Ambulatory intracranial pressure in humans: ICP increases during movement between body positions.

Introduction: Positional changes in intracranial pressure (ICP) have been described in humans when measured over minutes or hours in a static posture, with ICP higher when lying supine than when sitting or standing upright. However, humans are often ambulant with frequent changes in position self-generated by active movement. Research question: We explored how ICP changes during movement between body positions. Material and methods: Sixty-two patients undergoing clinical ICP monitoring were recruited. Patients were relatively well, ambulatory and of mixed age, body habitus and pathology. We instructed patients to move back and forth between sitting and standing or lying and sitting positions at 20 s intervals after an initial 60s at rest. We simultaneously measured body position kinematics from inertial measurement units and ICP from an intraparenchymal probe at 100 Hz. Results: ICP increased transiently during movements beyond the level expected by body position alone. The amplitude of the increase varied between participants but was on average ∼5 mmHg during sit-to-stand, stand-to-sit and sit-to-lie movements and 10.8 mmHg [95%CI: 9.3,12.4] during lie-to-sit movements. The amplitude increased slightly with age, was greater in males, and increased with median 24-h ICP. For lie-to-sit and sit-to-lie movements, higher BMI was associated with greater mid-movement increase (ß = 0.99 [0.78,1.20]; ß = 0.49 [0.34,0.64], respectively). Discussion and conclusion: ICP increases during movement between body positions. The amplitude of the increase in ICP varies with type of movement, age, sex, and BMI. This could be a marker of disturbed ICP dynamics and may be particularly relevant for patients with CSF-diverting shunts in situ.

Correlation Between Volume and Pressure of Intracranial Space With Craniectomy Surface Area and Brain Herniation: A Phantom-Based Study.

There are proponents of decompressive craniectomy (DC) and its various modifications who claim reasonable clinical outcomes for each of them. Clinical outcome in cases of traumatic brain injury, managed conservatively or aided by different surgical techniques, depends on multiple factors, which vary widely among patients and have complex interplay, making it difficult to compare one case with another in absolute terms. This forms the basis of the perceived necessity to have a standard model to study, compare, and strategize in this field. We designed a phantom-based model and present the findings of the study aimed at establishing a correlation of the volume of intracranial space and changes in intracranial pressure (ICP) with surface area of the craniectomy defect created during DC and brain herniation volume. A roughly hemispherical radio-opaque container was scanned on a 128-slice computed tomography scanner. Craniectomies of different sizes and shapes were marked on the walls of the phantom. Two spherical sacs of stretchable materials were subsequently placed inside the phantom, fixed to three-way connectors, filled with water, and connected with transducers. The terminals of the transducer cables were coupled with the display monitor through a signal amplifier and processor module. Parts of the wall of the phantom were removed to let portions of the sac herniate through the defect, simulating a DC. Volume measurements using AW volume share 7® software were done. Resection of a 12.7 × 11.5 cm part of the wall resulted in a 10-cm-diameter defect in the wall. Volume differential of 35 mL created a midline shift of 5 mm to the side with lesser volume. When measuring pressure in two stretchable sacs contained inside the phantom, there always remained a pressure differential ranging from 1 to 2 mm Hg in different recordings, even with sacs on both sides containing an equal volume of fluids. Creating a circular wall defect of 10 cm in diameter with an intracavitary pressure of 35 mm Hg on the ipsilateral sac and 33 mm on the contralateral sac recorded with intact walls, resulted in a true volume expansion of 48.411 cm3. The herniation resulted in a reduction of pressure in both sacs, with the pressure recorded as 25 mm in the ipsilateral sac and 24 mm in the contralateral sac. The findings closely matched those of the other model-based studies. Refinement of the materials used is likely to provide a valid platform to study cranial volume, ICP, craniectomy size, and brain prolapse volume in real time. The model will help in pre-operatively choosing the most appropriate technique between a classical DC, a hinge craniotomy, and an expansive cranioplasty technique in cases of refractory raised ICP.

Optimization of number and range of shunt valve performance levels in infant hydrocephalus: a machine learning analysis.

Shunt surgery is the main treatment modality for hydrocephalus, the leading cause of brain surgery in children. The efficacy of shunt surgery, particularly in infant hydrocephalus, continues to present serious challenges in achieving improved outcomes. The crucial role of correct adjustments of valve performance levels in shunt outcomes has been underscored. However, there are discrepancies in the performance levels of valves from different companies. This study aims to address this concern by optimizing both the number and range of valve performance levels for infant hydrocephalus, aiming for improved shunt surgery outcomes. We conducted a single-center cohort study encompassing infant hydrocephalus cases that underwent initial shunt surgery without subsequent failure or unimproved outcomes. An unsupervised hierarchical machine learning method was utilized for clustering and reporting the valve drainage pressure values for all patients within each identified cluster. The optimal number of clusters corresponds to the number of valve performance levels, with the valve drainage pressure ranges within each cluster indicating the pressure range for each performance level. Comparisons based on the Silhouette coefficient between 3-7 clusters revealed that this coefficient for the 4-cluster (4-performance level) was at least 28.3% higher than that of other cluster formations in terms of intra-cluster similarity. The Davies-Bouldin index for the 4-performance level was at least 37.2% lower than that of other configurations in terms of inter-cluster dissimilarity. Cluster stability, indicated by a Jaccard index of 71% for the 4-performance level valve, validated the robustness, reliability, and repeatability of our findings. Our suggested optimized drainage pressure ranges for each performance level (1.5-5.0, 5.0-9.0, 9.0-15.0, and 15.0-18.0 cm H2O) may potentially assist neurosurgeons in improving clinical outcomes for patients with shunted infantile hydrocephalus.

Long-term sequelae of normocephalic pansynostosis: a rare but insidious entity.

OBJECTIVE: Patients with normocephalic pansynostosis, who have a grossly normal head shape, are often overlooked early in life and present late with elevated intracranial pressure (ICP) requiring timely cranial vault expansion. This study evaluates the long-term clinical outcomes of patients with normocephalic pansynostosis. METHODS: We retrospectively reviewed patients with a clinical and radiographic diagnosis of primary pansynostosis who underwent vault reconstruction between 2000 and 2023. Clinical and treatment course after craniofacial interventions was followed in patients with normocephaly to assess outcomes. RESULTS: Thirty-five patients with primary pansynostosis were identified, of which eight (23.5%) had normocephaly and underwent initial vault expansion at a mean age of 5.0 ± 2.4 years. All eight patients (50.0% male) presented with symptoms of elevated ICP including headaches (50.0%), nausea and vomiting (50.0%), and developmental delay (62.5%) and/or signs of elevated ICP including papilledema (75.0%) and radiologic thumbprinting on head computed tomography scan (87.5%). Three of the four normocephalic patients who had over 7 years of postoperative follow-up developed subjective headaches, vision changes, or learning and behavioral issues in the long-term despite successful vault reconstruction. CONCLUSIONS: Our longitudinal experience with this rare but insidious entity demonstrates the importance of timely intervention and frequent postoperative monitoring, which are critical to limiting long-term neurological sequelae. Multidisciplinary care by craniofacial surgery, neurosurgery, ophthalmology, and neuropsychology with follow-up into adolescence are recommended to assess for possible recurrence of elevated ICP secondary to cranio-cerebral disproportion.

Black hole sign migration in short-term brain CT scans: A possible link with clot evolution and histology.

The black hole sign (BHS) is a rare radiological sign seen in the hyperacute phase of bleeding. It manifests within a hemorrhage in early hours, with limited studies exploring clot formation and evolution over a short duration. Despite various hypothesized mechanisms, the precise lifetime and dynamics of black hole sign development remain unclear. We describe the rare finding of a black hole sign within a deep brain hemorrhage, initially observed in the lateral portion of the clot during the first CT scan. Remarkably, in a subsequent CT scan, just 1 hour later, the BHS migrated towards the inner edge. Notably, while the hemorrhage size remained largely unchanged within this short timeframe, hyperacute bleeding led to increased perihematomal edema and sulci flattening. Histopathological features of the "evolving clot" are initially characterized by heightened cellularity. This increased cell density renders the hematoma less resistant to compressive forces, such as heightened endocranial pressure, offering a plausible explanation for the crushing and displacement of the BHS. Our study sheds light on the unique radiological progression of BHS within a deep brain ICH, emphasizing its association with dynamic clot formation and the consequential impact on surrounding structures.

Toward the "Perfect" Shunt: Historical Vignette, Current Efforts, and Future Directions.

As a concept, drainage of excess fluid volume in the cranium has been around for more than 1000 years. Starting with the original decompression-trepanation of Abulcasis to modern programmable shunt systems, to other nonshunt-based treatments such as endoscopic third ventriculostomy and choroid plexus cauterization, we have come far as a field. However, there are still fundamental limitations that shunts have yet to overcome: namely posture-induced over- and underdrainage, the continual need for valve opening pressure especially in pediatric cases, and the failure to reinstall physiologic intracranial pressure dynamics. However, there are groups worldwide, in the clinic, in industry, and in academia, that are trying to ameliorate the current state of the technology within hydrocephalus treatment. This chapter aims to provide a historical overview of hydrocephalus, current challenges in shunt design, what members of the community have done and continue to do to address these challenges, and finally, a definition of the "perfect" shunt is provided and how the authors are working toward it.

Exposure to topiramate and acetazolamide causes endocrine disrupting effects in female rats during estrus.

BACKGROUND: Idiopathic intracranial hypertension (IIH) is a disease characterized by elevated intracranial pressure (ICP) and is a disease of young females. The first line pharmacological treatments include acetazolamide and topiramate and given the nature of IIH patients and the dosing regimen of these drugs, their effect on the endocrine system is important to evaluate. We aimed to assess the effects of acetazolamide and topiramate on steroid profiles in relevant endocrine tissues. METHODS: Female Sprague Dawley rats received chronic clinically equivalent doses of acetazolamide or topiramate by oral gavage and were sacrificed in estrus. Tissue specific steroid profiles of lateral ventricle CP, 4th ventricle CP, CSF, serum, uterine horn and fundus, ovaries, adrenal glands and pituitary glands were assessed by quantitative targeted LC-MS/MS. We determined luteinizing hormone (LH) and follicle stimulating hormones (FSH) levels in paired serum by ELISA. RESULTS: Topiramate increased the concentration of estradiol and decreased the concentration of DHEA in lateral choroid plexus. Moreover, it decreased the concentration of androstenediol in the pituitary gland. Topiramate increased serum LH. Acetazolamide decreased progesterone levels in serum and uterine fundus and increased corticosteroid levels in the adrenal glands. CONCLUSION: These results demonstrate that both acetazolamide and topiramate have endocrine disrupting effects in rats. Topiramate primarily targeted the choroid plexus and the pituitary gland while acetazolamide had broader systemic effects. Furthermore, topiramate predominantly targeted sex hormones, whereas acetazolamide widely affected all classes of hormones. A similar effect in humans has not yet been documented but these concerning findings warrants further investigations.

Telemetric ICP monitoring in children: a national questionnaire-based study.

PURPOSE: Telemetric monitoring of intracranial pressure (ICP) facilitates long-term measurements and home monitoring, thus potentially reducing diagnostic imaging and acute hospital admissions in favour of outpatient appointments. Especially in paediatric patients, telemetric ICP monitoring requires a high level of collaboration and compliance from patients and parents. In this study, we aim to systematically investigate (1) patient and parent perception of telemetric ICP system utility and (2) hospital contact history and thus the potential cost-benefit of telemetric ICP monitoring in paediatric patients with a cerebrospinal fluid disorder. METHODS: We conducted a nationwide questionnaire study, including paediatric patients with either a current or previous telemetric ICP sensor and their parents. Additionally, a retrospective review of electronic health records for all included children was performed. RESULTS: We included 16 children (age range 3-16 years), with a total of 41 telemetric ICP sensors implanted. Following sensor implantation, the frequency of telephone contacts and outpatient visits increased. No corresponding decrease in hospital admissions or total length of stay was found. The telemetric ICP sensor provided most parents with an improved sense of security and was seen as a necessary and valuable tool in treatment guidance. The size and shape of the sensor itself were reported as disadvantages, while the external monitoring equipment was reported as easy to use but too large and heavy for a child to carry. CONCLUSION: Though, in quantitative terms, there was no cost-benefit of the telemetric ICP sensor, it contributed to extended parental involvement and a sense of improved safety.

Analysis of Cerebral Spinal Fluid Drainage and Intracranial Pressure Peaks in Patients with Subarachnoid Hemorrhage.

BACKGROUND: After aneurysmal subarachnoid hemorrhage (aSAH), elevated intracranial pressure (ICP) due to disrupted cerebrospinal fluid (CSF) dynamics is a critical concern. An external ventricular drainage (EVD) is commonly employed for management; however, optimal strategies remain debated. The randomized controlled Earlydrain trial showed that an additional prophylactic lumbar drainage (LD) after aneurysm treatment improves neurological outcome. We performed a post hoc investigation on the impact of drainage volumes and critical ICP values on patient outcomes after aSAH. METHODS: Using raw patient data from Earlydrain, we analyzed CSF drainage amounts and ICP measurements in the first 8 days after aSAH. Outcomes were the occurrence of secondary infarctions and the score on the modified Rankin scale after 6 months, dichotomized in values of 0-2 as favorable and 3-6 as unfavorable. Repeated measurements were considered with generalized estimation equations. RESULTS: Earlydrain recruited 287 patients, of whom 221 received an EVD and 140 received an LD. Higher EVD volumes showed a trend to more secondary infarctions (p = 0.09), whereas higher LD volumes were associated with less secondary infarctions (p = 0.009). The mean total CSF drainage was 1052 ± 659 mL and did not differ concerning infarction and neurological outcome. Maximum ICP values were higher in patients with poor outcomes but not related to drainage volumes via EVD. After adjustment for aSAH severity and total CSF drainage, higher LD volume was linked to favorable outcome (per 100 mL: odds ratio 0.61 (95% confidence interval 0.39-0.95), p = 0.03), whereas higher EVD amounts were associated with unfavorable outcome (per 100 mL: odds ratio 1.63 (95% confidence interval 1.05-2.54), p = 0.03). CONCLUSIONS: Findings indicate that effects of CSF drainage via EVD and LD differ. Higher amounts and higher proportions of LD volumes were associated with better outcomes, suggesting a potential quantity-dependent protective effect. Optimizing LD volume and mitigating ICP spikes may be a strategy to improve patient outcomes after aSAH. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01258257.

Transcranial Ultrasound in the Neurocritical Care Unit.

Ultrasound evaluation of the brain is performed through acoustic windows. Transcranial Doppler has long been used to monitor patients with subarachnoid hemorrhage for cerebral vasospasm. Transcranial color-coded sonography permits parenchymal B-mode imaging and duplex evaluation. Transcranial ultrasound may also be used to assess the risk of delayed cerebral ischemia, screen patients for the presence of elevated intracranial pressure, confirm the diagnosis of brain death, measure midline shift, and detect ventriculomegaly. Transcranial ultrasound should be integrated with other point-of-care ultrasound techniques as an essential skill for the neurointensivist.

Prediction of Intracranial Pressure in Patients with an Aneurysmal Subarachnoid Hemorrhage Using Optic Nerve Sheath Diameter via Explainable Predictive Modeling.

Background: The objective of this investigation was to formulate a model for predicting intracranial pressure (ICP) by utilizing optic nerve sheath diameter (ONSD) during endovascular treatment for an aneurysmal subarachnoid hemorrhage (aSAH), incorporating explainable predictive modeling. Methods: ONSD measurements were conducted using a handheld ultrasonography device during the course of endovascular treatment (n = 126, mean age 58.82 ± 14.86 years, and female ratio 67.46%). The optimal ONSD threshold associated with an increased ICP was determined. Additionally, the association between ONSD and ICP was validated through the application of a linear regression machine learning model. The correlation between ICP and various factors was explored through the modeling. Results: With an ICP threshold set at 20 cmH2O, 82 patients manifested an increased ICP, with a corresponding ONSD of 0.545 ± 0.08 cm. Similarly, with an ICP threshold set at 25 cmH2O, 44 patients demonstrated an increased ICP, with a cutoff ONSD of 0.553 cm. Conclusions: We revealed a robust correlation between ICP and ONSD. ONSD exhibited a significant association and demonstrated potential as a predictor of ICP in patients with an ICP ≥ 25 cmH2O. The findings suggest its potential as a valuable index in clinical practice, proposing a reference value of ONSD for increased ICP in the institution.

Using EEG total energy as a noninvasively tracking of intracranial (and cerebral perfussion) pressure in an animal model: A pilot study.

PURPOSE: This study aims to describe the total EEG energy during episodes of intracranial hypertension (IH) and evaluate its potential as a classification feature for IH. NEW METHODS: We computed the sample correlation coefficient between intracranial pressure (ICP) and the total EEG energy. Additionally, a generalized additive model was employed to assess the relationship between arterial blood pressure (ABP), total EEG energy, and the odds of IH. RESULTS: The median sample cross-correlation between total EEG energy and ICP was 0.7, and for cerebral perfusion pressure (CPP) was 0.55. Moreover, the proposed model exhibited an accuracy of 0.70, sensitivity of 0.53, specificity of 0.79, precision of 0.54, F1-score of 0.54, and an AUC of 0.7. COMPARISON WITH EXISTING METHODS: The only existing comparable methods, up to our knowledge, use 13 variables as predictor of IH, our model uses only 3, our model, as it is an extension of the generalized model is interpretable and it achieves the same performance. CONCLUSION: These findings hold promise for the advancement of multimodal monitoring systems in neurocritical care and the development of a non-invasive ICP monitoring tool, particularly in resource-constrained environments.

Effect of different positive end expiratory pressure levels on optic nerve sheath diameter in patients with or without midline shift who are undergoing supratentorial craniotomy.

PURPOSE: In general, high levels of PEEP application is avoided in patients undergoing craniotomy to prevent a rise in ICP. But that approach would increase the risk of secondary brain injury especially in hypoxemic patients. Because the optic nerve sheath is distensible, a rise in ICP is associated with an increase in the optic nerve sheath diameter (ONSD). The cutoff value for elevated ICP assessed by ONSD is between 5.6 and 6.3 mm. We aimed to evaluate the effect of different PEEP levels on ONSD and compare the effect of different PEEP levels in patients with and without intracranial midline shift. METHODS: This prospective observational study was performed in aged 18-70 years, ASA I-III, 80 patients who were undergoing supratentorial craniotomy. After the induction of general anesthesia, the ONSD's were measured by the linear transducer from 3 mm below the globe at PEEP values of 0-5-10 cmH2O. The ONSD were compered between patients with (n = 7) and without midline shift (n = 73) at different PEEP values. RESULTS: The increases in ONSD due to increase in PEEP level were determined (p < 0.001). No difference was found in the comparison of ONSD between patients with and without midline shift in different PEEP values (p = 0.329, 0.535, 0.410 respectively). But application of 10 cmH2O PEEP in patients with a midline shift increased the mean ONSD value to 5.73 mm. This value is roughly 0.1 mm higher than the lower limit of the ONSD cutoff value. CONCLUSIONS: The ONSD in adults undergoing supratentorial tumor craniotomy, PEEP values up to 5 cmH2O, appears not to be associated with an ICP increase; however, the ONSD exceeded the cutoff for increased ICP when a PEEP of 10 cmH2O was applied in patients with midline shift.

Navigating the Enigma: A Comprehensive Review of Idiopathic Intracranial Hypertension.

An unidentified source of increased intracranial pressure is a hallmark of idiopathic intracranial hypertension (IIH), also referred to as pseudotumor cerebri. It mainly affects young, obese women, yet it can happen to anyone, regardless of age, gender, or weight. IIH presents with symptoms such as headaches, visual disturbances, and pulsatile tinnitus and can lead to severe complications, including vision loss, if left untreated. Diagnosis involves clinical evaluation, neuroimaging, and lumbar puncture, while management options include medical interventions and surgical procedures. This review provides a comprehensive overview of IIH, including its etiology, clinical presentation, epidemiology, complications, management approaches, and challenges. Increased awareness among healthcare professionals, standardized diagnostic criteria, and further research efforts are essential for improving outcomes and quality of life for individuals with IIH.

Comparing surgical outcomes: Craniotomy versus decompressive craniectomy in acute subdural hematoma - A systematic review and meta-analysis.

Introduction: Acute subdural hematomas (SDH) pose a significant health risk, often resulting from traumatic head injuries. The choice between surgical interventions, craniotomy, and decompressive craniectomy, remains a subject of debate. This meta-analysis aims to compare outcomes and guide clinical decision-making. Methods: Following PRISMA guidelines, a comprehensive literature search was conducted in databases such as Ovid Medline, PubMed, and Cochrane, up to December 2023. Selection criteria included studies comparing craniotomy and decompressive craniectomy for acute SDH. Data extraction utilized the Newcastle-Ottawa Quality Assessment Tool, and statistical analysis employed the random-effects model. Results: The meta-analysis included 17 studies and 6848 patients. Craniotomy demonstrated a significant reduction in mortality rates (RR 0.80, 95% CI 0.73-0.89, P < 0.0001). GCS scores favored craniotomy for severe cases. GOS outcomes showed a trend favoring craniotomy, particularly in good recovery (RR 1.34, 95% CI 1.04-1.74, P = 0.03). Additional factors explored included co-existing sub-epidural hematoma, mydriasis, extracranial injuries, residual SDH, revision rates, and intracranial pressure. Conclusion: The meta-analysis suggests that craniotomy may be a favorable surgical strategy for acute SDH, displaying a significant decrease in mortality rates and a lower risk of raised intracranial pressure. However, the nuanced nature of outcomes emphasizes the need for a tailored approach, considering broader clinical contexts. Future research should address limitations and provide a basis for well-informed clinical decision-making.

Correlation of cerebral microvascular circulation with vital signs in cerebral compression and the validity of three concepts: vasodilation, autoregulation, and terminal rise in arterial pressure.

Background: Vasodilation, autoregulation, and rising arterial pressure are three common concepts in cerebral compression, believed to improve cerebral blood flow to maintain the brain's nutrition. However, these concepts are unclear, unproven, and based on assumptions. This study aimed to correlate cerebral circulation with alterations of vital signs and to evaluate the above concepts based on physics and hemodynamics. Methods: Without new animal experiments, a large amount of data: recording of vital signs, long movies of cerebral circulation, and numerous photos of histological examination and microvessels obstruction in cerebral compression in cats was studied, and only partial and preliminary results were reported in 1970. The experiments were supported by an NIH grant for head injury, done before the 1985 Institutional Animal Care and Use Committee requirement. The advent of digital technology facilitated digitizing and stepwise correlating them and evaluating the validity of the above concepts. Results: As cerebral compression increased intracranial pressure (ICP), veins dilated, not arteries, and arterial microvessels obstructed, diminished, and stopped cerebral circulation. Simultaneously, vital signs deteriorated, and pupils became fixed and dilated. There was no evidence for what is believed as autoregulation. Conclusion: In cerebral compression, rising ICP obstructs cerebral arterial microvessels while simultaneously deteriorating vital signs. There is no evidence for dilatation of the arteries; only veins dilate, best-called venodilation. There is no evidence of autoregulation; what occurs is a cerebral compartmental syndrome. The terminal rise of arterial pressure is the hemodynamic result of cerebral circulation cessation, overloading the aorta. None of the concepts benefit the brain's nutrition.

Clinical efficacy of neuroendoscopy combined with intracranial pressure monitoring for the treatment of hypertensive intracerebral hemorrhage.

OBJECTIVE: To compare the differences in postoperative complications and prognosis between patients treated with neuroendoscopy versus conventional craniotomy surgery for hypertensive intracerebral hemorrhage (HICH). METHODS: In this retrospective study, a total of 107 patients with HICH were included. Among them, 58 underwent neuroendoscopy (Group A), while 49 underwent conventional craniotomy under microscopic guidance (Group B). Intracranial pressure monitoring (ICPM) was applied in both groups. The clinical data, incidence of postoperative complications, preoperative and postoperative intracranial pressure values, and rate of favorable prognosis were compared between the two groups. RESULTS: No significant difference in baseline clinical data upon admission was observed between the two groups (P > 0.05). The preoperative intracranial pressure did not differ between the two groups (P > 0.05), but the postoperative intracranial pressure in Group A was significantly lower than that in Group B (P < 0.05). After intervention with the different surgical approaches, Group A showed a significantly lower incidence of postoperative cerebral infarction and a significantly higher rate of favorable prognosis compared with Group B (P < 0.05). CONCLUSION: Neuroendoscopy combined with ICPM is a safe and reliable approach for the treatment of HICH that reduces the incidence of postoperative cerebral infarction and improves the recovery of neurological function after surgery.

Is Glaucoma a Two-Pressure-Related Optic Neuropathy? A Systematic Review and Meta-Analysis.

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.

Management of an acute intracranial emergency in pregnancy.

We report a case of a mid-20s primigravida at 37 weeks' gestation who presented with severe headache and acute neurological deterioration. The CT brain scan showed hydrocephalus caused by a colloid cyst in the third ventricle. The patient underwent emergency placement of an external ventricular drain for decompression of acute hydrocephalus. Four hours later, labour commenced spontaneously, and in view of her neurological status, a decision was taken to perform a caesarean section under general anaesthetics. Four days postpartum, the patient underwent an endoscopic removal of the cyst. Intracranial emergencies during pregnancy are rare and challenging to manage. The mortality rate can be significant. Diagnostic and surgical intervention should not be delayed because of pregnancy. An individualised treatment approach is required with multidisciplinary input. The collaborative efforts of our multidisciplinary team resulted in prompt diagnosis and surgical treatment in this case that resulted in both a healthy mother and child.