significance of an enlarged ONSD and increased ODH in NSCLC‐LM.

Over the past decades, the buckling instability of layered materials has been the subject of analytical, experimental, and numerical research. These systems have traditionally been considered with stress-free surfaces, and the influence of surface pressure is understudied. In this study, we developed a finite element model of a bilayer experiencing compression, and found that it behaves differently under surface pressure. We investigated the onset of buckling, the initial wavelength, and the post-buckling behavior of a bilayer system under two modes of compression (externally applied and internally generated by growth). Across a wide range of stiffness ratios, 1 < µf/µs < 100, we observed decreased stability in the presence of surface pressure, especially in the low-stiffness-contrast regime, µf/µs < 10. Our results suggest the importance of pressure boundary conditions for the stability analysis of bilayered systems, especially in soft and living matter physics, such as folding of the cerebral cortex under cerebrospinal fluid pressure, where pressure may affect morphogenesis and buckling patterns. [ABSTRACT FROM AUTHOR]

Intracranial pressure (ICP) is an important parameter in clinical management and diagnosis of several neurological diseases which is indirectly measured via lumbar puncture (LP). In routine measurements of cerebrospinal fluid pressure (PCSF) from lumbar region, a spinal needle and a spinal manometer are used. PCSF measurement via LP with the use of a spinal manometer may not yield correct PCSF results due to prolonged times required to obtain an accurate pressure value. Equilibrium pressure may be underestimated in circumstances where spinal manometry procedure is terminated prematurely, with the wrong assumption that equilibrium pressure is reached. Elevated PCSF levels can lead to visual loss and brain damage when go undiagnosed. In this study, the spinal needle-spinal manometer combination was modelled with a first-order differential equation and a time constant (τ) was defined as the product of the resistance to flow of the needle with the bore area of the manometer divided by the dynamic viscosity of CSF, i.e. τ= RA/ρCSF. Each needle/manometer combination had a unique constant as a predictor of the equilibrium pressure. The fluid pressure in the manometer rose in an exponential manner which was tested in a simulated environment using 22G spinal needles namely Braun-Spinocan, Pajunk-Sprotte and M.Schilling. Curve fitting of the manometer readings were obtained with regression coefficients of R2 ≥ 0.99 to determine measurement time constants. The residual differences between predicted and true values were less than 1.18 cmH2O. For a given needle/manometer combination, time required to reach equilibrium pressure was identical for all pressure levels. PCSF measured at reduced times can easily be interpolated to their equilibrium level allowing clinicians to obtain PCSF values with high accuracy within seconds. This method can be used as an indirect estimation of ICP in routine clinical practice. [ABSTRACT FROM AUTHOR]

Purpose : Before the era of spinal imaging, presence of a spinal canal block was tested through gross changes in cerebrospinal fluid pressure (CSFP) provoked by manual compression of the jugular veins (referred to as Queckenstedt's test; QT). Beyond these provoked gross changes, cardiac-driven CSFP peak-to-valley amplitudes (CSFPp) can be recorded during CSFP registration. This is the first study to assess whether the QT can be repurposed to derive descriptors of the CSF pulsatility curve, focusing on feasibility and repeatability. Method : Lumbar puncture was performed in lateral recumbent position in fourteen elderly patients (59.7±9.3 years, 6F) (NCT02170155) without stenosis of the spinal canal. CSFP was recorded during resting state and QT. A surrogate for the relative pulse pressure coefficient was computed from repeated QTs (i.e., RPPC-Q). Results : Resting state mean CSFP was 12.3 mmHg (IQR 3.2) and CSFPp was 1.0 mmHg (0.5). Mean CSFP rise during QT was 12.5 mmHg (7.3). CSFPp showed an average 3-fold increase at peak QT compared to the resting state. Median RPPC-Q was 0.18 (0.04). There was no systematic error in the computed metrics between the first and second QT. Conclusion : This technical note describes a method to reliably derive, beyond gross CSFP increments, metrics related to cardiac-driven amplitudes during QT (i.e., RPPC-Q). A study comparing these metrics as obtained by established procedures (i.e., infusion testing) and by QT is warranted. [ABSTRACT FROM AUTHOR]

Background: Normal pressure hydrocephalus is a disease directly related to the change in intracranial compliance and consequent repercussions in the brain parenchyma. Invasive monitoring of such parameters proves to be reliable especially for prognosis in neurocritical patients; however, it is not applicable in an outpatient service setting. The present study describes the comparison between the tap test results and the parameters obtained with a non-invasive sensor for monitoring intracranial compliance in patients with suspected NPH. Methods: Twenty-eight patients were evaluated before and after lumbar puncture of 50mL of CSF (the tap test), comprising clinical assessment, magnetic resonance imaging, physical therapy assessment using the Timed Up and Go test, Dynamic Gait Index, BERG test, neuropsychological assessment, and recording of non-invasive intracranial compliance data using the Brain4care® device in three different positions (lying, sitting, and standing) for 5 min each. The tap test results were compared to the Time to Peak and P2/P1 ratio parameters obtained by the device. Results: The group that had a positive Tap test result presented a median P2/P1 ratio greater than 1.0, suggesting a change in intracranial compliance. In addition, there was also a significant difference between patients with positive, negative, and inconclusive results, especially in the lying position. Conclusion: A non-invasive intracranial compliance device when used with the patient lying down and standing up obtained parameters that suggest correspondence with the result of the tap test. [ABSTRACT FROM AUTHOR]

Objectives: To explore the diagnostic accuracy of ultrasound measurement of optic nerve sheath diameter (ONSD) and optic disc height (ODH) in detecting intracranial hypertension in non‐small‐cell lung cancer (NSCLC) patients with leptomeningeal metastases (LM). Methods: Seventy‐two patients with NSCLC‐LM and 65 patients with NSCLC were enrolled. The ONSD, ODH, eyeball transverse diameter (ETD), and eyeball vertical diameter (EVD) were measured by ultrasound. Subsequently, lumbar puncture was performed in NSCLC‐LM patients to measure cerebrospinal fluid pressure (CSFP), and intrathecal chemotherapy was regularly implemented. Pearson's correlation analysis was used to analyze the relationship between CSFP and ultrasound findings. The diagnostic accuracy of ONSD, ODH, and combined ONSD and ODH was evaluated by receiver operating characteristic (ROC) curve analysis and the corresponding area under the ROC curve (AUC). Results: The ONSD, ODH, ONSD/ETD, and ONSD/EVD values were higher in the NSCLC‐LM group (all p < 0.05). The ONSD, ODH, ONSD/ETD, and ONSD/EVD values were all elevated in the abnormally elevated CSFP group (all p < 0.05). ONSD, ODH, ONSD/ETD, and ONSD/EVD were positively correlated with CSFP (r = 0.531, 0.383, 0.534, and 0.535, all p < 0.0001). The AUCs for ONSD, ODH, ONSD/ETD, and ONSD/EVD to detect CSFP >280 mmH2O were 0.787 (95% CI: 0.64–0.93, sensitivity 68.75%, specificity 91.07%), 0.885 (95% CI: 0.81–0.96, sensitivity 100%, specificity 69.64%), 0.765 (95% CI: 0.64–0.89, sensitivity 81.25%, specificity 64.29%), and 0.788 (95% CI: 0.64–0.93, sensitivity 56.25%, specificity 91.07%), respectively. When ONSD was combined with ODH, the AUC was 0.913 (95% CI: 0.83–0.99, sensitivity 87.85%, specificity 85.70%). Furthermore, intrathecal chemotherapy was associated with a downtrend in CSFP and ultrasound findings. Conclusion: There are important advantages of using bedside ultrasonography for detecting elevated CSFP in NSCLC‐LM patients. Further research should be performed to evaluate the clinical significance of an enlarged ONSD and increased ODH in NSCLC‐LM. [ABSTRACT FROM AUTHOR]

Introduction: Retinal vessel dynamics analysis has proven to be a viable, non-invasive surrogate marker for increased intracranial pressure. We aimed to test this method in patients with suspected idiopathic intracranial hypertension. Methods: Patients with suspected idiopathic intracranial hypertension were prospectively enrolled for hand-held fundus-videography during diagnostic lumbar puncture. After extracting optic disc images, peripapillary arteriole-tovenule-ratios were measured using machine-learning algorithms with manual identification control. A general linear model was applied to arteriole-to-venule-ratios and corresponding lumbar opening pressures to estimate cerebrospinal fluid pressure. Results: Twenty-five patients were included with a significant difference in arteriole-to-venule-ratio between patients with (n=17) and without (n=8) idiopathic intracranial hypertension (0.78±0.10 vs 0.90±0.08, p=0.006). Arterioleto-venule-ratio correlated inversely with lumbar opening pressure (slope regression estimate -0.0043 (95% CI -0.0073 to -0.0023), p=0.002) and the association was stronger when lumbar opening pressure exceeded 15mmHg (20 cm H2O) (slope regression estimate -0.0080 (95% CI -0.0123 to -0.0039), p<0.001). Estimated cerebrospinal fluid pressure predicted increased lumbar opening pressure >20mmHg (27 cm H2O) with 78% sensitivity and 92% specificity (AUC 0.81, p=0.02). A stand-alone arteriole-to-venule-ratio measurement predicting lumbar opening pressure >20mmHg (27 cm H2O) was inferior with a 48% sensitivity and 92% specificity (AUC 0.73, p=0.002). Conclusion: Retinal vessel dynamics analysis with the described model for estimating cerebrospinal fluid pressure is a promising non-invasive method with a high sensitivity and specificity for detecting elevated intracranial pressure at follow-up assessments of patients with confirmed idiopathic intracranial hypertension if initial lumbar opening pressure and arteriole-to-venule-ratio data are available. [ABSTRACT FROM AUTHOR]

BackgroundSignal Transducer and Activator of Transcription 3 (STAT3) gain-of-function germline mutations are associated with diverse clinical manifestations, including autoimmune cytopenia, lymphadenopathy, immunodeficiency, endocrinopathy, and enteropathy. We describe a new feature: raised intracranial pressure with papilledema.Materials and methodsReport of two cases.ResultsThe first patient had a de novo heterozygous c.2144C>T (p.Pro715Leu) mutation in the STAT3 gene. At age 1 she had papilledema with marked sheathing of the proximal vessels on the optic discs. Follow-up 8 years later showed chronic papilledema, cystoid macular edema, and vision loss. The second patient had a de novo heterozygous c.2147C>T (p.Thr716Met) mutation. At age 12 he developed papilledema, which recurred despite treatment. In both patients, repeated sampling of the cerebrospinal fluid demonstrated a lymphocytic pleocytosis.ConclusionsPapilledema can occur as a manifestation of STAT3 gain-of-function mutation, sometimes accompanied by prominent vascular sheathing and cystoid macular edema. The mechanism may be chronic meningeal infiltration by white blood cells, impairing cerebrospinal fluid absorption.

Background: The purpose of this study is a non-invasive diagnosis of increasing the pressure of cerebrospinal fluid in patients involved in idiopathic intracranial hypertension (IIH) that is done with transbulbar sonography. Methods: In this descriptive cross-sectional study all the non-toxic children under 18 who were referred to the neurology clinic of Loghman Hospital of Tehran from October 2017 to October 2018 with increased intracerebral pressure symptoms were studied. The increased intracerebral pressure symptoms were headache or vomiting or blurred vision or 6th nerve palsy and they had papillary edema. Also, if their diagnostic brain imaging measures were normal such as: Magnetic Resonance Imaging (MRI), Computed Tomography scan (CT scan) and in some cases Magnetic Resonance Venography (MRV), they were suspected to Idiopathic intracranial hypertension and were entered into the study consecutively. Their complete medical history and comorbidities and biographical information were recorded in the file. All patients were candidates for a lumbar puncture to measure cerebrospinal fluid pressure. After full explanation to the parents and obtaining written consent from them before performing a lumbar puncture, patients in coordination with the ultrasound unit without delay in performing a lumbar puncture, first underwent trans orbital ultrasound in supine position and were awakened with closed eyes. Opticians were implanted in both eyes by a skilled sonographer. And then sedated with sedatives (ketamine or midazolam) prescribed by an anesthesiologist. It was placed in a sterile position in a supine semi-flexion position and with lateral decubitus aligned with the body. Cerebrospinal fluid pressure to cm of water was recorded using a serum set in the lumber intervertebral space 4-5. Then a sample was sent for analysis and smear. Results: Out of 10 patients (age 2.5–14 year, mean 9 years) 10% were girls, 90% were boys, and mean BMI was 22.5 kg/m2. Their symptoms included: 80% Headache, 40% Vomiting, 40% Diplopia, 20% Blurred vision, 10% 6th nerve palsy, and 10% Tinnitus when being reffered. In All patients, CSF pressure was more than 25 cm H2o (mean 40 cm H2o), right and left eyes optic nerve sheath diameter (ONSD) was more than the cutoff point (ONSD≤4.5 mm), the mean right ONSD was 6.31 mm and left eye was 6.64 mm. Conclusion: According to the findings of this study, the measuring of optic nerve sheath diameter in patients suspected of increasing the pressure of idiopathic intracranial hypertension can be helpful as a non–invasive diagnosis method.

• Physiological changes of CSF pressure are investigated during and after spine surgery. • CSF pressure rises significantly intra- to postoperative unrelated to decompression. • Increased CSF pressure persists after 24 h of monitoring. • Type of respiration, anesthesia, and level of consciousness are possible confounders. • CSF pressure may be correctly evaluated only in the same operative setting. Timely and sufficient decompression are critical objectives in degenerative cervical myelopathy (DCM) and spinal cord injury (SCI). We previously investigated intraoperative cerebrospinal fluid pressure (CSFP) for determining surgical outcomes. However, confounding factors during the intra- and postoperative setting need consideration. These are related to type of respiration (i.e., artificial vs. natural) and anesthesia, which affect CSFP dynamics through the interaction between the cardiorespiratory system and the CSF compartment. This retrospective cohort study (NCT02170155) aims to systematically investigate these factors to facilitate CSFP interpretation. CSFP was continuously measured through a lumbar catheter, intra- and postoperatively, in 21 patients with DCM undergoing decompression surgery. Mean CSFP and cardiac-driven CSFP peak-to-valley amplitude (CSFPp) were analyzed throughout the perioperative period, including the immediate extubation period in eight patients. Intraoperative mean CSFP had a median value and {interquartile range} of 10.8 {5.5} mmHg and increased 1.6-fold to 16.9 {7.1} mmHg postoperatively (p < 0.001). CSFPp increased 3-fold from 0.6 {0.7} to 1.8 {2.5} mmHg (p = 0.001). Increased CSFP persisted overnight. During extubation, there was a notable increase in CSFP and CSFPp of 14.0 {5.8} and 5.1 {3.1} mmHg, respectively. From case-based analysis, this was attributed to an arterial pCO 2 increase. There was no correlation between respirator settings and CSFP metrics. There were distinct and quantifiable changes in CSFP dynamics from the intra- to postoperative setting related to type of respiration, anesthesia, and level of consciousness. When monitoring CSFP dynamics in spine surgery across these settings, cardiorespiratory factors must be controlled for. [ABSTRACT FROM AUTHOR]

Background: Idiopathic intracranial hypertension (IIH) is a disease thought to be associated with obesity and rapid weight gain. There is no objective parameter with practical use in its follow-up and treatment other than optical coherence tomography. Objective: The aim of our study is to investigate the relationship between atherogenic index of plasma (AIP) and cerebrospinal fluid (CSF) pressure. Methods: Serum vitamin B12, vitamin D, homocysteine, folic acid, triglyceride (TG), high density lipoprotein cholesterol (HDL-C) levels, CSF pressure, CSF microprotein levels were recorded from the file data of patients diagnosed with IIH. AIP was calculated by dividing the TG level logarithmically by HDL-C. Height (kg) and weight (kg) data of the patients were used to calculate the body mass index (BMI). Results: File data of 64 patients were examined. 8 patients with secondary intracranial hypertension were excluded from the study. 80.36% of the patients were overweight, 16.07% were obese, 3.57% were with normal weight. There was no significant correlation between vitamin B12, vitamin D, homocysteine, HDL-C and CSF microprotein levels and CSF pressure level in patients with a diagnosis of IIH. There was a negative correlation between folic acid level and CSF pressure level, and a positive correlation between BMI, TG, AIP and CSF pressure level. Conclusion: Using folic acid supplements and drugs that reduce TG levels can contribute positively to the course of the disease.

Mukharram M Bikbov,1 Timur R Gilmanshin,1 Rinat M Zainullin,1 Gyulli M Kazakbaeva,1 Ildar F Nuriyev,1 Artur F Zaynetdinov,1 Songhomitrra Panda-Jonas,2 Guzel M Bikbova,1 Ellina M Rakhimova,1 Iulia A Rusakova,1 Timur A Khalimov,1 Kamila R Safiullina,1 Albina A Fakhretdinova,1 Azaliia M Tuliakova,1 Ainur V Gizzatov,1 Jost B Jonas3,4 1Ufa Eye Research Institute, Ufa, Bashkortostan, Russia; 2Privatpraxis Prof Jonas und Dr Panda-Jonas, Heidelberg, Germany; 3Department of Ophthalmology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany; 4Institute of Molecular and Clinical Ophthalmology Basel, Basel, SwitzerlandCorrespondence: Mukharram M Bikbov; Jost B Jonas Tel +7 347 272-37-75; +49-6221-3929320Email Bikbov.m@gmail.com; Jost.Jonas@medma.uni-Heidelberg.deAim: To assess prevalence and associated factors of diabetic retinopathy (DR) in a Russian population.Methods: Out of 7328 eligible individuals, the population-based cross-sectional Ural Eye and Medical Study included 5899 (80.5%) individuals aged 40+ years, who underwent a detailed medical and ophthalmological examination. Using ocular fundus photographs and optical coherence tomographic images, we assessed prevalence and degree of DR in 5105 participants.Results: DR was present in 99/5105 individuals (1.9%; 95% confidence interval [CI]: 1.6, 2.3). Its prevalence increased from 6/657 (1.0%; 95% CI: 0.2, 1.6) in the age group of 45– 50 years to 24/680 (3.5%; 95% CI: 2.1, 4.9) in the age group of 65– 70 years, and decreased to 3/153 (2.0%; 95% CI: 0.00, 4.2) in the age group of 80+ years. DR prevalence within the 577 (11.4%; 95% CI: 10.5, 12.2) individuals with diabetes was 99/577 (17.2%; 95% CI: 14.1, 20.2). DR was the cause for moderate-to-severe vision impairment (best corrected visual acuity < 6/18 but ≥ 3/60) in four individuals (4/5105; 0.07%). In multivariable analysis, higher DR prevalence was associated with higher serum glucose concentration (odds ratio [OR]: 1.30; 95% CI: 1.20, 141), longer diabetes duration (OR: 1.06; 95% CI: 1.02, 1.09), type of diabetes therapy (nil/diet/oral/insulin) (OR:4.19;95% CI:3.08, 5.70), lower educational level (OR:0.81;95% CI:0.67, 0.98), lower manual dynamometric force (OR: 0.96; 95% CI: 0.94, 0.99), shorter ocular axial length (OR: 0.73; 95% CI: 0.56, 0.96), and higher diastolic blood pressure (OR: 1.04; 95% CI: 1.01, 1.06), or alternatively, higher estimated cerebrospinal fluid pressure (OR: 1.09; 95% CI: 1.01, 1.18).Conclusion: In this urban and rural Russian population aged 40+ years, DR prevalence was relatively low (1.9%; 95% CI: 1.6, 2.3), showed an inverted U-shaped association with age, and in a cross-sectional study design it was associated with shorter axial length and higher estimated cerebrospinal fluid pressure.Keywords: diabetic retinopathy, cerebrospinal fluid pressure, myopia, axial length, blindness, ural eye and medical study

The clinical and hemodynamic characteristics of venous pulsatile tinnitus (PT) patients with normal or elevated cerebrospinal fluid pressure (CSFP) have not been clearly differentiated. This study aimed to explore CSFP among patients with PT as the solitary symptom, as well as quantitatively and qualitatively assess the role of the degree of transverse sinus (TS) stenosis and jugular hemodynamics in venous PT patients. A total of 50 subjects with venous PT with or without sigmoid sinus wall anomalies (SSWAs) were enrolled in this study. In addition to radiologic assessments for TS stenosis and invagination of arachnoid granulation (AG) in TS, CSFP and jugular hemodynamics were measured via cerebrospinal fluid (CSF) manometry and Doppler ultrasound. Apart from group comparisons and correlation analyses, multivariate linear regression, and receiver operating characteristic (ROC) models were used to identify the sensitivity and specificity of the index of transverse sinus stenosis (ITSS) and hemodynamic variables with inferential significance. The mean CSFP of all cases was 199.5 ± 52.7 mmH2O, with no statistical difference in CSFP between the diverticulum and dehiscence groups. Multivariate linear regression analysis demonstrated that CSFP was linearly correlated with ITSS and pulsatility index (PI). ROC analysis showed that the area under the ROC curve of PI was 0.693 at 200 mmH2O threshold, and the best PI cut-off value was 0.467, with a sensitivity of 65.7% and specificity of 81.8%. For 250 mmH2O threshold, the area under the ROC curve of PI was 0.718, and the best PI cut-off value was 0.467 with a sensitivity of 68.4% and specificity of 75.0%. Additionally, the area under the ROC curve of ITSS was 0.757, and the best ITSS cutoff value was 8.5 (p = 0.002, 95% CI = 0.616–0.898) with a sensitivity of 72.4% and specificity of 75.0% at 200 mmH2O threshold. In conclusion, patients with venous PT as the only presenting symptom should be suspected of having borderline or increased CSFP when they present with high ITSS, BMI and low PI. Further, AG in TS without encephalocele and empty sellae are not limiting findings for differentiating the level of CSFP in patients with venous PT. [ABSTRACT FROM AUTHOR]

Background: An increase in epidural pressure around the stenosis has been observed in patients with lumbar spinal stenosis (LSS) with positive signs of sedimentation or redundant nerve roots. Further analysis of the pressure conditions in the stenotic area would be of great interest. We hypothesized that it would be possible to determine the physiological parameters of the epidural pulse wave and its course in pathological stenosis as a basis for objective identification of LSS based on pressure using a new measuring method with continuous spatial and temporal resolution., Methods: We performed a single-case proof-of-principle in vivo animal trial and used a newly developed hybrid pressure-measurement probe with a fiber-tip Fabry-Pérot interferometer and several fiber Bragg gratings (FBG)., Results: With reproducible precision, we determined the mean epidural pressure to be 7.5 mmHg and the peak-to-peak value to be 4-5 mmHg. When analyzing the pressure measured by an FBG array, both the heart and respiratory rates can be precisely determined. This study was the first to measure the pulse wave velocity of the cerebrospinal fluid pressure wave as 0.97 m/s using the newly developed pressure probe. A simulated LSS was detected in real time and located exactly., Conclusions: The developed fiber-optic pressure sensor probe enables a new objective measurement of epidural pressure. We confirmed our hypothesis that physiological parameters of the epidural pulse wave can be determined and that it is possible to identify an LSS., (© 2024 The Author(s). Animal Models and Experimental Medicine published by John Wiley & Sons Australia, Ltd on behalf of The Chinese Association for Laboratory Animal Sciences.)

Objective: We report that lumbar puncture (LP) with removal of cerebrospinal fluid (CSF) induced rebound intracranial hypertension with increased papilledema as monitored by optical coherence tomography (OCT). Background: Severe papilledema causes visual field loss and central vision damage if untreated. Fundoscopy is a key to diagnose papilledema, but is not sensitive enough to monitor therapeutic effects. Methods: OCT was applied to follow a 24-year-old woman with headache, visual dysfunction, severe bilateral papilledema, and elevated CSF opening pressure. She was first treated with serial LP, which led to symptom deterioration, increased CSF pressure, and increased the retinal nerve fiber layer (RNFL) thickness. She was then successfully treated with acetazolamide and furosemide. Results: OCT showed reduction of RNFL thickness directly after LP with CSF removal, accompanied with reduced CSF pressure. Increased RNFL thickness accompanied with worsened headache, visual dysfunction, and increased CSF pressure was observed on the next day after LP. Less than 24 h after start of medication, the symptoms had reversed and RNFL thickness was reduced. The patient was symptom-free 2 weeks after starting on medical treatment. Papilledema had vanished on fundoscopy 6 weeks after the therapy, and RNFL thickness was normalized at 3 months of follow-up. Conclusion: This case provides evidence that OCT is an objective and sensitive tool to monitor papilledema and its response to therapy, and thereby important to help in correct clinical decision-making.

Spinal canal narrowing with consecutive spinal cord compression is considered a key mechanism in degenerative cervical myelopathy (DCM). DCM is a common spine condition associated with progressive neurological disability, and timely decompressive surgery is recommended. However, the clinical and radiological diagnostic workup is often ambiguous, challenging confident proactive treatment recommendations. Cerebrospinal fluid pressure dynamics (CSFP) are altered by spinal canal narrowing. Therefore, we aim to explore the potential value of bedside CSFP assessments for qualitative and quantitative assessment of spinal canal narrowing in DCM. In this prospective case series, seven patients with DCM underwent bedside lumbar puncture with measurement of CSFP dynamics and routine CSF analysis (NCT02170155). The patients were enrolled when standard diagnostic algorithms did not permit a clear treatment decision. Measurements include baseline CSFP, cardiac-driven CSFP peak-to-trough amplitude (CSFPp), and the Queckenstedt's test (firm pressure on jugular veins) in neutral and reclined head position. From the Queckenstedt's test, proxies for craniospinal elastance (i.e., relative pulse pressure coefficient; RPPC-Q) were calculated analogously to infusion testing. CSFPmetrics were deemed suspicious of canal narrowing when numbers were lower than the minimum value from a previously tested elderly spine-healthy cohort (N = 14). Mean age was 56 ± 13 years (range, 38-75; 2F); symptom severity was mostly mild to moderate (mean mJOA, 13.5 ± 2.6; range, 9-17). All the patients showed some extent of cervical stenosis in the MRI of unclear significance (5/7 following decompressive cervical spine surgery with an adjacent level or residual stenosis). Baseline CSFP was normal except for one patient (range, 4.7-17.4mmHg). Normal values were found for CSFPp (0.4-1.3 mmHg) and the Queckenstedt's test in normal head positioning (9.-25.3 mmHg). During reclination, the Queckenstedt's test significantly decreased in one, and CSFPp in another case (>50% compared to normal position). RPPC-Q (0.07-0.19) aligned with lower values fromspine-healthy (0.10-0.44). Routine CSF examinations showed mild total protein elevation (mean, 522 ± 108 mg/ml) without further evidence for the disturbed blood brain barrier. Intrathecal CSFP measurements allow discerning disturbed from normal CSFP dynamics in this population. Prospective longitudinal studies should further evaluate the diagnostic utility of CSFP assessments in DCM. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study is a non-invasive diagnosis of increasing the pressure of cerebrospinal fluid in patients involved in idiopathic intracranial hypertension (IIH) that is done with transbulbar sonography. Methods: In this descriptive cross-sectional study all the non-toxic children under 18 who were referred to the neurology clinic of Loghman Hospital of Tehran from October 2017 to October 2018 with increased intracerebral pressure symptoms were studied. The increased intracerebral pressure symptoms were headache or vomiting or blurred vision or 6th nerve palsy and they had papillary edema. Also, if their diagnostic brain imaging measures were normal such as: Magnetic Resonance Imaging (MRI), Computed Tomography scan (CT scan) and in some cases Magnetic Resonance Venography (MRV), they were suspected to Idiopathic intracranial hypertension and were entered into the study consecutively. Their complete medical history and comorbidities and biographical information were recorded in the file. All patients were candidates for a lumbar puncture to measure cerebrospinal fluid pressure. After full explanation to the parents and obtaining written consent from them before performing a lumbar puncture, patients in coordination with the ultrasound unit without delay in performing a lumbar puncture, first underwent trans orbital ultrasound in supine position and were awakened with closed eyes. Opticians were implanted in both eyes by a skilled sonographer. And then sedated with sedatives (ketamine or midazolam) prescribed by an anesthesiologist. It was placed in a sterile position in a supine semiflexion position and with lateral decubitus aligned with the body. Cerebrospinal fluid pressure to cm of water was recorded using a serum set in the lumber intervertebral space 4-5. Then a sample was sent for analysis and smear. Results: Out of 10 patients (age 2.5-14 year, mean 9 years) 10% were girls, 90% were boys, and mean BMI was 22.5 kg/m². Their symptoms included: 80% Headache, 40% Vomiting, 40% Diplopia, 20% Blurred vision, 10% 6th nerve palsy, and 10% Tinnitus when being reffered. In All patients, CSF pressure was more than 25 cm H2o (mean 40 cm H2o), right and left eyes optic nerve sheath diameter (ONSD) was more than the cutoff point (ONSD≤4.5 mm), the mean right ONSD was 6.31 mm and left eye was 6.64 mm. Conclusion: According to the findings of this study, the measuring of optic nerve sheath diameter in patients suspected of increasing the pressure of idiopathic intracranial hypertension can be helpful as a non-invasive diagnosis method. [ABSTRACT FROM AUTHOR]

The biomechanical environment within the optic nerve head (ONH) is complex and is likely directly involved in the loss of retinal ganglion cells (RGCs) in glaucoma. Unfortunately, our understanding of this process is poor. Here we describe factors that influence ONH biomechanics, including ONH connective tissue microarchitecture and anatomy; intraocular pressure (IOP); and cerebrospinal fluid pressure (CSFp). We note that connective tissue factors can vary significantly from one individual to the next, as well as regionally within an eye, and that the understanding of ONH biomechanics is hindered by anatomical differences between small-animal models of glaucoma (rats and mice) and humans. Other challenges of using animal models of glaucoma to study the role of biomechanics include the complexity of assessing the degree of glaucomatous progression; and inadequate tools for monitoring and consistently elevating IOP in animal models. We conclude with a consideration of important open research questions/challenges in this area, including: (i) Creating a systems biology description of the ONH; (ii) addressing the role of astrocyte connective tissue remodeling and reactivity in glaucoma; (iii) providing a better characterization of ONH astrocytes and non-astrocytic constituent cells; (iv) better understanding the role of ONH astrocyte phagocytosis, proliferation and death; (v) collecting gene expression and phenotype data on a larger, more coordinated scale; and (vi) developing an implantable IOP sensor.

Mucopolysaccharidosis (MPS) type-IH is a lysosomal storage disease that results from mutations in the IDUA gene causing the accumulation of glycosaminoglycans (GAGs). Historically, children with the severe phenotype, MPS-IH (Hurler syndrome) develop progressive neurodegeneration with death in the first decade due to cardio-pulmonary complications. New data suggest that inflammation may play a role in MPS pathophysiology. To date there is almost no information on the pathophysiologic changes within the cerebral spinal fluid (CSF) of these patients. We evaluated the CSF of 25 consecutive patients with MPS-IH. While CSF glucose and total protein were within the normal range, we found a significantly mean elevated CSF opening pressure at 24 cm H2O (range 14-37 cm H2O). We observed a 3-fold elevation in CSF heparan sulfate and a 3-8 fold increase in MPS-IH specific non-reducing ends, I0S0 and I0S6. Cytokine analyses in CSF of children with MPS-IH showed significantly elevated inflammatory markers including: MCP-1 SDF-1a, IL-Ra, MIP-1b, IL-8, and VEGF in comparison to unaffected children. This is the largest report of CSF characteristics in children with MPS-IH. Identification of key biomarkers may provide further insight into the inflammatory-mediated mechanisms related to MPS diseases and perhaps lead to improved targeted therapies.

Spinal canal narrowing with consecutive spinal cord compression is considered a key mechanism in degenerative cervical myelopathy (DCM). DCM is a common spine condition associated with progressive neurological disability, and timely decompressive surgery is recommended. However, the clinical and radiological diagnostic workup is often ambiguous, challenging confident proactive treatment recommendations. Cerebrospinal fluid pressure dynamics (CSFP) are altered by spinal canal narrowing. Therefore, we aim to explore the potential value of bedside CSFP assessments for qualitative and quantitative assessment of spinal canal narrowing in DCM. In this prospective case series, seven patients with DCM underwent bedside lumbar puncture with measurement of CSFP dynamics and routine CSF analysis (NCT02170155). The patients were enrolled when standard diagnostic algorithms did not permit a clear treatment decision. Measurements include baseline CSFP, cardiac-driven CSFP peak-to-trough amplitude (CSFPp), and the Queckenstedt's test (firm pressure on jugular veins) in neutral and reclined head position. From the Queckenstedt's test, proxies for craniospinal elastance (i.e., relative pulse pressure coefficient; RPPC-Q) were calculated analogously to infusion testing. CSFP metrics were deemed suspicious of canal narrowing when numbers were lower than the minimum value from a previously tested elderly spine-healthy cohort (N = 14). Mean age was 56 ± 13 years (range, 38–75; 2F); symptom severity was mostly mild to moderate (mean mJOA, 13.5 ± 2.6; range, 9–17). All the patients showed some extent of cervical stenosis in the MRI of unclear significance (5/7 following decompressive cervical spine surgery with an adjacent level or residual stenosis). Baseline CSFP was normal except for one patient (range, 4.7–17.4 mmHg). Normal values were found for CSFPp (0.4–1.3 mmHg) and the Queckenstedt's test in normal head positioning (9.-25.3 mmHg). During reclination, the Queckenstedt's test significantly decreased in one, and CSFPp in another case (>50% compared to normal position). RPPC-Q (0.07–0.19) aligned with lower values from spine-healthy (0.10–0.44). Routine CSF examinations showed mild total protein elevation (mean, 522 ± 108 mg/ml) without further evidence for the disturbed blood brain barrier. Intrathecal CSFP measurements allow discerning disturbed from normal CSFP dynamics in this population. Prospective longitudinal studies should further evaluate the diagnostic utility of CSFP assessments in DCM.

Purpose: Intracranial pressure (ICP) and ocular perfusion pressure (OPP) are both involved with the pathogenesis of glaucoma. The orbital ICP determines a retrolaminar counter pressure that is antagonistic to the intraocular pressure (IOP). The purpose of this study is to evaluate whether the translaminar pressure difference (TLPD) and the OPP varies in glaucoma patients with different optic disc sizes. Methods: In this university hospital-based, observational, cross-sectional clinical study, all patients underwent an ophthalmic evaluation. Blood pressure, height, weight, and the results of retinal nerve fiber layer examination with optical coherence tomography examination were recorded. TLPD and OPP were calculated for each patient using proxy algorithms to attain indirect surrogate parameter values. Patients' eyes were stratified into three quantiles according to optic disc sizes and the differences compared. Data from both eyes were used after using the appropriate correction for inter-eye dependency. Results: The sample consisted of 140 eyes of 73 patients with primary open-angle glaucoma and suspects. Patients with large disc size presented with higher TLPD as compared to those with average and small-sized discs (2.4 ± 4.5, 2.8 ± 3.8, and 3.7 ± 4.7 mmHg for first, second, and third tertile, respectively (P < 0.000). OPP did not vary according to the optic disc size. Conclusion: Glaucoma patients with larger optic discs have higher TLPD. The pathological significance of this finding warrants further investigation.

Qian Wang,1,* Jingyan Yang,1,* Jost B Jonas,2 Xuehui Shi,1 Shouling Wu,3 Shuohua Chen,4 Yanni Yan,1 Wenjia Zhou,1 Li Dong,1 Wenbin Wei,1 Ya Xing Wang5 1Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Ophthalmology & Visual Sciences Key Lab, Medical Artificial Intelligence Research and Verification Laboratory of the Ministry of Industry and Information Technology, Beijing Tongren Hospital, Capital Medical University, Beijing, People’s Republic of China; 2Department of Ophthalmology, Medical Faculty Mannheim of the Ruprecht-Karis-University, Mannheim, Germany; 3Cardiology Department, Kailuan General Hospital, Tangshan, People’s Republic of China; 4Health Care Center, Kailuan Group, Tangshan, People’s Republic of China; 5Beijing Institute of Ophthalmology and Beijing Ophthalmology and Visual Science Key Lab, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, People’s Republic of China*These authors contributed equally to this workCorrespondence: Wenbin WeiBeijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, 1 Dong Jiao Min Xiang, Dong Cheng District, Beijing, 100730, People’s Republic of ChinaTel +86-10-58269516Fax +86-10-6512 5617Email weiwenbintr@163.comPurpose: To investigate the prevalence of retinal vein occlusions (RVOs) and associated factors in a Chinese population.Patients and Methods: The cross-sectional community-based Kailuan Eye Study included individuals who participated in the Kailuan Study. RVOs were diagnosed on the fundus photographs. Estimated cerebrospinal fluid pressure (eCSFP) was calculated as “eCSFP=0.44*Body Mass Index+0.16*Diastolic Blood Pressure-0.18*Age”.Results: The study included 12,499 participants with a mean age of 52.9± 13.1 years. The overall prevalence of RVO was 120/12,499 or 0.96%, with branch RVOs observed in 116/12,499 individuals and central RVOs in 4/12,499 individuals. RVOs started at the optic disc in 19 participants (15.8% of all RVOs), and in 101 (84.2%) individuals arterio-venous crossings outside the optic disc. In multivariable analysis, a higher RVO prevalence was associated with older age (P< 0.001), higher eCSFP (P< 0.001), and higher fasting serum glucose concentration (P< 0.001). Differentiating between RVOs at arterio-venous crossings and RVOs at the optic disc revealed that the prevalence of both RVO types was associated with higher eCSFP (P< 0.001 and P=0.004, respectively) after adjusting for age and fasting serum glucose concentration.Conclusion: In this adult Chinese population recruited on a community basis, the prevalence of any RVO (mean: 0.96) was associated with older age, higher eCSFP and higher fasting serum glucose concentration. Higher eCSFP may play an etiologic role in RVOs.Keywords: retinal vein occlusion, blood pressure, arterial hypertension, glaucoma, intraocular pressure, cerebrospinal fluid pressure

Abstract Background Although widely used in the evaluation of the diseased, normal intracranial pressure and lumbar cerebrospinal fluid pressure remain sparsely documented. Intracranial pressure is different from lumbar cerebrospinal fluid pressure. In addition, intracranial pressure differs considerably according to the body position of the patient. Despite this, the current reference values do not distinguish between intracranial and lumbar cerebrospinal fluid pressures, and body position-dependent reference values do not exist. In this study, we aim to establish these reference values. Method A systematic search was conducted in MEDLINE, EMBASE, CENTRAL, and Web of Sciences. Methodological quality was assessed using an amended version of the Joanna Briggs Quality Appraisal Checklist. Intracranial pressure and lumbar cerebrospinal fluid pressure were independently evaluated and subdivided into body positions. Quantitative data were presented with mean ± SD, and 90% reference intervals. Results Thirty-six studies were included. Nine studies reported values for intracranial pressure, while 27 reported values for the lumbar cerebrospinal fluid pressure. Reference values for intracranial pressure were − 5.9 to 8.3 mmHg in the upright position and 0.9 to 16.3 mmHg in the supine position. Reference values for lumbar cerebrospinal fluid pressure were 7.2 to 16.8 mmHg and 5.7 to 15.5 mmHg in the lateral recumbent position and supine position, respectively. Conclusions This systematic review is the first to provide position-dependent reference values for intracranial pressure and lumbar cerebrospinal fluid pressure. Clinically applicable reference values for normal lumbar cerebrospinal fluid pressure were established, and are in accordance with previously used reference values. For intracranial pressure, this study strongly emphasizes the scarcity of normal pressure measures, and highlights the need for further research on the matter.

Short-term fluid loading is used as part of post-spaceflight medical procedures and clinical treatment in hospitals. Hypervolemia with hemodilution induced by rapid fluid infusion reportedly impaired dynamic cerebral autoregulation. However, the effects on intracranial pressure (ICP) remain unknown. Therefore, we estimated ICP noninvasively (nICP) to examine whether rapid fluid infusion would raise ICP. METHODS: Twelve healthy male volunteers underwent two discrete normal saline (NS) infusions (15 and 30 ml · kg−1 stages, NS-15 and NS-30, respectively) at a rate of 100 ml · min−1. The cerebral blood flow (CBF) velocity (CBFv) waveform from the middle cerebral artery obtained by transcranial Doppler ultrasonography was recorded, as was the arterial blood pressure (ABP) waveform at the radial artery obtained by tonometry. We then used these waveforms to calculate nICP, cerebral artery compliance, and the pulsatility index (PI) in an intracranial hydraulic model. RESULTS: nICP increased significantly in both infusion stages from preinfusion (preinfusion: 7.6 ± 3.4 mmHg; NS-15: 10.9 ± 3.3 mmHg; NS-30: 11.7 ± 4.2 mmHg). No significant changes were observed in cerebral artery compliance or PI. Although ABP did not change in any stage, CBFv increased significantly (preinfusion: 67 ± 10 cm · s−1; NS-15: 72 ± 12 cm · s−1; NS-30: 73 ± 12 cm · s−1). DISCUSSION: Hypervolemia with hemodilution induced by rapid fluid infusion caused increases in nICP and CBFv. No changes were observed in cerebral artery compliance or PI related to cerebrovascular impedance. These findings suggest that rapid fluid infusion may raise ICP with increased CBF. [ABSTRACT FROM AUTHOR]

Lumbar spinal drain use during thoracic and thoracoabdominal aortic aneurysm repair has reduced the incidence of ischemic spinal cord injury with relatively low risk. We report a case of pneumocephalus in a 55-year-old woman who had undergone open repair of a 6.7-cm type IV thoracoabdominal aortic aneurysm. After lumbar spinal drain removal, she developed a postdural headache, which was subsequently treated with blood patch placement. After discharge, she had presented with transient headaches, perioral numbness, and left-hand weakness. Computed tomography revealed intraventricular gas within the lateral ventricles. Pneumocephalus is an exceedingly rare and potentially dangerous complication of lumbar spinal drains and blood patch placement.

Degenerative cervical myelopathy (DCM) is hallmarked by spinal canal narrowing and related cord compression and myelopathy. Cerebrospinal fluid (CSF) pressure dynamics are likely disturbed due to spinal canal stenosis. The study aimed to investigate the diagnostic value of continuous intraoperative CSF pressure monitoring during surgical decompression. This prospective single center study (NCT02170155) enrolled DCM patients who underwent surgical decompression between December 2019 and May 2021. Data from n = 17 patients were analyzed and symptom severity graded with the modified Japanese Orthopedic Score (mJOA). CSF pulsations were continuously monitored with a lumbar intrathecal catheter during surgical decompression. Mean patient age was 62 ± 9 years (range 38-73; 8 female), symptoms were mild-moderate in most patients (mean mJOA 14 ± 2, range 10-18). Measurements were well tolerated without safety concerns. In 15/16 patients (94%), CSF pulsations increased at the time of surgical decompression. In one case, responsiveness could not be evaluated for technical reasons. Unexpected CSF pulsation decrease was related to adverse events (i.e., CSF leakage). Median CSF pulsation amplitudes increased from pre-decompression (0.52 mm Hg, interquartile range [IQR] 0.71) to post-decompression (0.72 mm Hg, IQR 0.96; p = 0.001). Mean baseline CSF pressure increased with lower magnitude than pulsations, from 9.5 ± 3.5 to 10.3 ± 3.8 mm Hg (p = 0.003). Systematic relations of CSF pulsations were confined to surgical decompression, independent of arterial blood pressure (p = 0.927) or heart rate (p = 0.102). Intraoperative CSF pulsation monitoring was related to surgical decompression while in addition adverse events could be discerned. Further investigation of the clinical value of intraoperative guidance for decompression in complex DCM surgery is promising. [ABSTRACT FROM AUTHOR]

Introduction: There is no previous literature on the use of telemetric sensors (telesensor) in the lumbar theca. We aim to provide novel data on telemetric pressure monitoring of the lumbar theca via lumboperitoneal shunts. Research question: Primary outcome is telemetric sensor malfunction of lumboperitoneal shunt. The secondary outcome is post-operative complications. Materials and methods: A single centre retrospective case series of patients with telemetric sensor in LP shunt system, between 2015 and 2021, consisting of 5 patients. Review of indications for use, duration of function of telemetric sensor and associated complications. Results: There was no procedural complications of LP shunt insertion with telemetric sensor. The patient with highest body weight patient had retraction of distal tubing which required distal resiting 3 times. Four out of five patients had no complications. In all cases, telemetric sensor functioned satisfactorily with no dysfunction. The duration of documentation was 1–40 months. Pressure readings were satisfactorily carried out in variety of positions. Discussion and conclusion: This is the first report of telemetric sensor use in the lumbar theca. It can provide a valuable way of measuring cerebrospinal fluid pressures, particularly in patients avoiding cranial surgery. More research is indicated to assess what pressure values would mean clinically.

Abstract Background Communicating hydrocephalus is a disease where the cerebral ventricles are enlarged. It is characterized by the absence of detectable cerebrospinal fluid (CSF) outflow obstructions and often with increased CSF pulsatility measured in the cerebral aqueduct (CA). We hypothesize that the cardiac-related pulsatile flow over the CA, with fast systolic outflow and slow diastolic inflow, can generate net pressure effects that could source the ventriculomegaly in these patients. This would require a non-zero cardiac cycle averaged net pressure difference (ΔP net ) over the CA, with higher average pressure in the lateral and third ventricles. Methods We tested the hypothesis by calculating ΔP net across the CA using computational fluid dynamics based on prospectively collected high-resolution structural (FIESTA-C, resolution 0.39 × 0.39 × 0.3 mm3) and velocimetric (2D-PCMRI, in-plane resolution 0.35 × 0.35 mm2) MRI-data from 30 patients investigated for communicating hydrocephalus. Results The ΔP net due to CSF pulsations was non-zero for the study group (p = 0.03) with a magnitude of 0.2 ± 0.4 Pa (0.001 ± 0.003 mmHg), with higher pressure in the third ventricle. The maximum pressure difference over the cardiac cycle ΔP max was 20.3 ± 11.8 Pa and occurred during systole. A generalized linear model verified an association between ΔP net and CA cross-sectional area (p = 0.01) and flow asymmetry, described by the ratio of maximum inflow/outflow (p = 0.04), but not for aqueductal stroke volume (p = 0.35). Conclusions The results supported the hypothesis with respect to the direction of ΔP net , although the magnitude was low. Thus, although the pulsations may generate a pressure difference across the CA it is likely too small to explain the ventriculomegaly in communicating hydrocephalus.

Introduction: In-office use of the Trendelenburg position has been shown to be a beneficial clinical tool to help decipher if a CSF pressure/volume component is part of the underlying etiologic process for a patient's persistent headache. Utilizing the Trendelenburg position at home could potentially be an additional diagnostic tool for the treating headache physician., Case Series: Our headache practice has been using at-home self-Trendelenburg for the past 2 years and will present the clinical scenarios in which it seems to be the most helpful utilizing a case series of patients. These include (1) in those who just had a lumbar puncture and call for worsening headaches and do not have an obvious orthostatic component; (2) in those who had a spinal epidural blood patch for a presumed CSF leak and state there was no improvement; (3) in those who are on daily preventive CSF volume-lowering medications and call in with worsening headaches; (4) in those with known CSF pressure-dependent headaches high or low but who are not on daily preventive CSF volume modulatory medications; (5) in those with a history of migraine or other primary headache disorder to see if a new type of headache is possibly from a CSF leak or an abnormal reset of CSF pressure to an elevated state; (6) in those with triggered only headaches like cough or exertional headache., Conclusion: Utilizing at-home self-Trendelenburg can provide valuable information for the treating headache physician on possible underlying headache etiology and can guide specific treatment strategies. Its simplicity and quick declaration of results are very patient pleasing., Competing Interests: The author declares that there are no conflicts of interest., (© 2024 The Author(s). Published by S. Karger AG, Basel.)

Abstract Cerebellar lesions could be a cause of fluctuating hearing loss, due to the increase of intracranial pressure by partially or complete blocking of the Foramen of Luschka. Patients with intracranial hypertension may present audio‐vestibular symptoms. Fluctuating sensorineural hearing loss may be the manifestation of different inner ear disorders such as Meniere's disease (MD), immune‐mediated inner ear disease (IMIED), otosyphilis, and labyrinthine fistula including semicircular canal dehiscence. A rare mechanism involved in the fluctuating hearing loss is the increase in cerebrospinal fluid (CSF) pressure, that may be caused by a cerebellar tumor. A 51‐year‐old female presented a 2‐year history of left ear fluctuating hearing loss and tinnitus, with fluctuations among the day, and normal otoscopy. Several audiometries showed a left ear moderate sensorineural hearing loss in low frequencies (Figure 1). The patient underwent a cerebral magnetic resonance imaging (MRI) (Figure 2). She was treated with three courses of systemic steroids showing improvement of symptoms during the treatment. However, the symptoms always returned when corticotherapy was interrupted. The patient was given two intratympanic steroids cycles combined with hydrochlorothiazide/ amiloride hydrochloride. The cerebral MRI described a left cerebellar focal lesion diagnosed as a cerebellar gangliocytoma. After receiving the second intratympanic steroids, cycle combined with systemic ameride showed a significant improvement of audition. Between the several causes of fluctuating hearing loss, a cerebellar gangliocytoma is a very rare disease, which needs a high degree of suspicion and otorhinolaryngologists should be familiar with this entity since patients may present with audiological and vestibular symptoms.

To investigate the changes in choroidal thickness (CT) after acute cerebrospinal fluid pressure (CSFP) reduction in human subjects. Before and 15 minutes after diagnostic lumbar puncture (LP), 44 patients underwent measurement of CT by swept-source optical coherence tomography. Thirty-two healthy volunteers imitated the body posture of LP procedure and underwent the same measurement before and 15 minutes after body posture change. After CSFP reduction from 10.9 ± 2.1 mmHg at baseline to 8.1 ± 1.5 mmHg (p < 0.001), CT decreased in subfoveal region (p = 0.005), small to medium vessel layer (SMVL, p < 0.001), peripapillary regions in temporal (p = 0.001), nasal (p < 0.001), superior (p < 0.001) and inferior (p < 0.001), respectively. However, no significant change in CT in the control group after body posture change (all p > 0.05). A significant association between CSFP and the ratio of small to medium vessel layer to total choroidal thickness was found (p = 0.009). The CSFP reduction rate was associated with the change rate of SMVL to total CT portion, for each percent decrease in CSFP was associated with a decrease by 0.22% in the rate of SMVL to total CT portion (R2 = 0.125, p = 0.018). A significant decrease in subfoveal CT, small to medium vessel layer and peripapillary region were observed following acute CSFP reduction. The CSFP reduction rate was associated with the change rate of small to medium vessel layer to total CT portion. [ABSTRACT FROM AUTHOR]

Glaucoma is a chronic, progressive optic neuropathy characterized by the loss of peripheral vision first and then central vision. Clinically, normal tension glaucoma is considered a special subtype of glaucoma, in which the patient’s intraocular pressure is within the normal range, but the patient experiences typical glaucomatous changes. However, increasing evidence has challenged the traditional pathophysiological view of normal tension glaucoma, which is based only on intraocular pressure, and breakthroughs in central nervous system imaging may now greatly increase our knowledge about the mechanisms underlying normal tension glaucoma. In this article, we review the latest progress in understanding the pathogenesis of normal tension glaucoma and in developing imaging techniques to detect it, to strengthen the appreciation for the connection between normal tension glaucoma and the brain.

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.