Intracranial pressure following surgery of an unruptured intracranial aneurysm-a model for normal intracranial pressure in humans.

OBJECTIVE: Optimizing the treatment of several neurosurgical and neurological disorders relies on knowledge of the intracranial pressure (ICP). However, exploration of normal ICP and intracranial pressure pulse wave amplitude (PWA) values in healthy individuals poses ethical challenges, and thus the current documentation remains scarce. This study explores ICP and PWA values for healthy adults without intracranial pathology expected to influence ICP. METHODS: Adult patients (age > 18 years) undergoing surgery for an unruptured intracranial aneurysm without any other neurological co-morbidities were included. Patients had a telemetric ICP sensor inserted, and ICP was measured in four different positions: supine, lateral recumbent, standing upright, and 45-degree sitting, at day 1, 14, 30, and 90 following the surgery. RESULTS: ICP in each position did not change with time after surgery. Median ICP was 6.7 mmHg and median PWA 2.1 mmHg in the supine position, while in the upright standing position median ICP was - 3.4 mmHg and median PWA was 1.9 mmHg. After standardization of the measurements from the transducer site to the external acoustic meatus, the median ICPmidbrain was 8.3 mmHg in the supine position and 1.2 mmHg in the upright standing position. CONCLUSION: Our study provides insights into normal ICP dynamics in healthy adults following a uncomplicated surgery for an unruptured aneurysm. These results suggest a slightly wider normal reference range for invasive intracranial pressure than previously suggested, and present the first normal values for PWA in different positions. Further studies are, however, essential to enhance our understanding of normal ICP. Trial registration The study was preregistered at www. CLINICALTRIALS: gov (NCT03594136) (11 July 2018).

Predictors of shunt insertion in patients with aneurysmal subarachnoid haemorrhage-a single-centre retrospective analysis.

BACKGROUND: No standard has been established regarding timing and choice of strategy for discontinuation of external ventricular drainage (EVD) in patients with aneurysmal subarachnoid haemorrhage (aSAH), and little is known about the importance of clinical variables. A proportion of the patients who initially pass their discontinuation attempt return with delayed hydrocephalus and the need of a permanent shunt. Early differentiation between patients who need a shunt and those who do not would facilitate care. We conducted a retrospective analysis on patients with aSAH and an EVD to search significant differences in treatment and clinical variables between patients who received a permanent shunt during initial hospitalization or after readmission, and those who never received a shunt. METHODS: We included 183 patients with aSAH who received an EVD over a 4-year period between 2015 and 2018 and divided them into three groups: those who received a shunt during primary admission, those who were readmitted for delayed hydrocephalus and received a shunt, and those who never needed a shunt. Between these groups, we compared selected clinical variables as well as outcome at discharge and after 6 months. Additionally, we assessed the ability of a shunt dependency score (SDASH) to predict the need for permanent drainage in the patients. RESULTS: Of 183 included patients, 108 (59%) ultimately received a ventriculoperitoneal (VP) shunt. Of these, 89 (82%) failed discontinuation during the primary admission and received a permanent shunt before discharge from the neurosurgical department. The remaining 19 (18%) were discharged after successful discontinuation, but subsequently developed delayed hydrocephalus and were admitted for shunt placement a median of 39 (range: 18-235) days after ictus. Ninety-four patients were discharged after successful discontinuation of the EVD, consisting of those who never developed the need for a permanent shunt and the 19 who were readmitted with delayed hydrocephalus, corresponding to a 20% (19/94) readmittance rate. Clinical variables such as drainage volume or discontinuation strategy did not differ across the three groups of patients. The SDASH score failed to provide any clinically useful information regarding prediction of shunt placement. CONCLUSION: In this study, clinical variables including use of the predictive score SDASH predicted neither the overall need for nor the timing of shunt placement after aSAH. The homogeneous distribution of data between the three different groups renders strong independent clinical predictive factors unlikely. Thus, attempts to predict a permanent shunt requirement from these variables may be futile in these patients.

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.

The intracranial pressure-volume relationship following decompressive hinge craniotomy compared to decompressive craniectomy-a human cadaver study.

OBJECTIVE: Decompressive hinge craniotomy (DHC) is an alternative treatment option to decompressive craniectomy (DC) for elevated intracranial pressure (ICP). The aim of this study was to characterize the difference in pressure-volume relationship between DHC and DC. METHODS: We compared the intracranial pressure-volume relationship in a human cadaver model following either DHC, DC, or fixing of the bone plate by titanium clamps. We inserted an intracranial expandable device in two human cadaver specimens, performed either DHC, DC, or bone plate fixation, and gradually increased the intracranial volume while measuring ICP. Following DHC, we also performed CT-scans at pre-defined intervals. RESULTS: Before ICP exceeded a threshold of 20 mmHg, a fixed bone plate tolerated an increase of 130 ml of intracranial volume, while DHC and DC allowed an increase of 190 ml and 290 ml, respectively. CT-derived calculations following DHC determined that the increase in intracranial volume at ICP 22 mmHg was 65 ml, the maximal increase of intracranial volume was 84 ml, the maximal bone displacement was 21 mm, and the bone plate volume to be 82 ml. Manual stress test of the hinged bone plate did not allow misalignment or intracranial displacement of the bone plate. CONCLUSION: DHC increases the intracranial volume by up to 84 ml and allows for approximately 60 ml increase of intracranial volume before ICP exceeds 20 mmHg. This indicates, when comparing with results from previous studies of herniation volumes, that DHC will be sufficient in many patients with head injury or cerebral infarction with treatment refractory intracranial hypertension.

Aortic Root Dilatation in Hypertensive Patients with Left Ventricular Hypertrophy-Application of A New Multivariate Predictive Model. The Life Study.

BACKGROUND: Available nomograms to predict aortic root (AoR) diameter for body surface area have limitations. The purpose of this study was to evaluate the use of a new multivariate predictive model to identify AoR dilatation in hypertensive patients with left ventricular hypertrophy. METHODS: 943 of 961 patients in the Losartan Intervention For Endpoint reduction in hypertension (LIFE) echocardiographic sub-study had the necessary baseline characteristics and echocardiographic 2D measurements of AoR size to be included. RESULTS: Predicted AoR (Sinus of Valsalva) diameter was 1.519 + (age [years] × 0.010) + (height [cm] × 0.010) - (gender [1 = M, 2 = F] × 0.247), and a measured AoR diameter exceeding the 97.5-percentile of this estimate was considered dilated. Measured AoR diameter was larger in men than in women (3.75 vs. 3.48 cm, p < 0.001) and AoR diameter predicted by the model was larger than predicted by nomogram (3.52 vs. 3.28 cm, p < 0.001). Using the multivariate model to identify patients with AoR dilatation, the prevalence was 13.7% in men and 12.3% in women (p = 0.537). There was consensus of AoR phenotype (normal/dilated) between model and nomogram in 92.8% of the patients. In multivariate logistic regression, AoR dilatation by model definition was predicted by presence of aortic regurgitation (OR 2.67, p < 0.001) and SD increase in age (OR 0.75, p = 0.023), pulse pressure (OR 0.64, p < 0.001), left ventricular mass index (OR 1.36, p = 0.08) and stroke volume (OR 1.45, p = 0.002), but not by body weight. CONCLUSIONS: Using the proposed model the prevalence of AoR dilatation was equal in men and women and the model seems to address the effects of gender, age and body size on AoR size. CLINICAL TRIAL REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT00338260.

Endoscopic third ventriculostomy for adults with hydrocephalus: creating a prognostic model for success: protocol for a retrospective multicentre study (Nordic ETV).

INTRODUCTION: Endoscopic third ventriculostomy (ETV) is becoming an increasingly widespread treatment for hydrocephalus, but research is primarily based on paediatric populations. In 2009, Kulkarni et al created the ETV Success score to predict the outcome of ETV in children. The purpose of this study is to create a prognostic model to predict the success of ETV for adult patients with hydrocephalus. The ability to predict who will benefit from an ETV will allow better primary patient selection both for ETV and shunting. This would reduce additional second procedures due to primary treatment failure. A success score specific for adults could also be used as a communication tool to provide better information and guidance to patients. METHODS AND ANALYSIS: The study will adhere to the Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis reporting guidelines and conducted as a retrospective chart review of all patients≥18 years of age treated with ETV at the participating centres between 1 January 2010 and 31 December 2018. Data collection is conducted locally in a standardised database. Univariate analysis will be used to identify several strong predictors to be included in a multivariate logistic regression model. The model will be validated using K-fold cross validation. Discrimination will be assessed using area under the receiver operating characteristic curve (AUROC) and calibration with calibration belt plots. ETHICS AND DISSEMINATION: The study is approved by appropriate ethics or patient safety boards in all participating countries. TRIAL REGISTRATION NUMBER: NCT04773938; Pre-results.

Trends in incidence of oral anticoagulant-related intracerebral hemorrhage and sales of oral anticoagulants in Capital Region of Denmark 2010-2017.

INTRODUCTION: Non-vitamin K-antagonist oral anticoagulants (NOAC) have become first choice oral anticoagulant (OAC) with decreasing use of vitamin K antagonists (VKA), partly due to lower risk of intracerebral hemorrhage (ICH). Aim: to identify trends in sale of OACs and relate them to trends in OAC-related ICH (OAC-ICH). PATIENTS AND METHODS: Study was based on the population in the Capital Region of Denmark (1.8 million inhabitants). We identified all patients admitted with a non-traumatic OAC-ICH in 2010-2017 and ascertained diagnosis and drug use through medical charts. We used information available in the public domain on sale of defined daily doses (DDD) of OAC in the Capital Region of Denmark. RESULTS: 453 patients with OAC-ICH out of a total of 2877 ICH-events were identified. From 2010 to 2017 sale of NOAC rose from 0.1 to 11.8 DDD/1000 inhabitants/day (p < 0.001); while VKA sale decreased from 7.6 to 5.2 DDD/1000 inhabitants/day (p < 0.001). The total number of ICH events was stable between 2010 and 2017, but the proportion of OAC-ICH events increased from 13% in 2010 to 22% in 2017 (p < 0.001). The proportion of ICH events related to NOAC had a significant increasing trend (p < 0.001), whereas a decreasing trend was observed for VKA (p = 0.04). DISCUSSION: In Denmark, the population on OACs has increased; resulting from increased use of NOACs. Parallel to this development, the proportion of OAC-ICH overall has increased based on an increasing trend in NOAC-related ICH. CONCLUSION: Our findings document a need for further research on prevention and treatment of this complication.

Lumbar puncture position influences intracranial pressure.

BACKGROUND: The standard lumbar puncture position involves maximum flexion of both lumbar and cervical spine. The cerebrospinal fluid opening pressure (CSFop) is measured in a horizontal position. This study investigated if flexion of hip and neck both separately and simultaneously influence intracranial pressure (ICP) to a clinically relevant extent. METHODS: Thirty-nine patients, undergoing invasive ICP monitoring as part of diagnostic work-up, were included. The patients underwent either a vertical postural examination (n = 24) or a horizontal postural examination (n = 15) to examine a varying degree of spine flexion. RESULTS: The vertical examination showed that ICP decreased by 15.2 mmHg when straightening the neck in a sitting lumbar puncture position (n = 24, IQR - 20.1 to - 9.7). In the horizontal examination, ICP increased in all but one patient when changing from supine position to lateral recumbent position (n = 15, median increase of 6.9 mmHg, IQR 3.1 to 9.9). Straightening the hips alone decreased ICP with 0.2 mmHg (n = 15, IQR - 0.5 to 2.0), while straightening the neck alone decreased ICP by 4.0 mmHg (n = 15, IQR - 5.9 to - 1.7). However, when straightening the hip and neck simultaneously ICP decreased by 6.4 mmHg (n = 6, IQR - 9.5 to - 4.4). CONCLUSIONS: Neck flexion alone, and neck flexion and hip flexion in combination, has significant confounding influence on ICP. This may cause patients to shift from a normal ICP range to a pathological ICP range, which will potentially affect treatment decisions. Consensus on guidelines for body position including neck and hip flexion measuring CSFop may be needed.

Optimal Cerebral Perfusion Pressure Based on Intracranial Pressure-Derived Indices of Cerebrovascular Reactivity: Which One Is Better for Outcome Prediction in Moderate/Severe Traumatic Brain Injury?

Intracranial pressure (ICP)-derived indices of cerebrovascular reactivity (e.g., PRx, PAx, and RAC) have been developed to improve understanding of brain status from available neuromonitoring variables. These indices are moving correlation coefficients between slow-wave vasogenic fluctuations in ICP and arterial blood pressure. In this retrospective analysis of neuromonitoring data from 200 patients admitted with moderate/severe traumatic brain injury (TBI), we evaluate the predictive value of CPPopt based on these ICP-derived indices of cerebrovascular reactivity. Valid CPPopt values were obtained in 92.3% (PRx), 86.7% (PAX), and 84.6% (RAC) of the monitoring periods, respectively. In multivariate logistic analysis, a baseline model that includes age, sex, and admission Glasgow Coma Score had an area under the receiver operating curve of 0.762 (P < 0.0001) for dichotomous outcome prediction (dead vs. good recovery). When adding time/dose of CPP below CPPopt, all multivariate models (based on PRx, PAx, and RAC) predicted the dichotomous outcome measure, but additional value of the prediction was only significantly added by the PRx-based calculations of time spent with CPP below CPPopt and dose of CPP below CPPopt.

Prompt closure versus gradual weaning of external ventricular drainage for hydrocephalus in adult patients with aneurysmal subarachnoid haemorrhage: a systematic review.

OBJECTIVES: To summarise the evidence on benefits and harms of prompt closure versus gradual weaning of external ventricular drainage (EVD) in patients with hydrocephalus following aneurysmal subarachnoid haemorrhage (aSAH) based on randomised clinical trials (RCTs) in humans. SETTING: RCTs comparing prompt closure versus gradual weaning of EVD in adult patients with hydrocephalus following aSAH were included. PARTICIPANTS: Patients aged equal to or greater than 18 years with an EVD due to hydrocephalus following aSAH were eligible for inclusion. PRIMARY AND SECONDARY OUTCOME MEASURES: Primary outcomes were all-cause mortality, any serious adverse event, rate of ventriculoperitoneal (VP) shunt placement and quality of life. Secondary outcomes were patients with shunt failure, hospital and neuro intensive care unit (NICU) length of stay (LOS) and complications related to treatment with an EVD. Data permitted report of rate of VP shunt placement, and hospital and NICU LOS. RESULTS: Six studies were assessed in full text. One RCT with 81 patients was included. Rate of VP shunt placement was 63.4% in the rapid weaning group (ie, prompt closure of the EVD; 41 patients) and 62.5% in the gradual weaning group (40 patients; p=0.932). LOS in hospital and NICU was significantly shorter in the rapidly weaned group compared with the gradually weaned group (mean 19.1 vs 21.5 days in hospital (p=0.03); and mean 14.1 vs 16.9 days in NICU (p=0.0002)). Data were insufficient to conduct meta-analysis, trial sequential analysis or subgroup analysis of heterogeneity and sensitivity. One RCT is currently ongoing. CONCLUSIONS: We found insufficient evidence to favour any of the two strategies for EVD discontinuation in patients with hydrocephalus following aSAH. PROSPERO REGISTRATION NUMBER: CRD42018108801.

Discontinuation of External Ventricular Drainage in Patients with Hydrocephalus Following Aneurysmal Subarachnoid Hemorrhage - a Scandinavian Multi-institutional Survey.

BACKGROUND: Hydrocephalus requiring external ventricular drainage is common following aneurysmal subarachnoid hemorrhage (aSAH). Timing and strategy for the discontinuation of the external ventricular drain (EVD) are, however, controversial as guidelines are based on limited scientific evidence. A recent similar survey showed that guidelines and recommendations are not being followed. We conducted a questionnaire survey regarding the management of EVD treatment in patients with aSAH and investigated current treatment practice, consensus, and adherence to guidelines within the neurosurgical departments in Scandinavia. METHODS: A questionnaire concerning the management of EVD discontinuation in patients with hydrocephalus following aSAH was distributed to all 14 neurosurgical departments in Scandinavia (Norway, Sweden, and Denmark). Neurosurgeons and neurosurgical trainees at all levels were asked to complete the questionnaire individually. A total of 175 completed questionnaires were received between May 2018 and April 2019, resulting in a response rate of 64 %. RESULTS: Eighty-five percent of respondents reported no knowledge of international guidelines regarding EVD discontinuation in patients with hydrocephalus following aSAH. Within every department, respondents disagreed on whether a common discontinuation strategy was followed or not. Seventy-four percent decided upon the EVD discontinuation strategy mainly determined by patients' clinical condition and drainage volume. Forty-five percent considered Glasgow Coma Score (GCS) the most important clinical variable when assessing the timing of EVD discontinuation. There was general agreement towards the initiation of EVD discontinuation 4-7 days after ictus of aSAH in a stable patient with a drainage volume of < 150 ml/day and intracranial pressure (ICP) < 15 mmHg. CONCLUSION: Awareness of and adherence to international guidelines regarding EVD discontinuation in patients with hydrocephalus following aSAH were limited in Scandinavia. Internal consensus at department level was absent. Initiation of the discontinuation process appeared to be case dependent and mainly influenced by the patients' clinical condition and drainage volume. GCS was the clinical variable considered most important when deciding on the initiation of EVD discontinuation.

Timing of intraventricular infusion test for diagnosing idiopathic normal pressure hydrocephalus.

BACKGROUND: Infusion tests, which measure resistance to outflow (Rout), are used in selecting patients suspected for idiopathic normal pressure hydrocephalus (iNPH) for shunt surgery. Infusion tests can be performed through an external ventricular drain (EVD). A 24-hour time gap from EVD insertion to an infusion test is a routine practice at our department due to concerns that the surgical procedure might influence the test results in the immediate postoperative period. The objective of the study was to investigate if timing of an intraventricular infusion test influences the results of the test in patients suspected for iNPH. METHODS: Ten patients scheduled for an intraventricular infusion test were included. Measurements of baseline intracranial pressure (ICP) and plateau ICP were obtained during constant rate intraventricular infusion test performed at two time points (1 and 24 h after EVD insertion) and Rout was calculated from these measures and compared within patients. RESULTS: Eight patients completed both infusion tests. In one of the 18 infusion tests performed, it was not possible to define an ICP plateau and this infusion test was excluded, leaving 7 paired infusion tests. Median Rout was 12.9 mmHg/ml/min (range 7.0-22.0) 1 h after EVD insertion and 11.3 mmHg/ml/min (range 7.8-18.1) after 24 h. Overall, there were no statistically significant differences in Rout (P = 0.83), baseline ICP (P = 0.70), or plateau ICP (P = 0.81) between the recordings performed 1 h and 24 h after EVD insertion. For two of the seven patients with paired infusion tests, there was poor agreement between Rout values at 1 and 24 h. CONCLUSION: Overall, Rout estimates do not change significantly between 1 and 24 h after EVD insertion. We therefore propose that infusion tests can be performed shortly after surgery to reduce the period of indwelling EVD and duration of hospitalization.

Telemetric intracranial pressure monitoring in children.

PURPOSE: Repeated intracranial pressure (ICP) measurements are essential in treatment of patients with complex cerebrospinal fluid (CSF) disorders. These patients often have a long surgical history with numerous invasive lumbar or intracranial pressure monitoring sessions and/or ventriculoperitoneal (VP) shunt revisions. Telemetric ICP monitoring might be an advantageous tool in treatment of these patients. In this paper, we evaluate our experience with this technology in paediatric patients. METHODS: During a 4-year period, we implanted telemetric ICP sensors (Raumedic NEUROVENT-P-tel) in 20 paediatric patients to minimise the number of future invasive procedures. Patients were diagnosed with hydrocephalus, idiopathic intracranial hypertension (IIH) or an arachnoid cyst. Most patients (85%) had a VP shunt at the time of sensor implantation. RESULTS: In total, 32 sensors were inserted in the 20 patients; the cause of re-implantation was technical malfunction of the implant. One sensor was explanted due to wound infection and one due to skin erosion. We experienced no complications directly related to the implantation/explantation procedures. A total of 149 recording sessions were conducted, including 68 home monitoring sessions. The median implantation period was 523 days with a median duration of clinical use at 202 days. The most likely consequence of a recording session was non-surgical treatment alteration (shunt valve adjustment or acetazolamide dose adjustment). CONCLUSION: Telemetric ICP monitoring in children is safe and potentially decreases the number of invasive procedures. We find that telemetric ICP monitoring aids the clinical management of patients with complex CSF disorders and improves everyday life for both patient and parents. It allows continuous ICP measurement in the patient's home and thereby potentially reducing hospitalisations, leading to significant cost savings.

Long-Term Effect of Decompressive Craniectomy on Intracranial Pressure and Possible Implications for Intracranial Fluid Movements.

BACKGROUND: Decompressive craniectomy (DC) is used in cases of severe intracranial hypertension or impending intracranial herniation. DC effectively lowers intracranial pressure (ICP) but carries a risk of severe complications related to abnormal ICP and/or cerebrospinal fluid (CSF) circulation, eg, hygroma formation, hydrocephalus, and "syndrome of the trephined." OBJECTIVE: To study the long-term effect of DC on ICP, postural ICP regulation, and intracranial pulse wave amplitude (PWA). METHODS: Prospective observational study including patients undergoing DC during a 12-mo period. Telemetric ICP sensors (Neurovent-P-tel; Raumedic, Helmbrechts, Germany) were implanted in all patients. Following discharge from the neuro intensive care unit (NICU), scheduled weekly ICP monitoring sessions were performed during the rehabilitation phase. RESULTS: A total of 16 patients (traumatic brain injury: 7, stroke: 9) were included (median age: 55 yr, range: 19-71 yr). Median time from NICU discharge to cranioplasty was 48 d (range: 16-98 d) and during this period, mean ICP gradually decreased from 7.8 ± 2.0 mm Hg to -1.8 ± 3.3 mm Hg (P = .02). The most pronounced decrease occurred during the first month. Normal postural ICP change was abolished after DC for the entire follow-up period, ie, there was no difference between ICP in supine and sitting position (P = .67). PWA was markedly reduced and decreased from initially 1.2 ± 0.7 mm Hg to 0.4 ± 0.3 mm Hg (P = .05). CONCLUSION: Following NICU discharge, ICP decreases to negative values within 4 wk, normal postural ICP regulation is lost and intracranial PWA is diminished significantly. These abnormalities might have implications for intracranial fluid movements (eg, CSF and/or glymphatic flow) following DC and warrants further investigations.

Intracranial pressure before and after cranioplasty: insights into intracranial physiology.

OBJECTIVE: Decompressive craniectomy (DC) is an emergency neurosurgical procedure used in cases of severe intracranial hypertension or impending intracranial herniation. The procedure is often lifesaving, but it exposes the brain to atmospheric pressure in the subsequent rehabilitation period, which changes intracranial physiology and probably leads to complications such as hydrocephalus, hygromas, and "syndrome of the trephined." The objective of the study was to study the effect of cranioplasty on intracranial pressure (ICP), postural ICP changes, and intracranial pulse wave amplitude (PWA). METHODS: The authors performed a prospective observational study including patients who underwent DC during a 12-month period. Telemetric ICP sensors were implanted in all patients at the time of DC. ICP was evaluated before and after cranioplasty during weekly measurement sessions including a standardized postural change program. RESULTS: Twelve of the 17 patients enrolled in the study had cranioplasty performed and were included in the present investigation. Their mean ICP in the supine position increased from -0.5 ± 4.8 mm Hg the week before cranioplasty to 6.3 ± 2.5 mm Hg the week after cranioplasty (p < 0.0001), whereas the mean ICP in the sitting position was unchanged (-1.2 ± 4.8 vs -1.1 ± 3.6 mm Hg, p = 0.90). The difference in ICP between the supine and sitting positions was minimal before cranioplasty (1.1 ± 1.8 mm Hg) and increased to 7.4 ± 3.6 mm Hg in the week following cranioplasty (p < 0.0001). During the succeeding 2 weeks of the follow-up period, the mean ICP in the supine and sitting positions decreased in parallel to, respectively, 4.6 ± 3.0 mm Hg (p = 0.0003) and -3.9 ± 2.7 mm Hg (p = 0.040), meaning that the postural ICP difference remained constant at around 8 mm Hg. The mean intracranial PWA increased from 0.7 ± 0.7 mm Hg to 2.9 ± 0.8 mm Hg after cranioplasty (p < 0.0001) and remained around 3 mm Hg throughout the following weeks. CONCLUSIONS: Cranioplasty restores normal intracranial physiology regarding postural ICP changes and intracranial PWA. These findings complement those of previous investigations on cerebral blood flow and cerebral metabolism in patients after decompressive craniectomy.

Prompt closure versus gradual weaning of extraventricular drainage for hydrocephalus in adult patients with aneurysmal subarachnoid haemorrhage: a systematic review protocol with meta-analysis and trial sequential analysis.

INTRODUCTION: In Neuro Intensive Care Units (NICU) and neurosurgical units, patients with an external ventricular drain (EVD) due to hydrocephalus following aneurysmal subarachnoid haemorrhage (SAH) are commonly seen. Cessation of the EVD involves the dilemma of either closing the EVD directly, or gradually weaning it before removal. Development of increased intracranial pressure (ICP) and acute hydrocephalus with subsequent need of a permanent shunt has been associated with prompt closure of theEVD, whereas increased risk of infection with possible spreading to the brain and subsequent patient fatality is suspected in connection to a longer treatment as seen in gradual weaning. Sparse data exist on the recommendation of cessation strategy and patients are currently being treated on the basis of personal experience and expert opinion. The objective of this systematic review is to assess the available evidence from clinical trials on the effects of prompt closure versus gradual weaning of EVD treatment for hydrocephalus in adult patients with SAH. METHODS AND ANALYSIS: We will search for randomised clinical trials in major international databases. Two authors will independently screen and select references for inclusion, extract data and assess the methodological quality of the included randomised clinical trials using the Cochrane risk of bias tool. Any disagreement will be resolved by consensus. We will analyse the extracted data using Review Manager and trial sequential analysis. To assess the quality of the evidence, we will create a 'Summary of Findings' table containing our primary and secondary outcomes using the GRADE assessment. ETHICS AND DISSEMINATION: Results will be published widely according to the interest of the society. No possible impact, harm or ethical concerns are expected doing this protocol. TRIAL REGISTRATION NUMBER: PROSPERO CRD42018108801.

[Aneurysmal subarachnoid haemorrhage].

The purpose of this review is to increase the knowledge about diagnosis and treatment of aneurysmal subarachnoid haemorrhage (aSAH), which is an infrequent and critical condition with a high risk of severe morbidity and mortality. The outcome is improved by correct and efficient diagnosis and early treatment, including aneurysm repair. General practitioners and doctors in the departments for emergency medicine should be aware of the symptoms of aSAH.

Deciding on Appropriate Telemetric Intracranial Pressure Monitoring System.

BACKGROUND: The clinical advantage of telemetric intracranial pressure (ICP) monitoring has previously been limited by issues with inaccuracy and zero-drift. Today, 2 comparable telemetric ICP monitoring systems are available performing adequately in these parameters. The objective of this study is to identify appropriate uses of each system. METHODS: The 2 telemetric ICP monitoring systems from Raumedic (implant: Neurovent-P-tel) and Miethke (implant: Sensor Reservoir) are compared in terms of fundamental differences, sensor survival, monitoring possibilities, complications, and cost/benefit. Two illustrative cases are presented highlighting clinical advantages and disadvantages of each system. RESULTS: Both systems provide transdermal (telemetric) ICP measurements through external application of a reader unit cabled to a portable data sampler. Thereby, they allow several ICP monitoring sessions without multiple surgical insertions of a cabled ICP sensor. The Miethke implant has a high sampling frequency (40 Hz) and a long CE (Conformité Européenne) approval (3 years) but cannot be used for long-duration monitoring sessions. In comparison, the Raumedic implant has a lower sampling frequency (5 Hz) and shorter CE approval (90 days) but can be used for long-duration monitoring sessions. The standard 3-year cost for a patient with a Neurovent-P-tel is 17,380 €, and for the Sensor Reservoir it is 15,790 €. CONCLUSIONS: The Miethke system is useful in outpatient clinics where patients have sequential point measurements of ICP performed, whereas the Raumedic system is ideal for long-duration ICP monitoring outside the hospital. When choosing between the 2 systems, it must primarily be decided if the clinical situation requires long-duration monitoring sessions or continuous repeated ambulatory follow-up sessions.