Intraparenchymal Intracranial Pressure Monitoring Research Articles

The initial intracranial pressure spike phenomenon.

Elective use of intraparenchymal intracranial pressure (ICP) monitoring is a valuable resource in the investigation of hydrocephalus and other cerebrospinal fluid disorders. Our preliminary study aims to investigate ICP changes in the immediate period following dural breach, which has not yet been reported on. This is a prospective cohort study of patients undergoing elective ICP monitoring, recruited between March and May 2022. ICP readings were obtained at opening and then at 5-min intervals for a 30-min duration. Ten patients were recruited, mean age 45 years, with indications of a Chiari malformation (n = 5), idiopathic intracranial hypertension (n = 3) or other ICP-related pathology (n = 2). Patients received intermittent bolus sedation (80%) vs general anaesthesia (20%). Mean opening pressure was 22.9 mmHg [± 6.0], with statistically significant decreases present every 5 min, to a total reduction of 15.2 mmHg at 20 min (p = < 0.0001), whereafter the ICP plateaued with no further statistical change. Our results highlight an intracranial opening pressure 'spike' phenomenon. This spike was 15.2 mmHg higher than the plateau, which is reached at 20 min after insertion. Several possible causes exist which require further research in larger cohorts, including sedation and pain response. Regardless of causation, this study provides key information on the use of ICP monitoring devices, guiding interpretation and when to obtain measurements.

Prediction of intracranial pressure crises after severe traumatic brain injury using machine learning algorithms.

Avoiding intracranial hypertension after traumatic brain injury (TBI) is a foundation of neurocritical care, to minimize secondary brain injury related to elevated intracranial pressure (ICP). However, this approach at best is reactive to episodes of intracranial hypertension, allowing for periods of elevated ICP before therapies can be initiated. Accurate prediction of ICP crises before they occur would permit clinicians to implement preventive strategies, minimize total time with ICP above threshold, and potentially avoid secondary injury. The objective of this study was to develop an algorithm capable of predicting the onset of ICP crises with sufficient lead time to enable application of preventative therapies. Thirty-six patients admitted to a level I trauma center with severe TBI (Glasgow Coma Scale score < 8) between April 2015 and January 2019 who underwent continuous intraparenchymal ICP monitor placement were retrospectively identified. Continuous ICP data were extracted from each monitoring period (range 4-96 hours of monitoring). An ICP crisis was treated as a binary outcome, defined as ICP > 22 mm Hg for at least 75% of the data within a 5-minute interval. ICP data preceding each ICP crisis were grouped into four total data sets of 1- and 2-hour epochs, each with 10- to 20-minute lead-time intervals before an ICP crisis. Crisis and noncrisis events were identified from continuous time-series data and randomly split into 70% for training and 30% for testing, from a subset of 30 patients. Machine learning algorithms were trained to predict ICP crises, including light gradient boosting, extreme gradient boosting, and random forest. Accuracy and area under the receiver operating characteristic curve (AUC) were measured to compare performance. The most predictive algorithm was optimized using feature selection and hyperparameter tuning to avoid overfitting, and then tested on a validation subset of 5 patients. Precision, recall, F1 score, and accuracy were measured. The random forest model demonstrated the highest accuracy (range 0.82-0.88) and AUC (range 0.86-0.88) across all four data sets. Further validation testing revealed high precision (0.76), relatively low recall (0.46), and overall strong predictive performance (F1 score 0.57, accuracy 0.86) for ICP crises. Decision curve analysis showed that the model provided net benefit at probability thresholds above 0.1 and below 0.9. The presented model can provide accurate and timely forecasts of ICP crises in patients with severe TBI 10-20 minutes prior to their occurrence. If validated and implemented in clinical workflows, this algorithm can enable earlier intervention for ICP crises, more effective treatment of intracranial hypertension, and potentially improved outcomes following severe TBI.

Intraparenchymal fiberoptic intracranial pressure monitoring and decompressive craniectomy in meningioma case with critical intracranial pressure: A case report during COVID-19 pandemic

IntroductionMeningioma is a slow-growing tumor that can cause neurological emergency due to intracranial hypertension. The definitive therapy is indeed emergency resection, but it is not always possible in several countries due to limited capacity and/or capability of the emergency operating room. The use of intraparenchymal fiberoptic intracranial pressure (ICP) monitoring and decompressive craniectomy (DC) in cases of brain tumors might be possible, but it is uncommon. We report a meningioma patient in whom immediate meningioma resection was considered too risky due to intensive care unit (ICU) shortage during COVID-19 pandemic and, therefore, underwent these procedures as life-saving measures.Case presentationA 24-year-old man was brought to the emergency room with a chief complaint of seizure. Physical examination was notable for decreased consciousness (Glasgow Coma Scale (GCS) 11) and a dilated left pupil with intact light reflex. A contrasted Brain CT Scan revealed extra-axial mass on the left sphenoid with extensive tentacle edema, which pushed the midline structures 2 cm toward the contralateral side.DiscussionThe patient was diagnosed with Left Sphenoid Meningioma. We decided to perform intraparenchymal fiberoptic ICP monitor insertion and DC considering the situation, device availability, safety, and efficacy. The patient slowly regained consciousness in the recovery room after the procedure. The best-observed GCS was 12. Two weeks afterward, the patient came back to our outpatient clinic neurologically intact. The patient was then planned for elective tumor resection.ConclusionICP monitoring and DC are not commonly performed on brain tumor cases. However, in suboptimal situations, these procedures might save lives. The present case showed that ICP monitor and DC were helpful in times of ICU shortage.

Intracranial pressure monitoring during stereoelectroencephalography implantation: a technical note.

Stereoelectroencephalography (SEEG) has become increasingly employed as a critical component of epilepsy workups for patients with drug-resistant epilepsy when information from noninvasive studies is not conclusive and sufficient to guide epilepsy surgery. Although exceedingly rare, clinically significant hemorrhagic complications can be caused during SEEG implantation procedures. Intracranial hemorrhage (ICH) can be difficult to recognize due to the minimally invasive nature of SEEG. The authors describe their technique using a commercially available intraparenchymal intracranial pressure (ICP) monitor as a method for early intraoperative detection of ICH during SEEG implantation. Between May 2019 and July 2021, 18 pediatric patients underwent SEEG implantation at a single, freestanding children's hospital with the use of an ICP monitor during the procedure. No patients experienced complications resulting from this technique. The authors have relayed their rationale for ICP monitor use during SEEG, the technical considerations, and the safety profile. In addition, they have reported an illustrative case in which the ICP monitor proved crucial in early detection of ICH during SEEG implantation.

Outcomes associated with brain tissue oxygen monitoring in patients with severe traumatic brain injury undergoing intracranial pressure monitoring.

Brain tissue oxygen monitoring combined with intracranial pressure (ICP) monitoring in patients with severe traumatic brain injury (sTBI) may confer better outcomes than ICP monitoring alone. The authors sought to investigate this using a national database. The National Trauma Data Bank from 2013 to 2017 was queried to identify patients with sTBI who had an external ventricular drain or intraparenchymal ICP monitor placed. Patients were stratified according to the placement of an intraparenchymal brain tissue oxygen tension (PbtO2) monitor, and a 2:1 propensity score matching pair was used to compare outcomes in patients with and those without PbtO2 monitoring. Sensitivity analyses were performed using the entire cohort, and each model was adjusted for age, sex, Glasgow Coma Scale score, Injury Severity Score, presence of hypotension, insurance, race, and hospital teaching status. The primary outcome of interest was in-hospital mortality, and secondary outcomes included ICU length of stay (LOS) and overall LOS. A total of 3421 patients with sTBI who underwent ICP monitoring were identified. Of these, 155 (4.5%) patients had a PbtO2 monitor placed. Among the propensity score-matched patients, mortality occurred in 35.4% of patients without oxygen monitoring and 23.4% of patients with oxygen monitoring (OR 0.53, 95% CI 0.33-0.85; p = 0.007). The unfavorable discharge rates were 56.3% and 47.4%, respectively, in patients with and those without oxygen monitoring (OR 1.41, 95% CI 0.87-2.30; p = 0.168). There was no difference in overall LOS, but patients with PbtO2 monitoring had a significantly longer ICU LOS and duration of mechanical ventilation. In the sensitivity analysis, PbtO2 monitoring was associated with decreased odds of mortality (OR 0.56, 95% CI 0.37-0.84) but higher odds of unfavorable discharge (OR 1.59, 95% CI 1.06-2.40). When combined with ICP monitoring, PbtO2 monitoring was associated with lower inpatient mortality for patients with sTBI. This supports the findings of the recent Brain Oxygen Optimization in Severe Traumatic Brain Injury phase 2 (BOOST 2) trial and highlights the importance of the ongoing BOOST3 trial.

Systemic Markers of Injury and Injury Response Are Not Associated with Impaired Cerebrovascular Reactivity in Adult Traumatic Brain Injury: A Collaborative European Neurotrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) Study

The role of extra-cranial injury burden and systemic injury response on cerebrovascular response in traumatic brain injury (TBI) is poorly documented. This study preliminarily assesses the association between admission features of extra-cranial injury burden on cerebrovascular reactivity. Using the Collaborative European Neurotrauma Effectiveness Research in TBI High-Resolution ICU (HR ICU) sub-study cohort, we evaluated those patients with both archived high-frequency digital intra-parenchymal intra-cranial pressure monitoring data of a minimum of 6 h in duration, and the presence of a digital copy of their admission computed tomography (CT) scan. Digital physiologic signals were processed for pressure reactivity index (PRx) and both the percent time above defined PRx thresholds and mean hourly dose above threshold. This was conducted for both the first 72 h and entire duration of recording. Admission extra-cranial injury characteristics and CT injury scores were obtained from the database, with quantitative contusion, edema, intraventricular hemorrhage, and extra-axial lesion volumes were obtained via semi-automated segmentation. Comparison between admission extra-cranial markers of injury and PRx metrics was conducted using Mann-Whitney U testing, and logistic regression techniques, adjusting for known CT injury metrics associated with impaired PRx. A total of 165 patients were included. Evaluating the entire ICU recording period, there was limited association between metrics of extra-cranial injury burden and impaired cerebrovascular reactivity. Using the first 72 h of recording, admission temperature (p = 0.042) and white blood cell % (WBC %; p = 0.013) were statistically associated with impaired cerebrovascular reactivity on Mann-Whitney U and univariate logistic regression. After adjustment for admission age, pupillary status, GCS motor score, pre-hospital hypoxia/hypotension, and intra-cranial CT characteristics associated with impaired reactivity, temperature (p = 0.021) and WBC % (p = 0.013) remained significantly associated with mean PRx values above +0.25 and +0.35, respectively. Markers of extra-cranial injury burden and systemic injury response do not appear to be strongly associated with impaired cerebrovascular reactivity in TBI during both the initial and entire ICU stay.

Hemorrhagic Complications of Invasive Intracranial Pressure Monitor Placement in Acute Liver Failure: Outcomes of a Single-Center Protocol and Comprehensive Literature Review.

Elevated intracranial pressure due to cerebral edema is associated with very poor survival in patients with acute liver failure (ALF). Placing an intracranial pressure monitor (ICPm) aids in management of intracranial hypertension, but is associated with potentially fatal hemorrhagic complications related to the severe coagulopathy associated with ALF. An institutional Acute Liver Failure Clinical Protocol (ALF-CP) was created to correct ALF coagulopathy prior to placing parenchymal ICP monitoring bolts. We aimed to investigate the frequency, severity, and clinical significance of hemorrhagic complications associated with ICPm bolt placement in the setting of an ALF-CP. All assessed patients were managed with the ALF-CP and had rigorous radiologic follow-up allowing assessment of the occurrence and chronology of hemorrhagic complications. We also aimed to compare our outcomes to other studies that were identified through a comprehensive review of the literature. Fourteen ALF patients were included in our analysis. There was no symptomatic hemorrhage after ICP monitor placement though four patients were found to have minor intraparenchymal asymptomatic hemorrhages after liver transplant when the ICP monitor had been removed, making the rate of radiographically identified clinically asymptomatic hemorrhage 28.6%. These results compare favorably to those found in a comprehensive review of the literature which revealed rates as high as 17.5% for symptomatic hemorrhages and 30.4% for asymptomatic hemorrhage. This study suggests that an intraparenchymal ICPm can be placed safely in tertiary referral centers which utilize a protocol such as the ALF-CP that aggressively corrects coagulopathy. The ALF-CP led to advantageous outcomes for ICPm placement with a 0% rate of symptomatic and low rate of asymptomatic hemorrhagic complications, which compares well to results reported in other series. A strict ICPm placement protocol in this setting facilitates management of ALF patients with cerebral edema during the wait time to transplantation or spontaneous recovery.

Use of Intracranial Pressure Monitoring in Patients with Severe Traumatic Brain Injury

The Brain Trauma Foundation (BTF) recommends intracranial pressure (ICP) monitoring for all salvageable patients with an abnormal computed tomography (CT) scan and a Glasgow Coma Scale <9. Studies have shown that compliance with this recommendation is low. We sought to obtain contemporary national rates of ICP monitor placement in patients with severe traumatic brain injury (TBI). Patients from the National Trauma Data Bank from 2013 to 2017 who met BTF criteria for ICP monitoring were included. Placement of an intraparenchymal ICP monitor or an external ventricular drain was queried. Binary logistic regression was used to determine factors that influenced the placement of an ICP monitor. A total of 21,374 patients with severe TBI and an abnormal CT scan were included in the study. An ICP monitor was placed in 6543 patients (30.6%). ICP monitor placement increased modestly from 28.6% in 2013 to 32.8% in 2017. The pooled odds of ICP monitor placement between 2014 and 2017 were not different from 2013 (odds ratio, 1.04; 95% confidence interval, 0.99-1.09), but the adjusted odds of ICP monitor placement in 2017 were significantly greater (odds ratio, 1.18; 95% confidence interval, 1.06-1.30). Treatment at a teaching hospital, subdural hematoma, multiple intracranial abnormalities on CT, and greater Injury Severity Score were associated with ICP monitor placement, whereas older age was negatively associated with ICP monitor placement. The rate of ICP monitoring in patients with severe TBI who meet BTF criteria is low and increased only slightly from 2013 to2017.

The Effect of Timing of Intracranial Pressure Monitor Placement in Patients with Severe Traumatic Brain Injury.

Intracranial pressure (ICP) monitor placement is indicated for patients with severe traumatic brain injury (sTBI) to minimize secondary brain injury. There is little evidence to guide the optimal timing of ICP monitor placement. A retrospective cohort study using the National Trauma Data Bank (NTDB) from 2013 to 2017 was performed. The NTDB was queried to identify patients with sTBI who underwent external ventricular drain or intraparenchymal ICP monitor placement. Propensity score matching was used to create matched pairs of patients who underwent early compared to late ICP monitor placement using 6-h and 12-h cutoffs. The outcomes of interest were in-hospital mortality, non-routine discharge disposition, total length of stay (LOS), intensive care unit (ICU) LOS, and number of days mechanically ventilated. A total of 5057 patients with sTBI were included in the study. In-hospital mortality for patients with early compared to late ICP monitor placement was 33.6% and 30.4%, respectively (p = 0.049). The incidence of non-routine disposition was 92.6% in the within 6h group and 94.4% in the late placement group (p = 0.037). Hospital LOS, ICU LOS, and number of days mechanically ventilated were significantly greater in the late ICP monitoring group. Similar results were seen when using a 12-h cutoff for late ICP monitor placement. In the Cox proportional hazards model, craniotomy (HR 1.097, 95% CI 1.037-1.160) and isolated intracranial injury (HR 1.128, 95% CI 1.055-1.207) were associated with early ICP monitor placement. Hypotension was negatively associated with early ICP monitor placement (HR 0.801, 95% CI 0.725-0.884). Despite a statistically marginal association between mortality and early ICP monitor placement, most outcomes were superior when ICP monitors were placed within 6 or 12h of arrival. This may be due to earlier identification and treatment of intracranial hypertension.

Evaluation of the relationship between slow-waves of intracranial pressure, mean arterial pressure and brain tissue oxygen in TBI: a CENTER-TBI exploratory analysis

Brain tissue oxygen (PbtO2) monitoring in traumatic brain injury (TBI) has demonstrated strong associations with global outcome. Additionally, PbtO2 signals have been used to derive indices thought to be associated with cerebrovascular reactivity in TBI. However, their true relationship to slow-wave vasogenic fluctuations associated with cerebral autoregulation remains unclear. The goal of this study was to investigate the relationship between slow-wave fluctuations of intracranial pressure (ICP), mean arterial pressure (MAP) and PbtO2 over time. Using the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) high resolution ICU sub-study cohort, we evaluated those patients with recorded high-frequency digital intra-parenchymal ICP and PbtO2 monitoring data of a minimum of 6 h in duration. Digital physiologic signals were processed for ICP, MAP, and PbtO2 slow-waves using a moving average filter to decimate the high-frequency signal. The first 5 days of recording were analyzed. The relationship between ICP, MAP and PbtO2 slow-waves over time were assessed using autoregressive integrative moving average (ARIMA) and vector autoregressive integrative moving average (VARIMA) modelling, as well as Granger causality testing. A total of 47 patients were included. The ARIMA structure of ICP and MAP were similar in time, where PbtO2 displayed different optimal structure. VARIMA modelling and IRF plots confirmed the strong directional relationship between MAP and ICP, demonstrating an ICP response to MAP impulse. PbtO2 slow-waves, however, failed to demonstrate a definite response to ICP and MAP slow-wave impulses. These results raise questions as to the utility of PbtO2 in the derivation of cerebrovascular reactivity measures in TBI. There is a reproducible relationship between slow-wave fluctuations of ICP and MAP, as demonstrated across various time-series analytic techniques. PbtO2 does not appear to reliably respond in time to slow-wave fluctuations in MAP, as demonstrated on various VARIMA models across all patients. These findings suggest that PbtO2 should not be utilized in the derivation of cerebrovascular reactivity metrics in TBI, as it does not appear to be responsive to changes in MAP in the slow-waves. These findings corroborate previous results regarding PbtO2 based cerebrovascular reactivity indices.

Intraparenchymal intracranial pressure monitoring for hydrocephalus and cerebrospinal fluid disorders

BackgroundElective intraparenchymal intracranial pressure (ICP) monitoring is useful for the diagnosis and treatment of hydrocephalus and cerebrospinal fluid (CSF) disorders. This retrospective study analyzes median ICP and pulse amplitude (PA) recordings in neurosurgically naïve patients undergoing elective ICP monitoring for suspected CSF disorders.MethodsRetrospective review of prospectively collated database of neurosurgically naïve patients undergoing elective ICP monitoring for suspected hydrocephalus and CSF disorders. Following extraction of the median ICP and PA values (separated into all, day and night time recordings), principal component analysis (PCA) was performed to identify the principal factors determining the spread of the data. Exploratory comparisons and correlations of ICP and PA values were explored, including by post hoc diagnostic groupings and age.ResultsA total of 198 patients were identified in six distinct diagnostic groups (n = 21–47 in each).The PCA suggested that there were two main factors accounting for the spread in the data, with 61.4% of the variance determined largely by the PA and 33.0% by the ICP recordings.Exploratory comparisons of PA and ICP between the diagnostic groups showed significant differences between the groups. Specifically, significant differences were observed in PA between a group managed conservatively and the Chiari/syrinx, IIH, and NPH/LOVA groups and in the ICP between the conservatively managed group and high-pressure, IIH, and low-pressure groups. Correlations between ICP and PA revealed some interesting trends in the different diagnostic groups and correlations between ICP, PA, and age revealed a decreasing ICP and increasing PA with age.ConclusionsThis study provides insights into hydrodynamic disturbances in different diagnostic groups of patients with CSF hydrodynamic disorders. It highlights the utility of analyzing both median PA and ICP recordings, stratified into day and night time recordings.

Inductive passive sensor for intraparenchymal and intraventricular monitoring of intracranial pressure.

Accurate measurement of intracranial hypertension is crucial for the management of elevated intracranial pressure (ICP). Catheter-based intraventricular ICP measurement is regarded as the gold standard for accurate ICP monitoring. However, this method is invasive, time-limited, and associated with complications. In this paper, we propose an implantable passive sensor that could be used for continuous intraparenchymal and intraventricular ICP monitoring. Moreover, the sensor can be placed simultaneously along with a cerebrospinal fluid shunt system in order to monitor its function. The sensor consists of a flexible coil which is connected to a miniature pressure sensor via an 8-cm long, ultra-thin coaxial cable. An external orthogonal-coil RF probe communicates with the sensor to detect pressure variation. The performance of the sensor was evaluated in an in vitro model for intraparenchymal and intraventricular ICP monitoring. The findings from this study demonstrate proof-of-concept of intraparenchymal and intraventricular ICP measurement using inductive passive pressure sensors.

Comparison Between Intraventricular and Intraparenchymal Intracranial Pressure Monitoring in Asian Patients With Severe Traumatic Brain Injury

Comparison Between Intraventricular and Intraparenchymal Intracranial Pressure Monitoring in Asian Patients With Severe Traumatic Brain Injury

Bedside burr hole for intracranial pressure monitoring performed by pediatric intensivists in children with CNS infections in a resource-limited setting: 10-year experience at a single center.

Intracranial pressure monitoring can help in early identification of raised intracranial pressure and in setting more informed goals for treatment. We describe our 10-year experience of bedside burr holes performed by pediatric intensivists to establish intracranial pressure monitoring in children with CNS infections in a resource-limited setting and the technical difficulties and complications encountered. Descriptive study of prospectively recorded data. PICU of a tertiary care academic institute. Consecutive comatose patients with raised intracranial pressure who underwent intracranial pressure monitoring from 2004 to 2013. An intraparenchymal (1.2 mm) or an intraventricular transducer (3.4 mm) (Codman) was placed by a pediatric intensivist through a micro burr hole using a standard protocol. Technical difficulties during the procedure and complications were recorded. Over 10 years, 265 intracranial pressure catheters were placed in 259 patients, mainly for acute CNS infections (n = 242, 93.4%). Median age of patients was 4.8 years, youngest being 6 weeks; 21 patients (8.1%) were younger than 1 year. Intraparenchymal transducer was used in 252 patients (97.3%). Median (interquartile range) duration of intracranial pressure monitoring was 96 hours (72-144 hr). Complications were seen in 3.5% of patients (n = 9/259); the incidence was 0.28 per 1,000 hours of intracranial pressure monitoring. Procedure-related ventriculitis occurred in three of seven patients (42.8%) with intraventricular catheter, in contrast to none in patients with intraparenchymal transducer. Overall mortality was 32.8% (n = 85). On Cox-regression analysis, "blood component therapy" was an independent predictor of poor outcome defined as death or severe neurodisability (adjusted hazard ratio, 1.58; 95% CI, 1.16-2.16; p = 0.004). In a resource-limited setting, pediatric intensivists can safely and successfully perform burr holes at bedside for establishing intraparenchymal intracranial pressure monitoring in children with acute CNS infections. However, our data do not support placement of ventriculostomy catheters by pediatric intensivists in similar settings.

The preoperative incidence of raised intracranial pressure in nonsyndromic sagittal craniosynostosis is underestimated in the literature.

The presence of raised intracranial pressure (ICP) in untreated nonsyndromic, isolated sagittal craniosynostosis (SC) is an important functional indication for surgery. A retrospective review was performed of all 284 patients presenting with SC to the Oxford Craniofacial Unit between 1995 and 2010. Intraparenchymal ICP monitoring was performed in 39 children following a standard unit protocol. Monitoring of ICP was offered for all patients in whom nonoperative management was considered on the basis of minimal deformity or in cases in which parents were reluctant to agree to corrective surgery. These patients presented at an older age than the rest of the cohort (mean age 56 months), with marked scaphocephaly (16/39, 41%), mild scaphocephaly (11, 28%), or no scaphocephalic deformity (12, 31%). Raised ICP was found in 17 (44%) patients, with no significant difference in its incidence among the 3 different deformity types. Raised ICP was not predicted by the presence of symptoms of ICP or developmental delay or by ophthalmological or radiological findings. The incidence of raised ICP in SC reported here is greater than that previously published in the literature. The lack of a reliable noninvasive method to identify individuals with elevated ICP in SC mandates consideration of intraparenchymal ICP monitoring in all patients for whom nonoperative management is contemplated.

Clinical and radiological findings in long-term intracranial pressure monitoring

Advantages of telemetric devices for long-term intracranial pressure (ICP) measurement have been mentioned several times in the literature. However, descriptions of associated complications are lacking. Therefore, the presented observational study focused on clinical and radiological findings after insertion of an intraparenchymal telemetric ICP monitor. Between April 2010 and February 2013, 185 telemetric ICP catheters were implanted for diagnostic purposes. All patients were clinically followed. Radiological, microbiological and clinical data were analysed. One brain abscess (0.5%) and two cutaneous infections (1.1%) occurred in 185 patients. Staphylococcus spp. could be detected in all cases. Six patients (3.2%) suffered from single new-onset seizures and one patient (0.5%) from a temporary hemiparesis. Intracerebral haemorrhages occurred in 15.6%, most of the time as small punctate bleedings. Perifocal oedematous reactions surrounding inserted telemetric catheters could be observed in 46.9%. Multiple imaging studies revealed a tendency of complete oedema resolution over time. Infectious as well as haemorrhagic complication rates are well comparable with the common literature. The long-term implantation of an ICP probe does not seem to increase the risk of wound infections or brain abscess formation. Surprisingly, very high numbers of oedematous reactions after insertion of the intraparenchymal ICP monitor were seen. Reasons therefore could only be speculated upon.

Measuring Elevated Intracranial Pressure through Noninvasive Methods

Elevated intracranial pressure (ICP) is an important cause of secondary brain injury, and a measurement of ICP is often of crucial value in neurosurgical and neurological patients. The gold standard for ICP monitoring is through an intraventricular catheter, but this invasive technique is associated with certain risks. Intraparenchymal ICP monitoring methods are considered to be a safer alternative but can, in certain conditions, be imprecise due to zero drift and still require an invasive procedure. An accurate noninvasive method to measure elevated ICP would therefore be desirable. This article is a review of the current literature on noninvasive methods for measuring and evaluating elevated ICP. The main focus is on studies that compare noninvasively measured ICP with invasively measured ICP. The aim is to provide an overview of the current state of the most common noninvasive techniques available. Several methods for noninvasive measuring of elevated ICP have been proposed: radiologic methods including computed tomography and magnetic resonance imaging, transcranial Doppler, electroencephalography power spectrum analysis, and the audiological and ophthalmological techniques. The noninvasive methods have many advantages, but remain less accurate compared with the invasive techniques. None of the noninvasive techniques available today are suitable for continuous monitoring, and they cannot be used as a substitute for invasive monitoring. They can, however, provide a reliable measurement of the ICP and be useful as screening methods in select patients, especially when invasive monitoring is contraindicated or unavailable.

The complications and the position of the Codman MicroSensor™ ICP device: an analysis of 549 patients and 650 Sensors

Complications of and insertion depth of the Codman MicroSensor ICP monitoring device (CMS) is not well studied. To study complications and the insertion depth of the CMS in a clinical setting. We identified all patients who had their intracranial pressure (ICP) monitored using a CMS device between 2002 and 2010. The medical records and post implantation computed tomography (CT) scans were analyzed for occurrence of infection, hemorrhage and insertion depth. In all, 549 patients were monitored using 650 CMS. Mean monitoring time was 7.0 ± 4.9 days. The mean implantation depth was 21.3 ± 11.1 mm (0-88 mm). In 27 of the patients, a haematoma was identified; 26 of these were less than 1 ml, and one was 8 ml. No clinically significant bleeding was found. There was no statistically significant increase in the number of hemorrhages in presumed coagulopathic patients. The infection rate was 0.6 % and the calculated infection rate per 1,000 catheter days was 0.8. The risk for hemorrhagic and infectious complications when using the CMS for ICP monitoring is low. The depth of insertion varies considerably and should be taken into account if patients are treated with head elevation, since the pressure is measured at the tip of the sensor. To meet the need for ICP monitoring, an intraparenchymal ICP monitoring device should be preferred to the use of an external ventricular drainage (EVD).

783 Management of Severe Paediatric Trauma Brain Injury (PTBI) Guided by Intracranial Pressure (ICP) Monitoring in a Picu in Algeria

Background and AimsPTBI is the leading cause of death and long-term morbidity. Current recommendations for the management of severe PTBI (Glasgow Coma [GCS] score ≤8) indicate that ICP monitoring is...

Short-Term Continuous Intraparenchymal Intracranial Pressure Monitoring in Presumed Idiopathic Intracranial Hypertension

The management of idiopathic intracranial hypertension (IIH) depends on a reliable assessment of intracranial pressure (ICP), particularly when visual function measures or ophthalmoscopic indicators are confusing and when invasive surgical procedures are being considered. Although ICP monitoring has been widely applied in many neurologic conditions as a more reliable measure of ongoing ICP than lumbar puncture (LP), it has not often been widely used in the management of IIH. We searched the records of the University of Michigan between 2001 and 2008 for patients with IIH who had undergone LP and continuous ICP monitoring with an intraparenchymal Codman ICP Monitoring System and in whom at least 1 year of follow-up information was available. Ten patients met entry criteria. There were no complications from the ICP monitoring. ICP monitoring influenced management in all 10 patients. In 8 patients, LP had shown elevated opening pressures; in 7 of them, ICP monitoring failed to confirm a consistently high ICP. In these patients, the decision to withdraw ICP-lowering agents or shunts, or not to revise indwelling shunts, produced no change in visual function or optic disc appearance over a follow-up period of at least 1 year. In 1 patient, ICP monitoring confirmed the high ICP suggested by LP, justifying placement of a ventriculoperitoneal shunt. In 1 patient, ICP monitoring was performed instead of LP because a petroclival mass posed a danger to the performance of LP; a shunt was subsequently placed due to elevated ICP. In providing more accurate information about ICP than about LP, short-term continuous ICP intraparenchymal monitoring may be a useful adjunct in the management of IIH when clinical data are confusing and invasive interventions are under consideration.