Idiopathic normal pressure hydrocephalus: Validation of the DESH score as a prognostic tool for shunt surgery response.

OBJECTIVE: Several radiological markers have been linked to clinical improvement after shunt surgery for idiopathic normal pressure hydrocephalus (iNPH). However, iNPH has no pathognomonic feature, and patients are still diagnosed as probable, possible, or unlikely cases based on clinical symptoms, imaging findings, and invasive supplementary tests. The predictive value of the disproportionately enlarged subarachnoid space hydrocephalus (DESH) score is not yet conclusively determined, but it might offer a more accurate diagnostic method. The aim of the present retrospective cohort study was to validate the predictive power of the DESH score for clinical improvement after shunt surgery in iNPH patients. METHODS: We retrospectively obtained presurgical MRI and/or CT scans from 71 patients with iNPH who underwent ventriculoperitoneal shunt surgery. Radiological images were evaluated for Evans index (EI), corpus callosal angle (CA), tight high convexity (THC), Sylvian fissure dilation, and focal sulci dilation. These markers were aggregated to determine the DESH score. Patient journal entries were used to subjectively determine the extent of improvement in gait function, urinary incontinence, and/or cognition as a measure of shunt surgery response. RESULTS: Multiple logistic regression analysis, controlling for age and sex (α = 0.05), showed that DESH score was significantly correlated (OR 1.77) with subjective shunt-surgery response at a minimum of 1-month follow-up. Patients with higher DESH scores were more likely to have a favorable response to shunt surgery. CONCLUSION: Aggregating radiological markers into the DESH score is useful for predicting shunt responders among iNPH patients and can aid the selection of patients for surgery. These findings provide further support for the DESH score as a diagnostic tool for iNPH.

Treatment of meningiomas involving the optic canal with endoscopic transnasal decompression of the optic nerve.

BACKGROUND: Management of patients with optic nerve sheath meningiomas (ONSM) is controversial and the treatment strategy in this patient group is still up for discussion. Transnasal endoscopic orbital and optic nerve decompression aims to reduce the pressure in the orbit and on the optic nerve and thereby prevent vision loss. This article presents material from seven cases of transnasal endoscopic orbital decompressions. METHODS: The study design is a retrospective cohort study. The aim was to include all patients with a meningioma residing along the nerve sheath and who were operated using endoscopic transnasal decompression of the orbit and if needed the optic canal at Odense University Hospital. Data from the medical records were collected and pre- and postoperative eye examinations were compared. In addition, it was recorded whether there were complications to the procedure and whether additional treatments were given. RESULTS: In total, four women and three men were included in the study. Four out of seven patients experienced improvement in vision after the operation. One patient experienced unchanged vision and two patients experienced deterioration of vision after surgery. CONCLUSIONS: The current report of seven patients with ONSM shows promising results for this surgical procedure as four out of seven patients experienced improvement in their vision at follow-up examinations. The two patients, who experienced deterioration of vision, already had severely reduced vision pre-operatively, which indicates that surgery should be considered before the vision becomes significantly reduced.

Reliability and performance of the IRRAflow® system for intracranial lavage and evacuation of hematomas-A technical note.

BACKGROUND: Intraventricular hemorrhage (IVH) is a severe condition with poor outcomes and high mortality. IRRAflow® (IRRAS AB) is a new technology introduced to accelerate IVH clearance by minimally invasive wash-out. The IRRAflow® system performs active and controlled intracranial irrigation and aspiration with physiological saline, while simultaneously monitoring and maintaining a stable intracranial pressure (ICP). We addressed important aspects of the device implementation and intracranial lavage. METHOD: To allow versatile investigation of multiple device parameters, we designed an ex vivo lab setup. We evaluated 1) compatibility between the IRRAflow® catheter and the Silverline f10 bolt (Spiegelberg), 2) the physiological and hydrodynamic effects of varying the IRRAflow® settings, 3) the accuracy of the IRRAflow® injection volumes, and 4) the reliability of the internal ICP monitor of the IRRAflow®. RESULTS: The IRRAflow® catheter was not compatible with Silverline bolt fixation, which was associated with leakage and obstruction. Design space exploration of IRRAflow® settings revealed that appropriate settings included irrigation rate 20 ml/h with a drainage bag height at 0 cm, irrigation rate 90 ml/h with a drainage bag height at 19 cm and irrigation rate 180 ml/h with a drainage bag height at 29 cm. We found the injection volume performed by the IRRAflow® to be stable and reliable, while the internal ICP monitor was compromised in several ways. We observed a significant mean drift difference of 3.16 mmHg (variance 0.4, p = 0.05) over a 24-hour test period with a mean 24-hour drift of 3.66 mmHg (variance 0.28) in the pressures measured by the IRRAflow® compared to 0.5 mmHg (variance 1.12) in the Raumedic measured pressures. CONCLUSION: Bolting of the IRRAflow® catheter using the Medtronic Silverline® bolt is not recommendable. Increased irrigation rates are recommendable followed by a decrease in drainage bag level. ICP measurement using the IRRAflow® device was unreliable and should be accompanied by a control ICP monitor device in clinical settings.

Evaluating the Efficacy of Perfusion MRI and Conventional MRI in Distinguishing Recurrent Cerebral Metastasis from Brain Radiation Necrosis.

Differentiating recurrent cerebral metastasis (CM) from brain radiation necrosis (BRN) is pivotal for guiding appropriate treatment and prognostication. Despite advances in imaging techniques, however, accurately distinguishing these conditions non-invasively is still challenging. This single-center retrospective study reviewed 32 cases (28 patients) with confirmed cerebral metastases who underwent surgical excision of lesions initially diagnosed by MRI and/or MR perfusion scans from 1 January 2015 to 30 September 2020. Diagnostic accuracy was assessed by comparing imaging findings with postoperative histopathology. Conventional MRI accurately identified recurrent CM in 75% of cases. MR perfusion scans showed significantly higher mean maximum relative cerebral blood volume (max. rCBV) in metastasis cases, indicating its potential as a discriminative biomarker. No single imaging modality could definitively distinguish CM from BRN. Survival analysis revealed gender as the only significant factor affecting overall survival, with no significant survival difference observed between patients with CM and BRN after controlling for confounding factors. This study underscores the limitations of both conventional MRI and MR perfusion scans in differentiating recurrent CM from BRN. Histopathological examination remains essential for accurate diagnosis. Further research is needed to improve the reliability of non-invasive imaging and to guide the management of patients with these post-radiation events.

PDP type brain tumor in association with multiple endocrine neoplasia type 1.

Multiple endocrine neoplasia type 1 (MEN1) is a rare autosomal dominant syndrome caused by inactivating pathogenic variants in the tumor suppressor gene menin 1 on chromosome 11q13 (Falchetti et al., 2009). The syndrome is characterized by neoplasia in two or more endocrine glands and has a high degree of penetrance. Pathogenic germline multiple neoplasia type 1 variants primarily result in neoplasia affecting the parathyroid glands, the pancreatic islet cells, and the anterior pituitary in combination. Primary hyperparathyroidism is the most common pathological manifestation of the syndrome, followed by pancreatic neuroendocrine tumors. Important genetic confirmation has been provided showing that ependymoma should be considered as a neoplasm that can occur in patients with MEN1 (Kato et al., 1996; Cuevas-Ocampo et al., 2017). The biphasic histopathological tumor entity shown in the present case we name Pleomorphic Xanthoastocytoma grade 3 differential pathology (PDP) in association with Multiple Endocrine Neoplasia type 1. This MEN1 associated tumor subtype is an extension of the findings on MEN1 associated ependymoma, where we show that the clinical phenotype itself may potentially be triggered by a frameshift germline pathogenic variant for the MEN1 gene, in combination with cyclin-dependent kinase inhibitor 1B gene germline variant and cyclin dependent kinase inhibitor 2A somatic deletion downstream of menin.

Treatment of chronic subdural haematoma.

A further rise in chronic subdural haematoma (CSDH) prevalence is expected with an ageing population, and evidence-based guidelines are needed to direct treatment, while creating a platform for research. The Danish Chronic Subdural Hematoma Study (DACSUHS) has implemented the first Danish national CSDH guidelines in 2018 and have standardised CSDH management on a national level. Based on CSDH literature published between 2016 and 2022, these guidelines were updated in 2022. The updated guidelines are presented in this review.

Intracranial ventricular shunts.

Permanent shunt diversion of cerebrospinal fluid away from the central nervous system is a widely recognized neurosurgical procedure. Still, patients with ventricular shunts are at substantial risk of shunt dysfunction, which includes complications like mechanical shunt failure, abnormal shunt drainage and infection. Early detection of shunt dysfunction is essential to proper and timely treatment, and acute shunt dysfunction might require immediate intervention. This review summarizes current and potential strategies for investigation of shunt dysfunction.

Descriptive registry study on outcome and complications of external ventricular drainage treatment of intraventricular haemorrhage in a Danish cohort: a study protocol.

INTRODUCTION: Intraventricular haemorrhage (IVH) is associated with high morbidity and mortality. External ventricular drainage (EVD) has been shown to decrease mortality. Although EVD is widely used, outcome and complication rates in EVD-treated patients with IVH are not fully elucidated. This study aims to describe EVD complication rates and outcomes in patients with primary and secondary IVH at two university hospitals in Denmark. The study will provide a historical reference of relevant endpoints for use in future clinical trials involving patients with IVH. METHODS AND ANALYSIS: This descriptive, multicentre registry study included adult patients (age 18+) with primary or secondary IVH and treated with at least one EVD between 2017 and 2021 at Aarhus University Hospital or Odense University Hospital. Patients are identified using the Danish National Patient Register. Data are collected and recorded from patient medical records. Relevant descriptive statistics and correlation analyses will be applied. ETHICS AND DISSEMINATION: Ethical approval and authorisation to access, store and analyse data have been obtained (Central Denmark Region Committee on Health Research Ethics). The research lead will present the results of the study. Data will be reported according to the Strengthening the Reporting of Observational Studies in Epidemiology and results submitted for publication in peer-reviewed journals.

Intraoperative Irrigation and Risk of Chronic Subdural Hematoma Recurrence.

BACKGROUND AND OBJECTIVES: In most neurosurgical centers, irrigation is an essential part of the surgical procedure for chronic subdural hematoma (CSDH). However, it is unknown whether the volume of irrigation fluid affects the risk of CSDH recurrence. This study aimed to investigate a potential association between the volume of irrigation fluid used during burr hole evacuation of CSDH and the risk of CSDH recurrence. METHODS: This study is a subanalysis of 2 randomized trials (Drain Time & Drain Time 2) designed to investigate the effect of drainage duration on the recurrence of CSDH. Intraoperative irrigation volume was measured, and patients were followed for 90 days for recurrent CSDH. RESULTS: A total of 525 patients with CSDH were included. There was no significant difference in the volume of irrigation fluid used between patients with recurrence (mean = 938 mL, SD = ±552) and without recurrence (mean = 852 mL, SD = ±454) ( P -value = .15). Patients with recurrent CSDH had larger primary CSDH volumes (mean = 134 cm 3 , SD = ±69) than patients without recurrence (mean = 119 cm 3 , SD = ±58) ( P = .04). Multiple logistic regression analysis revealed no association between irrigation volume and recurrence, also when stratified for hematoma size. CONCLUSION: There was no significant association between irrigation volume and recurrent CSDH within 90 days in patients undergoing burr hole surgery for CSDH.

Increased intracranial pressure in acute bacterial meningitis.

Acute bacterial meningitis (ABM) is associated with increased intracranial pressure (ICP) caused by bacterial invasion and the host response to infection. Antibiotic therapy is a sine qua non, and adjunct dexamethasone decreases mortality. The ICP increase may have a rapid course and death due to herniation is most often seen within the first week. Evidence regarding treatment of increased ICP in ABM is limited; this review summarises observational studies which point towards reduced mortality by applying a structured approach towards normalization of ICP in ABM.

Intraventricular Lavage vs External Ventricular Drainage for Intraventricular Hemorrhage: A Randomized Clinical Trial.

Importance: Intraventricular lavage has been proposed as a minimally invasive method to evacuate intraventricular hemorrhage. There is little evidence to support its use. Objective: To evaluate the safety and potential efficacy of intraventricular lavage treatment of intraventricular hemorrhage. Design, Setting, and Participants: This single-blinded, controlled, investigator-initiated 1:1 randomized clinical trial was conducted at Aarhus University Hospital and Odense University Hospital in Denmark from January 13, 2022, to November 24, 2022. Follow-up duration was 90 days. The trial was set to include 58 patients with intraventricular hemorrhage. Prespecified interim analysis was performed for the first 20 participants. Data were analyzed from February to April 2023. Interventions: Participants were randomized to receive either intraventricular lavage or standard drainage. Main Outcomes and Measures: The main outcome was risk of catheter occlusions. Additional safety outcomes were catheter-related infections and procedure time, length of stay at the intensive care unit, duration of treatment, and 30-day mortality. The main outcome of the prespecified interim analysis was risk of severe adverse events. Efficacy outcomes were hematoma clearance, functional outcome, overall survival, and shunt dependency. Results: A total of 21 participants (median [IQR] age, 67 [59-82] years; 14 [66%] male) were enrolled, with 11 participants randomized to intraventricular lavage and 10 participants randomized to standard drainage; 20 participants (95%) had secondary intraventricular hemorrhage. The median (IQR) Graeb score was 9 (5-11), and the median (IQR) Glasgow Coma Scale score was 6.5 (4-8). The study was terminated early due to a significantly increased risk of severe adverse events associated with intraventricular lavage at interim analysis (risk difference for control vs intervention, 0.43; 95% CI, 0.06-0.81; P = .04; incidence rate ratio for control vs intervention, 6.0; 95% CI, 1.38-26.1; P = .01). The rate of catheter occlusion was higher for intraventricular lavage compared with drainage (6 of 16 patients [38%] vs 2 of 13 patients [7%]; hazard ratio, 4.4 [95% CI, 0.6-31.2]; P = .14), which met the prespecified α = .20 level. Median (IQR) procedure time for catheter placement was 53.5 (33-75) minutes for intraventricular lavage vs 12 (4-20) minutes for control (P < .001). Conclusions and Relevance: This randomized clinical trial of intraventricular lavage vs standard drainage found that intraventricular lavage was encumbered with a significantly increased number of severe adverse events. Caution is recommended when using the device to ensure patient safety. Trial Registration: ClinicalTrials.gov Identifier: NCT05204849.

Meningioma animal models: a systematic review and meta-analysis.

BACKGROUND: Animal models are widely used to study pathological processes and drug (side) effects in a controlled environment. There is a wide variety of methods available for establishing animal models depending on the research question. Commonly used methods in tumor research include xenografting cells (established/commercially available or primary patient-derived) or whole tumor pieces either orthotopically or heterotopically and the more recent genetically engineered models-each type with their own advantages and disadvantages. The current systematic review aimed to investigate the meningioma model types used, perform a meta-analysis on tumor take rate (TTR), and perform critical appraisal of the included studies. The study also aimed to assess reproducibility, reliability, means of validation and verification of models, alongside pros and cons and uses of the model types. METHODS: We searched Medline, Embase, and Web of Science for all in vivo meningioma models. The primary outcome was tumor take rate. Meta-analysis was performed on tumor take rate followed by subgroup analyses on the number of cells and duration of incubation. The validity of the tumor models was assessed qualitatively. We performed critical appraisal of the methodological quality and quality of reporting for all included studies. RESULTS: We included 114 unique records (78 using established cell line models (ECLM), 21 using primary patient-derived tumor models (PTM), 10 using genetically engineered models (GEM), and 11 using uncategorized models). TTRs for ECLM were 94% (95% CI 92-96) for orthotopic and 95% (93-96) for heterotopic. PTM showed lower TTRs [orthotopic 53% (33-72) and heterotopic 82% (73-89)] and finally GEM revealed a TTR of 34% (26-43). CONCLUSION: This systematic review shows high consistent TTRs in established cell line models and varying TTRs in primary patient-derived models and genetically engineered models. However, we identified several issues regarding the quality of reporting and the methodological approach that reduce the validity, transparency, and reproducibility of studies and suggest a high risk of publication bias. Finally, each tumor model type has specific roles in research based on their advantages (and disadvantages). SYSTEMATIC REVIEW REGISTRATION: PROSPERO-ID CRD42022308833.

Focused ultrasound for the treatment of brain tumors.

This review investigates focused ultrasound for treating neuro-oncological diseases as an emerging treatment modality. The technique is based on focused ultrasound waves guided by MRI. By using high or low-frequency waves, thermoablation of smaller tissue volumes centrally in the brain or a safe, temporary opening of the blood-brain barrier can be carried out for better penetration of chemotherapy. Numerous studies on neuro-oncological treatments are ongoing, signaling increasing popularity for the technique in the near future.

Biomarkers used as risk assessment of mild head injuries.

In Denmark, head injuries are generally managed according to the Scandinavian Neurotrauma Committee Guideline (SNC), which aims to safely reduce head CTs. This review investigates how pre-injury vitamin K-antagonist treatment is associated with adverse outcome in head injury patients, but the significance of other antithrombotics is uncertain. Implementation of S100B in the SNC Guideline has reduced CT usage by approx. 30%. However, S100B could likely be used in a wider array of patients. Despite its usefulness, S100B's popularity is still hampered, likely due to poor practical implementation in Danish emergency rooms.

USP25 Inhibits Neuroinflammatory Responses After Cerebral Ischemic Stroke by Deubiquitinating TAB2.

Cerebral ischemic stroke is a leading cause of morbidity and mortality globally. However, the mechanisms underlying ischemic stroke injury remain poorly understood. Here, it is found that deficiency of the ubiquitin-specific protease USP25 significantly aggravate ischemic stroke injury in mice. USP25 has no impact on neuronal death under hypoxic conditions, but reduced ischemic stroke-induced neuronal loss and neurological deficits by inhibiting microglia-mediated neuroinflammation. Mechanistically, USP25 restricts the activation of NF-κB and MAPK signaling by regulating TAB2. As a deubiquitinating enzyme, USP25 removeds K63-specific polyubiquitin chains from TAB2. AAV9-mediated TAB2 knockdown ameliorates ischemic stroke injury and abolishes the effect of USP25 deletion. In both mouse and human brains, USP25 is markedly upregulated in microglia in the ischemic penumbra, implying a clinical relevance of USP25 in ischemic stroke. Collectively, USP25 is identified as a critical inhibitor of ischemic stroke injury and this data suggest USP25 may serve as a therapeutic target for ischemic stroke.

Inhibition of cystathionine-gamma lyase dampens vasoconstriction in mouse and human intracerebral arterioles.

AIM: In extracerebral vascular beds cystathionine-gamma lyase (CSE) activity plays a vasodilatory role but the role of this hydrogen sulfide (H2 S) producing enzyme in the intracerebral arterioles remain poorly understood. We hypothesized a similar function in the intracerebral arterioles. METHODS: Intracerebral arterioles were isolated from wild type C57BL/6J mouse (9-12 months old) brains and from human brain biopsies. The function (contractility and secondary dilatation) of the intracerebral arterioles was tested ex vivo by pressure myography using a perfusion set-up. Reverse transcription polymerase chain reaction was used for detecting CSE expression. RESULTS: CSE is expressed in human and mouse intracerebral arterioles. CSE inhibition with L-propargylglycine (PAG) significantly dampened the K+ -induced vasoconstriction in intracerebral arterioles of both species (% of maximum contraction: in human control: 45.4 ± 2.7 versus PAG: 27 ± 5.2 and in mouse control: 50 ± 1.5 versus PAG: 33 ± 5.2) but did not affect the secondary dilatation. This effect of PAG was significantly reversed by the H2 S donor sodium hydrosulfide (NaSH) in human (PAG + NaSH: 38.8 ± 7.2) and mouse (PAG + NaSH: 41.7 ± 3.1) arterioles, respectively. The endothelial NO synthase (eNOS) inhibitor, Nω-Nitro-l-arginine methyl ester (L-NAME), and the inhibitor of soluble guanylate cyclase (sGC), 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) reversed the effect of PAG on the K+ -induced vasoconstriction in the mouse arterioles and attenuated the K+ -induced secondary dilatation significantly. CONCLUSION: CSE contributes to the K+ -induced vasoconstriction via a mechanism involving H2 S, eNOS, and sGC whereas the secondary dilatation is regulated by eNOS and sGC but not by CSE.

Prompt closure versus gradual weaning of external ventricular drainage for hydrocephalus following aneurysmal subarachnoid haemorrhage: Protocol for the DRAIN randomised clinical trial.

BACKGROUND: Aneurysmal subarachnoid haemorrhage (aSAH) is a life-threatening disease caused by rupture of an intracranial aneurysm. A common complication following aSAH is hydrocephalus, for which placement of an external ventricular drain (EVD) is an important first-line treatment. Once the patient is clinically stable, the EVD is either removed or replaced by a ventriculoperitoneal shunt. The optimal strategy for cessation of EVD treatment is, however, unknown. Gradual weaning may increase the risk of EVD-related infection, whereas prompt closure carries a risk of acute hydrocephalus and redundant shunt implantations. We designed a randomised clinical trial comparing the two commonly used strategies for cessation of EVD treatment in patients with aSAH. METHODS: DRAIN is an international multi-centre randomised clinical trial with a parallel group design comparing gradual weaning versus prompt closure of EVD treatment in patients with aSAH. Participants are randomised to either gradual weaning which comprises a multi-step increase of resistance over days, or prompt closure of the EVD. The primary outcome is a composite outcome of VP-shunt implantation, all-cause mortality, or ventriculostomy-related infection. Secondary outcomes are serious adverse events excluding mortality, functional outcome (modified Rankin scale), health-related quality of life (EQ-5D) and Fatigue Severity Scale (FSS). Outcome assessment will be performed 6 months after ictus. Based on the sample size calculation (event proportion 80% in the gradual weaning group, relative risk reduction 20%, type I error 5%, power 80%), 122 patients are needed in each intervention group. Outcome assessment for the primary outcome, statistical analyses and conclusion drawing will be blinded. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03948256.

Ventriculosinus shunt: a pilot study to investigate new technology to treat hydrocephalus and mimic physiological principles of cerebrospinal fluid drainage.

OBJECTIVE: Devices draining CSF to the intracranial venous sinus for the treatment of hydrocephalus have been tested in the past, and while clinically effective, have not shown efficacy in the long term. The majority of these devices become obstructed within 3 months due to endothelial overgrowth. In this study, the authors investigated a newly developed ventriculosinus (VS) shunt outlet device with the objective of showing it would remain patent for at least 6 months. METHODS: Twelve patients in need of shunting for hydrocephalus underwent an operation using the investigational device and were followed for 6 months to record patency of the shunt. RESULTS: In 10 patients, the shunt was patent at 6 months, with the outlet device remaining unobstructed. In the remaining 2 patients, one died just before reaching the 6-month endpoint, and in the other the outlet was misplaced during surgery and therefore ceased to function after 3 months. No occlusion of the internal jugular vein or thrombus formation was noted in any of the 12 cases. CONCLUSIONS: These findings indicate that the outlet device can remain patent and has the capability to mimic physiological drainage by diverting CSF to the intracranial sinus. Additional confirmation of its potential as part of a new VS shunt system and ultimately as a viable alternative for ventriculoperitoneal and ventriculoatrial shunting to reduce complication rates requires further clinical trials.

Intraoperative neuromonitoring during intradural spinal neurosurgery.

Intraoperative neuromonitoring (IONM) allows for a perioperative evaluation of the functional integrity of the spinal cord and nerve roots during intradural neurosurgery. This review examines established techniques as somatosensory evoked potentials and motor evoked potentials, as well as electromyography which all provide real-time feedback for the surgical team. IONM represents a valuable tool which can identify emerging neurological complications, and thus can be utilised to reduce the incidence of postoperative neurological deficits by timely interventions.

Retinal vessel dynamics analysis as a surrogate marker for raised intracranial pressure in patients with suspected idiopathic intracranial hypertension.

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-to-venule-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). Arteriole-to-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 15 mm Hg (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 >20 mm Hg (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 >20 mm Hg (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.