How Much Cerebrospinal Fluid Should We Remove Prior to Measuring a Closing Pressure?

Clinical and prognostic importance of craniospinal elastance and pressure volume index in pediatric pseudotumor cerebri syndrome

OBJECTIVE

The aim of the study was to determine the clinical and prognostic significance of craniospinal elastance (Ecs), pressure volume index (PVI), and cerebrospinal fluid (CSF) total protein data in terms of resolution of papilledema and improvement of headache in children with pseudotumor cerebri syndrome (PTCS).

METHODS

This is a retrospective observational study of 33 children with definitive PTCS. The relationships between lumbar puncture (LP) measurements, especially Ecs and PVI, and papilledema and headache resolution time were investigated.

RESULTS

In children with definite primary and secondary PTCS, higher opening pressure and decreased PVI were found to be associated with faster resolution of papilledema and faster improvement of headache (r = 0.904, P < 0.01; r = 0.894, P < 0.01 respectively). This effect was higher in children with secondary PTCS (P = 0.022). While papilledema resolution time and treatment time were statistically significantly higher in the secondary group (P = 0.035, P = 0.040), there was no significant difference between the two groups in terms of headache relief time (P = 0.051). Based on the primary and secondary groups, from the cut-off points determined, it was found that ≤ 41.60 ((AUC = 0.706, P = 0.0420), specificity 56%, sensitivity 86.7%) for opening pressure and ≤ 69.37 ((AUC = 0.702, P = 0.0448), specificity 48.2%, sensitivity 83.3%) for PVI were statistically significant. A very strong negative linear correlation was found between CSF total protein and lumbar puncture measurements and clinical outcomes (P < 0.001).

CONCLUSION

Ecs and PVI may be markers that can provide potentially important data on pediatric PTCS prognosis. CSF total protein may also provide clinical benefit.

Comparison Of Digital Manometer And Water Column Manometer Pressures Measurements During Lumbar Puncture

Background

Cerebrospinal fluid (CSF) pressure measurement is routinely performed via a conventional water column manometer. There is increasing interest in using a digital manometer in measuring CSF pressures. The aim of this study is to compare column and digital manometers, in addition to measuring time to acquire the pressure readings.

Research design and methods

This prospective study included 27 patients who were referred for a fluoroscopically guided lumbar puncture. Opening pressure and closing pressure measurements were done with a digital manometer and then a traditional water column manometer. The time to obtain each pressure measurement was also recorded and compared.

Results

Mean time to obtain pressure reading was significantly lower in the digital manometer group when compared to the water column manometer group (8.1 seconds vs. 42.2 seconds, P<0.05 for opening pressure and 8.92 seconds vs. 45.15 seconds, P<0.05 for closing pressure). Correlation between the opening pressure measurements (Pearson coefficient r= 0.98) and closing pressure (Pearson coefficient r= 0.89) was strong. However, the digital manometer reading consistently read higher.

Conclusion

Digital manometry during an LP yielded is faster however there might be a clinical difference between the devices. Clinicians must be careful in using the device across all cases.

Pseudotumor Cerebri Syndrome in Children

PURPOSE OF REVIEW

Pseudotumor cerebri syndrome (PTCS) may affect both children and adults; however, the risk factors and clinical presentation vary greatly between these populations. This review aims to highlight the entity of PTCS in children and the unique considerations in this population; review the epidemiology and demographics; discuss the clinical presentation, revised diagnostic criteria, and approach to evaluation; review management strategies; and discuss the prognosis and long-term outcomes in children with PTCS.

RECENT FINDINGS

Clinical presentation can be variable in children and may be less obvious than in their adult counterparts. Papilledema can also be challenging to diagnose in this population. The upper limits for opening pressure on lumbar puncture differ in children, with a cut-off of 25 cm H20 (or 28 cm H2O in a sedated or obese child). Morbidity related to visual loss, pain and reduced quality of life lends urgency towards accurately identifying, evaluating and managing children with PTCS. There are no randomised controlled studies to allow for evidence-based recommendations for the management of PTCS in children. Further studies are needed to clarify and consolidate management approaches in this population.

Are CSF Pressure Factors Related to the Development of Post-dural Puncture Headache?

Post-dural puncture headache (PDPH) is an unfavorable situation seen in considerable number of patients even though atraumatic and small needle reduces its incidence. CSF pressures measured at the time of puncture change after CSF drainage. In the present study, we investigated relationships between CSF pressure-related factors and occurrence of PDPH. We prospectively enrolled 103 participants who underwent CSF studies for meningitis. Using a standardized protocol, CSF opening pressure (OP) and closing pressure (CP) were measured, and cerebrospinal elastance (ECS) and pressure-volume index (PVI) were investigated. Within 14 days after dural puncture, we confirmed PDPH. According to PDPH development, the CSF pressure factors and clinical variables were compared between PDPH and non-PDPH group. Of the 103 participants, 100 (97.0%) had decreased CP, 16 (15.5%) had values below 6 cmH₂O and the pressure change after dural puncture (OP-CP) was 6.1 ± 3.1 cmH₂O. PVI and ECS measured by CSF drainage were 99.8 ± 89.5 and 0.4 ± 0.2 cmH₂O/mL. Among the demographic factors, body weight was correlated with OP (r = 0.27), CP (r = 0.35), and PVI (r = 0.20). Height was weakly correlated with CP (r = 0.199) During the study period, 22 participants (21.34%) developed PDPH. None of the CSF pressure factors were significantly different between the PDPH and non-PDPH group and did not contributed to the development of PDPH. CSF pressure factors might not be related to the development of PDPH.

Intracranial hypertension: a current review

PURPOSE OF REVIEW

To provide a current review of recent publications with regards to intracranial hypertension.

RECENT FINDINGS

Attempts were made to provide pediatric data; however, the recent completion of the Idiopathic Intracranial Hypertension Treatment Trial (IIHTT) has provided a wealth of data with regards to adult intracranial hypertension.The pediatric incidence of intracranial hypertension ranges between 0.63 and 0.71 per 100 000 children. A majority of pediatric cases responded to acetazolamide, with resolution of headache averaging 3.8 weeks. Most patients require less than 1 year of treatment with male sex, older age at diagnosis, primary intracranial hypertension, and lack of headache being predictors of good response. Fluorescein angiography has the highest accuracy in distinguishing true papilledema from pseudopapilledema. The IIHTT found Frisen grade of papilledema was within 1 grade in 92.8% of patients. Monitoring of potassium levels is not required and aplastic anemia was not seen in patients taking acetazolamide.

SUMMARY

Although the newer pediatric studies report incidence rates in pediatric intracranial hypertension are lower than seen in adults, intracranial hypertension is still a concern in pediatrics. There has been a wealth of information with regards to symptomatology, treatment, and outcomes from the IIHTT that will hopefully assist with management in the pediatric population.

Standardized Method for Intra-Cisterna Magna Delivery Under Fluoroscopic Guidance in Nonhuman Primates

Intrathecal delivery of adeno-associated virus vectors and other therapeutics are currently being evaluated for the treatment of central nervous system sequelae of lysosomal storage diseases, motor neuron diseases, and neurodegenerative diseases. As products transition from preclinical to clinical studies, a standardized and clinically relevant method of intrathecal delivery is increasingly germane. Here, we describe a method of intrathecal delivery via suboccipital puncture into the cisterna magna under fluoroscopic guidance in nonhuman primates. This procedure is suitable for use in good laboratory practice compliant studies, has an excellent safety profile, and is highly similar to the procedure currently being explored for use in humans.

CSF Pressure Change in Relation to Opening Pressure and CSF Volume Removed

BACKGROUND AND PURPOSE

Idiopathic intracranial hypertension is a complex neurologic disorder resulting from increased intracranial pressure. Our aim was to determine whether a correlation exists between the CSF pressure-volume relationship, specifically the craniospinal elastance and pressure-volume index, in patients with idiopathic intracranial hypertension and whether opening pressure affects this relationship.

MATERIALS AND METHODS

Lumbar punctures performed for suspected idiopathic intracranial hypertension from 2006 to 2017 were identified. Opening and closing pressures, CSF volume removed, and clinical diagnosis of idiopathic intracranial hypertension were obtained from the medical records. The craniospinal elastance (pressure change per milliliter of CSF removed) and pressure-volume index were calculated, and the Pearson correlation coefficients between both the craniospinal elastance and pressure-volume index and opening pressure were determined. Linear regression models of craniospinal elastance and the pressure-volume index and interaction terms with opening pressure were assessed for covariate influence on this association.

RESULTS

One hundred sixteen patients were included in the final analysis. The mean craniospinal elastance according to opening pressure group was 0.52 ± 0.18 for <20 cm H₂O, 0.57 ± 0.20 for 20-29 cm H₂O, 0.91 ± 0.28 for 30-39 cm H₂O, and 1.20 ± 0.25 for ≥40 cm H₂O. There was a positive linear association between opening pressure and craniospinal elastance with a 0.28 cm H₂O/mL increase in craniospinal elastance (standard error = 0.03, P < .001) for every 10 cm H₂O increase in opening pressure. Of the covariables analyzed, only age older than 50 years and total volume of CSF removed affected this association.

CONCLUSIONS

As opening pressure increases, the craniospinal elastance increases in a linear fashion while the pressure-volume index decreases. Further studies are needed to determine whether these changes relate to the underlying pathophysiology of idiopathic intracranial hypertension or simply represent established CSF volume pressure dynamics.

Pediatric Intracranial Hypertension: a Current Literature Review

PURPOSE OF REVIEW

The purpose of this review is to provide an update on pediatric intracranial hypertension.

RECENT FINDINGS

The annual pediatric incidence is estimated at 0.63 per 100,000 in the USA and 0.71 per 100,000 in Britain. The Idiopathic Intracranial Hypertension Treatment Trial found improvement in visual fields, optical coherence tomography, Frisen grade, and quality of life with acetazolamide compared to placebo in adult patients, and these findings have been translated to the pediatric population. Pediatric intracranial hypertension is a disorder that if left untreated can lead to poor quality of life and morbidity. There are no current treatment studies in pediatrics, but adult data suggests acetazolamide remains an acceptable first-line medication.

Quantifying response to intracranial pressure normalization in idiopathic intracranial hypertension via dynamic neuroimaging

BACKGROUND

Idiopathic intracranial hypertension (IIH) is characterized by elevated intracranial pressure without a clear cause.

PURPOSE

To investigate dynamic imaging findings in IIH and their relation to mechanisms underlying intracranial pressure normalization.

STUDY TYPE

Prospective.

POPULATION

Eighteen IIH patients and 30 healthy controls.

FIELD STRENGTH/SEQUENCE

T₁ -weighted, venography, fluid attenuation inversion recovery, and apparent diffusion coefficients were acquired on 1.5T scanner.

ASSESSMENT

The dural sinus was measured before and after lumbar puncture (LP). The degree of sinus occlusion was evaluated, based on 95% confidence intervals of controls. We studied a number of neuroimaging biomarkers associated with IIH (sinus occlusion; optic nerve; distribution of cerebrospinal fluid into the subarachnoid space, sulci and lateral ventricles (LVs); Meckel's caves; arachnoid granulation; pituitary and choroid plexus), before and after LP, using a set of specially developed quantification techniques.

STATISTICAL TESTS

Relationships among various biomarkers were investigated (Pearson correlation coefficient) and linked to long-term disease outcomes (logistic regression). The t-test and the Wilcoxon rank test were used to compare between controls and before and after LP data.

RESULTS

As a result of LP, the following were found to be in good accordance with the opening pressure: relative compression of cerebrospinal fluid (R = -0.857, P < 0.001) and brain volumes (R = -0.576, P = 0.012), LV expansion (R = 0.772, P < 0.001) and venous volume (R = 0.696, P = 0.001), enlargement of the pituitary (R = 0.640, P = 0.023), and shrinkage of subarachnoid space (R = -0.887, P < 0.001). The only parameter that had an impact on long-term prognosis was cross-sectional size of supplemental drainage veins after LP (sensitivity of 92%, specificity of 20%, and area under the curve of 0.845, P < 0.001).

DATA CONCLUSION

We present an approach for quantitative characterization of the intracranial venous system and its implementation as a diagnostic assistance tool. We conclude that formation of supplementary drainage veins might serve as a long-lasting compensatory mechanism.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2018;47:913-927.

Pediatric Pseudotumor Cerebri Syndrome: Diagnosis, Classification, and Underlying Pathophysiology

Pseudotumor cerebri syndrome (PTCS) is defined by the presence of elevated intracranial pressure in the setting of normal brain parenchyma and cerebrospinal fluid. PTCS can occur in the pediatric and adult populations and, if untreated, may lead to permanent visual loss. In this review, discussion will focus on PTCS in the pediatric population and will outline its distinct epidemiology and key elements of diagnosis, evaluation and management. Finally, although the precise mechanisms are unclear, the underlying pathophysiology will be considered.