Abstracts from Hydrocephalus 2021: The Thirteenth Meeting of the International Society for Hydrocephalus and Cerebrospinal Fluid Disorders

Abstract

s: Young InvestigatorsY01 A multivariate analysis of 82 consecutive patients shunted for idiopathic normal pressure hydrocephalusAmit R Persad1, Bashir Daud Shah2, Kotoo Meguro1 1Division of Neurosurgery, Department of Surgery, University of Saskatchewan, Canada; 2Division of Neurology, Department of Medicine, University of Saskatchewan, Canada Correspondence: Amit Persad (amit.persad@usask.ca)Fluids Barriers CNS 2021, 18(2): Y01Introduction: Idiopathic normal pressure hydrocephalus (iNPH) can be treated with shunting. Little evidence exists to guide shunt selection, predictors of success, or patient follow- up.Methods: We performed retrospective reveiw of 82 consecutive iNPH patinets treated with shunting for iNPH between 2007 and 2018. Clinical factors included age, sex, Charlson Comorbidity Index (CCI), presence of hypertension and diabetes and follow-up. Surgical factors included pre-op spinal tap, type of shunt (LP, VP, fixed, adjustable), use of laparoscopic assistance and having surgery done by hydrocephalus specialist surgeon. Imaging factors included callosal angle (CA) and disproportional enlargement subarachnoid space hydrocephalus (DESH). Regressional statistics were performed.Results: 52 male and 30 female, patients were identified with average age 71.4 years. The cohort mRS improved from 3.84 to 2.66 post-operatively (p < 0.005). 63.6% of patients had clinical improvement with shunt surgery in the short-term and 48.7% in the long-term. Factors that predicted better shunt outcome short-term were lower CCI ( < 0.05), absence of hypertension ( < 0.05), more intensive follow-up (< 0.05) and pre-op CA ≤ 80° (<0.05). Factors that predicted better shunt outcome long-term were younger age at surgery (< 0.05), use of laparoscopic approach (< 0.005) and pre-op DESH (< 0.05). Factors that predicted reduced complications were smaller pre-op CA (< 0.05), use of laparoscopic approach (< 0.05), utilization of LP shunt (< 0.05) and having surgery done by hydrocephalus specialist (< 0.05).Conclusion: In our centre, iNPH patients had improvement following shunting. Age, CCI, CA, DESH, more intensive follow-up, absence of hypertension and use of laparoscopic approach helped predict success of shunting in iNPH patients.Y02 A novel model of acquired hydrocephalus for evaluation of neurosurgical treatmentsSarah Zwick1, Pat McAllister1, Michael Talcott1,2, Albert Isaacs3, Maria Garcia-Bonilla1, Leandro Castaneyra-Ruiz1, Alexis Hartman1, Ryan Dilger4,5, Stephen Fleming4,5, Rebecca Golden4, Diego Morales1, Carolyn Harris6,7, David Limbrick Jr.1,8 1Department of Neurosurgery, Washington University in St. Louis School of Medicine, St. Louis, Missouri, 63110, USA; 2Division of Comparative Medicine, Washington University in St. Louis School of Medicine, St. Louis, Missouri, 63110, USA; 3Department of Surgery, Division of Neurosurgery, University of Calgary School of Medicine, Calgary, Alberta, T2N2T0, Canada; 4Department of Animal Sciences, Division of Nutritional Sciences, Neuroscience Program, University of Illinois, Champaign-Urbana, Illinois, 61801, USA; 5Traverse Science, Champaign, Illinois, 61801, USA; 6Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, Michigan, 48202, USA; 7Department of Neurosurgery, Wayne State University School of Medicine, Detroit, Michigan, 48202, USA; 8Department of Pediatrics, St. Louis Children’s Hospital, St. Louis, Missouri, 63110, USA Correspondence: Sarah Zwick (sarahzwick@hotmail.com)Fluids Barriers CNS 2021, 18(2): Y02Introduction: Many animal models have been used to study the pathophysiology of hydrocephalus; most have been rodent models whose lissencephalic cerebral cortex may respond to ventriculomegaly differently than gyrencephalic brains, and whose size is not amenable to clinically relevant neurosurgical treatments. Thus, we present a porcine model of hydrocephalus in juvenile pigs and established shunting and endoscopic treatment methods.Methods: Acquired hydrocephalus was induced in 33-39-day old pigs by percutaneous intracisternal kaolin injections (n = 32). Controls received saline-injection (sham, n = 6) or none (intact, n = 4). MRI evaluated the progression of ventriculomegaly prior to surgery. With the aid of Stealth neuronavigation, ventriculoperitoneal shunts were inserted (n = 10) or choroid plexus cauterization (CPC, n = 3), with or without endoscopic third ventriculostomy (ETV+CPC, n = 5), were performed 1-4 weeks post-kaolin. Neurological status was assessed daily, and novel- object recognition tests (NOR) assessed cognition.Results: Bilateral ventriculomegaly in all cerebral ventricles occurred post-induction from solid casts of kaolin in the basal cisterns with a patent cisterna magna. In 17 untreated hydrocephalic animals, mean total ventricular volumes were 8158 + 5466 SD mm3, significantly larger than control values of 2251 + 213 SD mm3 (p < 0.0005). Although untreated pigs were asymptomatic despite exhibiting chronic moderate-severe ventriculomegaly, NOR testing revealed cognitive changes after kaolin injection. Treated animals developed ataxia and lethargy in the setting of shunt or ETV-CPC failure.Conclusion: Mechanical induction of acquired hydrocephalus produces a useful, translational in vivo model that allows systematic studies of the pathophysiology and clinical treatment of hydrocephalus.Y03 Biochemical profile of human infant cerebrospinal fluid in intraventricular hemorrhage and post-hemorrhagic hydrocephalus of prematurityAyodamola Otun1, Diego Morales1,2, James P. McAllister II1, Maria Garcia-Bonilla1, David Limbrick1,2 1Department of Pediatric Neurosurgery, Washington University, St. Louis, MO, 63110, USA; 2St. Louis Children’s Hospital, MO, 63110, USA Correspondence: Ayodamola Otun (aotun@wustl.edu)Fluids Barriers CNS 2021, 18(2): Y03Introduction: Intraventricular hemorrhage (IVH) and post-hemorrhagic hydrocephalus (PHH) have complex pathophysiology involving cell-junction disruption, and choroid-plexus (ChP) hypersecretion. Increased CSF cytokines, matrix proteins, and blood metabolites occur in IVH/PHH, and increased CSF electrolytes/osmolality have been shown in hydrocephalus but not in IVH/PHH. We hypothesized that total protein, osmolality, and electrolytes in CSF increase in PHH.Methods: CSF osmolality, total protein, and electrolytes were measured in 69 infants (26 controls, 18 IVH I/II, 14 IVH III/IV, and 11 PHH). Serum electrolyte concentrations within 1-day of clinical sampling were obtained from clinical charts.Results: CSF osmolality, sodium, potassium, chloride, and magnesium were increased in PHH compared to control, IVH I/II, and IVH III/IV (p ≤ 0.0001–0.03). CSF total protein was increased in IVH III/IV and PHH compared to control and IVH I/II (p ≤ 0.0001-0.03). CSF bicarbonate and calcium were increased in IVH III/IV and PHH compared to IVH I/II (p = 0.0004-0.02). Quantitatively, 87% of CSF osmolality change between control and PHH are due to sodium and chloride concentration changes. Serum osmolality, total protein, and electrolytes except calcium were not changed between all groups.Conclusion: CSF osmolality, and sodium, potassium, chloride, and magnesium levels increased only in PHH. However, total protein increased in both IVH III/IV and PHH. Serum electrolytes levels were unchanged across groups and lower than CSF values suggesting increased CSF electrolytes may be more likely secondary to increased ChP ion secretion rather than blood-CSF-barrier disruption. Findings also suggest osmolality changes may be due to electrolyte changes and might contribute to the development of PHH.Y04 Change in CSF pocket size after shunt placement in normal pressure hydrocephalusEmanuele Camerucci1, Jonathan Graff-Radford2, David T. Jones2, Benjamin D. Elder3,4, Jeffrey L. Gunter1, Jeremy Cutsforth-Gregory2, Hugo Botha2, Matthew C. Murphy1, Clifford, R. Jack Jr1, John Huston III1, Petrice M. Cogswell1 1Department of Radiology, Mayo Clinic, Rochester, MN, 55905, USA; 2Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA; 3Department of Neurologic Surgery, Mayo Clinic, Rochester, MN 55905, USA; 4Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN 55905, USA Correspondence: Emanuele Camerucci (camerucci.emanuele@mayo.edu)Fluids Barriers CNS 2021, 18(2): Y04Introduction: Cerebrospinal fluid (CSF) pockets are a component of disproportionately enlarged subarachnoid space hydrocephalus (DESH), used in some diagnostic criteria for idiopathic normal pressure hydrocephalus (iNPH). CSF pockets may be mistaken for brain atrophy. The purpose of this study is to assess for change in CSF pocket size after shunt placement in patients with iNPH.Methods: Inclusion criteria were clinical diagnosis of iNPH, ventriculoperitoneal shunt placement, and at least one MRI before and after shunt placement, performed from January 2015 through March 2021. We evaluated for the presence of CSF pockets on the pre-shunt MRI. For each pocket, the volume was estimated as an ellipsoid by measuring the x, y, and z dimensions on the pre-shunt MRI and each post-shunt MRI. A right-sided Wilcoxon signed rank test was performed to assess for decrease in size between the pre-shunt and first post-shunt MRI and similarly between the first post-shunt and last post-shunt MRI.Results: CSF pockets were present in 54/137 (39%) patients. CSF pocket volume decreased by 19.0% (median 1,630mm3 [Q1:371; Q3:6,701], p < 0.001) between the pre-shunt and first post- shunt MRI and by 16.9% (1,189mm3 [Q1:55; Q3:3,200], p < 0.001) between the first and the last post-shunt MRI at median 13.1 months post-shunt (Q1:8.1; Q3:18.5).Conclusion: CSF pockets decrease in size after shunt placement in patients with iNPH and continue to decrease in size in the following months. Findings provide further support for CSF pockets as an indicator of disordered CSF dynamics, and these pockets should be differentiated from atrophy.Y05 Establishment of age and gender specific normal cerebral ventricle volumesHarrison Synder1, Xue Feng2, Min Park3, Jan Vargas4, Ryan T Kellogg3 1School of Medicine, University of Virginia, Charlottesville, VA, 22901, USA; 2Department of Biomedical Engineeering, University of Virginia, Charlottesville, VA, 22901, USA; 3Department of Neurological Surgery, University of Virginia, Charlottesville, VA, 22901, USA; 4Division of Neurosurgery, Prisma Health, Greenville, SC, 29605, USA Correspondence: Ryan T Kellogg (rtk4u@virginia.edu)Fluids Barriers CNS 2021, 18(2): Y05Introduction: Ventriculomegaly is the most utilized radiographic finding of hydrocephalus. To date there has been no major reports of normative ventricle size for the adult population. Establishing a normative dataset would provide an objective volumetric measurement to help guide diagnosis of hydrocephalus. Our goal was to generate a normative data set of ventricular volume utilizing non pathologic CT scans for adults.Methods: The authors performed a retrospective analysis of non-contrast head CTs for adults that did not have a diagnosis of hydrocephalus or history of VP shunting or treatments for hydrocephalus. A convolutional neural network was trained on hand segmented scans from a variety of age ranges and then utilized to automate the segmentation of the entire data set. Ventricular volumes were produced for 1159 CT scans to generate a normative database.Results: A convolutional neural network was trained using 201 scans and achieved a Dice score of 0.91±0.05 on 16 validation scans. This network generated ventricular volumes on 1159 CT scans. The ventricle volumes were binned by age ranges (18-29, 30-39, 40-49, 50-59, 60-69, 70-79, 80-89, and >90 years) and significantly larger sizes were observed for older ages (e.g. male 80-89: 73,095±6,263 mm3, 51-60: 31,486±12,732 mm3).Conclusion: We have developed a convolutional neural network that can segment the ventricles on CT scans of adult patients for all ages. Using this entwork, a normative database that could be utilized in the future to help aid in the diagnosis of hydrocephalus based on normal ventricular volumes was generated.Y06 Hydrocephalus in paediatric posterior fossa tumors: the role of pre-operative etv and analysis of risk factors for CSF diversion following tumour resectionLucia Darie, Richard D.C. Moon, Michael R. Carter, Greg A. Fellows, Richard J. Edwards 1Department of Paediatric Neurosurgery, Bristol Royal Hospital for Children, University Hospitals Bristol and Weston NHS Foundation Trust, Bristol, UK Correspondence: Lucia Darie (darielucia@yahoo.com)Fluids Barriers CNS 2021, 18(2): Y06Introduction: This study aimed to identify radiological markers and validate existing prediction rules that predicted the need for CSF diversion following posterior fossa tumour resection.Methods: Cases were identified from a prospectively maintained database (2015- 2020). Clinical records were reviewed retrospectively. The modified Canadian preoperative prediction rule for hydrocephalus score (mCPPRH) was applied. Imaging review assessed the following: fronto-occipital horn ratio (FOHR), optic nerve sheet diameter (ONSD); brain, ventricular, and transependymal oedema volumes were determined using 3D segmentation software.Results: 63 children with a new cerebellar/fourth ventricle tumour (34 pilocytic astrocytoma, 19 medulloblastoma, 6 ependymoma, 4 miscellaneous) were identified. Eighteen (29%) required no pre-operative CSF diversion; 13/18 (72%) of these were pilocytic astrocytoma; the mean values are: ONSD(right) 4.6mm (S D±1.18 mm), FOHR 0.35 (SD ±0.04), mCPPRH 2 (SD±2.5); ventricles occupied 6.2% of the intracranial volume. Forty-two children (67%) had a pre- resection endoscopic third ventriculostomy (ETV). Images were available for 37 ETV patients; the mean values are: ONSD(right) 6.54mm (SD ±0.95), FOHR 0.44(SD ±0.5), mCPPRH 4.2 (SD ±1.5); ventricles and transependymal oedema occupied 17.8% and 3.5% of the intracranial volume, respectively. The values in the non-intervention vs ETV groups were significantly different (p ≤0.05). 9/42 (21%) failed ETV requiring a ventriculoperitoneal shunt; these patients had more severe hydrocephalus and higher mCPPRH scores: FOHR 0.48 (SD ±0.06), mCPPRH 5.2 (SD ±1.7).Conclusion: The risk of hydrocephalus correlates with tumor etiology. ETV failed in children with higher FOHR and mCPPRH scores. The mCPPRH is validated in this international patient cohort.Keywords: Paediatric posterior fossa tumors, Hydrocephalus, Endoscopic third ventriculostomy, Ventriculoperitoneal shunt, Papilledema, Optic nerve sheet diameter, FOHR, Modified Canadian preoperative prediction rule for hydrocephalus score (mCPPRH), Surface area calculation, 3D SlicerY07 Initial experiences with miethke m.blue® valve in inph patientsPetr Skalický1,3, Arnošt Mládek1,2, Aleš Vlasák3, Helen Whitley3, Ondřej Bradáč1,3 1Department of Neurosurgery and Neurooncology, 1st Faculty of Medicine, Charles University and Military University Hospital, Prague, Czech Republic; 2Department of Cognitive Systems and Neurosciences, Czech Institute of Informatics, Robotics and Cybernetics, Czech Technical University, Prague, Czech Republic; 3Department of Neurosurgery, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czech Republic Correspondence: Petr Skalicky (skalicky.petr@uvn.cz)Fluids Barriers CNS 2021, 18(2): Y07Introduction: Adjustable valves and devices preventing the so-called siphon effect received the greatest support in the literature for hydrocephalus treatment. This work describes the first experiences with an adjustable gravitational valve with fixed differential pressure unit M.blue® in iNPH patientsMethods: 21 patients were indicated to shunt surgery based on clinical symptoms, radiological sings, LIT results and improvement of the symptoms after ELD mimicking probable iNPH diagnosis according to the Japanese guidelines. Neuropsychological testing battery, Dutch Gait Scale, ICIQ-UI SF, SF12V2-Health Survey, Kiefer Scale and 3T MRI were used to measure outcomes at 3-month control. Angle of the valve, BMI, etc. were studied for any relation to the risk of overdrainage. Valves were set according to the manufacturer's recommendations.Results: Significant improvement at 3months was seen in Kiefer Scale, ICIQ-UI SF, MCS-12 (SF12), Dutch Gait Scale. Neuropsychological testing battery remained stable. 7 patients needed more than one adjustment of the valve. This subgroup significantly improved only in Dutch Gait Scale and MCS-12 but the trend was toward significant improvement in other variables. 8 patients had subdural effusions that were completely managed with adjustments until the 3-month control. BMI was significantly lower in patients with ≥2 adjustments than those with a maximum of one adjustment.Conclusion: The initial results with M.blue® shunt system in iNPH patients are promising. More studies are needed to provide rationale for its use in iNPH. We recommend increasing the initial valve setting by 2-4 cm H2O, especially in lean patient.Y08 Periventricular white matter changes are associated with less improvement after shunt surgery in iNPH patientsCarl Snöbohm1, Filip Malmberg2, David Fällmar3, Johan Virhammar1 1Department of Neuroscience, Neurology, Uppsala University, Sweden; 2Department of Information Technology, Division of Visual Information and Interaction, Uppsala University, Sweden; 3Department of Surgical Sciences, Radiology, Uppsala University, Sweden Correspondence: Carl Snobohm (car.snobohm@gmail.com)Fluids Barriers CNS 2021, 18(2): Y08Introduction: Hyperintense white matter changes (WMC) on brain imaging can be classified as deep white matter hyperintensities (DWMH) or periventricular hyperintensities (PVH) and are frequently seen in patients with idiopathic normal pressure hydrocephalus (iNPH). Contradictory results have been reported as to whether preoperative WMC are associated with outcome after shunt surgery in iNPH patients. The aim was to investigate the predictive role of PVH and DWMH on shunt outcome in iNPH patients using magnetic resonance (MR) volumetry.Methods: A total of 253 iNPH patients were included that were operated with shunt surgery between 2011 and 2015 and clinically assessed before and 12 months after surgery. All patients were investigated preoperatively with an MRI of the brain. Volume of DWMH and PVH were quantified on fluid-attenuated inversion recovery images using an in house semi-automatic volumetric segmentation software (SmartPaint). Clinical outcome was defined as the difference in symptom score between post- and preoperative investigations, measured with the iNPH- scale.Results: In a linear regression model, volume of PVH was negatively associated with shunt outcome (B = − 0.095, p = 0.042) after controlling for age and preoperative symptom score. Volume of DWMH was not associated with shunt outcome (p = 0.16). Whole brain WMC volume was associated with more severe cognitive symptoms at baseline (B = − 0.23, p = 0.008). In patients with high volume of PVH (>40 milliliters) 45% of the patients improved after shunting.Conclusion: The volume of PVH correlates with less favorable shunt outcome in iNPH patients. Patients with high volume of PVH may still benefit from shunt surgery.Y09 Usefulness of desh in predicting outcome of extended lumbar drainage and shunt insertionAdam Nunn1, Melissa Werndle2, Joao Alves Rosa2, Kelly McManus1, Rebecca Hodnett1, Jack Wildman1, William Singleton1, Alex Mortimer2, Richard Edwards1 1Department of Neurosurgery, Southmead Hospital, Bristol, UK; 2Department of Neuroradiology, Southmead Hospital, Bristol, UK. Correspondence: Adam Nunn (adam.nunn@nbt.nhs.uk)Fluids Barriers CNS 2021, 18(2): Y09Introduction: Disproportionately enlarged subarachnoid spaces hydrocephalus (DESH) is a series of radiological signs that together have been proposed to predict shunt responsiveness in patients with possible/suspected idiopathic normal pressure hydrocephalus (iNPH).Methods: Clinical notes of 741 consecutive new patients presenting to our service over a 15- year period were reviewed and patients included if they were felt to have possible/suspected iNPH and had no evidence of secondary NPH. The presence or absence of DESH was not considered when selecting patients for shunting. Clinical data was extracted at baseline, pre- and post-ELD and at 3 and 12 months post-shunt insertion. The referral scans were subjected to blinded review by a neuroradiologist.Results: Data were complete for 415 patients undergoing ELD (49.2% DESH) and 323 patients undergoing shunt insertion (47.4% DESH). Complete agreement was seen between the neuroradiologists regarding the diagnosis of DESH during independent review of 15 scans. However, DESH did not predict objective improvement after ELD (likelihood ratio 0.15, P = 0.70), nor did its presence predict improvement at 3 or 12 months post-shunting (LR 1.7 [P = 0.20], LR 1.9 [P = 0.16], respectively). The magnitude of gait or cognitive improvement at 3 and 12 months was also not statistically significantly different.Conclusion: In this large population of patients with possible/suspected iNPH (confirmed to have no evidence of decompensated arrested or secondary NPH both clinically and radiologically), DESH did not predict shunt responsiveness, suggesting that its usefulness as a prognostic marker should be re-evaluated.Y10 variants in SWI/SNF complex component smarcc1 lead to developmental hydrocephalus and other syndromic featuresAmrita K. Singh1, Stephen Viviano2, Phan Q. Duy1, Jay Ma3, August Allocco1, Tyrone Despenza1, Sheng Chih Jin3, Engin Deniz2, Kristopher T. Kahle1 1Department of Neurosurgery, Yale University, New Haven, Connecticut, United States; 2Department of Pediatrics, Yale University, New Haven, Connecticut, United States; 3Department of Genetics, Washington University School of Medicine, St Louis, Missouri, United States Correspondence: Amrita Singh (amrita.singh@yale.edu)Fluids Barriers CNS 2021, 18(2): Y010Introduction: Congenital hydrocephalus (CH) is a disorder of ventricular expansion related to CSF physiology. CH has been linked to a number of genes including SMARCC1, a core SWI/ SNF complex subunit which regulates gene expression required for neural stem cell (NSC) proliferation during forebrain development. Recent whole exome sequencing studies have identified SMARCC1 as a high confidence pathogenic gene in CH.Methods: We collected a cohort of 12 CH patients with SMARCC1 variants and used a Xenopus model to investigate observed phenotypes with optical coherence tomography, single cell RNA sequencing, in situ hybridization and immunohistochemistry.Results: Aqueductal stenosis (AS) was present in all 12 patients, with cardiac and craniofacial defects each present in 3/12 patients. AS and ventriculomegaly were observed in the majority of Smarcc1 Xenopus morphants and CRISPR knockdowns in both F0 and F1 generations. Importantly, we demonstrated rescue of the AS phenotype with human WT SMARCC1 mRNA. Single cell RNA sequencing of human fetal tissue identified downregulation of NEUROD2, a gene related to NSC proliferation. In situ hybridization showed decreased expression of NEUROD2 in Xenopus morphants and knockdowns compared with WT in the prosencephalon. In contrast, surrounding the cerebral aqueduct, we found evidence of increased proliferation in Smarcc1 morphants.Conclusion: The clustering of phenotypes in SMARCC1 human variants with replication in our Xenopus model illustrates variable expressivity and pleiotropy, suggesting that SMARCC1 may define a novel Mendelian CH syndrome. Our results also provide mechanistic insight into pathogenesis of SMARCC1-related CH, which may enable identification of novel therapeutic targets.Y11 Ventricular volumetry for non-invasive evaluation of shunt functionSimon Lidén1, Dan Farahmand2, Katarina Laurell1 1Department of Neuroscience, Neurology, Uppsala University, Sweden; 2Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, and Department of Neurosurgery, Sahlgrenska university Hospital, Sweden Correspondence: Simon Liden (simon.liden@hotmail.com)Fluids Barriers CNS 2021, 18(2): Y011Introduction: MRI-volumetry is an interesting alternative to invasive tests of shunt function. In this study we aimed to assess ventricular volume (VV) before and after surgery and at different opening pressure (OP) of the shunt.Methods: The material consisted of 33 patients with a median (Md) age of 76 years with idiopathic normal pressure hydrocephalus who received a Strata® shunt with OP 1.5. Participants underwent MRI with volumetric sequences before surgery and four times postoperatively; at one month before randomization to either OP 1.0 or 2.5, at two months before crossover to OP 2.5 or 1.0; at three months before lowering to OP 0.5 and finally at three months and one day after surgery before resetting OP to 1.5. VV was measured semiautomatically using SyMRI®. Both the patient and the examiner were blinded to the OP.Results: Significant changes were seen in VV from before (Md 129 ml) to one month after shunt surgery (Md 121 ml) and between OP 1.0 (Md 116 ml), 1.5 (Md 121 ml) and 2.5 (Md 127 ml) (p < 0.001). A unidirectional change in VV was seen for all participants between OP 1.0 and OP 2.5, (Md 11.5 ml, range 2.1-40.7) (p < 0.001). No significant change was seen in VV after 24 hours at OP 0.5.Conclusion: The consistent decrease in VV after shunt surgery and between high and low OP of the shunt supports that MRI-volumetry could be a non-invasive method for evaluating shunt function, preventing unnecessary shunt revisions.Y12 Ventricular zone response to blood exposure at various time pointsMira Zaranek1, Rooshan Arshad1, Kevin Zheng1, Carolyn Harris PhD1 1Chemical Engineering, Wayne State University, Detroit, Michigan, 48202, USA Correspondence: Mira Zaranek (gf9749@wayne.edu)Fluids Barriers CNS 2021, 18(2): Y012Introduction: Posthemorrhagic hydrocephalus is the progressive dilation of the ventricular space following a hemorrhage within the brain. Exposure of the ventricular zone to blood is known to cause astrogliosis, microglial activation, cell junction dislocation, impairment of neural stem cell differentiation, and overall loss of ependymal cells, potentially leading to cerebrospinal fluid accumulation. In this study, the effect blood has on cellular response to a shunt catheter is evaluated.Methods: Development of a novel custom-built 3D resin printed chamber was used to model the placement of a catheter sample on the ventricular zone. Undifferentiated neural stem cells extracted from C57BL/6 mice lateral ventricle and ATCC C8-D30 astrocytes were used. Cell counts were obtained to compared between control and whole blood exposed samples.Results: Cells exposed to blood showed a significant increase (P < 0.0001) in astrocyte attachment when added concurrently with a catheter sample. The average total expression of DAPI on the sample exposed to blood was 392.0 ± 317.1 and 94.7 ± 44.5 for the control samples. Analysis of the GFAP stain expressed a total averages cell count of 174.3 ± 116.5 and 854.4 ± 450.7 for the sample not exposed to and exposed to blood, respectively.Conclusion: An increase in cell count and a simultaneous increase in GFAP expression after whole blood exposure may be indicative of enhanced neuroinflammation, astrocyte activation, cytoskeletal changes, cell spreading, and/or increased cell communication. Altogether, these data suggest are indicative of the role blood products play in the activation of astrocytes and potentially shunt obstruction.