Delayed Minocycline Treatment Ameliorates Hydrocephalus Development and Choroid Plexus Inflammation in Spontaneously Hypertensive Rats.

Hydrocephalus is a complicated disorder that affects both adult and pediatric populations. The mechanism of hydrocephalus development, especially when there is no mass lesion present causing an obstructive, is poorly understood. Prior studies have demonstrated that spontaneously hypertensive rats (SHRs) develop hydrocephalus by week 7, which was attenuated with minocycline. The aim of this study was to determine sex differences in hydrocephalus development and to examine the effect of minocycline administration after hydrocephalus onset. Male and female Wistar-Kyoto rats (WKYs) and SHRs underwent magnetic resonance imaging at weeks 7 and 9 to determine ventricular volume. Choroid plexus epiplexus cell activation, cognitive deficits, white matter atrophy, and hippocampal neuronal loss were examined at week 9. In the second phase of the experiment, male SHRs (7 weeks old) were treated with either saline or minocycline (20 mg/kg) for 14 days, and similar radiologic, histologic, and behavior tests were performed. Hydrocephalus was present at week 7 and increased at week 9 in both male and female SHRs, which was associated with greater epiplexus cell activation than WKYs. Male SHRs had greater ventricular volume and epiplexus cell activation compared to female SHRs. Minocycline administration improved cognitive function, white matter atrophy, and hippocampal neuronal cell loss. In conclusion, while both male and female SHRs developed hydrocephalus and epiplexus cell activation by week 9, it was more severe in males. Delayed minocycline treatment alleviated hydrocephalus, epiplexus macrophage activation, brain pathology, and cognitive impairment in male SHRs.

CD47 blocking antibody accelerates hematoma clearance and alleviates hydrocephalus after experimental intraventricular hemorrhage.

Background CD47, a glycoprotein on red blood cell membranes, inhibits phagocytosis via interaction with signal regulatory protein α on phagocytes. Our previous research has demonstrated that blocking CD47 accelerates hematoma clearance and reduces brain injury after intracerebral hemorrhage. The current study investigated whether phagocytosis or erythrocyte CD47 impacts hematoma resolution and hydrocephalus development after intraventricular hemorrhage (IVH). Methods Adult (3-month-old) male Fischer 344 rats were intraventricularly injected with 200 µl autologous blood, mixed with either CD47 blocking antibody or isotype IgG, or 200 µl saline as control. In subgroups of CD47 blocking antibody treated rats, clodronate liposomes (to deplete microglia/monocyte-derived macrophages) or control liposomes were co-injected. Magnetic resonance imaging (MRI) was used to evaluate ventricular volume and intraventricular T2* lesion volume (estimating hematoma volume). The brains were harvested after 4 or 72 h for histology to evaluate phagocytosis. Results In adult male rats, CD47 blocking antibody alleviated hydrocephalus development by day 3. In addition, the CD47 blocking antibody reduced intraventricular T2* lesion and T2* non-hypointense lesion size after IVH through day 1 to day 3. Erythrophagocytosis was observed as soon as 4 h after IVH and was enhanced on day 3. Furthermore, intra-hematoma infiltration of CD68, heme oxygenase-1 and ferritin positive phagocytes were upregulated by CD47 blockade by day 3. Clodronate liposomes co-injection caused more severe hydrocephalus and weight loss. Conclusion Blocking CD47 in the hematoma accelerated hematoma clearance and alleviated hemolysis and hydrocephalus development after IVH, suggesting CD47 might be valuable in the future treatment for IVH.

Hydrocephalus Following Experimental Subarachnoid Hemorrhage in Rats with Different Aerobic Capacity.

Low aerobic capacity is considered to be a risk factor for stroke, while the mechanisms underlying the phenomenon are still unclear. The current study looked into the impacts of different aerobic capacities on early brain injury in a subarachnoid hemorrhage (SAH) model using rats bred for high and low aerobic capacity (high-capacity runners, HCR; low-capacity runners, LCR). SAH was modeled with endovascular perforation in HCR and LCR rats. Twenty-four hours after SAH, the rats underwent behavioral testing and MRI, and were then euthanized. The brains were used to investigate ventricular wall damage, blood-brain barrier breakdown, oxidative stress, and hemoglobin scavenging. The LCR rats had worse SAH grades (p < 0.01), ventricular dilatation (p < 0.01), ventricular wall damage (p < 0.01), and behavioral scores (p < 0.01). The periventricular expression of HO-1 and CD163 was significantly increased in LCR rats (p < 0.01 each). CD163-positive cells were co-localized with HO-1-positive cells. The LCR rats had greater early brain injuries than HCR rats. The LCR rats had more serious SAH and extensive ventricular wall damage that evolved more frequently into hydrocephalus. This may reflect changes in iron handling and neuroinflammation.

Intraoperative Phase Contrast MRI Analysis of Cerebrospinal Fluid Velocities During Posterior Fossa Decompression for Chiari I Malformation.

BACKGROUND: Cerebrospinal fluid (CSF) velocity at the craniovertebral junction (CVJ) is known to be altered in patients with Chiari I malformation (CMI), and normalization of CSF velocities is associated with symptom resolution. However, preoperative and intraoperative prediction methods have thus far failed to identify patients in whom CSF velocities can be normalized with posterior fossa decompression (PFD) without duraplasty. Phase contrast MRI (PC-MRI) may assist not only in diagnosis of CMI but also in guiding the intraoperative decision to perform duraplasty during PFD. PURPOSE: To use intraoperative MRI data to quantify changes in CSF hydrodynamics at the CVJ during each step of PFD with duraplasty (PFDD) in 12 consecutive patients. STUDY TYPE: Retrospective case series with all patients imaged before, during and after decompression, and all data analyzed postprocedure. POPULATION/SUBJECTS: Pediatric patients, mean age 14 years (range 4-18), undergoing PFD for CMI. FIELD STRENGTH/SEQUENCE: Intraoperative studies involved a dedicated 1.5T Siemens MRI imager. PC-MRI scans were in the axial plane at the CVJ. ASSESSMENT: Two observers assessed measurements. STATISTICAL TEST: The equality of matched pairs of observations was tested using the Wilcoxon matched-pairs signed-ranks test. RESULTS: Data analyses of the PC-MRI demonstrated a marked and immediate increase in CSF velocity at the posterior CVJ during PFDD. Mean cranially-directed velocities increased by a mean of 1.049cm/s (P = 0.028) from preincision to postoperative measurement. There was a mean 0.45 cm/s (P = 0.022) increase in mean cranial velocity from preincision to bone decompression scans, and a mean 0.48 cm/s (P = 0.018) increase in mean velocity from preincision to duraplasty. DATA CONCLUSION: In all subjects, significant increases in the mean and peak velocities of cranially- and caudally-directed velocities were observed from preincision to post-PFDD scans at the posterior CVJ. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 4 J. Magn. Reson. Imaging 2020;51:1463-1470.

2017 Infectious Diseases Society of America's Clinical Practice Guidelines for Healthcare-Associated Ventriculitis and Meningitis.

The Infectious Diseases Society of America (IDSA) Standards and Practice Guidelines Committee collaborated with partner organizations to convene a panel of 10 experts on healthcare-associated ventriculitis and meningitis. The panel represented pediatric and adult specialists in the field of infectious diseases and represented other organizations whose members care for patients with healthcare-associated ventriculitis and meningitis (American Academy of Neurology, American Association of Neurological Surgeons, and Neurocritical Care Society). The panel reviewed articles based on literature reviews, review articles and book chapters, evaluated the evidence and drafted recommendations. Questions were reviewed and approved by panel members. Subcategories were included for some questions based on specific populations of patients who may develop healthcare-associated ventriculitis and meningitis after the following procedures or situations: cerebrospinal fluid shunts, cerebrospinal fluid drains, implantation of intrathecal infusion pumps, implantation of deep brain stimulation hardware, and general neurosurgery and head trauma. Recommendations were followed by the strength of the recommendation and the quality of the evidence supporting the recommendation. Many recommendations, however, were based on expert opinion because rigorous clinical data are not available. These guidelines represent a practical and useful approach to assist practicing clinicians in the management of these challenging infections.

Molecular characterization reveals NF1 deletions and FGFR1-activating mutations in a pediatric spinal oligodendroglioma.

Pediatric spinal oligodendrogliomas are rare and aggressive tumors. They do not share the same molecular features of adult oligodendroglioma, and no previous reports have examined the molecular features of pediatric spinal oligodendroglioma. We present the case of a child with a recurrent spinal anaplastic oligodendroglioma. We performed whole exome (paired tumor and germline DNA) and transcriptome (tumor RNA) sequencing, which revealed somatic mutations in NF1 and FGFR1. These data allowed us to explore potential personalized therapies for this patient and expose molecular drivers that may be involved in similar cases.

Cerebrospinal fluid velocity amplitudes within the cerebral aqueduct in healthy children and patients with Chiari I malformation.

PURPOSE: To assess the effects of cerebrospinal fluid (CSF) bidirectional motion in Chiari malformation type I (CMI), we monitored CSF velocity amplitudes on phase contrast MRI (PC-MRI) in patients before and after surgery; and in healthy volunteers. MATERIALS AND METHODS: 10 pediatric volunteers and 10 CMI patients participated in this study. CMI patients underwent PC-MRI scans before and approximately 14 months following surgery. Two parameters-amplitude of mean velocity (AMV) and amplitude of peak velocity (APV) of CSF-were derived from the data. Measurements were made at the mid-portion of the cerebral aqueduct, and anterior and posterior compartments of the spinal canal at the craniovertebral junction (CVJ). RESULTS: AMV and APV within the cerebral aqueduct were greater in preoperative assessments of the CMI patients compared to normal volunteers. Statistical significance was noted when comparing aqueductal AMV between the preoperative values and normal controls (P = 0.03), and before and after surgery in the CMI patients (P = 0.02). Lower values of AMV (P = 0.02) were noted in the anterior CVJ compartment in the patients before and after surgery when compared to the normal volunteers. There were no significant correlations (P = 0.06) noted for the APV at the CVJ between the normal control and patients, before or after surgery. CONCLUSION: In pediatric CMI patients, AMV for CSF within the cerebral aqueduct and anterior CVJ subarachnoid space are significantly elevated preoperatively and normalize following surgery. Given the biphasic CSF motion, measuring amplitude accounts for cranial and caudal flow. It may offer an alternative parameter to assess postsurgical outcome. J. Magn. Reson. Imaging 2016;44:463-470.

Interobserver Variation in Cerebellar Tonsillar Tip Localization: Comparison of 3 Different Osseous Landmarks on Magnetic Resonance Imaging.

PURPOSE: The aim was to evaluate the interobserver agreement in the assessment of cerebellar tonsil position on sagittal magnetic resonance imaging using 3 different osseous landmarks. MATERIALS AND METHODS: This retrospective study consisted of brain magnetic resonance imagings performed at our institution in patients with and without Chiari I malformation between January 2010 and 2012. Sagittal T1-weighted images were reviewed by 2 senior board-certified neuroradiologists (blinded to underlying clinical diagnosis) with measurement of both cerebellar tonsillar positions based on lines drawn perpendicular from the tonsillar tip to the foramen magnum [FM] line, C1 line, and C2 line. Spearman correlation coefficients were calculated. Interobserver variation between the readers was assessed using Bland-Altman analysis and intraclass correlation coefficient. RESULTS: A total of 320 cerebellar tonsils on 160 patients, 50 with Chiari I malformations, and 110 control subjects without Chiari I malformation were evaluated. The Spearman correlation coefficients for the entire cohort were 0.86 (FM), 0.94 (C1), and 0.90 (C2). Bland-Altman analysis for the entire cohort showed the best interobserver agreement for C1 line (-0.3 mm bias) and the least for C2 line (4.6 mm bias). The Intraclass correlation coefficients for all patients were 0.84 (FM), 0.92 (C1), and 0.54 (C2). The least bias and highest correlation coefficients were also seen individually in the Chiari and non-Chiari cohorts with the C1 technique. CONCLUSIONS: Determination of cerebellar tonsillar position using a C1 arch landmark may be superior to the currently more commonly used FM-based landmark with lesser interobserver variability and higher interobserver correlation.

Skull fracture mimicking eosinophilic granuloma.

BACKGROUND: Delayed swelling after skull fractures is an uncommon complication following head trauma in children. Classically, growing skull fractures typically present in patients under 3 years of age with progressive subcutaneous fluid collections, or occasionally with neurologic symptoms. We present the case of a healthy 2-year-old boy with a lytic "punched-out" frontal skull lesion. The child presented 2 months after a minor forehead injury for which no medical attention was sought. METHODS: The skull defect had no associated leptomeningeal cyst or brain herniation. Imaging and presentation were thought to be consistent with eosinophilic granuloma. Histologic findings demonstrated a healing skull fracture. RESULTS: Cranioplasty was performed, and the patient had an uncomplicated postoperative course. CONCLUSIONS: In this report, we describe our experience with this atypical presentation of a healing skull fracture mimicking a typical eosinophilic granuloma.

Management of pediatric craniocervical arterial dissections.

PURPOSE: Craniocervical arterial dissections (CCADs) represent a preventable cause of acute ischemic stroke (AIS). Our objective was to describe clinical presentation, imaging features, treatment strategies, and report clinical and imaging outcomes of CCADs at a large pediatric tertiary referral center. METHODS: Electronic medical records were queried using variations of the word dissection for patients under 25 years of age with neuroimaging over a 13-year period. Medical and imaging records were reviewed to identify carotid, vertebral, or intracranial dissections. Demographics, presenting symptoms, presence of AIS, mechanism of injury, dissection location, dissection treatment, and complications stemming from treatment were collected. Clinical outcome was classified according to modified Rankin Scale (mRS) score. Imaging follow-up was obtained until the dissection healed or stabilized. RESULTS: A total 6,289 patients met initial search criteria. Of the 42 (0.7%) patients with CCADs, 23 (54.8%) had internal carotid artery (ICA) dissections, and 17 (40.5%) had vertebrobasilar (VB) dissections. More females had ICA dissections (p = 0.002), and more males had VB dissections (p = 0.01). CCADs associated with traumatic presentation occurred in 34 patients (81.0%), while 8 (19.0%) were spontaneous. Good outcomes (mRS 0-3) were noted for 36 patients, and 5 had poor outcomes (mRS 4-6). In the 17 patients with vessel occlusion, 50.0% had partial or complete recanalization at a mean follow-up of 23.9 months. CONCLUSIONS: CCAD is commonly related to trauma and presents with AIS. The majority of patients experience good clinical outcome. Recanalization of initial vessel occlusion occurs in half of cases at 2 years.

Influence of socioeconomic status on clinical outcomes of diffuse midline glioma and diffuse intrinsic pontine glioma.

OBJECTIVE: Given the lack of a definitive treatment and the poor prognosis of patients with diffuse midline glioma (DMG) and diffuse intrinsic pontine glioma (DIPG), socioeconomic status (SES) may affect treatment access and therefore survival. Therefore, this study aimed to examine the relationship between SES and treatment modalities, progression-free survival (PFS), and overall survival (OS) in children with DMG/DIPG. METHODS: A retrospective, single-institution review was conducted of medical records of patients ≤ 18 years of age who had DMG or DIPG that was diagnosed between 2000 and 2022. Patient demographics, surgical interventions, chemotherapy, radiation therapy, clinical trial enrollment, and medical care-related travel were extracted. SES variables (education and mean income) for associated patient census tracts were collected and stratified. Statistical analysis using unpaired t-tests, chi-square analysis, and log-rank tests was conducted. RESULTS: Of the 96 patients who met the inclusion criteria, the majority were female (59%) and non-Hispanic White (57%). The median PFS, median OS, and time from diagnosis to treatment did not differ between races/ethnicities or sex. Ninety-one of 96 patients had census tract data available. Patients from higher-income census tracts (> 50% of families with annual household income greater than $50,000) had a longer median OS (480 vs 235 days, p < 0.001) and traveled significantly longer distances for medical care (1550 vs 1114 miles, p = 0.048) than families from lower-income census tracts. Patients from the highest education quartile traveled significantly farther for treatment than the lowest education quartile (mean 2964 vs 478 miles, p = 0.047). Patients who received both oral and intravenous chemotherapy were more likely to be from higher-income census tracts than those who received intravenous or no chemotherapy. Duration of PFS, rates of clinical trial enrollment, biopsy rates, H3K27 mutation status, ventriculoperitoneal shunt placement rates, and radiotherapy rates were not associated with SES variables. CONCLUSIONS: Patients from families from higher-income census tracts experienced longer OS and traveled farther for treatment. Patients from families from higher-education-level census tracts traveled more often for treatment. The authors' findings suggest that SES influences DMG and DIPG OS. More studies should be done to understand the role of SES in the outcomes of children with DMG/DIPG.

A road map for the treatment of pediatric diffuse midline glioma.

Recent clinical trials for H3K27-altered diffuse midline gliomas (DMGs) have shown much promise. We present a consensus roadmap and identify three major barriers: (1) refinement of experimental models to include immune and brain-specific components; (2) collaboration among researchers, clinicians, and industry to integrate patient-derived data through sharing, transparency, and regulatory considerations; and (3) streamlining clinical efforts including biopsy, CNS-drug delivery, endpoint determination, and response monitoring. We highlight the importance of comprehensive collaboration to advance the understanding, diagnostics, and therapeutics for DMGs.

Effect of amusement park rides on programmable shunt valve settings.

BACKGROUND: Magnetically programmable shunt valves are susceptible to environmental factors including magnetic fields and accelerative forces. It is unknown if rollercoasters with or without magnetic brakes or linear induction motors (LIMs) are capable of altering the setting of a programmable shunt valve. METHODS: Two different valve types (type A, n = 10; type B, n = 9) were tested at varying resistance settings in 2 trials on 6 different amusement park rides including 2 rides with LIMs, 2 rides with magnetic brakes, and 2 rides without magnetic technology. RESULTS: The performance level of valve type A and the setting of valve type B changed on rollercoasters with magnets (A = 2.5% [2/80]; B = 5.6% [4/72]) and without magnets (A = 7.5% [3/40]; B = 2.8% [1/36]). Neither valve setting changed when exposed to a Ferris wheel or during ambulation throughout the park. CONCLUSION: Magnetically programmable valves are susceptible to changes in pressure settings when exposed to amusement park rides with elevated vertical gravitational forces, irrespective of the presence of LIMs or magnetic brakes.

Cervical arterial injury after blunt trauma in children: characterization and advanced imaging.

BACKGROUND: The incidence of cervical vascular injury (CVI) after blunt cervical trauma in children and adolescents is low. Potential harm from missed injury is high. Screening for CVI has increased with advances in noninvasive angiography, including computed tomographic angiography (CTA) and magnetic resonance angiography (MRA). We attempt to characterize CVI in children and adolescents and evaluate the utility of advanced imaging in CVI screening in this patient population. METHODS: Clinical and radiographic records of consecutive patients aged 4 to 18 years with blunt cervical spine trauma from 1998 to 2008 were reviewed. Patient demographics, injury pattern, neurological findings, and treatment were recorded. RESULTS: Sixty-one patients were identified. Nineteen underwent screening to evaluate for CVI, including 12 males and 7 females, mean age 13.5 years. The most common mechanism of injury was motor vehicle collision (n=11). Seven patients underwent MRA, 7 CTA, 3 had both studies, and 2 had traditional angiography. Seven patients had CVI, with an overall incidence of 11.5%. High-risk criteria (fracture extension to transverse foramina, fracture/dislocations or severe subluxations, or C1-C3 injury) were associated with increased rates of CVI. Neurological injury was found in 12/19 patients screened and 6/7 patients with CVI. Two of 7 patients underwent anticoagulation due to documented CVI. No delayed-onset ischemic neurological events occurred. CONCLUSIONS: After blunt cervical spine trauma, certain fracture patterns increase the risk of CVI. CVI is common, with a minimum incidence of 7/61 or >10% of pediatric patients with blunt cervical spine injury. Over 1/4 of patients studied on the basis of high-risk criteria had injury. Advanced imaging with noninvasive angiography (CTA/MRA) should be strongly considered in pediatric patients with cervical spine trauma. The presence of CVI may prompt a change in management. LEVEL OF EVIDENCE: Level IV-retrospective diagnostic study.

Glymphatic System and Post-hemorrhagic Hydrocephalus.

The glymphatic system is a recently identified route for exchanging parenchyma interstitial fluid and cerebrospinal fluid along perivascular space, facilitating brain waste clearance. Glymphatic system dysfunction has been reported in many neurological diseases. Here we discussed the possible role of glymphatic system in posthemorrhagic brain injury, especially posthemorrhagic hydrocephalus.

Ventriculoatrial and ventriculoperitoneal shunt malfunction and infection in infants with necrotizing enterocolitis.

OBJECTIVE: Necrotizing enterocolitis (NEC) and posthemorrhagic hydrocephalus are both conditions that can affect preterm infants. The peritoneum is the preferred terminus for shunt placement, but another terminus is sometimes used due to subjective concerns about infection and complications related to NEC. The aim of this study was to examine the rates of ventriculoatrial (VA) and ventriculoperitoneal (VP) shunt infection and failure in pediatric patients with a history of NEC. METHODS: A single-center retrospective review of medical records from 2009 to 2021 was performed to identify pediatric patients with NEC who underwent shunt placement before 2 years of age. Patients were excluded if shunt placement preceded NEC diagnosis. Patient demographic characteristics, timing of shunt placement, type of shunt, shunt infections or revisions, and timing and management of NEC were extracted. The Student t-test and Fisher exact test were used to calculate significance. Kaplan-Meier curves were calculated. RESULTS: Twenty-two patients met the inclusion criteria. Most patients underwent VP shunt placement (16 [71.4%]). Patients who underwent surgical management of NEC compared with those who underwent medical management were more likely to have a VA shunt placed (p = 0.02). One VA shunt and 3 VP shunts became infected during follow-up (p = 0.7). The mean time until infection was not significantly different between VA and VP shunts (p = 0.73). Significantly more VA shunts required revision (83% vs 31%, p = 0.04), and VA shunts had a significantly shorter time until failure (3.0 ± 0.8 vs 46.3 ± 7.55 months, p = 0.03). CONCLUSIONS: VP shunts had a significantly longer time until failure than VA shunts; these shunts had similar infection rates in infants with prior NEC. When feasible, neurosurgeons and pediatric general surgeons can consider placing a VP shunt even if the patient has a history of NEC.

Characteristics of activation of monocyte-derived macrophages versus microglia after mouse experimental intracerebral hemorrhage.

Both monocyte-derived macrophages (MDMs) and brain resident microglia participate in hematoma resolution after intracerebral hemorrhage (ICH). Here, we utilized a transgenic mouse line with enhanced green fluorescent protein (EGFP) labeled microglia (Tmem119-EGFP mice) combined with a F4/80 immunohistochemistry (a pan-macrophage marker) to visualize changes in MDMs and microglia after ICH. A murine model of ICH was used in which autologous blood was stereotactically injected into the right basal ganglia. The autologous blood was co-injected with CD47 blocking antibodies to enhance phagocytosis or clodronate liposomes for phagocyte depletion. In addition, Tmem119-EGFP mice were injected with the blood components peroxiredoxin 2 (Prx2) or thrombin. MDMs entered the brain and formed a peri-hematoma cell layer by day 3 after ICH and giant phagocytes engulfed red blood cells were found. CD47 blocking antibody increased the number of MDMs around and inside the hematoma and extended MDM phagocytic activity to day 7. Both MDMs and microglia could be diminished by clodronate liposomes. Intracerebral injection of Prx2 but not thrombin attracted MDMs into brain parenchyma. In conclusion, MDMs play an important role in phagocytosis after ICH which can be enhanced by CD47 blocking antibody, suggesting the modulation of MDMs after ICH could be a future therapeutic target.

Sports Participation and Sports-Related Neurologic Injuries in Pediatric Patients With Arachnoid Cysts.

BACKGROUND: Currently, there is no consensus recommendation regarding the safety of sports participation for pediatric patients with arachnoid cysts (ACs). OBJECTIVE: To prospectively survey patients with ACs to define the risk of sports-associated neurologic injury in untreated and treated patients. METHODS: A prospectively administered survey was given to all patients diagnosed with an AC who presented to a single pediatric neurosurgery clinic between December 2010 and December 2021. Data were recorded on demographic information, imaging characteristics, treatment, sports participation, and presence of sports-related neurologic injury. The type and date of surgery for the AC were noted if surgery was performed. RESULTS: Of the 303 patients with completed surveys, 189 patients participated in sports, and 94 patients had prospective data available. There was no significant difference in cyst location or Galassi score between patients who did and did not participate in contact vs noncontact sports and those who did and did not experience a concussion. A cumulative total of 2700.5 seasons of sports were played (2499.7 in untreated and 200.8 in treated patients). There were 44 sports-related concussions among 34 patients: 43 in untreated patients and 1 in a treated patient. For all participants, the concussion rate was 16.3 per 1000 seasons of all sports and 14.8 per 1000 seasons of contact sports. The concussion rate after AC treatment was 4.9 per 1000 seasons of all sports. Three patients experienced sports-related AC rupture or hemorrhage, none of which required surgery or resulted in lasting neurologic symptoms or deficits. CONCLUSION: The rates of sports-related concussion and cyst rupture in patients with AC in both treated and untreated populations were low. We advocate for a generally permissive posture toward sports participation in this population.

Sports Participation and Neurological Injuries in Pediatric Patients With Chiari I Malformation.

BACKGROUND: Currently, there is no consensus recommendation regarding the safety of sports participation for pediatric patients with Chiari I malformation (CM-I). OBJECTIVE: To prospectively survey the treated and untreated patients with CM-I to define the risk of sports-associated neurological injury. METHODS: A prospective survey was administered to 744 pediatric patients at one neurosurgery clinic between 2010 and 2021. Data were recorded on demographic information, imaging characteristics, treatment, sports participation, and presence of sports-related neurological injury. Patients with incomplete data were called. Two hundred seven patients completed at least 1 subsequent survey and were prospectively followed (mean 1.6 years). RESULTS: Of 744 patients with completed surveys, 462 participated in sports. Sports participants were more likely to be older at presentation ( P < .001) and have rounded cerebellar tonsil morphology ( P < .001). Seasons of sports played before and after CM-I decompression (CMD) totaled 5918.7 and 936, respectively. There were 84 sports-related concussions among 55 patients; 79 in untreated patients and 5 after CMD. For all sports participants, the concussion rate was 12.3/1000 seasons of all sports, 9.2/1000 seasons of limited-contact sports, and 13.8/1000 of contact sports. The concussion rate after CMD was 5.3/1000 seasons of all sports, 9.2/1000 seasons of limited-contact sports, and 7.1/1000 seasons of contact sports. There were no reports of long-lasting neurological issues postconcussion or of permanent spinal cord injury. CONCLUSION: No permanent or catastrophic sports-associated neurological injuries were reported. The concussion rates in treated and untreated patients with CM-I were low. Therefore, sports participation in this population should be permitted in most cases.

Attenuation of ventriculomegaly and iron overload after intraventricular hemorrhage by membrane attack complex inhibition.

OBJECTIVE: The pathophysiology of posthemorrhagic hydrocephalus (PHH) is not well understood, but recent data suggest blood components play a significant role. This study aimed to understand the timing of membrane attack complex (MAC) activation after intraventricular hemorrhage (IVH) and the effect of MAC inhibition on PHH development. METHODS: This study was composed of four parts. First, 24 young adult male rats underwent stereotactic intraventricular injection of autologous blood or saline and MRI on day 1, 3, or 7 after hemorrhage. Second, 18 rats underwent intraventricular injection of saline, autologous blood with aurin tricarboxylic acid (ATA) in vehicle, or autologous blood with vehicle and underwent serial MRI studies on days 1 and 3 after hemorrhage. Third, 12 rats underwent intraventricular injections as above and MRI 2 hours after hemorrhage. Finally, 24 rats underwent the intraventricular injections as above, as well as serial MRI studies on days 1, 7, 14, and 28 after hemorrhage. The MR images were used to calculate ventricular volume and iron deposition. Open field testing was performed to assess functional outcomes. Outcomes on day 28 were reported as a ratio to the animal's baseline values and normalized via log-transformation. Statistical analysis included the Shapiro-Wilk tests for normality and t-tests and 1-way analysis of variance for 2 and 3 groups of continuous variables, respectively. RESULTS: MAC was found within the hematoma 1 day after hemorrhage and persisted until day 7. Administration of ATA resulted in similar intraventricular hematoma volumes compared to vehicle 2 hours after hemorrhage. At 1 and 3 days after hemorrhage, ATA administration resulted in significantly smaller ventricular volumes and less hemolysis within the hematoma than in the vehicle animals. Administration of ATA also resulted in significantly smaller ventriculomegaly and less iron deposition in the periventricular area than in the vehicle rats 28 days after hemorrhage. Functionally, ATA rats were significantly faster, traveled longer distances, and spent less time resting than vehicle rats at 28 days. CONCLUSIONS: MAC was activated early and persisted within the hematoma until day 7 after IVH. MAC inhibition attenuated hemolysis in the clot and ventriculomegaly acutely after IVH. One month after hemorrhage, MAC inhibition attenuated ventriculomegaly and iron accumulation and improved functional outcomes.