Repeated complete atrioventricular block during remifentanil administration in a pediatric patient with brain tumor and acute hydrocephalus: a case report.

BACKGROUND: Remifentanil, an ultra-short-acting µ-opioid receptor agonist, is commonly used for anesthetic management due to excellent adjustability. Remifentanil is known to cause sinus bradycardia, however, because it has a direct negative chronotropic effect on the cardiac conduction system and there is an indirect negative chronotropic effect via the parasympathetic nervous system. CASE PRESENTATION: An 8-year-old Japanese boy was diagnosed with acute hydrocephalus due to a brain tumor in the fourth ventricle and underwent emergency surgery. Imaging examination showed brainstem compression. Endoscopic third ventriculostomy and ventriculoperitoneal shunt surgery were scheduled. Remifentanil was started during induction of general anesthesia, but electrocardiogram showed sinus bradycardia, then Wenckebach-type atrioventricular block, and then complete atrioventricular block. Remifentanil was immediately discontinued, and we administered atropine sulfate. Complete atrioventricular block was restored to sinus rhythm. When remifentanil was restarted, however, the electrocardiogram again showed sinus bradycardia, Wenckebach-type atrioventricular block, and then complete atrioventricular block. Remifentanil was again immediately discontinued, we administered adrenaline, and then complete atrioventricular block was restored to sinus rhythm. Fentanyl was used instead of remifentanil with continuous infusion of dopamine. There has since been no further occurrence of complete atrioventricular block. CONCLUSIONS: This is the first known case of complete atrioventricular block in a pediatric patient with increased intracranial pressure seemingly caused by administration of remifentanil.

Emotional Lability as a Symptom of Extra-axial Posterior Fossa Tumors: a Case-Control Review of Neuroanatomy and Patient-Reported Quality of Life.

Introduction Emotional lability (EL), the uncontrollable and unmotivated expression of emotion, is a rare and distressing symptom of brainstem compression. In published case reports, EL from an extra-axial posterior fossa tumor was alleviated by tumor resection. The primary aim herein was to radiographically establish the degree of compression from mass lesions onto brainstem structures. Secondarily, we compared changes in patient-reported quality of life (QOL) pre- and postoperatively. Methods A retrospective review of posterior fossa tumors treated between 2002 and 2018 at Vancouver General Hospital revealed 11 patients with confirmed EL. Each case was matched to three controls. A lateral brainstem compression scale characterized mass effect at the level of the medulla, pons, and midbrain in preoperative axial T2-weighted fluid-attenuated inversion recovery magnetic resonance imaging (FLAIR MRI) scans. Compression and clinical variables were compared between patient groups. Short Form-36 version 1 health surveys were retrospectively obtained from patient charts to compare pre- versus postoperative changes in survey scores between EL and control patients. Results EL symptoms ceased postoperatively for all EL patients. EL tumors exert greater compression onto the pons ( p = 0.03) and EL patients more commonly have cerebellar findings preoperatively ( p = 0.003). Patients with EL-causing tumors experienced greater improvement postoperatively in "Health Change" ( p = 0.05), which was maintained over time. Conclusion Findings suggest that compression onto the pons inhibits control over involuntary, stereotyped expression of emotion. This adds to evidence that EL may be attributed to cerebellum deafferentation from cortical and limbic structures through the basis pontis, leading to impaired modulation of emotional response. QOL results augment benefits of offering patients EL-alleviating tumor resection surgery.

Craniocervical instability in patients with Ehlers-Danlos syndromes: outcomes analysis following occipito-cervical fusion.

Craniocervical instability (CCI) is increasingly recognized in hereditary disorders of connective tissue and in some patients following suboccipital decompression for Chiari malformation (CMI) or low-lying cerebellar tonsils (LLCT). CCI is characterized by severe headache and neck pain, cervical medullary syndrome, lower cranial nerve deficits, myelopathy, and radiological metrics, for which occipital cervical fusion (OCF) has been advocated. We conducted a retrospective analysis of patients with CCI and Ehlers-Danlos syndrome (EDS) to determine whether the surgical outcomes supported the criteria by which patients were selected for OCF. Fifty-three consecutive subjects diagnosed with EDS, who presented with severe head and neck pain, lower cranial nerve deficits, cervical medullary syndrome, myelopathy, and radiologic findings of CCI, underwent open reduction, stabilization, and OCF. Thirty-two of these patients underwent suboccipital decompression for obstruction of cerebral spinal fluid flow. Questionnaire data and clinical findings were abstracted by a research nurse. Follow-up questionnaires were administered at 5-28 months (mean 15.1). The study group demonstrated significant improvement in headache and neck pain (p < 0.001), decreased use of pain medication (p < 0.0001), and improved Karnofsky Performance Status score (p < 0.001). Statistically significant improvement was also demonstrated for nausea, syncope (p < 0.001), speech difficulties, concentration, vertigo, dizziness, numbness, arm weakness, and fatigue (p = 0.001). The mental fatigue score and orthostatic grading score were improved (p < 0.01). There was no difference in pain improvement between patients with CMI/LLCT and those without. This outcomes analysis of patients with disabling CCI in the setting of EDS demonstrated significant benefits of OCF. The results support the reasonableness of the selection criteria for OCF. We advocate for a multi-center, prospective clinical trial of OCF in this population.

Combined transnasal/transoral endoscopic odontoid resection in pediatric patients: Otolaryngologic considerations to airway management, endoscopic exposure, and complication management.

BACKGROUND: Anterior brainstem compression from odontoid pathology can occur in patients with craniocervical disorders. Occasionally, odontoid resection is required. In adults, odontoid resection has evolved toward transnasal-only endoscopic techniques. Pediatric patients, however, pose special challenges due to abnormal anatomy and smaller working spaces. A combined transnasal/transoral endoscopic odontoid resection (TN/TO EOR) can overcome this limitation. We present a case series with emphasis on otolaryngologic considerations to airway management, endoscopic approach, and management of complications. METHODS: A single center, retrospective review of patients aged ≤18 undergoing combined transnasal/transoral endoscopic odontoid resection between 2011 and 2022 is presented. Clinical and surgical variables consisting of diagnosis, intubation approach, other airway procedures performed, symptoms, complications, blood loss, and time to extubation, return to oral feeding, and discharge were recorded. RESULTS: 19 patients aged 10.7 ± 4.3 (range: 3-18) were included. Diagnoses included congenital syndrome (n = 6), complex Chiari malformation (n = 11), and congenital syndrome with Chiari (n = 2). Patients commonly required indirect videolaryngoscopy for intubation, with or without fiberoptic endoscopic assistance. Seven underwent adenoidectomy, two underwent adenotonsillectomy, and one required adenoidectomy with midline palatal split and inferior turbinate outfracture. Four patients had undergone prior adenotonsillectomy. Presenting symptoms included extremity weakness (n = 9), dysphagia (n = 8), velopharyngeal insufficiency (n = 4), sleep disturbance (n = 5), and headaches (n = 8). Four patients had complications, including one re-operation for residual odontoid, one flap dehiscence, one cerebrospinal fluid (CSF) leak repaired primarily, and one complicated course including temporary spinal cord injury. Blood loss was 50 ± 43 cc (median 30). Time to extubation was 1.1 ± 2.1 days (median 0; one patient underwent tracheotomy for respiratory failure), time to oral intake was 2.9 ± 3.7 days (median 1), and time to discharge was 7.1 ± 7.5 days (median 4). CONCLUSIONS: A combined transnasal/transoral approach can be successfully used in pediatric patients to overcome difficult endoscopic access. Although complications exist, early extubation and return to oral intake occurs in the vast majority of cases. For pediatric TN/TO EOR, the otolaryngologist plays a key role in preoperative assessment, airway management, endoscopic exposure, and complication management.

Management of Ventral Brainstem Compression in Chiari Malformation Type I.

Craniovertebral junction (CVJ) abnormalities are associated with the Chiari malformation type I. These abnormalities may lead to ventral brainstem compression which can be reduced with traction and posterior reduction using instrumentation. In other cases, the irreducible CVJ pathology with persistent ventral brainstem compression requires ventral decompression. In all cases, a posterior extradural or extra-intradural decompression is required along with an occipitocervical fusion to maintain the reduced and realigned CVJ or stabilize the CVJ after a ventral decompression.

A rare complication of flow diverter: delayed migration causing aneurysm expansion and brainstem compression.

Flow-diverting stents (FD) are admitted therapeutic devices for challenging aneurysms. Delayed migrations of FD remain exceptional, particularly with brainstem compression. We report a case of delayed migration of pipeline embolization device (PED) responsible of medulla oblongata compression due to expansion of posterior inferior cerebellar artery (PICA) aneurysm. This is the first report of brainstem compression due to delayed migration of FD. Among the seven previously reported cases of FD delayed migration, two led to death. Our case illustrates the importance of technical issues of stenting and the role of surgery facing the clinical emergency of vascular compression of lower brainstem. We wanted to warn neurosurgeons of this rare and delayed complication, which likely could become less exceptional with the increase of indications and utilizations of FD.

A neonatal purely prepontine arachnoid cyst: a case report and review of the literature.

Purely prepontine arachnoid cysts not extending into the suprasellar region in neonates are rare. Herein, we report a purely prepontine arachnoid cyst in a neonate which caused central apnea and was successfully treated with microscopic cyst fenestration and C1 laminectomy.

Severe Basilar impression in osteogenesis imperfecta treated with halo gravity traction, occipitocervicothoracic fusion, foramen magnum and upper cervical decompression and expansive duroplasty: a technical note.

Osteogenesis imperfecta (OI) is a rare bone disease due to an abnormal synthesis of 1-type collagen. OI is frequently associated with basilar impression (BI), defined by the elevation of the clivus and floor of the posterior fossa with subsequent migration of the upper cervical spine and the odontoid peg into the base of the skull. Bone intrinsic fragility leading to fractures and deformity, brainstem compression and impaired CSF circulation at cranio-vertebral junction (CVJ) makes the management of these conditions particularly challenging. Different surgical strategies, including posterior fossa decompression with or without instrumentation, transoral or endonasal decompression with posterior occipito-cervical fusion, or halo gravity traction with posterior instrumentation have been reported, but evidence about best modalities treatment is still debated. In this technical note, we present a case of a 16-years-old patient, diagnosed with OI and BI, treated with halo traction, occipito-cervico-thoracic fixation, foramen magnum and upper cervical decompression, and expansive duroplasty. We focus on technical aspects, preoperative work up and postoperative follow up. We also discuss advantages and limitations of this strategy compared to other surgical techniques.

Tumor-Related and Patient-Related Variables Affecting Length of Hospital Stay Following Vestibular Schwannoma Microsurgery.

OBJECTIVE: Review a single institution's vestibular schwannoma (VS) microsurgery experience to determine (1) correlations between demographics, comorbidities, and/or surgical approach on hospital length of stay (LOS) and discharge disposition and (2) trends in surgical approach over time. METHODS: Retrospective case series from a multidisciplinary skull base program at a tertiary care, academic hospital. All adult (>18 years) patients undergoing primary microsurgery for VS between 2008 and 2018 were included. RESULTS: A total of 147 subjects were identified. Surgical approach was split between middle fossa (MF) (16%), retrosigmoid (RS) (35%), and translabyrinthine (TL) (49%) craniotomies. For the 8% of patients had other than routine (OTR) discharge. Mean LOS was significantly longer for patients undergoing RS than either MF or TL. Brainstem compression by the tumor was associated with longer LOS as were diagnoses of chronic obstructive pulmonary disease (COPD) and peripheral vascular disease (PVD). For all discharges, the 40 to 50- and 50 to 60-year-old subgroups had significantly shorter LOS than the 70-years-and-older patients. For the 92% of patients routinely discharged, there was a significantly shorter LOS in the 40 to 50-year-olds compared to the 70-years-and-older patients. There was a significant shift in surgical approach from RS to TL over the study period. CONCLUSION: Over 90% of VS microsurgery patients were routinely discharged with a median hospital LOS of 3.2 days, both of which are consistent with published data. There is an inverse relationship between age and LOS with patients older than 70 years having significantly longer LOS. Brainstem compression, COPD, PVD, and the RS approach negatively affect LOS. LEVEL OF EVIDENCE: 4.

Hypoglossal Nerve Schwannoma With Severe Brainstem Compression: Microsurgical Excision by Extreme Lateral Approach: 2-Dimensional Operative Video.

A 37-yr-old male presented with a history of left-sided tongue atrophy and fasciculations and weakness of upper limbs for 3 mo. Magnetic resonance imaging (MRI) revealed a large, partially cystic tumor with severe compression of the brainstem and spinal cord, with expansion and erosion of the hypoglossal canal. Computed tomography (CT) angiography showed the left vertebral artery to be anteriorly displaced by the tumor. A retrosigmoid craniotomy and craniectomy were performed followed by mastoidectomy with unroofing the posterior aspect of the sigmoid sinus. The foramen magnum was completely unroofed. The hypoglossal canal was exposed with a diamond drill and an ultrasonic bone curette, and a tumor was seen within the expanded canal. C1 lamina was removed partially in the lateral aspect, and the occipital condyle was partially removed. After opening the dura mater, the tumor was found to be stretching the eleventh cranial nerve. The tumor was debulked, and dissected from the cranial nerve fibers. The vertebral artery, anterior spinal artery, and other branches displaced by the tumor were carefully preserved. The tumor was removed from the hypoglossal canal with a curette. The patient recovered well, with the resolution of his upper limb weakness. Patient modified Rankin Scale was 1 at 6-mo follow-up. The postoperative MRI showed a small remnant inside the hypoglossal canal, and it was treated by radiosurgery. This 2-dimensional video demonstrates the technique of complete microsurgical removal of a complex tumor with preservation of cranial nerves and vertebral artery. Informed consent was obtained from the patient prior to the surgery, which included videotaping of the procedure and its distribution for educational purposes. Also, all relevant patient identifiers have been removed from the video and accompanying radiology slides.

Ventral Tonsillar Herniation Predicts Headaches in Adults With Chiari Malformation.

BACKGROUND: Radiographic characterization of Chiari malformation (CM) has historically focused on caudal tonsillar herniation (CH) below the foramen magnum. Previously, we published evidence linking ventral tonsillar herniation (VH) and medullary symptoms in very young children. We sought to extend that investigation by studying the radiographic and clinical significance of VH in adults diagnosed with CM. METHODS: We retrospectively reviewed adults with cerebellar ectopia who underwent posterior fossa decompression with or without duraplasty (PFD/D) at our institution. VH was defined as tonsils crossing a line bisecting the caudal medulla at the level of the foramen magnum on axial MRI. Degree of VH was measured as distance between this bisecting line and the ventral tip of the herniated tonsil. Dorsal brainstem compression was qualitatively determined by assessing for obliteration of CSF space between the dorsal brainstem and the tonsils. RESULTS: Out of 89 cases reviewed, 54 had some degree of VH. Compared with those without VH, the VH group was significantly older in age and more likely to also present with dorsal brainstem compression and headaches. No correlation was observed between degrees of CH and VH in the VH group. The degree of VH significantly decreased 3 months after PFD/D. CONCLUSIONS: VH is relatively common in CM patients and might be an important independent radiographic metric to evaluate and consider as part of the decision-making process, especially in those presenting with Chiari-like symptomatology referable to the medulla but who do not meet the traditional criteria of cerebellar ectopia greater than 5 mm.

Anesthetic Management for Resection of a Cerebellar Hemangioblastoma Leading to Brainstem Compression in a Patient With Von Hippel-Lindau Disease.

Von Hippel-Lindau (VHL) disease is a complex genetic syndrome characterized by multisystemic vascular neoplastic disorder. The affected population tends to develop tumors mainly involving the central nervous system, adrenal glands, pancreas, and kidneys. We describe anesthetic management for the resection of a cerebellar mass compressing the brainstem in a recently diagnosed 25-year-old female patient with a history of von Hippel-Lindau (VHL) syndrome. An uneventful occipital craniectomy for cerebellar tumor resection was performed under total intravenous anesthesia, without complications. The patient was discharged home on postoperative day five. This case depicts a situation in which a brainstem compressing lesion needs to be addressed urgently, and the pharmacological neuroprotective technique utilized for this procedure.

Occipital-Cervical Fusion and Ventral Decompression in the Surgical Management of Chiari-1 Malformation and Syringomyelia: Analysis of Data From the Park-Reeves Syringomyelia Research Consortium.

BACKGROUND: Occipital-cervical fusion (OCF) and ventral decompression (VD) may be used in the treatment of pediatric Chiari-1 malformation (CM-1) with syringomyelia (SM) as adjuncts to posterior fossa decompression (PFD) for complex craniovertebral junction pathology. OBJECTIVE: To examine factors influencing the use of OCF and OCF/VD in a multicenter cohort of pediatric CM-1 and SM subjects treated with PFD. METHODS: The Park-Reeves Syringomyelia Research Consortium registry was used to examine 637 subjects with cerebellar tonsillar ectopia ≥ 5 mm, syrinx diameter ≥ 3 mm, and at least 1 yr of follow-up after their index PFD. Comparisons were made between subjects who received PFD alone and those with PFD + OCF or PFD + OCF/VD. RESULTS: All 637 patients underwent PFD, 505 (79.2%) with and 132 (20.8%) without duraplasty. A total of 12 subjects went on to have OCF at some point in their management (PFD + OCF), whereas 4 had OCF and VD (PFD + OCF/VD). Of those with complete data, a history of platybasia (3/10, P = .011), Klippel-Feil (2/10, P = .015), and basilar invagination (3/12, P < .001) were increased within the OCF group, whereas only basilar invagination (1/4, P < .001) was increased in the OCF/VD group. Clivo-axial angle (CXA) was significantly lower for both OCF (128.8 ± 15.3°, P = .008) and OCF/VD (115.0 ± 11.6°, P = .025) groups when compared to PFD-only group (145.3 ± 12.7°). pB-C2 did not differ among groups. CONCLUSION: Although PFD alone is adequate for treating the vast majority of CM-1/SM patients, OCF or OCF/VD may be occasionally utilized. Cranial base and spine pathologies and CXA may provide insight into the need for OCF and/or OCF/VD.

Craniectomy size for subdural haematomas and the impact on brain shift and outcomes.

BACKGROUND: Midline shift in trauma relates to the severity of head injury. Large craniectomies are thought to help resolve brain shift but can be associated with higher rates of morbidity. This study explores the relationship between craniectomy size and subtemporal decompression for acute subdural haematomas with the resolution of brain compression and outcomes. No systematic study correlating these measures has been reported. METHOD: A retrospective study of all adult cases of acute subdural haematomas that presented to a Major Trauma Centre and underwent a primary decompressive craniectomy between June 2008 and August 2013. Data collection included patient demographics and presentation, imaging findings and outcomes. All imaging metrics were measured by two independent trained assessors. Compression was measured as midline shift, brainstem shift and cisternal effacement. RESULTS: Thirty-six patients with mean age of 36.1 ± 12.5 (range 16-62) were included, with a median follow-up of 23.5 months (range 2.2-109.6). The median craniectomy size was 88.7 cm2 and the median subtemporal decompression was 15.0 mm. There was significant post-operative resolution of shift as measured by midline shift, brainstem shift and cisternal effacement score (all p < .00001). There was no mortality, and the majority of patients made a good recovery with 82.8% having a Modified Rankin Score of 2 or less. There was no association between craniectomy size or subtemporal decompression and any markers of brain shift or outcome (all R2 < 0.05). CONCLUSIONS: This study suggests that there is no clear relationship between craniectomy size or extent of subtemporal decompression and resolution of brain shift or outcome. Further studies are needed to assess the relative efficacy of large craniectomies and the role of subtemporal decompression.

Adenoid cystic carcinoma of the parotid metastasising to the dura fifteen years post primary resection: A case report.

Adenoid cystic carcinoma (ACC), regardless of the primary site, is typically characterized by a long clinical course associated with a high rate of distant metastases. Intracranial metastasis of ACC is a very rare entity with only few reported cases in the literature. In this study, we report an unusual case of extra-axial intracranial metastasis of ACC in the dura. The primary parotid gland tumour was resected 15 y back. No recurrence had been detected before the occurrence of extra-axial metastasis. After surgical decompression, palliative radiotherapy was administered. To our knowledge, this is the longest interval for the development of metastases following excision of a parotid adenoid cystic carcinoma. This case can raise awareness across specialties that patients with adenoid cystic carcinoma are still at risk of developing metastases even following specialist discharge.

Neuroanatomic Correlates for the Neuropsychological Manifestations of Chiari Malformation Type I.

Chiari malformation comprises a spectrum of congenital malformations characterized by a herniation of the cerebellar tonsils below the foramen magnum. Chiari malformation type I (CM-I) is the most prevalent subtype seen in clinical practice. This condition variably compresses the cerebellum and medulla-spinal cord junction secondary to malformation of the posterior fossa. Most neurologists and neurosurgeons recognize the sensorimotor and lower brainstem manifestations that result in the clinical picture of CM-I. The effects of CM-I on cognitive functioning, however, and their impact on neuropsychological performance are poorly understood, despite having long been recognized. This article reviews neuropsychological deficits demonstrated by individuals with CM-I, and explores cerebellocortical neuroanatomic pathways to provide possible rationale for the neurocognitive impairments present in affected individuals.

Conditions associated with giant pituitary tumors at the time of surgery effecting outcome morbidity and mortality.

BACKGROUND: Surgical outcome prediction has assisted physicians in discussing surgical intervention or expectant management. While increasing pituitary tumor size would seem to be associated with increasing challenge of removal and associated complications, that relationship has not been borne in the literature. METHODS: We performed a retrospective review of a consecutive cohort of pituitary surgeries completed at our institution. Data included age at the time of surgery, presenting symptoms and Glasgow Coma scale (GCS), GCS at discharge or 7 days postoperatively, GCS at 6 months, adenoma size, imaging characteristics of the tumor and brain before resection, postoperative complications, the presence of preoperative hydrocephalus, brainstem compression, and patient mortality. RESULTS: Patients with giant adenomas were more likely to present with a cranial nerve palsy (P = 0.019), altered mental status (P = 0.0001), hydrocephalus (P = 0.002), and mass effect on the brainstem (P = 0.020). Patients who experienced a postoperative decline in mental status were more likely to present with altered mental (P = 0.006), had an increased prevalence of mass effect on the brainstem (P = 0.005), and were more likely to have either an ischemic stroke (P = 0.0001) and vasospasms or new intraparenchymal hemorrhage (P = 0.013). CONCLUSION: The results of this study demonstrate that postoperative mental status declines after pituitary adenoma resection can be directly related to brainstem compression and further surgical irritation of the surrounding vasculature. The intraoperative irritation can be multifactorial and may result as the decompressed brain structures assume their anatomical position.

Upper Cervical Subluxation and Cervicomedullary Junction Compression in Patients with Rheumatoid Arthritis.

OBJECTIVE: Rheumatoid arthritis (RA) is known to involve the cervical spine up to 86%. It often causes cervical instability like atlantoaxial subluxation (AAS), subaxial subluxation, and vertical subluxation (VS). In order to find the relation between RA and cord compression, we will evaluate the characteristics and risk factors of basilar invagination (BI) and cervicomedullary junction (CMJ) compression. METHODS: From January 2007 to May 2015, 12667 patients administrated to Hanyang University Medical Center. Four thousand three hundred eighty-six patients took cervical X-ray and 250 patients took cervical computed tomography or magnetic resonance imaging. Radiologic parameters, medication records were obtained from 242 patients. Multivariate logistic regression analysis was performed with correlation of CMJ compression, basin-dental interval (BDI), basin-posterior axial line interval (BAI), pannus formation, BI, and AAS. RESULTS: In the point of CMJ compression, atlantodental interval (ADI), posterior-atlantodental interval, BAI, AAS, and BI are relatively highly correlated. Patients with BI have 82 times strong possibility of radiologic confirmed CMJ compression, while AAS has 6-fold and pannus formation has the 3-fold possibility. Compared to the low incidence of BI, AAS and pannus formation have more proportion in CMJ compression. Furthermore, wrist joint erosion was correlated with VS and AAS. CONCLUSION: BI has a very strong possibility of CMJ compression, while AAS and pannus formation have a high proportion in CMJ compression. Hence bilateral wrist joint erosion can be used as an indicator for the timing of screening test for cervical involvement. We suggest the early recommendation of cervical spine examination for the diagnosis of cervical involvement in order to prevent morbidity and mortality.

A Dual Approach for the Management of Complex Craniovertebral Junction Abnormalities: Endoscopic Endonasal Odontoidectomy and Posterior Decompression with Fusion.

BACKGROUND: Ventral brainstem compression secondary to complex craniovertebral junction abnormality is an infrequent cause of neurologic deterioration in pediatric patients. However, in cases of symptomatic, irreducible ventral compression, 360° decompression of the brainstem supported by posterior stabilization may provide the best opportunity for improvement in symptoms. More recently, the endoscopic endonasal corridor has been proposed as an alternative method of odontoidectomy associated with less morbidity. We report the largest single case series of pediatric patients using this dual-intervention surgical technique. The purpose of this study was to evaluate the surgical outcomes of pediatric patients who underwent posterior occipitocervical decompression and instrumentation followed by endoscopic endonasal odontoidectomy performed to relieve neurologic impingement involving the ventral brainstem and craniocervical junction. METHODS: Between January 2011 and February 2017, 7 patients underwent posterior instrumented fusion followed by endonasal endoscopic odontoidectomy at our unit. Standardized clinical and radiological parameters were assessed before and after surgery. A univariate analysis was performed to assess clinical and radiologic improvement after surgery. RESULTS: A total of 14 operations were performed on 7 pediatric patients. One patient had Ehlers-Danlos syndrome, 1 patient had a Chiari 1 malformation, and the remaining 5 patients had Chiari 1.5 malformations. Average extubation day was postoperative day 0.9. Average day of initiation of postoperative feeds was postoperative day 1.0. CONCLUSIONS: The combined endoscopic endonasal odontoidectomy and posterior decompression and fusion for complex craniovertebral compression is a safe and effective procedure that appears to be well tolerated in the pediatric population.

Establishing reproducible predictors of cerebellar mutism syndrome based on pre-operative imaging.

PURPOSE: To establish some explicit, feasible, and reproducible predictors for CMS. MATERIALS AND METHODS: This study was a retrospective case study. Data were obtained from 82 patients with medulloblastoma at a single center, Beijing Tiantan Hospital. Based on medical records, we created two independent samples: the CMS group comprising 23 patients and the non-CMS group comprising 23 patients. Pre-operative imaging was studied by performing quantitative assessments of specific indicators. RESULTS: The CMS group showed greater differences in pre-operative imaging data with the non-CMS group. The Aaxi/daxi ratio in pre-operative MR imaging captured in the axial plane was used to quantify the compression of the cerebellum and brainstem, and significant differences were observed between the CMS group and non-CMS group (p = 0.0002). In the sagittal plane, Dsag*dsag was used to quantify the area of the tumor that invaded the brainstem, and significant differences were observed between the two groups (p = 0.0003). In the coronal plane, Acor/dcor was used to quantify the compression of the upper functional brain region, and significant differences were noted between the two groups (p = 0.0219). Additionally, Evans' index was introduced to quantify the degree of hydrocephalus. The CMS group tended to show an increased Evans' index (p = 0.0027). CONCLUSION: Based on pre-operative imaging data, some reproducible predictors, such as Aaxi/daxi, Dsag*dsag, Acor/dcor, and Evans' index, were established.