FIG 2 - uploaded by James P Mcallister
Content may be subject to copyright.
Upper: Graphic representation of results of cell counts for nucleated cells in CSF. Patients with infection (S) and without infection (S) cannot be separated in the relevant range of 0 to 200 nucleated cells per TCC (n/cumm), although mean and median cell counts of both groups are statistically different (see Table 4). A significant number of infected patients have a cell count less than 100 nucleated cells per TCC. This finding results in a loss of diagnostic power for this parameter. Lower: Graphic representation of results of the ratio of erythrocytes to nucleated cells (E/N) in CSF, computed to correct for blood contamination during the tap procedure. Groups are not separated.
Source publication
Exaggerated nocturnal intracranial pressure (ICP) dynamics are commonly observed in hydrocephalic children with a compromise of CSF compensatory reserve capacity. Successful shunting restores this cerebrospinal reserve. We used ICP overnight monitoring combined with positional maneuvers in complex hydrocephalic children with a suspected shunt malfu...
Contexts in source publication
Context 1
... patients were less scattered and lower than those in Group S and S patients (p 0.02 and p 0.005) but did not differ between the latter two (47.6 43.1, 127.3 202.7, and 143.6 227.9, respec- tively). Table 4 demonstrates that counts of nucleated cells in CSF were highest in S patients, compared with those in the S and control groups; however, as Fig. 2 upper dem- onstrates, there was an enormous overlap between groups, and no threshold could be defined that would have allowed for a separation of the S and S groups. The ratio of erythrocytes to nucleated cells, calculated to correct for contamination of CSF with blood, was lower in Group S than in Group S, but it was not different ...
Context 2
... could be defined that would have allowed for a separation of the S and S groups. The ratio of erythrocytes to nucleated cells, calculated to correct for contamination of CSF with blood, was lower in Group S than in Group S, but it was not different from the control group. Again, there was a large overlap between Groups S and S (Table 4 and Fig. 2 ...
Similar publications
Open third ventriculostomy (OTV) was performed on 4 infants with noncommunicating hydrocephalus and intractable shunt infections. All patients were resistant or relapsed after treatment with intravenous and intraventricular antibiotics along with change of the shunt apparatus. We performed phase-contrast cine magnetic resonance imaging (MRI) for pr...
Citations
... Intracranial pressure (ICP) plays a vital role both in normal life, and in a spectrum of acute neurosurgical and neurological disorders, such as intracranial haemorrhages and traumatic brain injury, as well as more chronic conditions, such as normal pressure hydrocephalus and idiopathic intracranial hypertension [1][2][3][4]. Invasive measurement of ICP is routinely used in managing these patients, and ICP-lowering treatment is used to reach an acceptable ICP. Despite this, the current literature on normal ICP values remains scarce. ...
... Thus, these patients had symptoms indicating increased ICP but no apparent ICP disturbance upon measuring ICP [8][9][10]. (2) Healthy patients with measurement of the lumbar cerebrospinal fluid (CSF) pressure [11][12][13]. However, the feasibility of lumbar CSF pressure as a surrogate for ICP remains a subject of ongoing debate, especially in patients with obstructive lesions. ...
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)
... This is clinically manifested with the patient being unable to assume an upright position. The constellation of symptoms may also include nuchal or upper back pain, nausea, vomiting, dizziness, fatigue, irritability, gait disturbance, diplopia, seizures, and lethargy [40,41]. Symptomatology associated with low intracranial pressure may eventually evolve to intermittent disabling headaches. ...
The main subject of the current review is a specific subtype of headache, which is related to shunt over-drainage and slit ventricle syndrome, in pediatric patients harboring an implanted shunt device for the management of hydrocephalus. This clinical entity, along with its impairment regarding the quality of life of the affected individuals, is generally underestimated. This is partly due to the absence of universally agreed-upon diagnostic criteria, as well as due to a misunderstanding of the interactions among the implicated pathophysiological mechanisms. A lot of attempts have been performed to propose an integrative model, aiming at the determination of all the offending mechanisms of the shunt over-drainage syndrome, as well as the determination of all the clinical characteristics and related symptomatology that accompany these secondary headaches. This subcategory of headache, named postural dependent headache, can be associated with nausea, vomiting, and/or radiological signs of slim ventricles and/or subdural collections. The ultimate goal of our review is to draw clinicians’ attention, especially that of those that are managing pediatric patients with permanent, long-standing, ventriculoperitoneal, or, less commonly, ventriculoatrial shunts. We attempted to elucidate all clinical and neurological characteristics that are inherently related to this type of headache, as well as to highlight the current management options. This specific subgroup of patients may eventually suffer from severe, intractable headaches, which may negatively impair their quality of daily living. In the absence of any other clinical condition that could be incriminated as the cause of the headache, shunt over-drainage should not be overlooked. On the contrary, it should be seriously taken into consideration, and its management should be added to the therapeutic armamentarium of such cases, which are difficult to be handled.
... This is clinically manifested with the patient been unable to tolerate a sitting up position. The constellation of symptoms may also include nuchal or upper back pain, nausea, vomiting, dizziness, fatigue, irritability, gait disturbance, diplopia, seizures and lethargy [39,40]. Symptomatology associated with low intracranial pressure may eventually evolve to intermittent, disabling headaches. ...
The ultimate goal of our review is to draw clinician’s attention, especially of those who are managing pediatric patients with permanent, long-standing, ventriculoperitoneal or, less commonly, ventriculo-atrial shunts. This specific subgroup of patients may eventually suffer from severe, intractable headaches which may negatively impair their quality of daily living. In the absence of any other clinical condition that could be attributed as the cause of the headache, shunt overdrainage should not be overlooked but, on the contrary, should be seriously taken into consideration in the therapeutic armamentarium of such cases, that are difficult to be handled.
... ICP monitoring, initially introduced by Lundberg [3], has been used for diagnosing and managing different brain diseases, such as hydrocephalus, idiopathic intracranial hypertension, traumatic brain injury, and cerebral haemorrhages [4][5][6]. Currently, only the mean ICP value is considered in clinical practice; however, a growing number of researchers are interested in studying the shape of the ICP pulse waveform [7][8][9] to better understand the pathology's origin [10]. Typically, the ICP pulse is composed of three peaks, P1, P2, and P3, which in healthy cases, P1 predominates in amplitude over P2 and P3 [11]. ...
Background:
Since arterial flow is the leading actor in neuro-fluids flow dynamics, it might be interesting to assess whether it is meaningful to study the arterial flow waveform in more detail and whether this provides new important information. Few studies have focused on determining the influence of heart rate variation over time on the arterial flow curve. Therefore, this study aimed to evaluate cerebral arterial flow waveforms at extracranial and intracranial compartments in young and elderly healthy adults, also considering systole and diastole phases.
Methods:
Cine phase-contrast magnetic resonance imaging (CINE-PC MRI) was performed on twenty-eight healthy young volunteers (HYV) and twenty healthy elderly volunteers (HEV) to measure arterial blood flows at the extracranial and intracranial planes. A semi-automated protocol using MATLAB scripts was implemented to identify the main representative points in the arterial flow waveforms. Representative arterial profiles were estimated for each group. Moreover, the effects of age and sex on flow times, amplitude-related parameters, and parameters related to systole and diastole phases were evaluated at the extracranial and intracranial compartments. Student's t-test or Wilcoxon's test (depending on the normality of the distribution) was used to detect significant differences.
Results:
In HYVs, significant differences were observed between extracranial and intracranial levels in parameters related to the AP1 amplitude. Besides the detected differences in pulsatility index (extracranial: 0.92 ± 0.20 vs. 1.28 ± 0.33; intracranial: 0.79 ± 0.15 vs. 1.14 ± 0.18, p < .001) and average flow (715 ± 136 vs. 607 ± 125 ml/min, p = .008) between HYV and HEV, differences in the amplitude value of the arterial flow profile feature points were also noted. Contrary to systole duration (HYV: 360 ± 29 ms; HEV: 364 ± 47 ms), diastole duration presented higher inter-individual variability in both populations (HYV: 472 ± 145 ms; HEV: 456 ± 106 ms). Our results also showed that, with age, it is mainly the diastolic phase that changes. Although no significant differences in duration were observed between the two populations, the mean flow value in the diastolic phase was significantly lower in HEV (extracranial: 628 ± 128 vs. 457 ± 111 ml/min; intracranial: 599 ± 121 vs. 473 ± 100 ml/min, p < .001). No significant differences were observed in the arterial flow parameters evaluated between females and males in either HYV or HEV.
Conclusion:
Our study provides a novel contribution on the influence of the cardiac cycle phases on cerebral arterial flow. The main contribution in this study concerns the identification of age-related alterations in cerebral blood flow, which occur mainly during the diastolic phase. Specifically, we observed that mean flow significantly decreases with age during diastole, whereas mean flow during systole is consistent.
... Evaluation of IVP dynamics clearly demonstrated the influence of body position on CSF drainage in hydrocephalic human adults. [42][43][44][45][46][47] Higher CSF draining was associated with a standing position and the addition of the hydrostatic pressure in the shunt system to IVP that in sum act on the valve's resistance to CSF flow. 48,49 The use of shunts without antisiphoning devices is another major risk factor for overdrainage and hematoma in most human studies. ...
Background
Overshunting and hemispheric collapse are well‐known complications after ventriculoperitoneal shunt (VPS) implantation. Risk factors that predispose to overshunting, treatment options, and prognosis after therapeutic intervention have not been described.
Hypothesis/Objectives
To identify preoperative risk factors for overshunting, the effect of surgical decompression, and their outcomes.
Animals
Seventy‐five dogs and 7 cats.
Methods
Retrospective case cohort study. Age, breed, sex, body weight, number of dilated ventricles, ventricle brain ratio, intraventricular pressure, and implanted pressure valve systems were evaluated as possible risk factors.
Results
Overshunting had a prevalence of 18% (Cl 95% 9.9‐26.66). An increase of 0.05 in VBR increased the risk of overshunting by OR 2.23 (Cl 95% 1.4‐3.5; P = .001). Biventricular hydrocephalus had the highest risk for overshunting compared to a tri‐ (OR 2.48 with Cl 95% 0.5‐11.1) or tetraventricular hydrocephalus (OR 11.6 with Cl 95% 1.7‐81.1; P = .05). There was no influence regarding the use of gravitational vs differential pressure valves (P > .78). Overshunting resulted in hemispheric collapse, subdural hemorrhage, and peracute deterioration of neurological status in 15 animals. Subdural hematoma was removed in 8 dogs and 2 cats with prompt postoperative improvement of clinical signs.
Conclusions and Clinical Importance
Biventricular hydrocephalus and increased VBR indicate a higher risk for overshunting. The use of differential valves with gravitational units has no influence on occurrence of overshunting related complications and outcomes. Decompressive surgery provides a favorable treatment option for hemispheric collapse and has a good outcome.
... For critically low intracranial compliance, the amplitude correlates well with mean pressure (and RAP≈1) [24]. The upper normal threshold of RAP is 0.6 [25]. ...
Intracranial pressure (ICP) monitoring is a standard diagnostic tool for various neurological conditions. Elevated ICP can complicate the pre-existing clinical disorders and can result in headaches, nausea, vomiting, obtundation, seizures, and even death. This monitoring is typically accomplished using intracranially placed pressure transducers, which although reasonably accurate, carry risks of infection and hemorrhage. Another drawback is that invasive techniques necessitate surgical expertise. Hence, an alternative non-invasive ICP monitoring approach would be highly desirable, especially if the method could be a rapid, reliable, simple-to-use, and easily interpretable. This chapter focuses on non-invasive approaches to ICP monitoring linked to the auditory system. Mechanical coupling between the brain’s subarachnoid space and perilymphatic space of the ear has allowed assessing ICP from auditory measurements. Measurements of tympanic membrane displacement, tympanometry, and otoacoustic emissions are the primary approaches of non-invasive ICP detection that stemmed from the auditory system. We have summed up the evaluation, development, limits, and current state of the art of these methods. More investigations and studies are needed to investigate the use of the non-invasive techniques in clinical settings.
... 16 The presence of B-waves is indicative of reduced intracranial compliance, and they appear mainly during the rapid eye movement (REM) sleep when there is an increase in cerebral blood flow (CBF) and brain metabolism. [18][19][20][21] The alteration of cerebral autoregulation or reactivity due to reduced intracranial compliance could be pathological in such a scenario. ...
... Nocturnal monitoring is associated with various benefits. For example, nocturnal ICP recordings were shown to be more reliable in children than day monitoring, 54 B-waves, which are of primary interest here, occur more frequently during the night, especially in REM sleep, 20,21 and ICP monitoring is prone to motion artifacts that are minimized during sleep. ...
Significance:
Benign external hydrocephalus (BEH) is considered a self-limiting pathology with a good prognosis. However, some children present a pathological intracranial pressure (ICP) characterized by quantitative and qualitative alterations (the so-called B-waves) that can lead to neurological sequelae.
Aim:
Our purpose was to evaluate whether there were cerebral hemodynamic changes associated with ICP B-waves that could be evaluated with noninvasive neuromonitoring.
Approach:
We recruited eleven patients (median age 16 months, range 7 to 55 months) with BEH and an unfavorable evolution requiring ICP monitoring. Bedside, nocturnal monitoring using near-infrared time-resolved and diffuse correlation spectroscopies synchronized to the clinical monitoring was performed.
Results:
By focusing on the timing of different ICP patterns that were identified manually by clinicians, we detected significant tissue oxygen saturation ( StO 2 ) changes ( p = 0.002 ) and blood flow index (BFI) variability ( p = 0.005 ) between regular and high-amplitude B-wave patterns. A blinded analysis looking for analogs of ICP patterns in BFI time traces achieved 90% sensitivity in identifying B-waves and 76% specificity in detecting the regular patterns.
Conclusions:
We revealed the presence of StO 2 and BFI variations-detectable with optical techniques-during ICP B-waves in BEH children. Finally, the feasibility of detecting ICP B-waves in hemodynamic time traces obtained noninvasively was shown.
... Thus, it is largely contributing to better understand posture-or maneuver-related ICP changes. Studies about normal values of ICP have described the crucial role of the venous system, especially in the transition phase from lying to the upright body postures and vice versa [10][11][12][13][14]. Hereby, it was found that ICP values diminish, especially during body erection from 0° to 20°, and they remain rather stable at negative values toward 90° vertical body position, most likely due to the collapse of the jugular veins, inhibiting further intracranial blood volume loss [9]. ...
... Methodologically, it was feasible to automatically detect the AMP changes offline by using the recently developed software ICPicture (Miethke Co., Potsdam, Germany), which appears to be a simple and user-friendly ICP analysis software. Another very valuable software tool such as ICM + (Cambridge, UK) was introduced by other authors in overnight ICP monitoring and shunt infusion studies in which amplitude analysis and other parameters are integrated [14,19,22], but seems to be more complex and less user friendly as it is mainly used as a more sophisticated research tool. ...
Introduction
Telemetric intracranial pressure measurement (tICPM) offers new opportunities to acquire objective information in shunted and non-shunted patients. The sensor reservoir (SR) provides tICPM modality at a decent sampling rate as an integrated component of the CSF shunt system. The aim of this study is to perform tICPM during a defined protocol of maneuvers in an outpatient setting as feasibility study including either shunt-dependent patients or candidates for possible shunt therapy.
Methods
A total of 17 patients received a SR and were investigated within a protocol of maneuver measurements involving different body postures (90°, 10°, 0°, and − 10°), breathing patterns (hypo- and hyperventilation), and mild venous congestion (Valsalva, Jugular vein compression), while the latter two were performed in lying postures (10° and 0°). The cohort included 11 shunted and 6 non-shunted (stand-alone-SR) patients. All measurements were evaluated using an ICP-analysis software (ICPicture, Miethke, Germany) looking at ICP changes and amplitude (AMP) characteristics.
Results
The shunted patient group consisted of 11 patients (median age: 15.8 years; range: 4–35.2 years) with either a primary shunt (n=9) and 2 patients received a shunt after stand-alone-SR tICPM. Six patients were enrolled with a stand-alone SR (median age 11.9 years, range 3.6–17.7 years). In the stand-alone SR group, maneuver related ICP and AMP changes were more sensitive compared to shunted patients. Postural maneuvers caused significant ICP changes in all body positions in both groups. The highest ICP values were seen during Valsalva maneuver, provoked by the patients themselves. In the stand-alone group, significant higher ICP values during hyperventilation were observed compared to shunted individuals. In shunted patients, a significant correlation between ICP and AMP was observed only during hyperventilation maneuver, while this correlation was additionally seen in Valsalva and jugular vein compression in stand-alone patients.
Conclusion
SR-related tICPM is helpful to objectify diagnostic evaluation in patients with CSF dynamic disturbances. The defined protocol did result in a wide range of ICP changes with promising potential for effective outpatient tICPM investigation. Since the correlation of ICP and AMP was observed during mild venous congestion maneuvers it appears to be specifically helpful for the evaluation of intracranial compliance. Further investigations of maneuver-related tICPM in a larger population, including variable pathologies, are needed to further establish the protocol in the clinical practice.
... The correlation coefficient between the ICP wave amplitude and the mean ICP level (RAP) was originally designed as a potential descriptor of neurological deterioration in patients with TBI by Czosnyka et al. (17). Schuhmann et al. (13) suggested that RAP > 0.6 indicates shunt malfunction or hydrocephalus. With the ability to effectively demonstrate how the CSF compensatory reserve changes over time, RAP has been gradually introduced as a nearly response assessment parameter to differentiate responders from non-responders early in hydrocephalus according to its relative dynamic variations (13,18,19). ...
... Schuhmann et al. (13) suggested that RAP > 0.6 indicates shunt malfunction or hydrocephalus. With the ability to effectively demonstrate how the CSF compensatory reserve changes over time, RAP has been gradually introduced as a nearly response assessment parameter to differentiate responders from non-responders early in hydrocephalus according to its relative dynamic variations (13,18,19). The current knowledge about RAP and the different proposed thresholds for diagnosis in NPH/iNPH are summarized in Table 1. ...
Objective
To evaluate the value of the correlation coefficient between the ICP wave amplitude and the mean ICP level (RAP) and the resistance to CSF outflow (Rout) in predicting the outcome of patients with post-traumatic hydrocephalus (PTH) selected for shunting.
Materials and Methods
As a training set, a total of 191 patients with PTH treated with VP shunting were retrospectively analyzed to evaluate the potential predictive value of Rout, collected from pre-therapeutic CSF infusion test, for a desirable recovery level (dRL), standing for the modified rankin scale (mRS) of 0–2. Eventually, there were 70 patients with PTH prospectively included as a validation set to evaluate the value of Rout-combined RAP as a predictor of dRL. We calculated Rout from a CSF infusion test and collected RAP during continuous external lumbar drainage (ELD). Maximum RAP (RAPmax) and its changes relative to the baseline (ΔRAPmax%) served as specific parameters of evaluation.
Results
In the training set, Rout was proved to be a significant predictor of dRL to shunting, with the area under the curve (AUC) of 0.686 (p < 0.001) in receiver-operating characteristic (ROC) analysis. In the validation set, Rout alone did not present a significant value in the prediction of desirable recovery level (dRL). ΔRAPmax% after 1st or 2nd day of ELD both showed significance in predicting of dRL to shunting with the AUC of 0.773 (p < 0.001) and 0.786 (p < 0.001), respectively. Significantly, Rout increased the value of ΔRAPmax% in the prediction of dRL with the AUC of 0.879 (p < 0.001), combining with ΔRAPmax% after the 1st and 2nd days of ELD. RAPmax after the 1st and 2nd days of ELD showed a remarkable predictive value for non-dRL (Levels 3-6 in Modified Rankin Scale) with the AUC of 0.891 (p < 0.001) and 0.746 (p < 0.001).
Conclusion
Both RAP and Rout can predict desirable recovery level (dRL) to shunting in patients with PTH in the early phases of treatment. A RAP-combined Rout is a better dRL predictor for a good outcome to shunting. These findings help the neurosurgeon predict the probability of dRL and facilitate the optimization of the individual treatment plan in the event of ineffective or unessential shunting.
... [48] Stroke volume (SV) which is defined as the mean volume of CSF passing through the aqueduct during both systole and diastole, ≥42 μL, serves as an indicator of post shunt outcomes in patients with NPH. [49] Functional imaging: Single-photon emission computed tomography (SPECT) and positron emission tomography (PET) can show decrease of brain metabolism and cerebral blood flow in frontobasal and anterior periventricular region. [39] Shunt responsive patients show an improvement in the brain glucose metabolism. ...
Hydrocephalus is a common clinical problem encountered in neurosurgical practice. With greater subspecialisation, pediatric neurosurgery has emerged as a special discipline in several countries. However, in the developing world, which inhabits a large pediatric population, a limited number of neurosurgeons manage all types of hydrocephalus across all ages. There are some essential differences in pediatric and adult hydrocephalus. The spectrum of hydrocephalus of dysgenetic origin in a neonate and that of normal pressure hydrocephalus of the old age has a completely different strategy of management. Endoscopic third ventriculostomy outcomes are known to be closely associated with age at presentation and surgery. Efficacy of alternative pathways of CSF absorption also differs according to age. Managing this disease in various age groups is challenging because of these differences in etiopathology, tempo of the disease, modalities of investigations and various treatment protocols as well as prognosis.
