Increased Intracranial Pressure Values Research Articles

Hinge craniotomy versus standard decompressive hemicraniectomy: an experimental preclinical comparative study.

Decompressive craniectomy (DC) is the most common surgical procedure to manage increased intracranial pressure (ICP). Hinge craniotomy (HC), which consists of fixing the bone operculum with a pivot, is an alternative method conceived to avoid some DC-related complications; nonetheless, it is debated whether it can provide enough volume expansion. In this study, we aimed to analyze the volume and ICP obtained with HC using an experimental cadaver-based preclinical model and compare the results to baseline and DC. Baseline conditions, HC, and DC were compared on both sides of five anatomical specimens. Volume and ICP values were measured with a custom-made system. Local polynomial regression was used to investigate volume differences. The area of the bone opercula resulting from measurements was 115.55 cm2; the mean supratentorial volume was 955 mL. HC led to intermediate results compared to baseline and DC. At an ICP of 50 mmHg, HC offers 130 mL extra space but 172 mL less than a DC. Based on local polynomial regression, the mean volume difference between HC and the standard craniotomy was 10%; 14% between DC and HC; both are higher than the volume of brain herniation reported in the literature in the clinical setting. The volume leading to an ICP of 50 mmHg at baseline was less than the volume needed to reach an ICP of 20 mmHg after HC (10.05% and 14.95% from baseline, respectively). These data confirm the efficacy of HC in providing sufficient volume expansion. HC is a valid intermediate alternative in case of potentially evolutionary lesions and non-massive edema, especially in developing countries.

Application of Intracranial Pressure-Directed Therapy on Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage

ObjectiveElevated ICP is a well-recognized phenomenon in aneurysmal subarachnoid hemorrhage (aSAH) that has been demonstrated to lead to poor outcomes. Delayed cerebral ischemia (DCI) is the most important reason for a poor clinical outcome after a subarachnoid hemorrhage. DCI is understood as a multifactorial process that evolves over time, largely caused by the sequelae of increased intracranial pressure (ICP). The study aimed to assess how to better define the association between ICP and DCI, and whether rational ICP management can improve the outcome of aSAH patients.MethodsWe prospectively reviewed patients diagnosed with aSAH and received microsurgery clipping at our department from December 2019 to January 2021. Subdural ICP monitoring devices were kept to monitor the ICP. The ICP values were recorded every 1-h epochs. ICP -guided dehydration treatments were routinely performed to control the ICP level of patients after surgery. To evaluate whether the subdural ICP-directed management improved the prognosis of the aSAH patients, we compared the outcome data of the patients in our cohort with those treated at another ward of our hospital at the same period.ResultsIn total, 144 consecutive aSAH patients received microsurgery clipping at our department, 68 of whom underwent ICP monitoring. A total of 11,424 1-h ICP measurements were recorded for the included patients (1.30 years of recordings). Of 68 patients with ICP monitoring, 27 (27/68, 39.7%) patients developed DCI. Univariate analysis showed that higher Hunt-Hess grade (OR 2.138, 95% CI 1.025–4.459, p = 0.043), higher preoperative modified Rankin Scale score (OR 1.534, 95% CI 1.033–2.276, p = 0.034), and the max ICP value of each day value >28.5 mmHg (OR 4.442, 95% CI 1.509–13.082, p = 0.007) were associated with DCI. Also, patients with ICP-directed treatment showed a significantly lower DCI incidence than patients without ICP monitoring.ConclusionOur study suggests that I less than 15 mmHg possibly constitute normal values and that 28.5 mmHg is the ICP threshold most strongly associated with the occurrence of DCI in aSAH patients. Patients who received the ICP-directed treatment presented a lower incidence of DCI. Our findings provide a basis for the recommendation of ICP-directed treatment after aSAH.Trial Registration NumberNCT04785976.

Intracranial pressure monitoring following traumatic brain injury: evaluation of indications, complications, and significance of follow-up imaging\u2014an exploratory, retrospective study of consecutive patients at a level I trauma center

BackgroundMeasurement of intracranial pressure (ICP) is an essential part of clinical management of severe traumatic brain injury (TBI). However, clinical utility and impact on clinical outcome of ICP monitoring remain controversial. Follow-up imaging using cranial computed tomography (CCT) is commonly performed in these patients. This retrospective cohort study reports on complication rates of ICP measurement in severe TBI patients, as well as on findings and clinical consequences of follow-up CCT.MethodsWe performed a retrospective clinical chart review of severe TBI patients with invasive ICP measurement treated at an urban level I trauma center between January 2007 and September 2017.ResultsClinical records of 213 patients were analyzed. The mean Glasgow Coma Scale (GCS) on admission was 6 with an intra-hospital mortality of 20.7%. Overall, complications in 12 patients (5.6%) related to the invasive ICP-measurement were recorded of which 5 necessitated surgical intervention. Follow-up CCT scans were performed in 192 patients (89.7%). Indications for follow-up CCTs included routine imaging without clinical deterioration (n = 137, 64.3%), and increased ICP values and/or clinical deterioration (n = 55, 25.8%). Follow-up imaging based on clinical deterioration and increased ICP values were associated with significantly increased likelihoods of worsening of CCT findings compared to routinely performed CCT scans with an odds ratio of 5.524 (95% CI 1.625–18.773) and 6.977 (95% CI 3.262–14.926), respectively. Readings of follow-up CCT imaging resulted in subsequent surgical intervention in six patients (3.1%).ConclusionsInvasive ICP-monitoring in severe TBI patients was safe in our study population with an acceptable complication rate. We found a high number of follow-up CCT. Our results indicate that CCT imaging in patients with invasive ICP monitoring should only be considered in patients with elevated ICP values and/or clinical deterioration.

Intracranial pressure monitoring for malignant stroke: It is too soon to call it off.

Malignant cerebral infarction (MCI) is a large middle cerebral artery infarction. MCI frequently results in increased intracranial pressure (ICP) because of its extent of the infarction. MCI management focuses on lowering ICP, but monitoring ICP has not been a standard of care. Studies have found insignificant clinical value in monitoring ICP because of doubtful correlations between ICP values and clinical findings. However, this conclusion is largely based on unilateral ICP measurements. Bilateral ICP measurements and differentials accompanying clinical findings are needed to draw a concrete conclusion on the usage of ICP monitoring in MCI management.

The relationship between patient height and intracranial pressure in children and adults

The management of increased intracranial pressure (ICP) and monitoring of ICP is an important part of neurosurgery, but reference values for ICP have not been established differentiating between children and adults. The same estimated reference of 7-15 is used indiscriminately for children and adults, and does not take in to account that adults and children differ physiologically. The effect on ICP of a postural change from a supine to a upright standing position has been established, though the association between height and ICP in upright position has not been studied. The purpose of this study is to address if ICP values could depend on height.

First Clinical Results With a New Telemetric Intracranial Pressure-Monitoring System

The knowledge of intracranial pressure (ICP) is the basis of an appropriate neurosurgical treatment. Because clinical, fundoscopic, or radiological data alone are often elusive, a pre- or postoperative long-term monitoring of the ICP itself is desirable. We describe the first clinical experiences with a new telemetric ICP-monitoring device. The transducer of this telemetric intraparenchymal pressure probe is placed under the galea over the calvaria. ICP can be monitored via a special telemetric reader, placed over the intact skin, and the ICP values are stored in a small portable computer. The system does not require an intensive care environment and can be used in any ward or even at home. The system was successfully applied in 10 patients (age, 3-56 years) in whom raised ICP due to hydrocephalus, shunt dysfunction, endoscopic third ventriculostomy failure, craniostenosis, or pseudotumor cerebri was suspected. Continuous telemetric monitoring of ICP was performed for 2 to 24 weeks. In 7 patients, increased ICP values could be excluded, and further surgical maneuvers were avoided. In 3 patients, repeated plateaus or continuously raised ICP indicated surgery resulting in a normalization of ICP. This new telemetric system was safe and effective for ICP measurement over a long period, including home monitoring. For the patients, it was easy to handle, and reliable data could be recorded over many weeks. Based on this preliminary experience, the authors consider the new system extremely advantageous in surgical decision making in particularly difficult cases of suspected abnormalities of ICP.

Cerebral blood flow autoregulation during intracranial hypertension: a simple, purely hydraulic mechanism?

In this paper, we re-propose the role of a hydraulic mechanism, acting where the bridging veins enter the dural sinuses in cerebral blood flow (CBF) autoregulation. We carried out an intraventricular infusion in ten albino rabbits and increased intracranial pressure (ICP) up to arterial blood pressure (ABP) levels. We measured CBF velocity by an ultrasound probe applied to a by-pass inserted in a carotid artery and recorded ICP by an intraventricular needle. Diastolic and pulsatile ICP and ABP values were analyzed from basal conditions up to brain tamponade and vice versa. A biphasic pattern of pulsatile intracranial pressure (pICP) was observed in all trials. Initially, until the CBF velocity remained constant, pICP increased (from 1.2 to 5.4 mmHg) following a rise in diastolic intracranial pressure (dICP); thereafter, in spite of a further rise in dICP, pICP decreased (2.87 mmHg) following CBF velocity reduction until intracranial circulation arrest (pICP=1.2 mmHg). A specular pattern was observed when the intraventricular infusion was stopped and CBF velocity returned to basal levels. These findings can be interpreted as indicating a hydraulic mechanism. Initially, when CBF is still constant, pICP rise is due to an increase in venous outflow resistance; subsequently, when CBF decreases following a further increase in venous outflow resistance, the vascular engorgement produces an arteriolar vasodilation. This vasodilation determines an increase in vascular wall stiffness, thus reducing pulse transmission to surrounding subarachnoid spaces.

Respuesta de la presión intracraneal durante la aspiración de secreciones previa administración de un relajante muscular

Aspiration of secretions is a usual nursing technique in patients undergoing mechanical ventilation that may be the cause of increased Intracranial Pressure (ICP).This study aims to evaluate the repercussion of a muscle relaxant on ICP with secretion aspiration.Clinical trial using the same patient as case and control, performing two endotracheal aspirations in each patients, on of them after administration of a muscle relaxant (Cis-Atracurium) and another no. The bolus administration of the relaxant in the first or second aspiration was done randomly. Thirteen patients with intraparenchymatous ICP measurement catheter were studied within the first 36 hours post-placement and with sedoanalgesia for a score of 6 on the Ramsay scale. ICP and CPP were measured before, during and after each aspiration.SPSS 11.0 program was used. Data analysis by Student's t test for paired data. Statistical significance level accepted was 95%.On comparing the cases in which muscle relaxant was administered with those in which it was not administered, statistically significant differences were found in the ICP and CCP values during secretion aspiration.According to the data obtained in the study, a lower increase of ICP was observed during secretion aspiration in those cases in which muscle relaxant was administered prior to the aspiration.

Cerebral venous flow velocity predicts poor outcome in subarachnoid hemorrhage.

Predictors of clinical outcome in aneurysmal subarachnoid hemorrhage (SAH) vary in reliability. Measurement of cerebral venous hemodynamics by transcranial color-coded duplexsonography (TCCS) has become of increasing interest lately, and correlation with intracranial pressure (ICP) seems to be high. The aim of the presented study was to assess changes of cerebral venous hemodynamics in SAH and evaluate its relationship with clinical outcome. We performed sequential TCCS of venous peak flow velocities (vp-FVs) in the transversal sinus in 28 consecutive patients with aneurysmal SAH (Hunt and Hess scale 1 to 5). Measurement was initiated at onset of arterial vasospasm up to 5 days after SAH. All patients had a continuous ICP monitoring. Clinical outcome was evaluated with the modified ranking scale (MRS) 30 days after SAH. Patients were divided according to outcome: group I good recovery (MRS 0-III) and group II poor outcome (death or MRS IV-V). Maximum vp-FV, time-averaged vp-FV (mv-FV), and ICP were compared between groups. Vp-FV and mv-FV as well as ICP of group II exceeded values of group I (P<0.001 for all 3 parameters). Vp-FV showed a positive correlation with ICP (r=0.63; P<0.001). A vp-FV exceeding 35.4 cm/s (sensitivity 100%; specificity 90.9%), an mv-FV exceeding 27.3 cm/s (sensitivity 94.1%; specificity 81.8%), and an ICP exceeding 24 mm Hg (sensitivity 87.5%; specificity 81.8%) predicted poor outcome (receiver operating characteristic analysis). Increased ICP values correlate with increased venous flow velocities. In SAH, increased ICP and increased venous flow velocities are associated with poor outcome. Flow velocity of the transversal sinus is a highly sensitive, reliable, and early predictor of outcome in SAH.

Prolonged ICP monitoring in Sylvian arachnoid cysts

Background The decision making process for patients with Sylvian fissure arachnoid cysts still represents a challenge for the neurosurgeon. A high percentage of patients are indeed asymptomatic, despite neuroimaging signs of apparently increased intracranial pressure (ICP). The present study was conducted to evaluate the usefulness of prolonged ICP recording in the preoperative work-up. Methods Eleven children (10 M/1 F) harboring temporal arachnoid cysts were investigated (mean age: 5.9 years). According to Galassi classification they were subdivided in three groups. Group I was made up of three patients with Type I cysts; Group II comprised six children with Type II cysts; Group III consisted of two children with Type III cysts. An extensible silicone microprocessor (Codman), developed for continuous ICP recording, was implanted intraparenchymally, adjacent to the major extension of the cyst. The collected information was cable unloaded to a PC and stored. All the patients underwent a minimum of 48 hours to a maximum of 72 hours of ICP continuous check. In resting conditions, 10 mm Hg was arbitrarily chosen as the upper normal limit of ICP, and the patients were classified according to the percentile distribution of their ICP daily and nightly pressure values. Results ICP recordings were in the normal range in all the three children with Type I cysts (49-86%< 10 mm Hg during the entire recording), despite the fact that two of them were apparently symptomatic. Three of the six children with a Type II temporal cyst had elevated ICP values (69-99%> 10 mm Hg), even though they had an incidental (1 case) or prenatal (2 cases) diagnosis. The remaining three patients had normal ICP values for more than 70% of the recording time period. The two patients with type III temporal arachnoid cysts had almost constantly abnormal ICP values (95-99%> 10 mm Hg). Five patients were operated; in four of them the surgical indication was based on ICP recordings (two of the three children with a Type II cyst and increased ICP and the two patients with a Type III cyst). The last child, harboring a Type I cyst, was operated upon parents’ request, as a preventive measure. At a mean follow-up of 9.3 months all the patients operated on are in excellent clinical condition; one of them (Type II cyst) initially undergoing a craniotomy and cystic membrane excision required a subduro-peritoneal shunt implant 3 months after surgery for a symptomatic subdural hygroma on the side of the cyst. Postoperative computed tomography showed signs of brain expansion in the two patients operated on for a Type III cyst, and in the patient operated on for a Type I cyst. Conclusions With the limit of the relatively small series presented here, prolonged ICP recording appeared to be an important preoperative tool to rule out the necessity of operating on children with Type I cysts. Furthermore, the study confirmed that an increase of the ICP is almost constantly present in children with Type III cysts. In cases of Type II lesions, the study results were less discriminating, though the ICP monitoring contributed in identifying those patients in whom surgery was indicated despite the absence of symptoms.

Effects of alterations in arterial CO2 tension on cerebral blood flow during acute intracranial hypertension in rats.

Cerebrovascular reactivity to CO2 in clinical and experimental studies has been found to be impaired during increased intracranial pressure (ICP). However, from previous study results it has not been possible to estimate whether the impairment was caused by elevated ICP, or caused by decreased cerebral perfusion pressure (CPP). The current study was carried out in a group of unmanipulated control rats and in six investigation groups of six rats each: two groups with elevated ICP (30 and 50 mm Hg) and spontaneous arterial blood pressure (MABP), two groups with spontaneous ICP and arterial hypotension (77 and 64 mm Hg), and two groups with elevated ICP (30 and 50 mm Hg) and arterial hypertension (124 mm Hg). Intracranial hypertension was induced by continuous infusion of lactated Ringer's solution into the cisterna magna, arterial hypotension by controlled bleeding, and arterial hypertension by continuous administration of norepinephrine intravenously. Cerebral blood flow (CBF) was measured repetitively by the intraarterial 133Xe method at different levels of arterial PCO2. In each individual animal, CO2 reactivity was calculated from an exponential regression line obtained from the corresponding CBF/PaCO2 values. By plotting each individual value of CO2 reactivity against the corresponding CPP value from the seven investigation groups, CPP was significantly and directly related to CO2 reactivity of CBF (P < .001). No correlation was found by plotting CO2 reactivity values against the corresponding MABP values or the corresponding ICP values. Thus, the results show that CO2 reactivity is at least partially determined by CPP and that the impaired CO2 reactivity observed at intracranial hypertension and arterial hypotension may be caused by reduced CPP.

The Diagnostic Value of Optic Disc Evaluation in Acute Elevated Intracranial Pressure

Ophthalmologists often are asked to evaluate the optic disc for evidence of acute increased intracranial pressure (ICP). The authors studied the incidence of papilledema in a population of patients with a documented acute increase in ICP. Included in this study were 37 patients with acute elevated ICP due to a spontaneous hemorrhage or craniocerebral trauma. In all patients, the ICP was monitored continuously. Fundus examination was performed twice daily on at least 7 consecutive days. According to the level and duration of the ICP, the patients were divided into three groups. Group 1 included 13 patients who had a slightly elevated ICP (range, 20-30 mmHg) on at least 3 consecutive days. In this group, 3 of 13 patients demonstrated venous congestion on the fifth or sixth day. No swelling of the optic disc was seen in this group. Group 2 included seven patients with an elevated ICP, with values ranging from 30 to 70 mmHg lasting for at least 3 consecutive days. In this group, one patient had a blurred disc margin on the sixth day. Group 3 included 17 patients with shortlasting ICP values, ranging from 30 to 60 mmHg for less than 72 hour. Neither papilledema nor abnormalities of fundus vessels were seen in this group. Papilledema in acute elevation of ICP is an uncommon event. Its absence does not preclude the presence of ICP elevation.

Value of transcranial Doppler indices in predicting raised ICP in infantile hydrocephalus. A study with review of the literature.

Cerebral hemodynamic changes in infants with progressive hydrocephalus have been studied with the transcranial Doppler (TCD) technique. Several authors have referred to the correlation between the hemodynamic changes and increased intracranial pressure (ICP). Despite conflicting conclusions on the value of pulsatility index (PI) and resistance index (RI) measurements for monitoring infantile hydrocephalus, these pulsatility indices are the most commonly used for this purpose. Although clinical signs of raised ICP are highly variable and unreliable in infants, assumptions have been made in most of the studies about the presence of elevated ICP on the basis of the patient's clinical state. Few studies have reported on actual ICP values, however, and a direct relationship between ICP and TCD changes has never been adequately demonstrated. In the present study, this relationship was investigated in long-term simultaneous TCD/ICP measurements, in an attempt to develop a noninvasive method of monitoring the effect of ICP on intracranial hemodynamics. Two groups of data sets were established. Group I consisted of pre- and postoperative (shunt implantation) TCD/ICP measurements. Group II were long-term simultaneous TCD/ICP recordings showing significant ICP variations. In most of the postoperative measurements there was a decrease in the average PI and RI values. The correlation between PI or RI and ICP in the long-term simultaneous recordings, however, was generally poor. The risk of obtaining false positive or false negative PI or RI values in short-term measurements was also demonstrated. It can be concluded from our results, besides the wide range of reference values for the Doppler indices and extracranial influences upon them, that the present Doppler indices are inadequate for monitoring the complex intracranial dynamic responses in patients with raised ICP.