Supracerebellar infratentorial resection of a torcular lesion causing fulminant intracranial hypertension: illustrative case.

BACKGROUND: Venous sinus stenosis has been implicated in intracranial hypertension and can lead to papilledema and blindness. The authors report the unique case of a cerebellar transtentorial lesion resulting in venous sinus stenosis in the torcula and bilateral transverse sinuses that underwent resection. OBSERVATIONS: A 5-year-old male presented with subacute vision loss and bilateral papilledema. Imaging demonstrated a lesion causing mass effect on the torcula/transverse sinuses and findings of increased intracranial pressure (ICP). A lumbar puncture confirmed elevated pressure, and the patient underwent bilateral optic nerve sheath fenestration. Cerebral angiography and venous manometry showed elevated venous sinus pressures suggestive of venous hypertension. The patient underwent a craniotomy and supracerebellar/infratentorial approach. A stalk emanating from the cerebellum through the tentorium was identified and divided. Postoperative magnetic resonance imaging showed decreased lesion size and improved sinus patency. Papilledema resolved and other findings of elevated ICP improved. Pathology was consistent with atrophic cerebellar cortex. Serial imaging over 6 months demonstrated progressive decrease in the lesion with concurrent improvements in sinus patency. LESSONS: Although uncommon, symptoms of intracranial hypertension in patients with venous sinus lesions should prompt additional workup ranging from dedicated venous imaging to assessments of ICP and venous manometry.

PspA-mediated aggregation protects Streptococcus pneumoniae against desiccation on fomites.

IMPORTANCE: Spn is a dangerous human pathogen capable of causing pneumonia and invasive disease. The virulence factor PspA has been studied for nearly four decades with well-established roles in pneumococcal evasion of C-reactive protein and neutralization of lactoferricin. Herein, we show that mammalian (m)GAPDH in mucosal secretions promotes aggregation of pneumococci in a PspA-dependent fashion, whereas lactoferrin counters this effect. PspA-mediated GAPDH-dependent bacterial aggregation protected Spn in nasal lavage elutes and grown in vitro from desiccation on fomites. Furthermore, surviving pneumococci within these aggregates retained their ability to colonize naïve hosts after desiccation. We report that Spn binds to and forms protein complexes on its surface composed of PspA, mGAPDH, and lactoferrin. Changes in the levels of these proteins therefore most likely have critical implications on Spn colonization, survival on fomites, and transmission.

PspA-mediated aggregation protects Streptococcus pneumoniae against desiccation on fomites.

Streptococcus pneumoniae (Spn) resides in the nasopharynx where it can disseminate to cause disease. One key Spn virulence factor is pneumococcal surface protein A (PspA), which promotes survival by blocking the antimicrobial peptide lactoferricin. PspA has also been shown to mediate attachment to dying epithelial cells in the lower airway due to its binding of cell surface-bound mammalian (m)GAPDH. Importantly, the role of PspA during colonization is not well understood. Wildtype Spn was present in nasal lavage elutes collected from asymptomatically colonized mice at levels ~10-fold higher that its isogenic PspA-deficient mutant (ΔpspA). Wildtype Spn also formed aggregates in mucosal secretions composed of sloughed epithelial cells and hundreds of pneumococci, whereas ΔpspA did not. Spn within the center of these aggregates better survived prolonged desiccation on fomites than individual pneumococci and were capable of infecting naïve mice, indicating PspA-mediated aggregation conferred a survival/transmission advantage. Incubation of Spn in saline containing mGAPDH also enhanced tolerance to desiccation, but only for wildtype Spn. mGAPDH was sufficient to cause low-level aggregation of wildtype Spn but not ΔpspA. In strain WU2, the subdomain of PspA responsible for binding GAPDH (aa230-281) is ensconced within the lactoferrin (LF)-binding domain (aa167-288). We observed that LF inhibited GAPDH-mediated aggregation and desiccation tolerance. Using surface plasmon resonance, we determined that Spn forms multimeric complexes of PspA-GAPDH-LF on its surface and that LF dislodges GAPDH. Our findings have important implications regarding pneumococcal colonization/transmission processes and ongoing PspA-focused immunization efforts for this deadly pathogen.

Influenza A virus modulation of Streptococcus pneumoniae infection using ex vivo transcriptomics in a human primary lung epithelial cell model reveals differential host glycoconjugate uptake and metabolism.

Background: Streptococcus pneumoniae (Spn) is typically an asymptomatic colonizer of the nasopharynx but it also causes pneumonia and disseminated disease affecting various host anatomical sites. Transition from colonization to invasive disease is not well understood. Studies have shown that such a transition can occur as result of influenza A virus coinfection. Methods: We investigated the pneumococcal (serotype 19F, strain EF3030) and host transcriptomes with and without influenza A virus (A/California/07 2009 pH1N1) infection at this transition. This was done using primary, differentiated Human Bronchial Epithelial Cells (nHBEC) in a transwell monolayer model at an Air-Liquid Interface (ALI), with multispecies deep RNA-seq. Results: Distinct pneumococcal gene expression profiles were observed in the presence and absence of influenza. Influenza coinfection allowed for significantly greater pneumococcal growth and triggered the differential expression of bacterial genes corresponding to multiple metabolic pathways; in totality suggesting a fundamentally altered bacterial metabolic state and greater nutrient availability when coinfecting with influenza. Surprisingly, nHBEC transcriptomes were only modestly perturbed by infection with EF3030 alone in comparison to that resulting from Influenza A infection or coinfection, which had drastic alterations in thousands of genes. Influenza infected host transcriptomes suggest significant loss of ciliary function in host nHBEC cells. Conclusions: Influenza A virus infection of nHBEC promotes pneumococcal infection. One reason for this is an altered metabolic state by the bacterium, presumably due to host components made available as result of viral infection. Influenza infection had a far greater impact on the host response than did bacterial infection alone, and this included down regulation of genes involved in expressing cilia. We conclude that influenza infection promotes a pneumococcal metabolic shift allowing for transition from colonization to disseminated disease.

Cranial pilomatricoma: a diagnosis to consider.

Pilomatricomas are benign tumors of the hair follicle that occur frequently in the scalp region. They occur most often in children. We describe a case of pilomatricoma in a teenager, referred to neurosurgery for excision. This diagnosis should be considered in the workup of scalp lesions, and this case report should serve to draw attention to this entity.

A Jack of All Trades: The Role of Pneumococcal Surface Protein A in the Pathogenesis of Streptococcus pneumoniae.

Streptococcus pneumoniae (Spn), or the pneumococcus, is a Gram-positive bacterium that colonizes the upper airway. Spn is an opportunistic pathogen capable of life-threatening disease should it become established in the lungs, gain access to the bloodstream, or disseminate to vital organs including the central nervous system. Spn is encapsulated, allowing it to avoid phagocytosis, and current preventative measures against infection include polyvalent vaccines composed of capsular polysaccharide corresponding to its most prevalent serotypes. The pneumococcus also has a plethora of surface components that allow the bacteria to adhere to host cells, facilitate the evasion of the immune system, and obtain vital nutrients; one family of these are the choline-binding proteins (CBPs). Pneumococcal surface protein A (PspA) is one of the most abundant CBPs and confers protection against the host by inhibiting recognition by C-reactive protein and neutralizing the antimicrobial peptide lactoferricin. Recently our group has identified two new roles for PspA: binding to dying host cells via host-cell bound glyceraldehyde 3-phosphate dehydrogenase and co-opting of host lactate dehydrogenase to enhance lactate availability. These properties have been shown to influence Spn localization and enhance virulence in the lower airway, respectively. Herein, we review the impact of CBPs, and in particular PspA, on pneumococcal pathogenesis. We discuss the potential and limitations of using PspA as a conserved vaccine antigen in a conjugate vaccine formulation. PspA is a vital component of the pneumococcal virulence arsenal - therefore, understanding the molecular aspects of this protein is essential in understanding pneumococcal pathogenesis and utilizing PspA as a target for treating or preventing pneumococcal pneumonia.

Preoperative risk and postoperative outcome from subdural fluid collections in African infants with postinfectious hydrocephalus.

OBJECTIVE: This study investigated the incidence of postoperative subdural collections in a cohort of African infants with postinfectious hydrocephalus. The authors sought to identify preoperative factors associated with increased risk of development of subdural collections and to characterize associations between subdural collections and postoperative outcomes. METHODS: The study was a post hoc analysis of a randomized controlled trial at a single center in Mbale, Uganda, involving infants (age < 180 days) with postinfectious hydrocephalus randomized to receive either an endoscopic third ventriculostomy plus choroid plexus cauterization or a ventriculoperitoneal shunt. Patients underwent assessment with the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III; sometimes referred to as BSID-III) and CT scans preoperatively and then at 6, 12, and 24 months postoperatively. Volumes of brain, CSF, and subdural fluid were calculated, and z-scores from the median were determined from normative curves for CSF accumulation and brain growth. Linear and logistic regression models were used to characterize the association between preoperative CSF volume and the postoperative presence and size of subdural collection 6 and 12 months after surgery. Linear regression and smoothing spline ANOVA were used to describe the relationship between subdural fluid volume and cognitive scores. Causal mediation analysis distinguished between the direct and indirect effects of the presence of a subdural collection on cognitive scores. RESULTS: Subdural collections were more common in shunt-treated patients and those with larger preoperative CSF volumes. Subdural fluid volumes were linearly related to preoperative CSF volumes. In terms of outcomes, the Bayley-III cognitive score was linearly related to subdural fluid volume. The distribution of cognitive scores was significantly different for patients with and those without subdural collections from 11 to 24 months of age. The presence of a subdural collection was associated with lower cognitive scores and smaller brain volume 12 months after surgery. Causal mediation analysis demonstrated evidence supporting both a direct (76%) and indirect (24%) effect (through brain volume) of subdural collections on cognitive scores. CONCLUSIONS: Larger preoperative CSF volume and shunt surgery were found to be risk factors for postoperative subdural collection. The size and presence of a subdural collection were negatively associated with cognitive outcomes and brain volume 12 months after surgery. These results have suggested that preoperative CSF volumes could be used for risk stratification for treatment decision-making and that future clinical trials of alternative shunt technologies to reduce overdrainage should be considered.

Aneurysmal and arteriovenous malformation hemorrhage during pregnancy: An update on the epidemiology, risk factors and prognosis.

INTRODUCTION: Intracranial hemorrhage (ICH) is a devastating condition with a high rate of morbidity and mortality. Aneurysm or arteriovenous malformation (AVM) rupture are two common etiologies leading to ICH. Here we provide an update on ICH during pregnancy with a focus on those caused by aneurysm or AVM rupture. METHODS: Here we systematically review 25 studies reported in the literature to provide an update on ICH during pregnancy focusing on aneurysm or AVM rupture. We also reviewed the prognosis of ICH during puerperium. RESULTS: Discrepancies exist between studies supporting or refuting the hypothesis of a higher rate of ICH during pregnancy, obscuring the overall rate of aneurysm and AVM rupture in pregnant ICH patients. However, risk factors such as maternal age and hypertension have shown to increase the frequency of ICH in pregnant patients. We also show increased morbidity and mortality in patients suffering from preeclampsia/eclampsia. DISCUSSION: ICH is rare, but the various studies demonstrating its increased frequency, morbidity, and mortality during pregnancy should raise our awareness of this condition. The management and treatment decisions for a pregnant ICH patient should follow the same principles as nonpregnant patients, but with the knowledge that not all medications are appropriate for use in the pregnant patient. Although there seems to be a higher frequency of AVM rupture, further research must be conducted in order to fully determine the effects of pregnancy on aneurysm and AVM ruptures.

Suprasellar central nervous system ganglioneuroblastoma: a case in a 9-year-old child and review of the literature.

PURPOSE: Intracranial ganglioneuroblastomas are incredibly rare neuroectodermal tumors with only 8 described cases total, 5 of those having imaging findings METHODS: Here we present a 9-year-old female patient with 4 months progressive headaches, personality changes, and vomiting. We also present a review of the current literature of intracranial ganglioneuroblastomas. RESULTS: Imaging demonstrated a partially calcified suprasellar mass measuring 4.6 × 6.3 × 5 cm composed of both solid and cystic components, diagnosed to be a ganglioneuroblastoma, with mass effect on the lateral and 3rd ventricles, with a midline shift of right to left of 6-7 mm. She was treated with subtotal surgical resection, an intensive chemotherapeutic regimen, and radiation and has no residual disease on imaging 1 year and 4 months status post-surgery. CONCLUSION: To our knowledge, this is the first case of a ganglioneuroblastoma to mimic a craniopharyngioma based upon imaging findings and suprasellar location. As these cases are extremely rare, an optimal therapeutic regimen has not been defined. However, a combination of surgical resection, chemotherapy, and radiation therapy can be effective, as shown here with successful treatment and no evidence of residual disease.

Double dermal sinus tracts of the cervical and thoracic regions: a case in a 3-year-old child and review of the literature.

INTRODUCTION: Dermal sinus tracts are rare congenital abnormalities characterized by an epithelium-lined tract that extends from the subcutaneous tissue to the underlying thecal sac or neural tube. These developmental anomalies can present asymptomatically with a cutaneous dimple or with devastating complications including recurrent episodes of meningitis, or neurological complications including paralysis. Dermal sinus tracts generally occur as single lesions, and the presentation of midline double dermal sinus tracts of the cervical and thoracic regions has not been previously described. METHODS: Here, we present the case of a 3-year-old girl suffering from recurrent episodes of myelitis, paraparesis, and intramedullary intradural masses, who was diagnosed with double dermal sinus tracts of the cervical and thoracic regions. We also present a summary of all previous reported cases of multiple dermal sinus tracts. RESULTS: Our patient was successfully treated surgically and is now 2 years status post her last procedure with a significant improvement in her neurologic function and normal muscle strength and tone for her age, and there was no recurrence of her symptoms. CONCLUSIONS: Early treatment with prophylactic surgery should be performed when possible, but removal of these lesions once symptoms have arisen can also lead to success, as in the case presented here. Complete excision and intradural exploration is required to excise the complete tract.

A prospective natural history study of nonoperatively managed Chiari I malformation: does follow-up MRI surveillance alter surgical decision making?

OBJECT Chiari malformation Type I (CM-I) in children is a common incidental finding. Resolution of cerebellar tonsil ectopia has been reported, but no studies have followed tonsil position over regular intervals throughout childhood. To better elucidate the clinical and radiological natural history of CM-I in children, the authors prospectively followed up children with nonoperatively managed CM-I for up to 7 years. METHODS The study included all children evaluated for CM-I over a period of 12 years for whom surgery was not initially recommended. The study excluded patients with associated conditions, including syringomyelia and hydrocephalus. For all patients, initial management was nonoperative, and follow-up management consisted of annual cervical spine or brain MRI and clinical examination. At each follow-up examination, the neurological examination findings, subjective symptoms, and the position of the cerebellar tonsils on MR images were recorded. An alteration in tonsillar descent of 2 mm or greater was considered a change. RESULTS Neurological examination findings did not change over the course of the study in the 52 children who met the inclusion criteria. Although radiological changes were common, no surgeries were performed solely because of radiological change. Overall, tonsil position on radiological images remained stable in 50% of patients, was reduced in 38%, and increased in 12%. Resolution was seen in 12% of patients. Radiological changes in tonsil position were seen during every year of follow-up. On average, in any given year, 24% of images showed some form of change in tonsil position. A total of 3 patients, for whom no changes were seen on MR images, ultimately underwent surgery for subjective clinical reasons. CONCLUSIONS CM-I in children is not a radiologically static entity but rather is a dynamic one. Radiological changes were seen throughout the 7 years of follow-up. A reduction in tonsillar descent was substantially more common than an increase. Radiological changes did not correlate with neurological examination finding changes, symptom development, or the need for future surgery. Follow-up imaging of asymptomatic children with CM-I did not alter treatment for any patient. It would be reasonable to follow these children with clinical examinations but without regular surveillance MRI.

Evidence for a role of the rare p.A152T variant in MAPT in increasing the risk for FTD-spectrum and Alzheimer's diseases.

Rare mutations in the gene encoding for tau (MAPT, microtubule-associated protein tau) cause frontotemporal dementia-spectrum (FTD-s) disorders, including FTD, progressive supranuclear palsy (PSP) and corticobasal syndrome, and a common extended haplotype spanning across the MAPT locus is associated with increased risk of PSP and Parkinson's disease. We identified a rare tau variant (p.A152T) in a patient with a clinical diagnosis of PSP and assessed its frequency in multiple independent series of patients with neurodegenerative conditions and controls, in a total of 15 369 subjects. Tau p.A152T significantly increases the risk for both FTD-s (n = 2139, OR = 3.0, CI: 1.6-5.6, P = 0.0005) and Alzheimer's disease (AD) (n = 3345, OR = 2.3, CI: 1.3-4.2, P = 0.004) compared with 9047 controls. Functionally, p.A152T (i) decreases the binding of tau to microtubules and therefore promotes microtubule assembly less efficiently; and (ii) reduces the tendency to form abnormal fibers. However, there is a pronounced increase in the formation of tau oligomers. Importantly, these findings suggest that other regions of the tau protein may be crucial in regulating normal function, as the p.A152 residue is distal to the domains considered responsible for microtubule interactions or aggregation. These data provide both the first genetic evidence and functional studies supporting the role of MAPT p.A152T as a rare risk factor for both FTD-s and AD and the concept that rare variants can increase the risk for relatively common, complex neurodegenerative diseases, but since no clear significance threshold for rare genetic variation has been established, some caution is warranted until the findings are further replicated.

The pediatric neurosurgical workforce: defining the current supply. Clinical article.

OBJECT: The purpose of this study was to determine a reliable estimate of the size, demographic, and practice characteristics of the current pediatric neurosurgical workforce. The authors also sought to differentiate pediatric from nonpediatric neurosurgical practitioners and compare the demographic and practice characteristics of these 2 groups. The term "pediatric practitioner" will be used in this study to describe a practitioner whose practice is > 75% pediatric patients in accordance with the American Board of Pediatric Neurological Surgery (ABPNS) requirements for board certification in pediatric neurosurgery. Those practitioners with < 75% pediatric patients in their practice will be designated as "nonpediatric practitioners." METHODS: The authors aggregated multiple databases of professional neurosurgical societies in an effort to identify pediatric neurosurgical practitioners. A 30-question survey was then administered to all identified practitioners, and responses were collected for 6 months. Primary analysis of pediatric versus nonpediatric practitioners was performed. Subgroup analyses of the characteristics of the pediatric practitioners were also performed to identify the effects of practitioner age, sex, and practice setting on survey responses. RESULTS: A total of 342 practitioners received the survey, and 267 responded (78.1% response rate); 158 pediatric practitioners and 92 nonpediatric practitioners were identified. Seventeen respondents were excluded from analysis. Pediatric practitioners were more likely to be women, ABPNS certified, have completed a pediatric fellowship, do fewer operative cases per year, have a more frequent call schedule, practice in a freestanding children's hospital, be in academic practice, and in need of recruiting additional faculty. Pediatric practitioners spent fewer hours per week in patient care, and were less likely to have a productivity-based salary or salary incentive based on relative value unit-production. Among pediatric practitioners, American Board of Neurological Surgery and ABPNS certification rates differed significantly among age groups, with older age groups being more likely to be certified by the American Board of Neurological Surgery and ABPNS. The rate of pediatric fellowship completion was significantly higher in the younger age groups. Anticipating retirement by age 65 was significantly more likely in the younger age groups, and hours spent per week spent in teaching and administrative duties were lower in the younger age groups. There were 27 female and 131 male pediatric practitioners. The women were more likely to have completed a pediatric fellowship and performed fewer operative cases per year than the men. Nonacademic pediatric practitioners were more likely to have a relative value unit-based salary incentive, be reimbursed for call coverage, and spend more hours per week in patient care than academic pediatric practitioners. Academic pediatric practitioners spent more hours per week in clinical research. CONCLUSIONS: The authors estimate that there are fewer than 200 pediatric neurosurgeons currently practicing in the United States. Current practice patterns unique to pediatrics may have important implications in recruiting and retaining the next generation of pediatric neurosurgeons.