Elevated Intracranial Pressure Research Articles

The Na+,K+,2Cl- Cotransporter, Not Aquaporin 1, Sustains Cerebrospinal Fluid Secretion While Controlling Brain K+ Homeostasis.

Disturbances in the brain fluid balance can lead to life-threatening elevation in intracranial pressure (ICP), which represents a vast clinical challenge. Targeted and efficient pharmaceutical therapy of elevated ICP is not currently available, as the molecular mechanisms governing cerebrospinal fluid (CSF) secretion are largely unresolved. To resolve the quantitative contribution of key choroid plexus transport proteins, this study employs mice with genetic knockout and/or viral choroid plexus-specific knockdown of aquaporin 1 (AQP1) and the Na+, K+, 2Cl- cotransporter 1 (NKCC1) for in vivo determinations of CSF dynamics, ex vivo choroid plexus for transporter-mediated clearance of a CSF K+ load, and patient CSF for [K+] quantification. CSF secretion and ICP management occur independently of choroid plexus AQP1 expression, whereas both parameters are reduced by 40% upon choroid plexus NKCC1 knockdown. Elevation of [K+]CSF increases the choroid plexus Na+/K+-ATPase activity, and favors inwardly-directed net NKCC1 transport, which, together, promote CSF K+ clearance, while maintaining undisturbed CSF secretion rates. CSF from patients with post-hemorrhagic hydrocephalus does not display elevated [K+]CSF, suggesting that NKCC1 maintains net outward transport direction during post-hemorrhagic hydrocephalus formation. Direct or indirect therapeutic modulation of choroid plexus NKCC1 can thus be a potential promising pharmacological approach against brain pathologies associated with elevated ICP.

Meningitis criptocócica en un paciente sin VIH. Reporte de caso clínico

Cryptococcal meningitis is a mycosis caused by Cryptococcus neoformans and Gattii, which is transmitted by air and affects the lungs and central nervous system. This disease is a common cause of meningitis in patients with HIV/AIDS; however, in recent years there has been an increase of cases in immunocompetent patients, for this reason, the following case report is made. The objective of this report is to present the case of a patient with cryptococcal meningitis in the absence of HIV infection by reviewing the clinical history. The following is the case of a 67-year-old male with a history of arterial hypertension, under treatment with losartan and amlodipine, who came to the emergency room with a clinical picture of asthenia, algic with severe headache 7/10 VAS scale, the clinical picture evolves with decreased strength in the lower limbs and severe headache 10/10. The need for further investigation of the immunopathological mechanisms of cryptococcal infection in seronegative individuals is emphasized, as understanding the immune responses could improve diagnosis and treatment. In cryptococcal meningitis, elevated intracranial pressure influences prognosis in 50% of cases. Limited diagnostic resources and time hinder accurate identification of the cause and effective treatment in seronegative patients.

High intracranial pressure following endoscopic third ventriculostomy: illustrative case.

Endoscopic third ventriculostomy (ETV) is an effective procedure for the treatment of triventriculomegaly associated with aqueductal stenosis. However, some patients can develop severe and symptomatic intracranial pressure (ICP) elevations in the immediate postoperative period that can be monitored and treated with external ventricular drain (EVD) placement and controlled cerebrospinal fluid (CSF) diversion until the ICP normalizes and symptoms resolve. The authors describe the case of a 39-year-old male who underwent ETV and intraoperative EVD placement for obstructive hydrocephalus associated with aqueductal stenosis. The patient was noted to have sustained ICP elevations in the immediate perioperative period but ultimately experienced a successful clinical outcome without requiring a ventriculoperitoneal shunt. Significant sustained ICP elevations in the immediate postoperative period following ETV can occur and may indicate a prolonged adjustment period. These elevations can be tolerated if the patient's symptoms and ICP are well controlled, with temporary external CSF diversion if the patient becomes symptomatic, as the ICP will likely normalize with a reassuring clinical outcome. https://thejns.org/doi/10.3171/CASE24478.

Prospective comparative clinical trials of novel non-invasive intracranial pressure pulse wave monitoring technologies: preliminary clinical data.

Intracranial pressure (ICP) monitoring is crucial in the management of traumatic brain injury (TBI) and other neurological conditions. Elevated ICP or too low intracranial compliance (ICC) can compromise brain perfusion. Simultaneous monitoring of ICP and ICC is needed to optimize patient-specific brain perfusion in pathological conditions. Surrogate ICC changes can be extracted by analysis of ICP pulse wave morphology. Non-invasive, fully passive sensor and ICC changes monitoring are needed. This study introduces Archimedes, a novel, fully passive, non-invasive ICP wave monitor that utilizes mechanical pulsatile movement of the eyeball to assess ICP pulse waveforms. Preliminary findings indicate a high correlation r = [0.919; 0.96] between non-invasive and invasive ICP pulse wave morphologies, demonstrating the device's potential for accurate ICP pulse waveform monitoring. Additionally, the monitor can discern ICC changes, providing valuable insights for TBI and normal tension glaucoma patients according to the shape of non-invasive measured ICP pulse wave. The k-nearest neighbours algorithm used in preliminary glaucoma studies yielded promising diagnostic performance, with an accuracy of 0.89, sensitivity of 0.82, specificity of 1.0 and area under curve 0.91. Ethical approvals for ongoing studies have been secured. Initial results indicate that Archimedes real-time ICC non-invasive monitor is safe, cost-effective alternative to conventional monitoring techniques.

The Impact of Venous Stenting on Symptoms and Quality of Life in Patients with Idiopathic Intracranial Hypertension and Spontaneous Cerebrospinal Fluid Leak

Abstract Background Elevated intracranial pressure can cause skull base defects and a spontaneous cerebrospinal fluid (CSF) leak. Venous sinus stenting (VSS) has emerged as a promising treatment option for patients with a CSF leak in the setting of idiopathic intracranial hypertension (IIH). There is a lack of literature on symptomatology and quality of life (QOL) after VSS for IIH patients with a CSF leak. This study explores the effects of VSS on symptoms and QOL in IIH patients with a CSF leak. Methods This is a retrospective study on patients who have IIH complicated by a CSF leak and underwent VSS. A QOL questionnaire was developed from the migraine disability assessment test and the PROMIS-PI was given to patients included in this study. Results A total of 10 patients were included in this study. Nine patients underwent endoscopic closure of CSF prior to stent placement and one patient was treated with VSS only. There was no evidence of CSF leak recurrence in this population following VSS. Headaches improved in 5/8, tinnitus in 5/6, and visual disturbance in 4/5 patients. Diamox was discontinued in seven out of eight patients after VSS. There was an improvement in headache-specific questions (p = 0.0140) and overall QOL (p = 0.0061) on the QOL questionnaire. Discussion This preliminary study demonstrates that VSS is effective in alleviating many symptoms in IIH patients with a CSF leak, especially headaches. Diamox may be able to be discontinued in many patients following VSS. No CSF leak recurrence was noted in this patient population.

Craniosynostosis: Current Evaluation and Management.

Craniosynostosis is characterized by the premature fusion of one or more cranial sutures, which can lead to abnormal skull shape and restricted skull growth. Although most cases are present in isolation, some are associated with genetic syndromes, such as Pfeiffer, Muenke, Couzon, Apert, and others, which increases the complexity of care. Today, a spectrum of surgical options to treat craniosynostosis are available and range from traditional open cranial vault remodeling to newer and less invasive suturectomy-based techniques. Which procedure is offered to a patient depends on not only the specific synostosis pattern but also factors such as patient age, the need for additional procedures or interventions, and evidence of elevated intracranial pressure. Thorough consultations with families to discuss achievable goals for cosmesis and function are essential in providing optimal care to each impacted child.

Vascular insult in neonatal retinal hemorrhage: computational analysis of a fundus-segmented blood vessel network

Common hypotheses for the biomechanical cause underlying neonatal retinal hemorrhage include elevated intracranial pressure (ICP) inducing venous outflow obstruction and retinal deformation. A finite element computational model of the eye, optic nerve, and orbit was simulated with particular attention to the retinal vessels to analyze stress and strain on these structures during external head compression associated with normal vaginal delivery. Pressure from maternal contractions displaced the eye backward into the orbit, and the stiff optic nerve sheath provided localized resistance to this posterior displacement at its insertion point, resulting in tensile strain of 2.5% in the peripapillary (central) retina. Correspondingly, retinal vessels experienced tensile stress of up to 2.3 kPa near the optic nerve insertion point and opposing compressive stress of up to 3.2 kPa further away. The optic nerve was longitudinally compressed and experienced a mean radial tensile strain of 2.0%. Overall, forces associated with maternal labor resulted in a pattern of eye deformation that stretched the central retina in this simulation, mirroring the classical posterior localization of neonatal retinal hemorrhage. The optic nerve increased modestly in diameter despite rising ICP, suggesting retinal deformation is a more likely mechanism for retinal hemorrhage than occlusion of the central retinal vein.

Utility of Papilledema for Detection of Elevated Intracranial Pressure in Craniosynostosis

Papilledema is swelling of the optic disk due to fluid accumulation around the optic nerve and is commonly used to detect increased intracranial (ICP) in craniosynostosis. This study aimed to assess the prevalence and utility of papilledema detection in patients with single-suture, multi-suture, and syndromic craniosynostosis and the differences before and after surgical intervention. A retrospective review of ophthalmology examinations of patients diagnosed with craniosynostosis treated between 2008 and 2023 was performed. Demographics, diagnosis, and operative data were collected. A total of 1509 ophthalmology exams of 519 patients were reviewed. The overall rate of papilledema in patients with craniosynostosis was 2.12%. The single-suture and multi-suture involvement rates were 1.15% and 5.81%, respectively. Non-syndromic patients with preoperative and postoperative examinations had an overall rate of 3.13%. Most had single suture involvement, and the average age of papilledema examination was 72 months. Syndromic patients with preoperative and postoperative examinations had an overall rate of 17.65%. The majority had multiple suture involvement, and the average age of papilledema examination was 26 months. The overall papilledema detection rate was low in patients with craniosynostosis. Multi-suture involvement and syndromic diagnosis had increased rates of papilledema. The average age of diagnosis was in older children. Syndromic patients had papilledema examination at a younger age. The authors' findings support the concept that fundoscopic ophthalmologic examination will benefit patients with multi-suture involvement, an associated syndrome, and older age.

Challenges in identifying papilledema amid myopic peripapillary atrophy in a patient with idiopathic intracranial hypertension and high myopia: a case report

BackgroundIdiopathic intracranial hypertension (IIH) is a disease entity characterized by elevated intracranial pressure, which usually accompanied by papilledema. However, diagnosing papilledema can be challenging in patients with preexisting ocular conditions, such as high myopia.Case presentationA 39-year-old woman with a long-standing history of high myopia presented with visual field constriction. Her visual acuity was decreased in both eyes, and she also reported morning headaches, pulsatile tinnitus, and intermittent periocular pain. Although she was diagnosed with IIH based on a cerebrospinal fluid study, there was no evident papilledema, which may have been masked by myopic changes in optic nerve and peripapillary retinal nerve fiber layer. After treatment for IIH with acetazolamide, her visual field and visual acuity markedly improved, and her symptoms were relieved.ConclusionsIn highly myopic patients, myopic changes in optic nerve head may obscure papilledema, complicating the diagnosis of IIH. This unusual case highlights the need for detailed history taking and a comprehensive clinical evaluation in patients with high myopia. Clinicians should suspect IIH in the presence of symptoms such as pulsatile tinnitus, morning headache, and visual field constriction, even in the absence of evident papilledema.

Unilateral papilledema: illustrative case.

Idiopathic intracranial hypertension is caused by an elevation of intracranial pressure and can present with slowly progressive visual deterioration from bilateral papilledema. Unilateral papilledema is an exceedingly rare phenomenon, and the mechanisms underlying asymmetric optic nerve involvement remain unknown. A 42-year-old woman presented with acute left-eye blurred vision and extraocular pain. Examination revealed unilateral left optic disc edema with an enlarged blind spot, while the right optic disc appeared flat. Neuroimaging examination was suggestive of intracranial hypertension, characterized by flattening of the posterior globes and narrowing of bilateral distal transverse sinuses. Increased intracranial pressure was confirmed by lumbar puncture. Acetazolamide and weight loss yielded initial improvement, but recurrence prompted cerebral arteriography, revealing a transstenotic gradient in the right distal transverse sinus and hypoplastic left sigmoid and transverse sinuses with extensive collateralization to the left cavernous sinus. Stenting of the right transverse sinus successfully alleviated the optic disc swelling. This case highlights the intricate interplay between venous sinus dynamics and unilateral papilledema, underscoring the importance of tailored interventions. https://thejns.org/doi/10.3171/CASE24385.

Transcranial Ultrasound Guided Assessment of Brain Midline Shift in Neuro Intensive Care Unit

Background: Neuro Intensive Care Unit (Neuro-ICU) handles neurological emergencies that involve intracranial (IC) hemorrhages. It can be challenging to manage elevated intracranial pressure (ICP) and midline shift (MLS), as they requires constant monitoring and frequent imaging. Trans-cranial Color Coded Sonography (TCCS), a bedside monitoring tool, may be helpful in monitoring MLS under such conditions. Objectives: To correlate MLS of the third ventricle in the brain measured by TCCS with CT midline shift. Method: A prospective observational study was conducted on patients with IC bleed who were mechanically ventilated and had a head CT done to rule out MLS. Within an hour of doing a CT brain, TCCS-MLS was identified. Data was collected and analyzed. Results: A total of fifty patients studied, the MLS (mean ±SD) was 5.3mm ± 3.1 mm using TCCS and 6.7±4.4 mm using CT brain. The calculated midline shift between TCCS and CT brain demonstrated a Pearson's correlation of 0.78 (P<0.001). With TCCS, the area under the ROC curve to identify a significant MLS was 0.91 (95%CI=0.8-1). TCCS-MLS of 3.9mm as a cut-off, predicted the occurrence of >5mm MLS on CT scan with a sensitivity of 95% and specificity of 90%. Conclusions: This study suggests that TCCS could serve as an alternative bedside monitoring tool in patients whose transportation is risky, in predicting the transcranial MLS >5mm with reasonable accuracy.

The Value of Machine Learning Models in Predicting Factors Associated with the Need for Permanent Shunting in Patients with Intracerebral Hemorrhage Requiring Emergency Cerebrospinal Fluid Diversion

ObjectiveTo assess the efficacy of machine learning models (MLMs) in identifying factors associated with the need for permanent ventricular shunt placement in patients experiencing intracerebral hemorrhage (ICH) who require emergency cerebrospinal fluid (CSF) diversion. MethodsA retrospective review was performed on patients with ICH requiring urgent CSF diversion who were admitted to our facility between July 2009 and May 2023. A binary logistic regression analysis was carried out to determine independent predictors linked to the development of shunt-dependent hydrocephalus following ICH. Five different machine learning models—random forest (RF), support vector machine (SVM), k-nearest neighbor (k-NN), logistic regression (LR), and Adaptive Boosting (AdaBoost)—were utilized to predict the need for permanent shunting in those with spontaneous ICH necessitating emergency CSF diversion. Additionally, RF techniques were applied to identify the factors affecting the need for permanent ventricular shunt placement in these patients. ResultsA total of 578 patients were included in the analysis. Shunt-dependent hydrocephalus occurred in 121 individuals (20.9%). In the multivariate analysis, the Graeb Score, the length of time the external ventricular drain (EVD) was in place, and an elevated intracranial pressure (ICP) greater than 30 mm Hg were significant predictors for the need for permanent CSF diversion (p<0.05). All predictive models showed commendable performance, with RF achieving the highest accuracy (0.921), followed by SVM (0.906), k-NN (0.889), LR (0.881), and AdaBoost (0.823). RF also excelled over the other models in terms of sensitivity and specificity, with a sensitivity of 0.912 and specificity of 0.892. The area under the curve (AUC) values for RF, SVM, k-NN, LR, and AdaBoost were recorded at 0.903, 0.820, 0.804, 0.801, and 0.798, respectively. ConclusionThis research demonstrates that machine learning models can effectively predict the need for permanent CSF diversion in patients with ICH who underwent EVD placement for urgent CSF diversion, offering important prognostic insights that could facilitate early intervention and lead to potential cost reductions.

A systematic review of surgical and interventional radiology procedures for pediatric idiopathic intracranial hypertension.

Idiopathic intracranial hypertension (IIH) is defined as elevated intracranial pressure and consequent symptoms (mainly headache and visual deterioration) occurring in the absence of secondary causes. Surgical and interventional radiology procedures should be considered for refractory IIH and mainly include cerebrospinal fluid (CSF) diversion techniques, optic nerve sheath fenestration (ONSF), and venous sinus stenting (VSS). Our study aims to review the current literature on the application of these techniques in clinical practice. A systematic literature review on the surgical and interventional radiology treatment of IIH was conducted, focusing on ONSF, VSS, and CSF diversion techniques. According to PRISMA guidelines, all reports published in PubMed in the last 30 years (1993-2023) were considered, and among 722 papers, 48 were included in the present study, resulting in a total study population of 454 children or adolescents (11 months-17 years old). Among 454 patients, 193 underwent an invasive approach, divided into CSF diversion (115/193), ONSF (65/193), VSS (11/193), cranial subtemporal decompression (8/193), and internal cranial expansion (9/193). Sixteen of the 193 patients (8%) required reintervention due to relapsing symptoms or surgical complications, particularly those who underwent CSF diversion. Furthermore, 9/115 required shunt revision due to shunt obstruction or malfunction. We extracted data on the outcome of each procedure: of the 193 patients, 71 experienced a positive outcome with symptom resolution or improvement, while 27 demonstrated a negative outcome. Severe and refractory cases of IIH are eligible for invasive treatments. CSF diversion is the most frequently used technique, despite its high failure risk and need for reintervention. ONSF has shown good results in terms of outcome and safety, particularly in children with visual symptoms. VSS is the most recent approach, indicated in children with stenosis of the venous sinus. In our study population, VSS demonstrated good results in terms of symptom resolution and need for reintervention, but its use remains limited to a few centers. https://www.crd.york.ac.uk/, PROSPERO (CRD42024504244).

A Case Report of Systemic Steroid Therapy for False Brain Tumors in Children

Study design: Case report. Purpose: to study the efficacy of systemic steroid in pediatric pseudotumor cerebri. Introduction: Pseudotumor cerebri is a condition caused by elevated intracranial pressure presenting most commonly with headache. It is a diagnosis of exculsion. Methods: A 15 year old girl presented in our OPD with headache since 3months, more in the posterior aspect, continuous type with severe intensity, non - radiating. On examination, her best corrected visual acuity in right eye was 6/9 and left eye was 6/6parts. She had normal anterior segment, normal IOP. Fundoscopy showed both optic discs edematous, pink in color with blurry disc margins, tortuous disc vessels, edematous peripapillary area. Rest of the retina was normal. Lumbar puncture showed elevated opening CSF pressure and normal CSF composition. Hence, she was diagnosed with IIH. She was started on oral prednisolone 1mg/kgbw once a day dosage, oral acetazolamide 250mg once a day, topical nepafenac 0.1% one drop thrice a day and timolol 0.5% eye drops twice a day. Discussion: The main goals of treatment are alleviation of symptoms, including headache, and preservation of vision. Steroids were commonly used for treating IIH in the past, but cause significant long - term side effects, such as weight gain, that are undesirable in IIH patients. Furthermore, withdrawal of steroids can cause rebound intracranial hypertension. Thus, steroids should not be used routinely for IIH treatment. Results: By the end of one month, patient was relieved of symptoms, best corrected visual acuity was 6/6 in both eyes with normal IOP, normal optic disc in both eyes. Conclusion: Steroids are an effective way of managing idiopathic intracranial hypertension in pediatric patients.

Use of extracorporeal membrane oxygenation during a decompressive hemicraniectomy for severe traumatic brain injury: illustrative case.

Decompressive hemicraniectomy (DHC) can be a life-saving treatment for patients with severe traumatic brain injury (TBI) with a focal mass lesion who develop refractory elevated intracranial pressure (ICP). Nonetheless, successful completion of this procedure requires maintaining hemodynamic and respiratory stability. Extracorporeal membrane oxygenation (ECMO) use in patients with respiratory or cardiac failure is well described in the literature and has become routinely used in patients with refractory hypoxia unresponsive to traditional mechanical ventilation strategies, but few cases of its use have been reported in the neurosurgical literature. Herein, the authors describe a unique case in which a man presented after an unwitnessed fall that caused severe TBI without a focal mass lesion. The patient subsequently developed medically refractory elevated ICP secondary to traumatic cerebral edema. He required DHC, but the procedure could only be completed safely with the utilization of intraoperative ECMO. As more is learned about the techniques and pitfalls of ECMO, its indications are rapidly expanding. The case presented describes the safe use of ECMO during a major neurosurgical procedure, showing that the technique can be completed safely and offering a therapeutic option for effectively addressing refractory hypoxia and hypercarbia in patients with severe TBI who require urgent or emergency neurosurgical procedures. https://thejns.org/doi/10.3171/CASE24264.

Cerebral haemodynamics and intracranial pressure during haemorrhagic shock and resuscitation with total endovascular balloon occlusion of the aorta in an animal model.

To assess changes of cerebral haemodynamic and intracranial pressure (ICP) in animals, with or without elevated ICP, during controlled haemorrhagic shock and resuscitation with Total REBOA (tREBOA). In 22 anaesthetized and normoventilated pigs, after placement of catheters for monitoring invasive proximal blood pressure (pMAP), ICP, and vital parameters, and 60min stabilisation phase, a controlled haemorrhagic shock (HS), was conducted. In 11 pigs (EICPG), an elevated ICP of 25-30 mmHg at the end HS was achieved by simulating an epidural mass. In 11 pigs (NICPG), the ICP was normal. tREBOA was then applied for 120min. The changes of pMAP and ICP were followed, and cerebral perfusion pressure (CPP) calculated. The integrity of the autoregulation was estimated using a calculated Modified-Long Pressure Reactivity Index (mL-PRx). After stabilisation, hemodynamics and physiological parameters were similar and normal in both groups. At the end of the HS, ICP was 16 mmHg in NICPG vs. 32 in EICPG (p = 0.0010). CPP was 30 mmHg in NICPG vs. 6 mmHg in EICPG (p = 0.0254). After aorta occlusion CPP increased immediately in both groups reaching after 15min up to104 mmHg in NICPG vs. 126 mmHg in EICPG. Cerebrovascular reactivity seems to be altered during bleeding and occlusion phases in both groups with positive mL-PRx. The alteration was more pronounced in EICPG, but reversible in both groups. tREBOA is lifesaving by restoration the cerebral circulation defined as CPP in animals with HS with normal or elevated ICP. Despite the observation of short episodes of cerebral autoregulation impairment during the occlusion, mainly in EICPG, tREBOA seems to be an effective tool for improving cerebral perfusion in HS that extends the crucial early window sometimes known as the "golden hour" for resuscitation even after a traumatic brain injury.

Non-invasive assessment of intracranial pressure through the eyes: current developments, limitations, and future directions.

Detecting and monitoring elevated intracranial pressure (ICP) is crucial in managing various neurologic and neuro-ophthalmic conditions, where early detection is essential to prevent complications such as seizures and stroke. Although traditional methods such as lumbar puncture, intraparenchymal and intraventricular cannulation, and external ventricular drainage are effective, they are invasive and carry risks of infection and brain hemorrhage. This has prompted the development of non-invasive techniques. Given that direct, non-invasive access to the brain is limited, a significant portion of research has focused on utilizing the eyes, which uniquely provide direct access to their internal structure and offer a cost-effective tool for non-invasive ICP assessment. This review explores the existing non-invasive ocular techniques for assessing chronically elevated ICP. Additionally, to provide a comprehensive perspective on the current landscape, invasive techniques are also examined. The discussion extends to the limitations inherent to each technique and the prospective pathways for future advancements in the field.

No Benefit of 3% Hypertonic Saline Following Experimental Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is a stroke subtype with a high mortality rate (~ 40%). After ICH, the mass effect of the hematoma and edema contribute to raised intracranial pressure (ICP) and poor outcome. Endogenous compensatory mechanisms that blunt ICP elevations include redirection of venous blood and cerebrospinal fluid, along with brain tissue compliance (e.g., decreased cell volume, increased cell density); however, these limited reserves can be exhausted after severe stroke, resulting in decompensated ICP that requires careful clinical management. Management strategies can include administration of hypertonic saline (HTS), an osmotic agent that putatively attenuates edema, and thereby ICP elevations. Evidence regarding the efficacy of HTS treatment following ICH remains limited. In this study, adult male rats were given a collagenase-induced striatal ICH and a bolus of either 3% HTS or 0.9% saline vehicle at 2- and 14-hours post-stroke onset. Neurological deficits, edema, ipsilateral cell volume and density (in areas S1 and CA1), and contralateral CA1 ultrastructural morphology were assessed 24 h post-ICH. Animals had large bleeds (median 108.2 µL), extensive edema (median 83.9% brain water content in ipsilateral striatum), and evident behavioural deficits (median 5.4 neurological deficit scale score). However, HTS did not affect edema (p ≥ 0.4797), behaviour (p = 0.6479), cell volume (p ≥ 0.1079), or cell density (p ≥ 0.0983). Qualitative ultrastructural assessment of contralateral area CA1 suggested that HTS administration was associated with paradoxical cellular swelling in ICH animals. Overall, there was no benefit with administering 3% HTS after ICH.

Brain hypoxia and metabolic crisis are common in patients with acute brain injury despite a normal intracranial pressure

Patients with acute brain injury are vulnerable to secondary deterioration, which may go undetected by traditional monitoring. However, multimodal neuromonitoring of brain tissue oxygen tension (PbtO2) and energy metabolism may be able to detect such episodes. We report a retrospective, observational study of 94 patients with aneurysmal subarachnoid haemorrhage (SAH) or traumatic brain injury (TBI) who underwent multimodal neuromonitoring during admission. We examined the co-occurrence of pathological neuromonitoring values: elevated intracranial pressure (ICP, > 20 mmHg), inadequate cerebral perfusion pressure (CPP, < 60 mmHg), brain hypoxia (PbtO2 < 20 mmHg), and metabolic crisis (lactate/pyruvate ratio > 40 and a glucose level < 0.2 mmol/L in cerebral microdialysate). Mixed effects linear regression demonstrated significant associations between abnormal ICP/CPP, cerebral hypoxia and metabolic crisis. However, brain hypoxia occurred in 40% and 31% of observations in patients with SAH and TBI, respectively, despite normal concurrent values of ICP. Similarly, metabolic crisis was observed in 8% and 16% of measurements for SAH and TBI, respectively, despite a normal ICP. The pattern was identical for CPP. In conclusion, although all neuromonitoring variables are interrelated, brain hypoxia and metabolic crisis are common despite an absence of abnormalities in conventional monitoring. Multimodal neuromonitoring may help identify such episodes and guide individualised treatment.

Deep learning from head CT scans to predict elevated intracranial pressure.

Elevated intracranial pressure (ICP) resulting from severe head injury or stroke poses a risk of secondary brain injury that requires neurosurgical intervention. However, currently available noninvasive monitoring techniques for predicting ICP are not sufficiently advanced. We aimed to develop a minimally invasive ICP prediction model using simple CT images to prevent secondary brain injury caused by elevated ICP. We used the following three methods to determine the presence or absence of elevated ICP using midbrain-level CT images: (1) a deep learning model created using the Python (PY) programming language; (2) a model based on cistern narrowing and scaling of brainstem deformities and presence of hydrocephalus, analyzed using the statistical tool Prediction One (PO); and (3) identification of ICP by senior residents (SRs). We compared the accuracy of the validation and test data using fivefold cross-validation and visualized or quantified the areas of interest in the models. The accuracy of the validation data for the PY, PO, and SR methods was 83.68% (83.42%-85.13%), 85.71% (73.81%-88.10%), and 66.67% (55.96%-72.62%), respectively. Significant differences in accuracy were observed between the PY and SR methods. Test data accuracy was 77.27% (70.45%-77.2%), 84.09% (75.00%-85.23%), and 61.36% (56.82%-68.18%), respectively. Overall, the outcomes suggest that these newly developed models may be valuable tools for the rapid and accurate detection of elevated ICP in clinical practice. These models can easily be applied to other sites, as a single CT image at the midbrain level can provide a highly accurate diagnosis.