Intracranial investigation of piriform cortex epilepsy during odor presentation.

The piriform cortex (PC) is part of the olfactory system, principally receiving input from the lateral olfactory tract and projecting to downstream components of the olfactory network, including the amygdala. Based on preclinical studies, PC is vulnerable to injury and can be easily kindled as an onset site for seizures. While the role of PC in human epilepsy has been studied indirectly and the subject of speculation, cases of demonstrated PC seizure onset from direct intracranial recording are rare. We present a pediatric patient with drug-resistant focal reflex epilepsy and right mesial temporal sclerosis with habitual seizures triggered by coconut aroma. The patient underwent stereoelectroencephalography with implantation of olfactory cortices including PC, through which we identified PC seizure onset, mapped high-frequency activity associated with presentation of olfactory stimuli and performance on cognitive tasks, and reproduced habitual seizures via cortical stimulation of PC. Coconut odor did not trigger seizures in our work with the patient. Surgical workup resulted in resection of the patient's right amygdala, PC, and mesial temporal pole, following which she has been seizure free for 20 months without functional decline in cognition or smell. Histological findings from resected tissue showed astrogliosis and subpial gliosis.

Endoscopic third ventriculostomy versus shunt for pediatric hydrocephalus: a systematic literature review and meta-analysis.

BACKGROUND: Optimized management of pediatric hydrocephalus remains the subject of debate. Ventriculoperitoneal shunt is largely considered the standard of care. However, the advancements and introduction of new cerebrospinal fluid (CSF) diversion approaches including the use of endoscopic third ventriculostomy (ETV) offer appealing alternatives that have been reported in numerous observational series. OBJECTIVE: To evaluate the comparative safety and efficacy of shunting and ETV in pediatric hydrocephalus cases. METHODS: This systematic literature review was performed according to the PRISMA guidelines. Eligible studies were identified through a search of PubMed (Medline) and Cochrane until October 2018. A random effects model meta-analysis was conducted and the I-square was used to assess heterogeneity. The ROBINS-1 tool and Cochrane tool were used to assess risk of bias in the observational and randomized studies, respectively. RESULTS: Fourteen studies including 8419 patients were identified. Patients in the ETV group had a statistically significant lower risk of infection compared to shunt (OR: 0.19; 95% CI: 0.07-0.53; I2: 0%). All-cause mortality (OR: 0.77; 95% CI: 0.35-1.68; I2: 0%), post-operative CSF leak (OR: 1.53; 95% CI: 0.37-6.31; I2: 0%), and reoperation rates were similar between the two study groups (OR: 0.72; 95% CI: 0.39-1.32; I2: 93.5%). Subgroup analyses for re-operation demonstrated that ETV in Africa (OR: 0.13; 95% CI: 0.03-0.48; I2: 0%) and Europe (OR: 0.39; 95% CI: 0.30-0.52; I2:1.4%) was associated with significantly lower odds of re-operation compared to shunt, but not in USA/Canada (OR: 1.49; 95% CI: 0.85-2.63; I2:86.2%). Meta-regression analyses of age and duration of follow-up did not affect re-operation rates. CONCLUSIONS: ETV was associated with a statistically significant lower risk of procedure-related infection compared to shunt. All-cause mortality, CSF leak, and re-operation rates were similar between the study groups. Subgroup analysis based on the geographic region showed that ETV is associated with statistically significant lower odds for re-operation in Europe and Africa, but not in USA/Canada. Future RCTs are needed to validate the results of this study and elucidate the cause of this heterogeneity.

Elbow flexion in neonatal brachial plexus palsy: a meta-analysis of graft versus transfer.

BACKGROUND: Functional elbow flexion recovery is one of the main goals of neonatal brachial plexus palsy (NBPP) reconstruction. The current neurosurgical treatment options include nerve grafting and nerve transfer. OBJECTIVE: The present study sought to examine the literature for comparison of functional elbow flexion recovery in NBPP following nerve grafting or nerve transfer. We conducted a systematic literature review and meta-analysis according to PRISMA guidelines. A search was conducted on Pubmed/Medline and Cochrane for eligible studies published until November of 2018. Odd ratios (OR) and 95% confidence intervals (CI) were calculated to compare functional elbow flexion outcomes between nerve graft and nerve transfer. A random effects model meta-analysis was conducted. A Medical Research Council (MRC) score ≥ 3 or Active Movement Scale (AMS) ≥ 5 was considered a functional recovery of elbow flexion. RESULTS: The present study included 194 patients from 1990 to 2015 across five observational trials. Only pediatric patients with obstetric brachial plexus injury were included. The mean patient age at surgery varied between studies from 5.7 months to 11.9 months and mean follow-up from 12 to 70 months. No complications or cases of donor site morbidity were reported. From the included studies, 118 patients were reported with MRC or AMS scoring usable for odd ratio comparison. Functional recovery occurred with nerve transfer in 95.2% of patients (n = 59/62) and with nerve grafting in 96.4% of patients (n = 54/56). Overall, the outcomes for elbow flexion between the groups appeared similar (OR 1.15, 95% CI 0.19-7.08, I2 2.9%). CONCLUSION: Comparing nerve grafting and nerve transfer for NBPP, there is no statistically significant difference in functional elbow flexion recovery.

Embryology of the craniocervical junction and posterior cranial fossa, part II: Embryogenesis of the hindbrain.

Although pathology of the hindbrain and its derivatives can have life altering effects on a patient, a comprehensive review on its embryology is difficult to find in the peer-reviewed medical literature. Therefore, this review article, using standard search engines, seemed timely. The embryology of the hindbrain is complex and relies on a unique timing of various neurovascular and bony elements. Derailment of these developmental processes can lead to a wide range of malformations such as the Chiari malformations. Therefore, a good working knowledge of this embryology as outlined in this review of the hindbrain is important for those treating patients with involvement of this region of the central nervous system. Clin. Anat. 31:488-500, 2018. © 2018 Wiley Periodicals, Inc.

Embryology of the craniocervical junction and posterior cranial fossa, part I: Development of the upper vertebrae and skull.

Although the embryology of the posterior cranial fossa can have life altering effects on a patient, a comprehensive review on this topic is difficult to find in the peer-reviewed medical literature. Therefore, this review article, using standard search engines, seemed timely. The embryology of the posterior cranial fossa is complex and relies on a unique timing of various neurovascular and bony elements. Derailment of these developmental processes can lead to a wide range of malformations such as the Chiari malformations. Therefore, a good working knowledge of this embryology as outlined in this review of its bony architecture is important for those treating patients with involvement of this region of the cranium. Clin. Anat. 31:466-487, 2018. © 2018 Wiley Periodicals, Inc.

The newer classifications of the chiari malformations with clarifications: An anatomical review.

In 1891, Hans Chiari described a group of congenital hindbrain anomalies, which were eventually named after him. He classified these malformations into three types (Chiari malformations I, II, and III), and four years later added the Chiari IV malformation. However, numerous reports across the literature do not seem to fit Chiari's original descriptions of these malformations, so researchers have been encouraged to propose new classifications to encompass these variants (e.g., Chiari 0, Chiari1.5, and Chiari 3.5 malformations). Moreover, there is a continued misunderstanding and misuse of the term "Chiari IV malformation." Therefore, the current review intended to describe anatomical, pathophysiological, and clinical aspects of the newer classifications with clarifications of the Chiari malformations. We reviewed available literature about Chiari malformations and their variants using "PubMed" and "Google Scholar." We also looked into the term Chiari IV, clarifying its original description and citing examples where the term has been used erroneously. References in the reviewed articles were searched manually. Variants of the originally described Chiari malformations are termed Chiari 0, Chiari 1.5, and Chiari 3.5. Each has distinct anatomical characteristics and some of these are extremely rare and incompatible with life (e.g. Chiari 3.5). Chiari IV malformation has been further clarified. Some physicians might be unfamiliar with the newer classifications of Chiari malformations because these conditions are rare or even unique. Furthermore, care is needed in using the term "Chiari IV malformation", which must be consistent with Chiari's original description, i.e. an occipital encephalocele containing supratentorial contents. Clin. Anat. 31:314-322, 2018. © 2018 Wiley Periodicals, Inc.

Quality Improvement in Concussion Care: Influence of Guideline-Based Education.

OBJECTIVE: To evaluate the potential impact of a concussion management education program on community-practicing pediatricians. STUDY DESIGN: We prospectively surveyed 210 pediatricians before and 18 months after participation in an evidence-based, concussion education program. Pediatricians were part of a network of 38 clinically integrated practices in metro-Atlanta. Participation was mandatory for at least 1 pediatrician in each practice. We assessed pediatricians' self-reported concussion knowledge, use of guidelines, and comfort level, as well as self-reported referral patterns for computed tomography (CT) and/or emergency department (ED) evaluation of children who sustained concussion. RESULTS: Based on responses from 120 pediatricians participating in the 2 surveys and intervention (response rate, 57.1%), the program had significant positive effects from pre- to postintervention on knowledge of concussions (-0.26 to 0.56 on -3 to +1 scale; P < .001), guideline use (0.73-.06 on 0-6 scale; P < .01), and comfort level in managing concussions (3.76-4.16 on 1-5 scale; P < .01). Posteducation, pediatricians were significantly less likely to self-report referral for CT (1.64-1.07; P < .001) and CT/ED (4.73-3.97; P < .01), but not ED referral alone (3.07-3.09; P = ns). CONCLUSIONS: Adoption of a multifaceted, evidence-based, education program translated into a positive modification of self-reported practice behavior for youth concussion case management. Given the surging demand for community-based youth concussion care, this program can serve as a model for improving the quality of pediatric concussion management.

Histological study of the occipital bone from patients with Chiari I malformation.

BACKGROUND: This study is focused on the histologic characteristics of occipital bone removed during Chiari I decompression in the hope of discovering unique features that may be related to the pathogenesis of this condition. METHODS: Ten consecutive pediatric patients with Chiari I malformation underwent standard posterior fossa decompression surgery. Bone that was removed from the posterior fossa was sent for histological examination. Bone from age-matched controls also underwent histological analysis. RESULTS: For all study and control specimens, bony samples were found to be made up of dense lamellar bone without marrow elements. In all aspects, histologically, the bone tissue had a normal appearance compared to control samples. CONCLUSIONS: Although many authors have mentioned that the occipital bone in patients with Chiari I malformation is abnormal on imaging or at operation (e.g., thinned, thickened), based on our study, there is no histological difference between the occipital bone removed at operation and controls.

Evolution of cerebellar tonsillar ischemia to cerebellar tonsillar cysts in the Chiari I malformation: radiological, surgical, and histological evidence.

BACKGROUND: Rare reports in the literature have documented the presence of a cyst at the tip of the cerebellar tonsil in patients with Chiari I malformation. The current study aimed to better elucidate these cysts and identify their etiology via a histological and radiologically analysis. PATIENTS AND METHODS: We prospectively reviewed all new Chiari I malformation (CM-I) patients who presented to our clinic during a 2-year period. This was a pediatric cohort made up of 340 children aged 3 to 18 years. Specifically, all patients were screened for ischemic or cystic lesions of the herniated cerebellar tonsils on MRI. RESULTS: Out of 340 patients, 2.9 % were found to have signal changes on MRI consistent with ischemia or cysts in the cerebellar tonsils. Of the 340 patients, 20 % underwent posterior fossa decompression. Of the 67 patients, cerebellar tonsillar ischemia was observed in 10.4 % and cerebellar tonsillar cysts were seen in 6 %. Four of the seven operative patients with cerebellar tonsillar ischemia and concomitant syringomyelia and three of these patients with tonsillar cysts concomitant syringomyelia and cerebellar tonsillar cysts underwent subpial dissection of some cerebellar tonsil to ensure that CSF egress from the fourth ventricle to the cervical subarachnoid space, and this transected tissue was also sent for histological analysis. Three of the four patients found to have intraoperative tonsillar cysts were noted to have tonsillar ischemic changes on preoperative imaging in this same region. For both ischemic and cystic cerebellar tonsils, histologically, the tissue demonstrated loss of Purkinje cells with concomitant Bergmann gliosis. The ischemic and cystic tissues were virtually the same, histologically. CONCLUSIONS: Based on our findings, cerebellar tonsillar ischemia and cysts in patients with CM-I can often be seen radiologically. Histologically, these ischemic and cystic tissues are the same. Moreover, we document patients where ischemic lesions progressed to cysts, radiologically. Taken together, cerebellar tonsillar ischemia and cysts are on a continuum and represent chronic compression of this herniated part of the cerebellum.

Do the cerebellar tonsils move during flexion and extension of the neck in patients with Chiari I malformation? A radiological study with clinical implications.

BACKGROUND: In the past, diagnosis of the Chiari I malformation has primarily been made on midsagittal MRI. We hypothesized that based on the frequent presentation of opisthotonos in patients with hindbrain hernia (primarily Chiari II malformation but sometimes Chiari I malformation) that the hyperextension might be a compensatory technique used by such patients to bring the cerebellar tonsils up out of the cervical spine. PATIENTS AND METHODS: This prospective study reviewed imaging of patients with Chiari I malformation who underwent flexion/extension MRI for evaluation of their hindbrain herniation. Age-matched controls were used for comparison. RESULTS: In general, there was elevation of the cerebellar tonsils with extension and increased descent with flexion of the cervical spine. In 72 % of patients, flexion of the neck resulted in descent of the cerebellar tonsils. In 64 % of patients, extension of the neck resulted in ascent of the cerebellar tonsils. In the 14 patients with an associated syrinx, 71 % were found to have caudal movement of the cerebellar tonsils with neck flexion, and only 43 % were observed to have any movement of the cerebellar tonsils in neck extension compared to patients without a syrinx where ascent of the tonsils was seen in only nine during neck extension. Two patients were observed to have the reverse finding of ascent of the cerebellar tonsils with neck flexion and descent of the cerebellar tonsils with neck extension. Five patients had no movement of the cerebellar tonsils in either flexion or extension of the neck, and one of these had a small syrinx. CONCLUSIONS: Although minimal and not in all patients, we observed elevation of the herniated cerebellar tonsils with extension of the cervical spine in patients with Chiari I malformation. This finding provides evidence as to why some patients with hindbrain herniation present with opisthotonos and supports earlier findings that CSF flow is reduced at the craniocervical junction in flexion in patients with Chiari I malformation.

Sagittal MRI often overestimates the degree of cerebellar tonsillar ectopia: a potential for misdiagnosis of the Chiari I malformation.

BACKGROUND: We hypothesized that by using coronal MRI, Chiari I malformation could be more precisely diagnosed, would provide simple anatomic landmarks, would provide information regarding asymmetry of hindbrain herniation, and would be a better method for analyzing the tonsillar herniation postoperatively when the opisthion has been removed. METHODS: Fifty consecutive pediatric patients diagnosed with Chiari I malformation had comparison between the measurements of their caudally descended cerebellar tonsils on midsagittal and coronal MRI images. RESULTS: On MRI coronal imaging, tonsillar asymmetry was found in 48 patients. Maximal left tonsillar descent was 20.9 mm, and maximal right tonsillar descent was 17.4 mm. On MRI sagittal imaging, tonsillar descent ranged from 5 to 27.4 mm. Fifty-eight % of patients had syringomyelia. Five patients (10 %) on coronal MRI were found to have both cerebellar tonsils that were less than 3 mm below the foramen magnum. However, all of these patients had greater than 3 mm of tonsillar ectopia on sagittal imaging. Nineteen patients (38 %) on coronal MRI were found to have one of the cerebellar tonsils that were less than 3 mm below the foramen magnum. Similarly, each of these had greater than 3 mm of tonsillar ecotpia as measured on midsagittal MRI. Also, based on these findings, Chiari I malformation is almost always an asymmetrical tonsillar ectopia. CONCLUSIONS: Sagittal MRI overestimates the degree of tonsillar ectopia in patients with Chiari I malformation. Misdiagnosis may occur if sagittal imaging alone is used. The cerebellar tonsils are paramedian structures, and this should be kept in mind when interpreting midline sagittal MRI.

Preventability of Pediatric 30-Day Readmissions following Ventricular Shunt Surgery.

OBJECTIVE: To compare the preventability of 30-day pediatric ventricular shunt readmissions using clinical and administrative data review. STUDY DESIGN: We performed a retrospective chart review of one hundred forty-seven 30-day ventricular shunt readmissions at a tertiary pediatric center from May 2009-April 2013 under 2 scenarios: scenario 1 considered all ventricular shunt failures preventable; and scenario 2 considered shunt failures with excellent/good catheter positioning and no contributing deficiencies in care not preventable. Three physician reviewers independently assessed readmissions to determine their preventability and whether deficiencies in care existed that contributed to the readmission. We also evaluated the degree of interrater agreement in adjudicating readmission preventability. RESULTS: Only 42% of 30-day readmissions following ventricular shunt procedures were preventable when considering all shunt failures as preventable. When classifying shunts with excellent/good proximal catheter position as not preventable, 21% of ventricular shunt readmissions were deemed preventable. Interrater agreement on readmission preventability was high (kappa 0.88). Deficiencies in care existed in 29 readmissions (20%), the largest category being physician related, but not all deficiencies contributed to a readmission. CONCLUSIONS: Significant discrepancy exists in the preventability adjudication of ventricular shunt readmissions between administrative and chart review. Although using administrative data has determined that a majority of readmissions following pediatric ventricular shunt procedures are preventable, our review suggests a significantly lower degree of preventability.

Relationship between pharyngitis and peri-odontoid pannus: A new etiology for some Chiari I malformations?

The pathophysiology underlying Chiari I malformations (CIMs) provides room for debate with several theories attempting to address this issue. We retrospectively reviewed many of our past patients with pediatric CIMs (specifically, those with peri-odontoid pannus), and present a hypothesis for the development of the malformation in some of said patients. Our experience with the pediatric CIM has shown that almost 1 in 20 patients who present with symptoms is found to have a peri-odontoid pannus. These masses ranged in size from 4 to 11 mm in diameter. Forty percent had a history of clinically significant pharyngitis or pharyngeal abscess. Pannus formation around the dens (odontoid) resulted in ventral compression of the craniocervical junction in each of these patients. Highlighting the hypermobility that causes such lesions, following fusion, the pannus and symptoms in several patients were diminished. Impairment of normal cerebrospinal fluid circulation out of the fourth ventricle and across the craniocervical junction appears to be a plausible endpoint in this discussion and a suitable explanation for some patients with CIM. Still, the mechanisms by which cerebrospinal fluid circulation is compromised may be variable and are not well understood. This is the first study dedicated to the evaluation of pannus formation in the CIM population. We hypothesize that pharyngeal inflammatory conditions contribute to the formation and progression of hindbrain herniation in a small subset of patients with CIMs.

Ventricular access device infection rate: a retrospective study and review of the literature.

PURPOSE: Ventricular access devices (VAD) are often used for treatment of posthemorrhagic hydrocephalus (PHH) in preterm infants. The reported rates of infection have varied and range from 0 to 22 %. The objective of our study is to present our VAD associated infection at our institution. METHODS: The charts for patients that had VADs inserted between May 1, 2009 and October 31, 2013 at a single institution (Children's Healthcare of Atlanta) were retrospectively reviewed. The number of VAD infections, defined as either cerebrospinal fluid (CSF)-positive cultures or wound complication, was recorded. Of patients that survived, the number of VAD to shunt conversions was also examined. The data from 15 previously published studies were pooled to determine overall VAD infection and VAD to shunt conversion rates. RESULTS: A total of 142 VADs were placed. There were 13 infections (9.2 %), 11 of which had CSF-positive cultures (7.7 %). There were two wound complications with negative CSF cultures. Six patients died after VAD placement for reasons unrelated to their VAD surgeries (4.2 %). In the remaining patients, there were 113 VAD to shunt conversions (83.1 %). Fifteen studies that reported VAD infections were analyzed; an overall infection rate of 7.0 % and VAD to shunt conversion rate of 79 % were calculated. CONCLUSIONS: While VAD is a valuable tool to treat PHH, it remains a procedure with an infection rate between 7.0 and 8.0 %. Close follow-up is needed to capture these adverse events as early as possible. Approximately 80 % of patients with PHH will require permanent CSF diversion.

Sonographic determination of normal Conus Medullaris level and ascent in early infancy.

INTRODUCTION: Controversial reports exist in the literature regarding both the spinal level of the conus medullaris (CM) in normal infants and the age at which the CM achieves its adult level. Autopsy studies have demonstrated ascent continuing into early infancy while more recent imaging study series' suggest the adult conus level is attained by the 40th postmenstrual week. METHODS: The authors conducted a retrospective review of 1,273 screening lumbar ultrasound studies performed over 5 years at a pediatric tertiary referral center. All patients were infants referred for initial imaging to rule out the presence of a tethered spinal cord. Referral sources included urban academic, urban private practice, and rural private practice pediatricians. After excluding studies lacking sufficient documentation (n = 90) and those reported as abnormal (n = 106), 1,077 remained for review. The CM level and patient age in days were recorded from each study. Statistical analysis was performed using unpaired t testing and ANOVA for continuous variables; chi-square for categorical data. RESULTS: The mean CM level for infants in group I (ages 0-30 days) was compared to those in groups II (31-60 days) and group III (61-100 days). Group I had a mean CM level of 0.125 and 0.2 vertebral segments lower than groups II and III (p = 0.0005 and <0.0001, respectively). ANOVA comparison of all three groups confirmed a rostral migratory trend (p < 0.001). The prevalence of CM level caudal to L2 in group I was 13 %, group II 11.4 %, and group III 4.7 %; also indicating a significant rostral trend (p = 0.004). CONCLUSIONS: Rostral migration of CM level continues through the first few months of post-natal life, albeit of limited extent. Documentation of continued ascent in a neonate may obviate the need for magnetic resonance imaging.

A comprehensive review with potential significance during skull base and neck operations, Part II: glossopharyngeal, vagus, accessory, and hypoglossal nerves and cervical spinal nerves 1-4.

Knowledge of the possible neural interconnections found between the lower cranial and upper cervical nerves may prove useful to surgeons who operate on the skull base and upper neck regions in order to avoid inadvertent traction or transection. We review the literature regarding the anatomy, function, and clinical implications of the complex neural networks formed by interconnections between the lower cranial and upper cervical nerves. A review of germane anatomic and clinical literature was performed. The review is organized into two parts. Part I discusses the anastomoses between the trigeminal, facial, and vestibulocochlear nerves or their branches and other nerve trunks or branches in the vicinity. Part II deals with the anastomoses between the glossopharyngeal, vagus, accessory and hypoglossal nerves and their branches or between these nerves and the first four cervical spinal nerves; the contribution of the autonomic nervous system to these neural plexuses is also briefly reviewed. Part II is presented in this article. Extensive and variable neural anastomoses exist between the lower cranial nerves and between the upper cervical nerves in such a way that these nerves with their extra-axial communications can be collectively considered a plexus.

Anastomoses between lower cranial and upper cervical nerves: a comprehensive review with potential significance during skull base and neck operations, part I: trigeminal, facial, and vestibulocochlear nerves.

Descriptions of the anatomy of the neural communications among the cranial nerves and their branches is lacking in the literature. Knowledge of the possible neural interconnections found among these nerves may prove useful to surgeons who operate in these regions to avoid inadvertent traction or transection. We review the literature regarding the anatomy, function, and clinical implications of the complex neural networks formed by interconnections among the lower cranial and upper cervical nerves. A review of germane anatomic and clinical literature was performed. The review is organized in two parts. Part I concerns the anastomoses between the trigeminal, facial, and vestibulocochlear nerves or their branches with any other nerve trunk or branch in the vicinity. Part II concerns the anastomoses among the glossopharyngeal, vagus, accessory and hypoglossal nerves and their branches or among these nerves and the first four cervical spinal nerves; the contribution of the autonomic nervous system to these neural plexuses is also briefly reviewed. Part I is presented in this article. An extensive anastomotic network exists among the lower cranial nerves. Knowledge of such neural intercommunications is important in diagnosing and treating patients with pathology of the skull base.

Preclinical Evaluation of a Novel Steerable Robotic Neuroendoscope Tool.

BACKGROUND AND OBJECTIVES: To improve the outcomes of minimally invasive, endoscopic, intracranial procedures, steerable robotic tools have been developed but still require thorough evaluation before use in a clinical setting. This paper compares a novel steerable robotic neuroendoscope tool against a standard rigid tool. METHODS: Seventeen participants, 8 nonmedical and 9 medical (neurosurgery residents and fellows), were recruited. The evaluation trial consisted of a task that was completed using either a rigid tool or the steerable tool, followed by the completion of a qualitative survey. Target reach time and tool movement volume (TMV) were recorded for each trial and analyzed. The tools were evaluated within a realistic phantom model of the brain. RESULTS: Preclinical evaluation of both tools showed that average target reach time for the steerable tool among medical personnel (15.0 seconds) was longer than that of the rigid tool (5.9 seconds). However, the average TMV for the steerable tool (0.178 cm 3 ) was much lower than that of the rigid tool (0.501 cm 3 ) for medical personnel, decreasing the TMV by 64.47%. CONCLUSION: The steerable tool required more training and practice in comparison with the standard rigid tool, but it decreased the overall endoscope movement volume, which is a source of parenchymal injury associated with endoscopic procedures.

Pediatric infectious aneurysms: individual patient pooled analysis on presentation, management and outcomes.

BACKGROUND: Infectious intracranial aneurysms (IIAs) are a rare sequel of systemic infection and occur most commonly in patients with infective endocarditis (IE). Despite the increasing use of non-invasive screening angiography in patients with IE, the incidence remains low, yielding limited data on the management of IIAs in pediatric populations. We performed a pooled analysis of all published series of pediatric patients with IIAs to study the disease landscape including presentation, management, and outcomes. METHODS: Data included in this study were pooled from published literature on IIAs between 1960 and 2023. Abstracts were selected for full review to include only manuscripts reporting at least one case of pediatric IIA (age 0-18 years). RESULTS: A total of 145 pediatric patients with 178 IIAs were included. Patients presented with rupture in 68% of cases, of which 36% had intraparenchymal hemorrhage and 39% had subarachnoid hemorrhage. Using multivariate logistic regression, independent predictors of rupture were posterior location (aOR 10, P=0.041) and history of IE (aOR 7.2, P=0.001). Primary medical management was successful in 82% of cases with unruptured aneurysms while, in those with ruptured IIAs, medical management was successful in 26% of cases. The 90-day mortality rate was 28%. Using multivariate logistic regression, ruptured IIAs (aOR 5.4, P<0.01) and failure of medical management (aOR 11.1, P<0.05) were independent predictors of 90-day mortality. CONCLUSION: Pediatric IIAs remain a rare complication of systemic or localized CNS infection in the pediatric population. Medical management of unruptured aneurysms is highly successful, while ruptured aneurysms have a remarkably high rate of failure of medical management and should be treated by early surgical or endovascular intervention when feasible.

The role of occipital condyle and atlas anomalies on occipital cervical fusion outcomes in Chiari malformation type I with syringomyelia: a study from the Park-Reeves Syringomyelia Research Consortium.

OBJECTIVE: Congenital anomalies of the atlanto-occipital articulation may be present in patients with Chiari malformation type I (CM-I). However, it is unclear how these anomalies affect the biomechanical stability of the craniovertebral junction (CVJ) and whether they are associated with an increased incidence of occipitocervical fusion (OCF) following posterior fossa decompression (PFD). The objective of this study was to determine the prevalence of condylar hypoplasia and atlas anomalies in children with CM-I and syringomyelia. The authors also investigated the predictive contribution of these anomalies to the occurrence of OCF following PFD (PFD+OCF). METHODS: The authors analyzed the prevalence of condylar hypoplasia and atlas arch anomalies for patients in the Park-Reeves Syringomyelia Research Consortium database who underwent PFD+OCF. Condylar hypoplasia was defined by an atlanto-occipital joint axis angle (AOJAA) ≥ 130°. Atlas assimilation and arch anomalies were identified on presurgical radiographic imaging. This PFD+OCF cohort was compared with a control cohort of patients who underwent PFD alone. The control group was matched to the PFD+OCF cohort according to age, sex, and duration of symptoms at a 2:1 ratio. RESULTS: Clinical features and radiographic atlanto-occipital joint parameters were compared between 19 patients in the PFD+OCF cohort and 38 patients in the PFD-only cohort. Demographic data were not significantly different between cohorts (p > 0.05). The mean AOJAA was significantly higher in the PFD+OCF group than in the PFD group (144° ± 12° vs 127° ± 6°, p < 0.0001). In the PFD+OCF group, atlas assimilation and atlas arch anomalies were identified in 10 (53%) and 5 (26%) patients, respectively. These anomalies were absent (n = 0) in the PFD group (p < 0.001). Multivariate regression analysis identified the following 3 CVJ radiographic variables that were predictive of OCF occurrence after PFD: AOJAA ≥ 130° (p = 0.01), clivoaxial angle < 125° (p = 0.02), and occipital condyle-C2 sagittal vertical alignment (C-C2SVA) ≥ 5 mm (p = 0.01). A predictive model based on these 3 factors accurately predicted OCF following PFD (C-statistic 0.95). CONCLUSIONS: The authors' results indicate that the occipital condyle-atlas joint complex might affect the biomechanical integrity of the CVJ in children with CM-I and syringomyelia. They describe the role of the AOJAA metric as an independent predictive factor for occurrence of OCF following PFD. Preoperative identification of these skeletal abnormalities may be used to guide surgical planning and treatment of patients with complex CM-I and coexistent osseous pathology.