Hello, my name is Tala Roberts. I'm a neurosurgeon here in New Orleans at the Children's Hospital. My co-moderator, Dr. Bui, and I would like to welcome you to the fourth and final scientific session for the section meeting. Our first presentation will be from Dr. Jerome Volk and Dr. Nihal Gadiwala. They'll be going over a very interesting case. Hi, good afternoon to everyone. My name is Jerome Volk. I'm a pediatric neurosurgeon down here in New Orleans at Children's Hospital of New Orleans. I'm here with my colleague, Dr. Nihal Gadiwala, who is one of our critical care doctors here at Children's Hospital, and I would call him our COVID czar, so to speak. Deputy czar, excuse me. We're going to be talking about a patient that came in in the height of the COVID season here in New Orleans. Our patient is very, the decision making from the neurosurgical standpoint is pretty cut and dry. However, the presentation and the care after our portion is nothing of that sort. This is a very complicated both presentation and hospital course. She's a three-year-old female who presented with a one-day history of decreased oral intake, abdominal pain, bilateral hand and foot pain, back pain, constipation, and also a rash on the palms of her hands. Mom reports that the patient has been increasingly tired throughout this day, but it wasn't until she had an episode of shaking and eye deviation that really prompted the mother to bring her into the emergency room. As I said earlier, the neurosurgical team, actually we weren't involved at the very beginning of this patient. She came into the emergency room, and a lot of the notes are between our emergency room neurology and ICU doctors, but she was noted to be very interactive. She was sitting on her mother's lap, and they thought she looked pretty good. They actually were working her up for endosusception at the time. However, one hour after admission into the emergency room, she developed emesis followed by unresponsiveness and eye deviation, not noted to which side. And after that, everything kind of changed with the patient. Her physical exam afterwards, she was noted to be very sleepy, but if you stimulated her, she would awaken, she would groan a little bit. She was noted to have pupils that were four millimeters bilaterally and reactive. However, when Dr. Gadiwala saw her in the ICU, she was noted to have endosaccharia with the left pupil slightly bigger than the right pupil. She was also noted to have clonus in the right foot, as well as increased reflexes in the right lower extremity. In the emergency room, they performed the CAT scan right after this event. The CT of the head was normal. They consulted neurology to see the patient who performed an EEG and a lumbar puncture in the emergency room. The EEG showed focal slowing and suppression over the left hemisphere. The lumbar puncture, as you see right here, was pretty non-contributory, a negative culture. In a second, Dr. Gadiwala is going to discuss the algorithm, which in discussing the case with him, I didn't realize that we had literally just put our algorithm in place about a day or two prior to this patient arriving. But just some notable labs, you can see her white count is 17, hemoglobin hematocrit is 4.3 at 19, and her platelets are over a million. Now, you might ask, why does she have anemia? The child loves milk. She drinks about a gallon of milk a day, excuse me, a week, and she has severe iron deficiency anemia. Now, you can see her ferritin level is less than 1.0, which Dr. Gadiwala discussed as kind of an outlier for some of these patients that we were seeing. But when taken to the context of everything, you'll see why. The other triggers were the troponin. Her troponin was mildly elevated at 1.05. However, it did increase very quickly to 3.9 and then 5.6. Her BNP was 404 and then it increased to 931. She had blood cultures and urine cultures taken in the emergency room, which were negative. She actually had two COVID tests per protocol, a rapid and a PCR, both of which were normal. Now, I'm going to pass it over to Dr. Gadiwala so we can discuss our algorithm. Thank you, guys. So around May 4th, a cohort in London published a paper about an inflammatory syndrome that they were noticing from a group of children that presented very much like a Kawasaki's viral exam and viral picture. Shortly after, a group from Cohen Children's in New York published their own literature where they saw upwards of 30 to 40 children admitted to the ICU with symptoms of cardiac and systemic inflammatory processes going on. Our hospital tasked myself, a cardiac intensivist with an expertise in heart failure, an infectious disease specialist, and one of our allergy immunology specialists with coming up with an algorithm for this new phenomenon that we were seeing all over the country that was known initially as COVID-associated multisystem inflammatory syndrome. The name had various iterations throughout the course of that week, but basically in that one week following March or May 4th, we were on multiple conference calls with centers all around the country with intensivists, cardiologists, and infectious disease experts, and all of us started to share these similar experiences of seeing a good number of patients come in with this Kawasaki's-like inflammatory process. So collectively with centers from around the country, we came up with this algorithm that really centered around the symptoms of abdominal pain, fever, conjunctivitis, myalgias, altered mental status that would trigger in a series of labs that fell along the spectrum of Kawasaki's disease. So this patient did not have fever, but she did come in with rash, exanthem, abdominal pain, and altered mental status, and because it was around that time that we were seeing a large number of kids with Kawasaki's-like syndrome, we put her on our pathway and it involved us getting an echocardiogram. So once she got that echocardiogram, it was very significant for showing bilateral right pulmonary artery and left pulmonary artery clots. Her ventricular function was intact, but there was significant evidence of right heart strain. A repeat echo showed a thrombus on the tricuspid valve. At that point, we performed a CT angio and a CT abdomen and showed bilateral filling defects and multiple renal parenchyma infarcts along with liver infarcts and significant pleural effusions. So actually, they consulted the hematology and the cardiology service at this point, and the recommendation was to start the patient on systemic heparin as well as TPA. Throughout the course of that day in the ICU, they were able to correct her anemia and at least get it to a suitable point where both our anesthesiologist and our radiologist felt comfortable to send the patient for a sedated MRI. As you know, the patient had an altered mental status, so we have to make sure what's going on in the head. The MRI was performed roughly 24 hours after admin, and you can see here the patient had a very large left-sided stroke involving both the anterior and middle cerebral artery distribution. You can see the patient had significant midline shift of over six millimeters. And here is the CT, excuse me, the MRI performed of the neck and the head, which show this occlusion in the common carotid on the left side, and then showing the filling deficit seen in the head as well. For me as a neurosurgeon, it's always very complicated when this is the phone call you get. You know, thankfully, the patient was in the MRI for a little while and they weren't able to titrate the heparin and the TPA. But when I saw the patient in the recovery room, she still had sedation on board, but she was very altered. She only grimaced to very, very deep stimulus. She had a very dense right-sided hemiparesis. The decision at this time after discussing the risks and benefits was to bring her for emergency decompressive craniotomy on that left side. We took her, the surgery was uneventful, she did very well. As we'll discuss in a second, again, you know, one algorithm then leads to another protocol. So on post-operative day number one, the patient started on high-dose steroids as well as IVIG for this suspect due to our protocol. The patient also started on aspirin and anticoagulation. 24 hours after her surgery, she developed worsening, very small ischemic strokes in the right parietal lobe as well. The patient was started on Keppra initially when she presented. However, she began to seize again and had to be started on phenobarbital at that time. Dr. Godewald will discuss kind of the next pathway that we go through for the treatment of these patients. So it's important to note that throughout this admission so far, her COVID tests, both the Abbott lab and Roche lab tests for PCR and COVID antigen were negative. At that point, her COVID antibody test was also negative. At this point, we really weren't entirely sure what the primary diagnosis was. We seemed, it seemed to fit the COVID multisystem inflammatory syndrome. But the other presumption was that if all these COVID tests being negative, including the antibody, that this might have been a catastrophic antiphospholipid antibody syndrome that hematology would manage. Nevertheless, subsequently, she went on this treatment algorithm, which involves steroids, IVIG, plasmapheresis. And probably about six to seven days after admission and that initial echocardiogram, the patient developed a left coronary artery aphasia or aneurysm. And that figure almost slammed down for this COVID inflammatory syndrome process. She started developing fever subsequently. And she continued to have these erythematous, papules for a face, trunk, upper extremities, periorbital and oral edema. And throughout that hospital stay, she ended up being put on remdesivir and multiple antiviral agents to treat her for what we now presumed was this COVID inflammatory syndrome. But as the hospital admission progressed, dermatology was eventually consulted because she subsequently developed a DRESS reaction, which is drug reaction with eosinophilia and systemic symptoms, presumably from her anti-epileptics, which involved phenobarbital and Keppra relief. So as Dr. Goddewall was saying, about two weeks after her admission, one week after she had the coronary artery aphasia, she developed very high fevers. Her fevers were getting as high as 105 degrees. A very extensive workup was performed. And actually what we saw is she had some evidence of lymphadenopathy when she initially presented, but it was more profound at this time. So she actually had a lymph node biopsy as well as a lumbar puncture performed. As we also stated, she developed this erythematous edematous papules to the face, trunk, bilateral, upper and lower extremities with periorbital and oral edema. We diagnosed her with DRESS, drug reaction with eosinophilia and systemic symptoms. And as we said, we were finally able to come down to the anti-epileptics. The issue became then as we started stopping some anti-epileptics, she went into status epilepticus requiring intubation again, prolonged care. And so we could finally pick out the right anti-epileptic that we could put her on to help with her symptoms. As we've stated numerous times, this was a very complicated hospital course. Eventually she was able to be transitioned to the floor and then we have our own inpatient rehab center in our hospital. So we were able to transition the patient there after a couple of months. Throughout the course, her coronary artery ectasia resolved, DRESS improved with resuming the high-dose steroids that we had started initially. We actually had her set up and we performed her cranioplasty while she was still an inpatient. This was complicated by the fact that she developed the high fevers and erythematous rash again roughly four days after her cranioplasty. So she actually had to go back to the ICU, get started back on high-dose steroids again, which then resolved. She was eventually discharged home in mid-October. Dr. Gottingwald and I will talk about a couple of studies. One of these, the study from the Lancet actually was published one week before our patient presented. Correct. So the slide on the right shows the cohort in London, which included seven patients with this inflammatory process and that was published around May 4th. The study on the left involves multiple centers in the United States, including our own hospital, published in the New England Journal of Medicine, describing a cohort of children all throughout the U.S. with COVID-MIS-C, multisystem inflammatory syndrome. So of note, towards the end of May and early June, because this case was so complex, we consulted with centers from the Indiana Hemophilia and Thrombosis Center, as well as sick kids in Toronto and Cincinnati children's on a Zoom call and presented her. And the underlying etiology that they all agreed upon was that this child, because of her iron deficiency anemia, had a phenomenal thrombocytosis as a bone marrow response to the anemia, ramping up her platelets. That coupled with the thrombotic storm that adults often present with in COVID, ended up causing a rampant cascade of clots that involved pulmonary artery, brain, renal parenchyma, liver, and even the coronary arteries. So, in summary, I want to be absolutely clear that this patient never exactly tested positive for COVID. She had five negative PCRs, four negative rapid COVID tests, and has had three antibody tests that were negative. But as Dr. Gadiwala described, this syndrome is very well documented in the literature now, and she fits every checkpoint in the algorithm and so forth. Other things to note, we always kind of joke about the pay and consult in medicine. This clearly was one of those. Every service in the hospital was consulted. In her care, we had to numerous patient care coordinated conferences just to discuss that we were doing the right thing with all these other services. The thing I do want to highlight, though, is the time in the hospital. This patient was in the hospital for five, almost six months. I won't even go into some of the socioeconomic things that happened to this family throughout her hospital course. Actually, I saw the patient Tuesday in clinic as a post-op, and the mother, she was just happy we were able to get her home for the holidays so they could spend Thanksgiving and Christmas at home. We hear a lot about numbers and wearing masks, not wearing masks, politicians using four-plus agendas. This is very real. This is a disease that is affecting countless people, and our patient is just one of those. We just wanted to highlight some of the care that we as doctors, not just neurosurgeons, but critical care and other pediatric subspecialists are doing to fight the good fight in these patients. Thank you so much. Thank you. Thank you, Jerome. I think that was a fantastically complicated case, but just getting the patient home is definitely a win. Unfortunately, due to the constraints on time, we will skip the Q&A. It would have been a wonderful Q&A, but I think if anyone has questions, feel free to either message Jerome or message us, and we'll try to get answers back to you. I think we're going to try to move on to the next section. So, Tola. Hello. My name is Catherine Holstey. I'm from the University of Michigan, and I'll be presenting on the prevalence of subdural hematomas in pediatric patients with benign expansion of the subarachnoid spaces. We have nothing to disclose. BESS, or benign external hydrocephalus, is characterized by rapid increase in head circumference combined with typical neuroimaging findings, such as enlarged subarachnoid spaces and normal or only moderately enlarged ventricles. This is a self-limiting condition found in infancy and is rarely treated, but seen commonly by neurologists and neurosurgeons. In this retrospective study, we queried one institution's entire patient sample from 1996 to 2020 for any mention of benign external hydrocephalus, or BESS. Patients who were seen by neurology or neurosurgery and had neurologic imaging underwent further review. Those whose head circumference was less than the 80th percentile for their corrected age and diagnosed after the age of two were excluded. Data on demographics, development, subdural hematomas, and surgeries were extracted. In total, 391 patients were included in our study between 1996 and 2020. A majority of patients were seen before 2008. Average age at presentation was roughly nine months and length of follow-up was about 4.6 years. The majority of images were obtained due to macrocrania. Almost one-third of these patients had some kind of developmental Almost one-third of these patients had some kind of developmental delay. Mild gross motor delay was the most common, and more than half of those had resolution of their delay at around two years of age. About one-third had global delay. Half had some kind of chromosomal abnormality diagnosed later on in life. And interestingly, 16, or about 4 percent of the total population, went on to be diagnosed with an autism spectrum disorder. 57 patients, or about 15 percent, were born premature and almost all of them had some kind of developmental delay, most commonly speech-language and global delay. Before we discuss the subdural hematoma data, I wanted to point out that these data should be viewed with detection bias in mind. Patients who are found to have subdural hematomas are likely to have pseuocranial imaging, leading to increased detection of BESS compared to the general population. In total, 47 patients, about 12%, had any subdural hematoma during follow-up. When non-XNL trauma, as confirmed by skeletal survey, retinal hemorrhage, and CPS notes, as well as major trauma, such as a fall from height or motor vehicle accident, were excluded, 8% were found to have subdural hematomas which occurred spontaneously or after minor trauma. In this case, minor trauma included bumping their head on a table, fall from standing, or other minor events that normally would not cause a subdural hematoma in a child. There were 9 patients who were diagnosed with BESS prior to subdural hematoma. In this small cohort, their subdural hematoma was diagnosed between 1 month and 1.5 years after being seen. All were due to minor trauma or found incidentally on root hemorrhaging and only one required surgical evacuation. There were no permanent neurologic deficits in this group. In conclusion, this is one of the largest single-center retrospective studies of children with BESS. BESS is a common condition seen by neurology and neurosurgery, although the number of patients referred has decreased over the years. BESS has a known association with gross motor delay, with most children having resolution of their delay at around 2 years of age. An association with autism is a new and novel finding in our study. Our study found 8% of patients had a spontaneous subdural hematoma, which is twice as high as the reported 3-4% in the literature that could be due to detection bias. Thank you so much for your time and attention. Hello, my name is Nathan Kostic. I'm a third-year medical student at the University of Central Florida. Today, I'm going to be talking to you about a non-invasive method for detecting elevated intracranial pressure. No conflicts of interest. Measuring intracranial pressure is something that all neurosurgeons are very familiar with. Current techniques for monitoring ICP are very invasive, involving lumbar puncture implanted intracranial sensors. Many non-invasive methods have been investigated, such as transocular ultrasound or carotid doppler. However, none have been proven to be reliable. One technique that we were interested in was tympanic membrane oscillation for measurement of intracranial pressure. The theory behind this is the ICP waveform is transmitted from the CSF to the inner ear via the cochlear aqueduct, and then from the inner ear to the tympanic membrane via the ossicles. This vibration, in theory, could be picked up by a sufficiently advanced sensor. Our previous work has shown these waveforms are nearly identical in patients with direct ICP monitoring. However, certain waveform characteristics, such as amplitude and offset, are not preserved. Since then, we have simplified our recording setup, now consisting of a modified set scope connected to an ultrasensitive magnetic reluctance pressure sensor, which is capable of picking up the tympanic membrane pulsations. Our theory is that we can work around the loss of amplitude and offset metrics by analyzing the changes in waveform caused by altered brain compliance secondary to elevated ICP. In order to test this theory, we took 17 healthy subjects between the ages of 18 and 32 and recorded their tympanic membrane pulsation waveform as they underwent tilt tests and hyperventilation. These are maneuvers that have been established in the literature to cause increases and decreases in intracranial pressure, respectively. Previous literature shows the effects of tilt table testing via approximately 15 to 25 millimeters mercury at 45 degree head down angle. An example of this can be seen here, where a subject with a shot in reservoir underwent memonitory testing and his intracranial pressure increased with angle. Here you can see an example of a subject's TMP waveform at rest, and you can see the dramatic change in the waveform that occurs when they are tilted head down and their intracranial pressure increases. To quantify this change, using the slope ratio method, we divide the slope of the rise time of the TMP by the slope of the fall. In the plot to the right, we see the expected result, which is a decrease in slope ratio as the subject's ICP is increased with tilt test. There's a partial recovery with hyperventilation and a complete return to normal after a brief rest. Each of these steps are statistically significant. So far, we have demonstrated our device's ability to detect ICP changes. However, this is clinically meaningless unless we can predict subjects ICP status without performing evocative maneuvers. In order to try to turn this into a clinically useful tool, we trained an algorithm from the initial cohort of three subjects. The algorithm predicts ICP status from a single recording sample about 10 seconds long. Data from the second cohort was fed into the algorithm to predict the subject's ICP status. Across 60 independent recordings, the algorithm accurately predicted 100% of subjects' ICP status. With this algorithm, we have demonstrated our device's ability to predict ICP status from isolated recordings. Despite its promising results, there are some limitations of the study that must be discussed. First off, as a low sample size, use healthy subjects instead of subjects that have ICP pathology. It's using an indirect measurement of intracranial pressure and did not test the device's ability to guide clinical practice. It's also important to note the device would most likely not work in individuals with ear pathology. To address these limitations, we have a number of future studies we would like to do. First, we would like to record our device from a large group of subjects with implanted intracranial pressure marrs that would have a direct ICP comparison. Additionally, we would like to try to use our device to identify subjects undergoing shunt failure. We would take our device into the ED and record from patients who are being evaluated for shunt failure, and then compare our device's recording to their eventual disposition. In conclusion, the brain stethoscope can derive the ICP waveform from tympanic membrane pulsation. Simple maneuvers show the expected physiological changes. Our algorithm can predict normal versus abnormal ICP from 10-second recording with high accuracy, and the brain stethoscope shows potential to be a practical, inexpensive tool for identifying subjects with elevated intracranial pressure. I'd like to take a moment to thank my mentor, Dr. Manwaring, as well as the Hanson Acoustics Labs for all of their work on this project. Hello, my name is Aaron Iago-Kahn. Thank you for the opportunity to present our project entitled Support Participation Following Cranios and Osteosis Correction, a Survey Study. We have no disclosures. Cranios and osteosis are the premature closure of one or more cranial sutures. It is common and occurs in every one of 2,500 births. Single suture synostosis comprises most cases. Surgical correction is optimally performed during the first year of life. Those that undergo correction have comparable gross neurodevelopment to those that do not have craniosynostosis. Given comparable gross neurodevelopment, children that underwent correction of craniosynostosis develop the same desires and see their peers involved in sports. This leads to questions from parents such as, can my child even play sports? What sports? When? And what's the risk of participating in sports? The objectives of the study were to, one, broadly describe the sports experience of post-surgical craniosynostosis patients via cross-sectional survey, and two, describe the frequency of significant head injuries in these patients. We hypothesized that these patients would report a wide array of sports participation with a comparable injury rate to the general population. We conducted a cross-sectional survey study. We distributed the REDCap survey via the FACES National Cranial Facial Association email listserv, as well as through Facebook craniosynostosis support and info groups. The survey consisted of 15 questions. The primary outcome was whether or not patients participated in sports, and the secondary outcome was whether or not patients experienced significant head injuries. The survey was completed by 187 respondents. 74% report sport participation, which started around five years old. You'll notice that a greater proportion of children who did not play sports were Hispanic, and a greater proportion of those who did play sports had undergone a second surgery at around five years of age. Craniosynostosis patients participated in a wide array of sports, as expected. The majority participated in collision or contact sports, as defined by the AAP. The most common sport played was soccer, followed by baseball, basketball, and 15% of respondents participated in football. The vast majority of patients reported no head injuries related to sports. 4% reported concussions. 2% reported vague head injuries, which did not clearly result in a hospitalization or a surgery. You can see the descriptions taken directly from the survey of these vague head injuries here. Neither age at participation or sport type was associated with head injuries. In conclusion, sport participation is common among craniosynostosis patients. Distribution of sports largely reflects the top sports for U.S. high school and youth participation. Sport participation appears safe and common after craniosynostosis correction. Thank you. ...to sagittal vertical alignment and Chiari 1 malformation, a study using the Park Reeves Syringomyelia Research Consortium. Here are C2 sagittal vertical alignment and Chiari 1 malformation. A study using the Park Reeves Syringomyelia Research Consortium. C2 sagittal vertical alignment and Chiari 1 malformation. A study using the Park Reeves Syringomyelia Research Consortium. Here are our disclosures. The condylar C2 sagittal vertical axis or C2SVA is the position of a plumb line from the midpoint of the OC1 joint in relation to the C2-3 disc space measured in millimeters. The C2SVA, specifically a value greater than or equal to five millimeters, was predictive for requiring occipital cervical fusion or ventral brainstem decompression. The primary aim of the current investigation was to validate the C2SVA. Our hypothesis is that the C2SVA will identify at-risk children for requiring occipital cervical fusion or ventral brainstem decompression or reoperation for posterior fossa decompression and will have superior test characteristics compared to other commonly used measures. The Park Reeves Syringomyelia Research Consortium is an ambispective registry from 36 centers greater than 1,200 patients enrolled. These are all children who presented for management of Chiari 1 malformation with Syringomyelia. All children underwent posterior fossa decompression with or without duroplasty. We identified patients who underwent occipital cervical fusion and ventral brainstem decompression and then approximately 10 age gender match controls for comparison. The primary outcome was occipital cervical fusion or ventral brainstem decompression. CXA and PBC2 were measured by a central reader and C2SVA was measured by three authors and measurements were made using proprietary software. The measurements were made by drawing a line, parallel to the C2 end plate on a midline MRI and on a parasagittal image identifying the midpoint of the OC1 joint. Using the OC1 reference point, drew a line perpendicular to the C2 reference line and the distance from the plumb lines was the CC2SVA measured in millimeters. We treated the CC2SVA greater than or equal to 5 millimeters as a screening test and calculated the following test characteristics. Interrater reliability included the interclass correlation coefficient for continuous and Cohen's kappa coefficient for binary variables. A total of 186 patients underwent posterior decompression only and served as the comparison group and 20 patients underwent ventral brainstem decompression or occipital cervical fusion. There is no difference in the main baseline characteristics as can be seen here. Patients who underwent ventral brainstem decompression or occipital cervical fusion had a lower CXA and subsequently a higher CC2SVA. A higher proportion of children had a CXA value of less than 125 degrees and 100% of children undergoing ventral brainstem decompression or occipital cervical fusion had a CC2SVA value of greater than or equal to 5 millimeters. The sensitivity for requiring ventral brainstem decompression or occipital cervical fusion was 100% for a CC2SVA value of greater than or equal to 5 millimeters versus 55% for a CXA of less than 125 and 20% for a PBC2 greater than 9. Interrater reliability demonstrated an inner class correlation coefficient of 0.52 and a kappa value of 0.471 and 0.473 indicating moderate agreement. We have successfully validated the CC2SVA and a large multicenter external cohort and it was a highly associated with a more complex Chiari phenotype and predicted for the need for oc fusion or ventral decompression. Multicenter prospective tracking of the CC2SVA is necessary and further teaching and education on measuring the CC2SVA is needed. Thank you and I'd like to thank our co-authors and specifically all members of the Park Reef Syringomyelia Research Consortium. Hi, my name is Eric Montgomery. I am a medical student at UT Southwestern Medical Center in Dallas, Texas. Thank you for taking the time to attend this talk on the clinical significance of craniovertebral joint anomalies in Chiari malformation type 1. My co-authors and I have nothing to disclose. Adnormalities of the craniovertebral junction are found in a minority of Chiari malformation patients. In 2007 Bahari et al. characterized the association of reducible and irreducible linoaxial dislocations with clinical signs and symptoms. As you can see here there are interesting discrepancies and difficulty in swallowing and nasal regurgitation, vertigo, and nystagmus between the two groups. However, overall is a very small cohort and the clinical relevance of craniovertebral joint anomalies is yet to be fully elucidated. Therefore, the objective of this current study is to characterize the association of craniovertebral joint anomalies with clinical presentation and outcome. In a consecutive series of 391 pediatric Chiari patients that underwent surgical treatment from 2001-2019, we characterized linoocipital and linoaxial joint anomalies defined as abnormality or displacement of the joint noted on perioperative MRI. The mean age of the cohort was 8.3 years with 49.6 percent male and a mean follow-up of 32.3 months. There were 23 patients with linoocipital joint anomalies, 12 with linoaxial joint, 16 patients that demonstrated PANUS, and 34 patients with basilar invagination. The group was relatively homogeneous with no difference in the presence of craniovertebral joint anomalies between sexes. There was also no significant association with any craniovertebral joint anomaly with patients that had scoliosis or searings. Preoperatively, brain stem and spinal cord symptoms were associated with the presence of PANUS and basilar invagination. However, no other preoperative symptoms demonstrated an association. Radiographically, decreased clival angle was associated with each craniovertebral joint anomaly. Increased distance from the posterior opisthian to spinal cord was associated with PANUS and basilar invagination, but neither linoocipital or linoaxial joint anomaly, and decreased foramen magnum width was associated with basilar invagination. Interestingly, the ratio of posterior opisthian to spinal cord length to foramen magnum width was associated with linoocipital joint anomaly, while neither of those two variables individually was associated. Intraoperatively, none of the craniovertebral joint anomalies were associated with any of the surgical subgroups. However, all of the joint anomalies were associated with the usage of vertebral joint fusion, and after multivariate regression, all but linoocipital joint anomalies remained associated. Postoperatively, multivariate logistic regression demonstrated that searings improvement was inversely associated with the presence of an linoocipital joint anomaly. Symptom improvement was inversely associated with a linoaxial joint anomaly, and re-operation was directly associated with basilar invagination in the patient cohort. So, in conclusion, the impact of craniovertebral joint anomalies and QRA malformation type 1 remains to be fully elucidated. However, our series demonstrated that preoperatively brain stem and spinal cord symptoms were associated with PANUS and basilar invagination. Craniovertebral joint anomalies were not associated with any surgical subgroup. However, they were all strongly associated with vertebral joint fusion, and postoperatively, a linoocipital joint anomaly was inversely associated with the improvement of searings. A linoaxial joint anomaly was inversely associated with symptom improvement, and basilar invagination directly associated with the need for re-operation. Thank you for your time. Hello, my name is Ryan Giuffrani. I'm the chief resident of Penn State Milton S. Hershey Medical Center, and I'll be presenting the following. Routine use of intradural tonsilloid coagulation, i.e. tonsillopexy, in pediatric CRE decompression surgery results in longer hospital stays and increased anti-emetic use postoperatively. While surgery is a first-line treatment for CRE1 malformation, the ideal surgery for any given patient remains a matter of debate. The extradural portion of CRE surgery is fairly standard amongst neurosurgeons and consists of frame and magnet decompression usually in conjunction with cervical laminectomy or laminectomies and releases of associated extradural fascia. The same cannot be said for extended or intradural decompression. Extended decompression consists of variations on any or all of the following. One, dural opening with arachnoid dissection allowing for tonsillar manipulation and direct view of CSF outflow. Two, expanse aldeoplasty. Three, cerebellar tonsillar volume reduction via coagulation, i.e. tonsillopexy or sub-PL resection. Extended decompression of some form has been well established in routine practice for many surgeons for decades. That said, there's a trend in the pediatric literature in recent years away from routine extended decompression for all patients. Each aspect of this extended decompression, including whether routine use on all patients is even appropriate or necessary, remains a matter of significant debate. Comparative analysis of various surgical options are limited. Not surprising practice patterns regarding handling of the cerebellar tonsils during caries surgery is widely variable. Literature on tonsillopexy is particularly limited. Considering this, we compared post-operative outcomes in caries surgery patients who underwent routine intradural exploration with and without tonsillar volume reduction via bipolar coagulation or tonsillopexy. The remaining aspects of the surgery was standardized across both groups and included standard extradural decompression and expanse aldeuroplasty in all patients. The primary endpoints of the study were to determine if cerebellar tonsillopexy resulted in increased length of stays post-operatively and increased use of anti-medics post-operatively. Secondary outcomes included searance improvement and post-op complications, including the need for redo decompression. We retrospectively reviewed 145 consecutive patients undergoing surgery from 2006 to 2019. Patients who underwent coagulation of the cerebellar tonsils as part of surgery were compared to those who did not. Over 40 patients were identified to have cary malformation on imaging. Of these, 160 underwent suboccipital decompressive surgery. Patients who had bone-only decompression or had their first decompression elsewhere or had a shunt placed prior to decompression or had incomplete records were excluded from the study. This left us with a total of 140 patients for data collection, with 120 in the tonsillopexy group and 25 in the non-tonsillopexy group. We found that the two groups did not significantly differ in baseline characteristics, including age, sex, extent of tonsillar herniation pre-op or presence of searance pre-op. Tonsillopexy did indeed have longer hospitalizations with 4.62 days versus 3.28 days in the non-tonsillopexy group, which was significant with non-overlapping 95% confidence intervals. Additionally, there was a significant increase in both post-operative steroid and anti-emetic use in the tonsillopexy group compared to the non-tonsillopexy group. The radiographic searance improvement follow-up was increased in the tonsillopexy group, but this did not translate into an increased rate of failure requiring surgical re-operation. There were 10 wound infections in the tonsillopexy group or an 8.3% infection rate in none in the non-tonsillopexy group. While there was a trend towards increased post-operative CSF leak, pseudomeningocele, and the need for shunting in the tonsillopexy group, these did not reach significance. Our experience has led us to believe that intradural tonsillopexy is not necessarily a completely benign adjunct and should possibly be reserved for select patients, e.g. patients with a large searance, arachnoid web, or a failed prior decompression, et cetera. This has led to a change in practice at our institution away from the routine use of tonsillopexy in all patients. Our experience is in line with a recent trend in the literature towards a more selective approach in utilizing extended intradural decompression techniques in Chiari surgery. Thank you for your time. Do you have any comments or questions? Well, I definitely want to thank all the speakers. That was a fantastic session. However, we are running a little bit behind time, so the schedule will change a little bit. We won't actually be pausing the four minutes for the Q&A. However, all those speakers are actually waiting in the, I guess, the remote discussion lounge. So please feel free to log into that, ask your question, and then log on back. I think all the speakers for this last session and the next session will be there too. So since we won't be pausing, I think if you have questions, just feel free to log in and log back out. But with that, I think we're gonna roll into, obviously, my favorite topic of a hydrocephalus. Good afternoon. My name is David Hirsch from Connecticut Children's, and today I'll be discussing hydrocephalus surveillance following shunt placement or endoscopic third ventriculostomy, a survey of surgeons in the hydrocephalus clinical research networks. Leaf failure is a well-documented complication of CSF shunts. And while we know that 30% of shunt malfunctions occur within the first year after surgery, beyond that, there's a persistent two to 5% rate of malfunction per year. Leaf failure has also been described following endoscopic third ventriculostomies, though at a lower rate. With that in mind, clinical and radiological surveillance very much depends on the practitioner. On the one hand, there's a very low likelihood of diagnosing a shunt malfunction during a routine annual follow-up visit. On the other hand, routine clinical follow-up allows the neurosurgeon to reinforce the red flag signs and symptoms of shunt failure and cultivate a relationship with the family so that they understand where to seek care. Aside from clinical follow-up, there's also a lack of consensus regarding radiological surveillance for asymptomatic patients, with some providers only obtaining imaging for concerning signs and symptoms, and others obtaining imaging at routine intervals. Therefore, the objective of this study was to provide a cross-sectional overview of variations in practice patterns with regard to hydrocephalus surveillance following shunt placement or ETV. A 24-question survey was developed. The survey was distributed in July 2020 to 138 pediatric neurosurgeons across 39 centers who participate in the HCRN or its Implementation and Quality Improvement Arm, the HCRNQ, of which Connecticut Children's is a participating site. We obtained an overall response rate of 88%. Following a shunt placement or revision, over half of the respondents considered the patient's hydrocephalus to have stabilized within one to three months, whereas following an ETV, most respondents chose three, six, or 12 months. Once quote-unquote stable, most respondents had patients return for annual follow-up, though a small percentage have patients follow-up every other year. And regardless of the chosen time interval, the vast majority of respondents, 83%, consider lifelong clinical follow-up to be necessary following a shunt placement. Interestingly, only 56% of respondents recommend lifelong follow-up after an ETV. When it comes to imaging, 75% of respondents obtain routine surveillance imaging after shunt surgery and 67% following an ETV. A rapid MRI is usually the modality of choice, though as you can see in this figure, the frequency of imaging varies widely. What about changes that are identified on routine imaging in asymptomatic patients? When there's an asymptomatic increase in ventricle size, 44% of the respondents would monitor the patient more frequently, and almost 30% would go on to obtain a shunt series, with further management depending on whether the shunt is intact or not. When a routine shunt series demonstrates an asymptomatic shunt fracture, the majority of respondents will go on to obtain cranial imaging. There's a lot more that we can unpack from this survey, but in the interest of time, I'll conclude by stating that although there is a general consensus that hydrocephalus patients should have long-term follow-up after shunt placement, there's considerable variability with respect to long-term follow-up after an ETV, the modality and frequency of radiological surveillance, and what actions to take when radiological changes are identified in asymptomatic patients. These data highlight a powerful opportunity for future clinical research. Finally, I'd like to acknowledge several individuals. Rahul Kumar is an MD-PhD student who assisted with the data analysis in putting together the figures that you saw. Rahul's participating in the match this year and is an outstanding applicant. I'd like to thank my division chief, John Martin, for his assistance and support throughout this project. And I'd like to extend a sincere thank you to Jason Clausen and Dr. John Kessel of the ACRN for facilitating distribution of this survey. Last but not least, thank you to the scientific committee for putting together a great program, and I hope you'll enjoy the meeting. Thank you for your time. Thank you very much to the pediatric section for this opportunity to share our work. My name is Andrew Hale, and I'm an MD-PhD student at Vanderbilt currently applying to neurosurgery residency programs. As you know, hydrocephalus is a heterogeneous disease with many etiologies. And here, genetic causes are listed as a separate category. But we hypothesize that genetic variation may play a broader and even shared role in conferring risk of hydrocephalus across etiologies. But how does genetic susceptibility functionally contribute to hydrocephalus, and what are the roles of these genetic associations in the pathophysiology of the disease? To answer this question, we had to first conduct a systematic genetic study of hydrocephalus. And while many genes have been associated with hydrocephalus, these genes have been identified using sequencing and approaches that have focused on identifying rare, either inherited or de novo protein coding variants leading to loss of function of a single gene. However, far less is known about the common genetic variant contribution to hydrocephalus and these common genetic variants that regulate gene expression. And thus, we hypothesize that by understanding the common genetic variation contribution to hydrocephalus, we may elucidate a broader role for genetic susceptibility in the disease. To answer this question, we performed a transcriptome-wide association to identify genes associated with hydrocephalus across brain regions. And here, you can see genes associated with hydrocephalus in the frontal cortex using a large-scale reference resource called GTEx. And what's shown here is a Manhattan plot where each individual dot is a gene. And after the most rigorous and conservative statistical correction, we identify a transcriptome-wide predictor of hydrocephalus, a gene called MAEL. However, you can also see that a number of genes are contributing risk. MAEL is a gene that's involved in DNA transposon regulation. And DNA transposons are these pieces of DNA that move around the genome and influence a cell's identity and genomic size. But we can see that there are a number of genes conferring risk. And what are the shared function of these genes and how might they be influencing genetic risk in aggregate? And is there a way to delineate the pathophysiological function of these genes? As we were pondering this question, this paper was published in 2018 in Nature. And it was an atlas linking genetic information to brain MRI phenotypes. And they looked at around 3,000 brain MRI phenotypes across 8,000 individuals. And these were healthy individuals without no neurological disease to look at the normal distribution of quantifiable MRI features and the role of genetics in the distribution of these phenotypes across a population. And since hydrocephalus is the accumulation of CSF volume, and the goal of treatment is to maximize brain growth and improve cognitive development, we first took a hypothesis-driven approach to try to answer these targeted questions. Thus, we compared our set of hydrocephalus-associated genes in red to a randomly selected set of genes in blue. And what you can see is that the hydrocephalus-associated genes, including MAEL, are left-shifted or deviate from null expectation with respect to white matter and total brain volumes, but not CSF volumes. So these results suggest that genetic susceptibility to hydrocephalus in aggregate primarily involves alterations in brain structure or growth rather than direct regulation of CSF volume. So in conclusion, we demonstrate that common genetic variation leading to changes in gene expression underlie genetic risk of hydrocephalus, and that genetic susceptibility to hydrocephalus may be driven, at least in part, due to alterations in brain structure and or growth. This work would not have been possible without the extraordinary support of my co-authors and funding sources shown here. Thank you very much for your attention, and I'm happy to take any questions. Hello, my name is Tracy Flanders, and I will be speaking to you regarding a study conducted at CHOP the past couple years looking at non-invasive measurements of cerebral blood flow and oxygenation in infant hydrocephalus. I received funding from the Pediatric Hydrocephalus Foundation, as well as a T32 grant from the NIH to run this study. Frequency-domain diffuse optical spectroscopy uses light in the near-infrared spectrum that traverses biological tissue, within which changes in oxyhemoglobin and deoxyhemoglobin are quantified to understand intravascular oxygenation. Diffuse correlation spectroscopy offers meaningful information regarding cerebral blood flow. Combination of these two optical techniques gives us non-invasive indices of cerebral blood flow, an oxygen extraction fraction, and an intracranial pressure measurement. Cerebral oxygen saturation and total hemoglobin concentration are calculated. A non-invasive ICP is derived from pulsatility indices, where the pulsatility index of blood pressure is calculated from blood pressure measurements, and the pulsatility index of cerebral blood flow is calculated from DCS data using Fourier analysis. This was a prospective study in the CHOP NICU from September 2018 to March 2020. The inclusion criteria are admission to CHOP NICU, age less than one year, with a diagnosis of hydrocephalus, a neurosurgery consult, who met local surgical criteria for CSF diversion. Exclusion criteria were patients who underwent palliative treatment in lieu of neurosurgical intervention. After enrollment, non-invasive measurements were performed in the NICU at the bedside within seven days of surgical diversion. At the time of surgery, after induction of anesthesia, an intraoperative measurement was obtained. An invasive ICP measurement was acquired with a manometer during shunt placement. Postoperatively, an optical measurement was performed at the bedside within seven days from surgery. All optical measurements were performed when the infant was stable as assessed by vitals and clinical exam. Bilateral measurements were acquired at each time point. NICU measurements were performed at the bedside without any sedation. We chose an ICP of 15 millimeters of mercury as the threshold for dichotomization for NICU. This is consistent with values chosen in the pediatric literature, as well as extrapolation from adult TBI literature. A total of 39 patients were enrolled in the study of which 28 received intraoperative non-invasive bedside measurements. The population had a male predominance and 74% of the patients were born prematurely. Post-hemorrhagic hydrocephalus was the most common etiology. The primary method of CSF diversion was VP shunt. No patients received inhalational anesthetics or ketamine during the surgery. Of the patients who received intraoperative non-invasive and invasive ICP measurements, 64% were found to have intracranial hypertension. These patients had a significantly lower cerebral oxygen saturation and higher oxygen extraction fraction. Total hemoglobin concentration and cerebral blood flow were also found to be lower in the hypertension group, but these differences were not significant. 18 patients had both intraoperative and post-operative non-invasive measurements. Patients with hypertension showed significant post-operative increases in cerebral blood flow, cerebral metabolic rate of oxygen, total hemoglobin concentration, and cerebral oxygen saturation. We show here that our novel non-invasive bedside optical index for ICP is significantly associated with intracranial hypertension in intrathent hypercephalus. Our hybrid machine found that there was improved oxygen delivery in infants with intracranial hypertension after CSF diversion therapy. This optical technique may improve on the current clinical practice by offering better ways to classify patients to individualized surgical care in infant hydrocephalus. I would like to thank the CHOP attending, specifically Dr. Gregory Hoyer, for his unwavering mentorship and support. I would also like to thank Dr. Wes Baker, the biophysicist, without whom this project would not be possible. Thank you. This is Bill Whitehead presenting the paper comparing anterior and posterior entry site for CSF shot insertion. This is an HCRN study done in partnership with the Hydrocephalus Association. The trial was funded by PCORI. The controversy over which entry site is best has existed for decades, and the existing medical literature has not clarified the issue. Our goal was to address the controversy with level one evidence. We designed the study to answer the following question. In pediatric patients, does the choice of entry site reduce the rate of shunt failure by 10% or more in one year? This is a parallel design, randomized trial. All patients were pediatric patients receiving their first shunt. Randomization was stratified by surgeon, and all patients were followed prospectively for at least 18 months. Eligibility and the primary outcome of shunt failure were determined by a blinded adjudication committee. It was their decisions that we used for the primary analysis. Over 1,500 patients were screened for the study. 467 were randomized. 236 were allocated to posterior entry, 231 to anterior entry. Seven patients in each group were deemed ineligible by the adjudication process. All patients were analyzed in the group they were randomized to. When we compared baseline characteristics between the two groups after randomization, we found no significant differences. We compared sex, race, ethnicity, and corrected age. We also compared etiologies in each group and found no significant differences. This is the primary outcome. These are the shunt survival curves for anterior and posterior shunts. Blue is anterior, red is posterior. At one year, just under 80% of the anterior shunts are functioning. At one year, just under 70% of the posterior shunts are functioning. However, the difference between these two curves by the log-rank test stratified by age is not statistically significant with a p-value of 0.06. We calculated the hazard ratio for posterior shunts compared to anterior shunts and obtained a value of 1.35 with a 95% confidence interval of 0.98 and 1.85. This was done using the Cox regression model, also stratified by age. Although this shows that the risk of shunt failure increases by about a third with a posterior shunt, these results are not statistically significant. We compared complication rates between the two techniques. The shunt infection rate in the anterior group was 6%. The shunt infection rate in the posterior group was 7%. Again, not statistically significant. Same story for the incidence of seizure after surgery, incidence of epilepsy, incidence of CSF leak, pseudomeningocele, interventricular hemorrhage, and skull fractures. None of these complications were different in the two techniques. To conclude, we can say the entry site does not affect the risk of shunt failure. This was a null hypothesis for the study and we cannot reject it. Both techniques are acceptable and the techniques have a similar complication profile. I wanna thank the 14 HARN centers that recruited patients for the study. There's over 44 research coordinators who helped manage the trial. The patient partner committee at HA helped with the design, implementation, and recruitment of patients. The DSMB provided oversight for patient safety, and the adjudication committee spent countless hours reviewing the subjects to make the trial a success. Thank you. I'd like to thank all the presenters for their excellent work. Judging from the chat page, they've generated a lot of excitement. I'd like to remind the audience that you're welcome to go to the remote conversation lounge if you have any questions that you'd like to pose to the presenters. We will continue to proceed with the remaining presentations. Thank you. Hello. My name is Mohamed El-Sharif, and I will be talking about complement activation and how it affects neurocognitive outcomes following dermal matrix hemorrhage, and this is done in a chronic mouse model. I have no disclosures myself. Dr. Thomason, my PI, is the inventor of the drug that we'll be discussing during this talk. So dermal matrix hemorrhage, as we know, is a devastating disease of infancy. It affects too many children, especially those under 34 weeks of gestational age, and it has no effective pharmacologic treatment at this time. We know that some risk factors are low birth weight and low gestational age, but outside of those parameters, we really don't have much control. We know that GMH acts in the same way as any other brain injury in the sense that there is a primary mechanism where there's a direct mechanical insult, and that's followed by a secondary mechanism where you have recruitment of the immune cells, cytotoxic edema, and the cyclic neuroinflammation that takes place. And ultimately, this results in the sequelae that we know very well, including post-hemorrhagic hydrocephalus and periventricular leukomalacia that ultimately results in cerebral palsy. In our work, we've previously shown that complement inhibition actually reduces the rates of hydrocephalus in the dermal matrix hemorrhage model, as we showed last year at this meeting. However, this year we wanted to discuss the effects of complement inhibition on the secondary injury cascade in a more chronic animal model. The model used for this work is the same that we've described in the past, which utilizes collagenase injection into the subventricular zone, and as you can see, blood deposition on the ipsilateral ventricle as well as the contralateral ventricle on the right-hand side. And we utilized a similar experimental setup as we described the last time, where following the hemorrhage, we treat the animals at four days of age and then treat them every three days until about 14 days. And for the chronic model, we then treat them every seven days afterwards. There are three different groups. The vehicle group, which is treated with only PBS, the treatment group treated with CR2-CRY, and then the naive group with no injury whatsoever. And these are MRI comparisons that we briefly showed last time, where you see a normal brain on the left-hand side, a vehicle brain with severe hydrocephalus untreated, and a treatment brain on the right-hand side, where you can see reduced amount of hydrocephalus and preservation of brain tissue. So last time, we showed that we successfully reduced the rate of hydrocephalus in the acute model from 61% to only 7% in the treated animals. And since then, we performed MRIs every 30 days on these animals until 90 days, and we're able to find that although there was an increase overall of the rates of hydrocephalus, the vehicle group had an increase to 100% at about 90 days of age, while the treated groups only developed hydrocephalus 50% of the time, which reduced it by half. Furthermore, we saw a significant increase in the weight gain for the animals treated with CR2-CRY compared to the vehicles, with the percent weight gain going above 400% from their day two of life compared to the vehicle group, which was under 400%. And animal survival at both 45 days and 90 days was almost double in the treatment group compared to the vehicle group. Furthermore, we looked at motor and cognitive performance of these animals, and you can see that there is a significant improvement of the animals treated with CR2-CRY compared to the vehicle. As you can see, they go back to almost normal in the naive animals. This was both in the catwalk motor performance task, which shows pure motor function, as well as the passive avoidance test, which is a shock test, a shock memory test. And then we also look at cognitive evaluation with the Barnes-Mays test, in which the animal is supposed to remember which hole is the safety hole. And you can see that the time it takes for the animals to find the correct hole is significantly improved within the treated animals compared to the vehicle, in both the total time and then the time to peak, which is the first moment that they are able to recognize the hole. You can see at the bottom a heat map of where the vehicle animals are just all over the place. They cannot find that hole compared to CR2-CRY and naive animals, which go directly to that safety. So complement inhibition in GMH reduces post-hormergic hydrocephalus, but it also increases neonatal mouse survival and, as we saw, improves neurocognitive outcomes. Now we must look at the role of complement not only in post-hormergic hydrocephalus, but also in periventricular leukomalacia, as we know that plays a significant role in humans developing cerebral palsy. And we also need to validate the underlying mechanism of action for this complement inhibitor and which subset of complement cascades is mostly playing a role here. And finally, we hope to bring this to the bedside with a clinical trial once all of this data is validated and put back to work. Thank you. Good afternoon. My name is Smriti Patel, and I'm currently the Clinical Fellow in Pediatric Neurosurgery at the Cincinnati Children's Hospital Medical Center. Today I will be sharing the results of our proof-of-principle study, which shows that programmable shunt valves can be investigated accurately using smartphones. The authors have no financial interests or relationships with any of the products and or manufacturers discussed in this presentation. Smartphone-integrated magnetometers detect and quantify magnetic flux densities, such as those emitted by commonly used electromagnetic devices, including programmable valves. The objective of this study was to determine if this technology could accurately predict programmable valve shunt settings. The Codman-Certis Plus valve and Medtronic Strata II valves were investigated with two smartphones, the Samsung S9 and Sony Xperia, running Firefox, an open-source magnetometer application, and the default smartphone camera. Using the manufacturer valve programmer, the Codman-Certis Plus valve was set sequentially to all eight settings. Similarly, the Medtronic Strata II valve was set sequentially to all five settings. To blind the investigator, another team member programmed the valve to undisclosed settings over 20 times. The Earth's magnetic field was subtracted from setting readings by orienting the valve in the same cardinal direction for all source and background measurements. To obtain consistent measurements with the Samsung S9, we used a target overlay placed in the upper left-hand corner of the display within the camera app. Similarly, for the Sony Xperia, this overlay was placed in the lower right-hand corner. These locations corresponded to where the compass and magnetometer were located on each of the smartphones. This calibration was completed prior to each trial. For the first step, the shunt valve is aligned with its arrow facing north. The second step involved obtaining a photo with the target overlay on it. This was done so that the measurement was consistent each time. The target overlay is then placed directly over the center clock face or ruby ball of the shunt valve. Once aligned, the applications are switched, and with the phone still in place over the center clock face or the ruby ball of the valve, the Firefox magnetometer application is opened, and using the simple measurement tool, we obtain the magnetic field strength as measured in X, Y, and Z coordinates and record those values. Maintaining this orientation, the phone is then raised approximately 20 centimeters over the valve. The X, Y, and Z measurements are then recorded from this elevated position. To review, the compass is first calibrated. The valve is then aligned so that the arrow is facing the cardinal direction north. The target overlay is then centered over the clock face or the ruby ball of the valve. Applications are then switched so that Firefox is opened, and magnetometer measurements are obtained in X, Y, and Z coordinates. The phone is then elevated to 20 centimeters above the level of the valve, and X, Y, and Z measurements are obtained again and recorded. Source measurements were then entered into a predefined algorithm that subtracted these values from the average background values. The differences were then summed. The lowest sum difference was declared as the unknown shunt setting. This technique resulted in determination of all shunt settings ranging from 1 through 8 with 100% accuracy on the Codman Certus Plus valve, and ranging from 0.5 to 2.5 with 100% accuracy on the Medtronic Strata II valve. This investigation provides proof of principle that smartphone-integrated applications can be used to predict the Certus Plus and Strata II valve settings. Future studies include applying this technique to other commonly used programmable valves. While convoluted in its raw form, the current algorithm could ultimately be integrated into software readily available on any smartphone, allowing universal access to a programmable valve shunt reader. The authors would like to thank the AANS and CNS Pediatric Section on Neurological Surgery for the opportunity to present our work. Hello. My name is Karl Bulsaro. I'm an assistant professor at Indiana University and Riley Children's Hospital. I want to thank the section for the opportunity to present our retrospective series on intracranial hemorrhage related to proximal catheter obstruction. Anecdotally, this complication is somewhat commonly experienced, but the associated morbidity is quite underreported, which is the genesis of this work. I have no disclosures to report. We understand proximal shunt obstruction to be caused frequently by the ingrowth of some tissue into the proximal shunt. The origin and nature of this tissue is debated, but is frequently vascularized and the surgeon is often blind to this and has some tactile sense only that the proximal catheter is stuck. We understand the hemorrhage experienced to be a product of the manipulation of the stuck proximal catheter and weigh the value of removing that catheter against the risk of doing so. The assumed risk of iatrogenic hemorrhage as a result of proximal shunt revision is a presumption for early shunt failure, which leads surgeons to recommend an extended period of hospitalization for these patients. There's also the additional risk of additional surgical intervention, including clot evacuation or drain placement, and the separate risk of death or disability from the primary injury. We used a retrospective study design. We queried all patients with proximal shunt revisions during a three-and-a-half-year period. This covers the practice of eight separate surgeons with a range of experience of similar technique. We included only cases with postoperative head CTs and were guided in the call for hemorrhage or not by the radiological report. Size was reported as an area greater or less than five milliliters. The endpoints for the study were the need for a subsequent shunt revision versus the last reported failure-free contact. We did exclude those patients who were re-revised due to catheter malposition or fracture, which was not attributable to hemorrhage. We made notes of any morbidity or mortality. The results were somewhat surprising. The rate of hemorrhage in the 196 cases we looked at was just under 25 percent, a somewhat surprising frequency. However, we did not find significant morbidity associated with that population. The overall re-revision rate of the population was 30 percent, but only nine of the 58 revisions had hemorrhage associated with the index case. This is only 18 percent of all cases associated with hemorrhage, as compared to a revision rate of 33 percent of cases where there was no hemorrhage. The follow-up rates and duration were similar across the groups. There was one death in the hemorrhage group, but this was related to tumor progression two years after the index shunt revision. There were no significant differences in the early revision rates or the number of patients who required multiple re-revisions after the index case. There were two cases where the patient required re-revision of the shunt within two days of the operation where hemorrhage was encountered, but there were three similar instances in patients without hemorrhage. Finally, there were no cases where clot evacuation or drain placement was required to deal with the hemorrhage. We plotted survival over time and compared with a log-rank test. Here, there was, again, no significant difference between the two populations. However, there was a trend actually towards a protective effect correlating with hemorrhage. So, in conclusion, we note a hemorrhage rate after proximal shunt revision of approximately 25%. However, we did not find that hemorrhage after proximal shunt revision predisposes the patient to requiring a subsequent shunt revision or experiencing an early shunt failure. I do note the caveat that nearly all of the hemorrhages we encountered in our series were less than five cubic centimeters in size. Our study is somewhat limited by sample size and design, but we did think the trend towards increased survival with hemorrhage was interesting. One reason we conjectured may be that the surgeon, upon noting a hemorrhage, makes some effort to relocate the catheter away from the site of hemorrhage, and this makes it be separately protective. The literature on the subject is mixed. A small but recent series from the Albany group found similar conclusions to ours in a smaller sample size. A group from Calgary did find a statistically significantly quicker rate of shunt failure, albeit in a smaller group. The benchmark hemorrhage rate was similar across both studies. The conclusion we draw from our series implied that the asymptomatic patient with a small hemorrhage probably does not require more than routine postoperative monitoring. I'd like to conclude by acknowledging my partners and colleagues in this work, particularly Dr. Peretti and Mr. Metzman, a resident and med student whose efforts in collecting data for this study was instrumental. Thank you very much. Hello, my name is Andrew Nyangokon. Thank you for the opportunity to discuss treatment strategies for Dandy-Walker syndrome-related hydrocephalus today, a project that we did with the Hydrocephalus Clinical Research Network. We have no conflicts of interest or disclosures relevant to this presentation. No funding directly supported in this project was obtained. However, here is the general funding information for the HCRN. Dandy-Walker syndrome is a continuum of congenital malformations posterior fossa, frequently associated with hydrocephalus, requiring diagnosis and treatment early in life. The etiology of hydrocephalus is considered obstructive either at the aqueduct or at the fourth ventricular outlet. It's typically treated by cyst or ventricular peritoneal shunt, or classically dual compartment shunting. An endoscopic third ventriculostomy, with or without choroid plexus cauterization, should be an option based on the etiology of the hydrocephalus. International cohorts have demonstrated good success with this procedure in Dandy-Walker syndrome in modern series. However, there's no modern North American comparative study of treatment strategies. Our objective was to compare revision-free survival between shunt-based and ETV-based treatment strategies. We hypothesized that these treatment groups would have similar rates of revision and would be similarly durable. We analyzed data from the HCRN Core Data Project of patients treated between 2008 and 2018 across 14 centers. We used patients with a recorded hydrocephalus etiology of posterior fossa cyst, including Dandy-Walker and variants. All patients had to have at least six months of follow-up. Treatment was defined as either shunt-based or ETV-based, and our primary outcome was failure of the index procedure. The full cohort contained 151 patients. 102 of these patients received shunt-based treatment, the majority of which were single ventricular catheters. There were 49 patients that underwent ETV. 57% of them had a planned CPC. Patients receiving shunt-based treatment were younger and had more comorbidities. However, the groups were similar in terms of symptoms and signs at presentation, as well as radiographic findings. We found that ETV-based treatment was associated with a 36.7% rate of failure at six months, an overall failure rate of 51%. Similarly, shunt-based treatment had a 30% failure rate at six months and 50% overall. Using cost-proportional hazards modeling, adjusting for age, frontal occipital horn ratio, and comorbidities, we found that there was no increased risk of failure for ETV. In terms of subgroup analysis and secondary outcomes, there are similar complication rates between the two procedures, as you see there. We found that 100% of complex or dual compartment shunts failed, of which there was only four of these. There is similar event-free survival for cyst peritoneal and ventricular peritoneal shunts, and there is no difference in risk of failure for ETV CPC versus ETV alone. In conclusion, either shunt-based or ETV-based initial treatment may be considered for Dandy Walker Syndrome-related hydrocephalus. ETV-based is reasonable for North American patients. It may be associated with similar durability, low complication rates, and the ability to avoid shunt dependence. Future studies may be better able to determine clinical and radiographic factors associated with ETV's success in Dandy Walker Syndrome. I just wanted to thank all of the HCRN members, colleagues, and staff at member institutions that made this work possible. Thank you. My thanks again to each and every one of the presenters for their very good work. Judging by the chat page, the excitement hasn't diminished at all, and I hope you're all taking advantage of the opportunity to meet with them in the remote conversation lounge for further questions. Dr. Bui? Yeah, so this brings the last scientific session to an end. There's definitely nothing like a big dose of hydrocephalus going into your call weekend, so hopefully not many of you guys are on call. I was told I literally got two calls for shunt failures as soon as the hydrocephalus session started. But I want to thank everyone. I also want to thank the session for allowing us to be moderators for this great session. And with that, I think we're going to close out the session. Thank you.

hydrocephalus

studies

tonsillopexy

Arnold-Chiari malformation

surveillance

shunt placement

endoscopic third ventriculostomy

cerebral blood flow

oxygenation

smartphone-integrated magnetometers

hemorrhage

Dandy-Walker syndrome