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INTRODUCTION: The fibrous posterior atlanto-occipital membrane (PAOM) at the craniocervical junction is typically removed during decompression surgery for Chiari malformation type I (CM-I); however, its importance and ultrastructural architecture have not been investigated in children. We hypothesized that there are structural differences in the PAOM of patients with CM-I and those without. METHODS: In this prospective study, blinded pathological analysis was performed on PAOM specimens from children who had surgery for CM-I and children who had surgery for posterior fossa tumors (controls). Clinical and radiographic data were collected. Statistical analysis included comparisons between the CM-I and control cohorts and correlations with imaging measures. RESULTS: A total of 35 children (mean age at surgery 10.7 years; 94.3% white) with viable specimens for evaluation were enrolled: 24 with CM-I and 11 controls. There were no statistical demographic differences between the two cohorts. Four children had a family history of CM-I and five had a syndromic condition. The cohorts had similar measurements of tonsillar descent, syringomyelia, basion to C2, and condylar-to-C2 vertical axis (all p>0.05). The clival-axial angle was lower in patients with CM-I (138.1 vs. 149.3 degrees, p = 0.016). Morphologically, the PAOM demonstrated statistically higher proportions of disorganized architecture in patients with CM-I (75.0% vs. 36.4%, p = 0.012). There were no differences in PAOM fat, elastin, or collagen percentages overall and no differences in imaging or ultrastructural findings between male and female patients. Posterior fossa volume was lower in children with CM-I (163,234 mm3 vs. 218,305 mm3, p

Statement of the Problem: Determination of remaining growth potential of patients is the most important factor in orthodontic treatment.Purpose: This study aimed to assess the correlation of clivus length and angle with age, gender, sagittal growth pattern of the jaws, and skeletal maturation using lateral cephalometry.Materials and Method: This cross-sectional study was conducted on 390 lateral cephalograms (Vatech, paX-i3D Green, South Korea) of patients aged 6 to 25 years. The patients were assigned to three groups of skeletal class I, II, III (n=130) with equal gender distribution. The clivus length and angle, Welcher angle, maxillary and mandibular effective length, sella turcica to Nasion (SN), and the angles between SN and point A (SNA), between SN and point B (SNB), and between NA and NB (ANB )were measured. Correlations of variables with age and gender, and cervical vertebral maturation stage (CVMS) were analyzed using the Pearson and Spearman’s correlation tests, independent t-test, and one-way ANOVA at 0.05 level of significance.Results: Clivus length had a significant correlation with SNA (r= 0.103, p= 0.042), SNB (r= 0.108, p= 0.033), maxillary (r= 0.547, p< 0.001) and mandibular (r= 0.589, p< 0.001) effective lengths, SN length (r= 0.586, p< 0.001), and CVMS (r= 0.697, p< 0.001). Clivus angle had a significant correlation with SNA (r= 0.105, p= 0.039), SNB (r= 0.155, p= 0.002), maxillary (r= 0.507, p< 0.001) and mandibular (r= 0.596, p= 0.001) effective lengths, SN length (r= 0.566, p< 0.001), and CVMS (r= 0.699, p< 0.001). The mean clivus length (p= 0.006) and angle (p= 0.002) were significantly higher in males, and had a significant correlation with age (r= 0.636 and r= 0.718, p< 0.001). The mean clivus length and angle were not significantly different in class I, II, III (p> 0.05).Conclusion: All parameters were greater in males, and increased with age (except Welcher angle). Clivus length and angle had significant correlations with position of both jaws but not with sagittal relationship.

Statement of the Problem: Determination of remaining growth potential of patients is the most important factor in orthodontic treatment. Purpose: This study aimed to assess the correlation of clivus length and angle with age, gender, sagittal growth pattern of the jaws, and skeletal maturation using lateral cephalometry. Materials and Method: This cross-sectional study was conducted on 390 lateral cephalograms (Vatech, paX-i3D Green, South Korea) of patients aged 6 to 25 years. The patients were assigned to three groups of skeletal class I, II, III (n=130) with equal gender distribution. The clivus length and angle, Welcher angle, maxillary and mandibular effective length, sella turcica to Nasion (SN), and the angles between SN and point A (SNA), between SN and point B (SNB), and between NA and NB (ANB )were measured. Correlations of variables with age and gender, and cervical vertebral maturation stage (CVMS) were analyzed using the Pearson and Spearman’s correlation tests, independent t-test, and one-way ANOVA at 0.05 level of significance. Results: Clivus length had a significant correlation with SNA (r= 0.103, p= 0.042), SNB (r= 0.108, p= 0.033), maxillary (r= 0.547, p< 0.001) and mandibular (r= 0.589, p< 0.001) effective lengths, SN length (r= 0.586, p< 0.001), and CVMS (r= 0.697, p< 0.001). Clivus angle had a significant correlation with SNA (r= 0.105, p= 0.039), SNB (r= 0.155, p= 0.002), maxillary (r= 0.507, p< 0.001) and mandibular (r= 0.596, p= 0.001) effective lengths, SN length (r= 0.566, p< 0.001), and CVMS (r= 0.699, p< 0.001). The mean clivus length (p= 0.006) and angle (p= 0.002) were significantly higher in males, and had a significant correlation with age (r= 0.636 and r= 0.718, p< 0.001). The mean clivus length and angle were not significantly different in class I, II, III (p> 0.05). Conclusion: All parameters were greater in males, and increased with age (except Welcher angle). Clivus length and angle had significant correlations with position of both jaws but not with sagittal relationship. [ABSTRACT FROM AUTHOR]

Cerebellar mutism syndrome (CMS) is a prevalent postoperative complication in children following posterior fossa tumor surgery, with a significantly variable incidence rate across different pathological types of tumors, being highest in medulloblastoma (24%-30%). The pathogenesis of CMS remains to be elucidated, but it is believed to be associated with damage to the cerebellocerebral circuits, harm to the fastigial nuclei of cerebellum and periaqueductal gray matter of the midbrain, and alterations in brain networks. Predictive models constructed based on the risk factors of CMS have not yet demonstrated the anticipated stability and have not been widely adopted in clinical settings. Pharmacological treatments are primarily based on clinical experience, yet their efficacy requires further validation, hence there is currently a lack of a clearly effective treatment method; non-pharmacological treatments, such as physical therapy, occupational therapy, and speech therapy, have shown some effect on improving the long - term quality of life. This review summarizes the pathogenesis and therapeutic advances of CMS, and future research should be dedicated to exploring the pathophysiological mechanisms of CMS, constructing more accurate predictive models, devising personalized treatment plans, and enhancing the long-term prognosis for children. [ABSTRACT FROM AUTHOR]

Objective To investigate the imaging diagnosis and differential diagnosis methods for common tumors in the posterior fossa of children, and to propose a flow chart for the diagnosis of common tumors in the posterior fossa of children based on the limited diffusion of DWI according to the idea localization diagnosis followed by qualitative diagnosis. Methods A total of 118 pediatric patients with posterior fossa tumors who underwent surgical resection in Huashan Hospital, Fudan University from January 2021 to January 2024 were enrolled, and all of them underwent head CT and MRI examinations, and preoperative localization diagnosis and qualitative diagnosis were carried out accordingly. Then, based on whether DWI was diffusion limited, a flow chart for the diagnosis of common tumors in the posterior fossa of children was proposed. Results A total of 118 children with posterior fossa tumors were localization and qualitatively diagnosed, including 41 cases of fourth ventricular tumors, including medulloblastoma (27 cases), pilocytic astrocytoma (7 cases), ependymoma (5 cases), choroid plexus papilloma (one case), and rosette-forming glioneuronal tumor (RGNT, one case). There were 38 cases of brainstem tumors, including 24 cases of diffuse midline glioma, H3 K27 - altered, 5 cases of pilocytic astrocytoma, 3 cases of cavernous hemangioma, 2 cases of pediatric-type diffuse high-grade glioma (prone to diffuse midline glioma, H3 wild type), 2 cases of ganglio glioma, one case of atypical teratoid/rhabdoid tumor (AT/RT), and one case of pediatric - type diffuse low - grade glioma. There were 9 cases of cerebellopontine angle (CPA) tumors, including 3 cases of pilocytic astrocytoma, 2 cases of cholesteatoma, one case of medulloblastoma, one case of diffuse midline glioma, H3 K27-altered, one case of pilomyxoid astrocytoma, and one case of Ewing sarcoma. There were 30 cases of cerebellar tumors, including 15 cases of pilocytic astrocytoma, 7 cases of medulloblastoma, 2 cases of cavernous hemangioma, one case of ependymoma, one case of pediatric-type diffuse low-grade glioma, one case of pediatric-type diffuse high- grade glioma (prone to diffuse midline glioma, H3 wild type), one case of dysembryoplastic neuroepithelial tumor (DNT), one case of hamartoma, and one case of extrarenal rhabdomyomatoid tumor cerebellar metastases. Localization diagnosis, the accuracy of preoperative CT was 93.22% (110/118), while the accuracy of preoperative MRI was 100% (118/118). Qualitative diagnosis, 74 cases (62.71%) had accurate qualitative diagnosis, 23 cases (19.49%) had general diagnosis, and 21 cases (17.80%) had wrong diagnosis. The imaging differential diagnosis of posterior fossa tumors in children focuses on medulloblastoma, pilocytic astrocytoma, ependymoma, and diffuse midline glioma, H3 K27-altered. The incidence of limited diffusion of DWI in medulloblastoma, pilocytic astrocytoma and ependymoma outside the brainstem was 100% (35/35), 4% (1/25) and 5/6, and the difference among the three tumors was statistically significant (Z = - 5.601, P = 0.000). The incidence of limited diffusion of DWI in diffuse midline glioma, H3 K27- altered and pilocytic astrocytoma in the brainstem was 79.17% (19/24) and 1/5, and the difference between the two tumors was also statistically significant (Fisher's exact possibility: P = 0.038). Conclusions The early diagnosis of posterior fossa tumors in children is difficult, and DWI is an important basis for differential diagnosis. [ABSTRACT FROM AUTHOR]

BACKGROUND AND PURPOSE: The traditionally described Dandy-Walker malformation comprises a range of cerebellar and posterior fossa abnormalities with variable clinical severity. We aimed to establish updated imaging criteria for Dandy-Walker malformation on the basis of cerebellar development. MATERIALS AND METHODS: In this multicenter study, retrospective MR imaging examinations from fetuses and children previously diagnosed with Dandy-Walker malformation or vermian hypoplasia were re-evaluated, using the choroid plexus/tela choroidea location and the fastigial recess shape to differentiate Dandy-Walker malformation from vermian hypoplasia. Multiple additional measures of the posterior fossa and cerebellum were also obtained and compared between Dandy-Walker malformation and other diagnoses. RESULTS: Four hundred forty-six examinations were analyzed (174 fetal and 272 postnatal). The most common diagnoses were Dandy-Walker malformation (78%), vermian hypoplasia (14%), vermian hypoplasia with Blake pouch cyst (9%), and Blake pouch cyst (4%). Most measures were significant differentiators of Dandy-Walker malformation from non-Dandy-Walker malformation both pre- and postnatally (P  .3). The superior posterior fossa angle, torcular location, and vermian height differentiated groups postnatally (P  .07). CONCLUSIONS: As confirmed by objective measures, the modern Dandy-Walker malformation phenotype is best defined by inferior predominant vermian hypoplasia, an enlarged tegmentovermian angle, inferolateral displacement of the tela choroidea/choroid plexus, an obtuse fastigial recess, and an unpaired caudal lobule. Posterior fossa size and torcular location should be eliminated from the diagnostic criteria. This refined phenotype may help guide future study of the numerous etiologies and varied clinical outcomes.

The skull base provides a platform for supporting the brain while serving as a conduit for major neurovascular structures. In addition to malignant lesions originating in the skull base, there are many benign entities and developmental variants that may simulate disease. Therefore, a basic understanding of the relevant embryology is essential. Lesions centered in the skull base can extend to the adjacent intracranial and extracranial compartments; conversely, the skull base can be secondarily involved by primary extracranial and intracranial disease. CT and MRI are the mainstay imaging methods and are complementary in the evaluation of skull base lesions. Advances in cross-sectional imaging have been crucial in the management of patients with skull base pathology, as this represents a complex anatomical area that is hidden from direct clinical exam. Furthermore, the clinician must rely on imaging studies for therapy planning and to monitor treatment response. It is crucial to have a thorough understanding of skull base anatomy and its various pathologies, as well as to recognize the appearance of treatment-related changes. In this review, we aim to describe skull base tumors and tumor-like lesions in an anatomical compartmental approach and present imaging methods that aid in diagnosis, management, and follow-up.

The skull base provides a platform for supporting the brain while serving as a conduit for major neurovascular structures. In addition to malignant lesions originating in the skull base, there are many benign entities and developmental variants that may simulate disease. Therefore, a basic understanding of the relevant embryology is essential. Lesions centered in the skull base can extend to the adjacent intracranial and extracranial compartments; conversely, the skull base can be secondarily involved by primary extracranial and intracranial disease. CT and MRI are the mainstay imaging methods and are complementary in the evaluation of skull base lesions. Advances in cross-sectional imaging have been crucial in the management of patients with skull base pathology, as this represents a complex anatomical area that is hidden from direct clinical exam. Furthermore, the clinician must rely on imaging studies for therapy planning and to monitor treatment response. It is crucial to have a thorough understanding of skull base anatomy and its various pathologies, as well as to recognize the appearance of treatment-related changes. In this review, we aim to describe skull base tumors and tumor-like lesions in an anatomical compartmental approach and present imaging methods that aid in diagnosis, management, and follow-up. [ABSTRACT FROM AUTHOR]

BACKGROUND:Open transcranial approaches to the anterior skull base remain an integral component of current skull base practice. Evolution of these and other techniques has resulted in revisions of standard, tried-and-true methods in attempts to improve patient outcomes and cosmesis, while still providing the best combination of surgical exposure and ergonomics. OBJECTIVE:To describe a modified approach for midline tumors of the anterior skull base. METHODS:We describe the anatomy and techniques of a modified extended bifrontal craniotomy for anterior skull base tumors. Case examples and a postoperative 3-dimensional computed tomographic reconstruction of the craniotomy are provided. RESULTS:The technique has been employed with success in 3 tuberculum sellae meningiomas where the anterior limit of the tumor is several centimeters back from the inner table of the frontal bone. The mean distance from the tumor to inner table was 2.8 cm (range 1.3-3.8 cm). Mean tumor dimensions were 3.0 cm (transverse), 3.5 cm (anterior-posterior), and 2.2 cm (craniocaudal). Average operative time was 557 min. No cases had new T2/fluid-attenuated inversion recovery magnetic resonance imaging signal of the inferior frontal lobe to indicate retraction injury. CONCLUSION:The tailored extended bifrontal craniotomy for anterior skull base tumors provides adequate access to the anterior cranial fossa and has replaced our standard extended bifrontal approach. Keeping the osteotomy cut lines outside of the orbit reduces orbital swelling and mechanical disruption of conjugate eye movements in the early postoperative period, while allowing for minimal frontal lobe retraction and providing sufficient surgical exposure along the anterior skull base.

OBJECTIVE Chordomas are rare malignant tumors thought to arise from remnants of the notochord. They can be located anywhere along the axial skeleton but are most commonly found in the clival and sacrococcygeal regions, where the notochord regresses during fetal development. Chordomas are resistant to many current therapies, leaving surgery as the primary method of treatment. Cancer cell lines have been useful for developing new cancer treatments in a laboratory setting that can then be transferred to the clinic, but there are only 4 validated chordoma cell lines available. The objective of this work was to establish chordoma cell lines from surgical tissue in order to expand the library of lines available for laboratory research. METHODS Chordoma tissue from the clivus was processed and sorted by flow cytometry to obtain an isolated population of chordoma cells. These cells were grown in culture and expanded until enough doublings to consider the line established. Identification of a chordoma cell line was made with known markers for chordoma, and the line was observed for ALDH (aldehyde dehydrogenase) subpopulations and tested in serum-free growth conditions as well as in vivo. RESULTS A fifth chordoma cell line, UM-Chor1, was successfully established. This is the first chordoma cell line originating from the clivus. Validation was confirmed by phenotype and positivity for the chordoma markers CD24 and brachyury. The authors also attempted to identify an ALDHhigh cell population in UM-Chor1, UCH1, and UCH2 but did not detect a distinct population. UM-Chor1 cells were able to form spheroids in serum-free culture, were successfully transduced with luciferase, and could be injected parasacrally and grown in NOD/SCID mice. CONCLUSIONS The availability of this novel clival chordoma cell line for in vitro and in vivo research provides an opportunity for developments in treatment against the disease.

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Aim of the study: To show our postoperative cerebrospinal fluid (CSF) leak rate for patients who underwent endoscopic endonasal approach for anterior and middle fossa pathology. Materials and methods: Retrospective analysis of 164 patients with anterior and middle fossa pathology, operated via endoscopic endonasal approach between 2018 and 2021, with minimal postoperative follow-up of three months. Results: We managed to reduce the postoperative CSF leak rate from 12.4% (2014–2018) to 2.4%. The CSF leaks were as following: grade 0, 0%, grade 1, 3.85%, grade 2, 8.3%, grade 3 6.9%. Conclusion: A planned graded approach in managing skull base defects reduces the postoperative CSF leak rate. Our CSF leak rate of 2.4% is comparable with international standards for endoscopic endonasal approach.

Background and purposeThe 2016 World Health Organization Classification of Tumors of the Central Nervous System includes "diffuse midline glioma with histone H3 K27M mutation" as a new diagnostic entity. We describe the MR imaging characteristics of this new tumor entity in pediatric patients.Materials and methodsWe retrospectively reviewed imaging features of pediatric patients with midline gliomas with or without the histone H3 K27 mutation. We evaluated the imaging features of these tumors on the basis of location, enhancement pattern, and necrosis.ResultsAmong 33 patients with diffuse midline gliomas, histone H3 K27M mutation was present in 24 patients (72.7%) and absent in 9 (27.3%). Of the tumors, 27.3% (n = 9) were located in the thalamus; 42.4% (n = 14), in the pons; 15% (n = 5), within the vermis/fourth ventricle; and 6% (n = 2), in the spinal cord. The radiographic features of diffuse midline gliomas with histone H3 K27M mutation were highly variable, ranging from expansile masses without enhancement or necrosis with large areas of surrounding infiltrative growth to peripherally enhancing masses with central necrosis with significant mass effect but little surrounding T2/FLAIR hyperintensity. When we compared diffuse midline gliomas on the basis of the presence or absence of histone H3 K27M mutation, there was no significant correlation between enhancement or border characteristics, infiltrative appearance, or presence of edema.ConclusionsWe describe, for the first time, the MR imaging features of pediatric diffuse midline gliomas with histone H3 K27M mutation. Similar to the heterogeneous histologic features among these tumors, they also have a diverse imaging appearance without distinguishing features from histone H3 wildtype diffuse gliomas.

Background: Pituitary gland dysfunction might be predicted by examining the alteration of Sella turcica during the routine radiological examination of lateral cephalogram. Aim: The study aimed to analyze the variation in size and shape of sella turcica according to age and gender on lateral cephalogram among the people in the south zone of Chennai city. Materials and Method: A series of lateral cephalogram images from 200 patients comprising 94 males and 106 females were collected retrospectively from archives in the database. The shape and size of sella turcica were measured digitally. Statistical analysis was done using the Chi-square test and unpaired sample t-test. Results: The frequency of distribution of shapes of sella turcica among the people in Chennai city was 46% normal followed by 15.5% irregular dorsum sellae, 14.5% pyramidal shape, 11.5% bridging, 7% oblique anterior wall, 5.5% double contour. The length and depth of Sella turcica was greater in males when compared with that of the females which were statistically significant (P < 0.01). The depth and diameter were higher in the 10–20 years age group than the 20–30 year age group, which was statistically significant (P = 0.01). Conclusion: The size of Sella turcica alters between different age groups and gender. Variations in the shape of Sella turcica were present in nearly half of the individuals in the present study. Thus, the morphology of Sella turcica should be assessed as a part of routine radiographic examination.

Laser interstitial thermal therapy (LITT) is a minimally invasive procedure used to treat a variety of intracranial lesions. Utilization of robotic assistance with stereotactic procedures has gained attention due to potential for advantages over conventional techniques. The authors report the first case in which robot-assisted MRI-guided LITT was used to treat radiation necrosis in the posterior fossa, specifically within the cerebellar peduncle. The use of a stereotactic robot allowed the surgeon to perform LITT using a trajectory that would be extremely difficult with conventional arc-based techniques. A 60-year-old man presented with facial weakness and brainstem symptoms consistent with radiation necrosis. He had a history of anaplastic astrocytoma that was treated with CyberKnife radiosurgery 1 year prior to presentation, and he did well for 11 months until his symptoms recurred. The location and form of the lesion precluded excision but made the patient a suitable candidate for LITT. The location and configuration of the lesion required a trajectory for LITT that was too low for arc-based stereotactic navigation, and thus the ROSA robot (Medtech) was used. Using preoperative MRI acquisitions, the lesion in the posterior fossa was targeted. Bone fiducials were used to improve accuracy in registration, and the authors obtained an intraoperative CT image that was then fused with the MR image by the ROSA robot. They placed the laser applicator and then ablated the lesion under real-time MR thermometry. There were no complications, and the patient tolerated the procedure well. Postoperative 2-month MRI showed complete resolution of the lesion, and the patient had some improvement in symptoms.

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Copyright of Revista de Ciencias Médicas de Pinar del Río is the property of Editorial Ciencias Medicas and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

ObjectPatients with posterior fossa arteriovenous malformations (AVMs) are more likely to present with hemorrhage than those with supratentorial AVMs. Observed patients subject to the AVM natural history should be informed of the individualized effects of AVM characteristics on the clinical course following a new, first-time hemorrhage. The authors hypothesize that the debilitating effects of first-time bleeding from an AVM in a previously intact patient with an unruptured AVM are more pronounced when AVMs are located in the posterior fossa.MethodsThe University of California, San Francisco prospective registry of brain AVMs was searched for patients with a ruptured AVM who had a pre-hemorrhage modified Rankin Scale (mRS) score of 0 and a post-hemorrhage mRS score obtained within 2 days of the hemorrhagic event. A total of 154 patients met the inclusion criteria for this study. Immediate post-hemorrhage presentation mRS scores were dichotomized into nonsevere outcome (mRS ≤ 3) and severe outcome (mRS > 3). There were 77 patients in each group. Univariate and multivariate logistic regression analyses using severe outcome as the binary response were run. The authors also performed a logistic regression analysis to measure the effects of hematoma volume and AVM location on severe outcome.ResultsPosterior fossa location was a significant predictor of severe outcome (OR 2.60, 95% CI 1.20-5.67, p = 0.016) and the results were strengthened in a multivariate model (OR 4.96, 95% CI 1.73-14.17, p = 0.003). Eloquent location (OR 3.47, 95% CI 1.37-8.80, p = 0.009) and associated arterial aneurysms (OR 2.58, 95% CI 1.09, 6.10; p = 0.031) were also significant predictors of poor outcome. Hematoma volume for patients with a posterior fossa AVM was 10.1 ± 10.1 cm(3) compared with 25.6 ±28.0 cm(3) in supratentorial locations (p = 0.003). A logistic analysis (based on imputed hemorrhage volume values) found that posterior fossa location was a significant predictor of severe outcome (OR 8.03, 95% CI 1.20-53.77, p = 0.033) and logarithmic hematoma volume showed a positive, but not statistically significant, association in the model (p = 0.079).ConclusionsPatients with posterior fossa AVMs are more likely to have severe outcomes than those with supratentorial AVMs based on this natural history study. Age, sex, and ethnicity were not associated with an increased risk of severe outcome after AVM rupture, but posterior fossa location, associated aneurysms, and eloquent location were associated with poor post-hemorrhage mRS scores. Posterior fossa hematomas are poorly tolerated, with severe outcomes observed even with smaller hematoma volumes. These findings support an aggressive surgical posture with respect to posterior fossa AVMs, both before and after rupture.

Microcephalies vary widely in clinical severity and in morphology. The purpose of this study is to determine the frequency of disproportion between the size of the cerebrum and the size of midbrain and hindbrain structures in infants and children with microcephaly, as analysis of such disproportions might aid understanding of these disorders and facilitate testing for specific genetic causes. The relative sizes of the forebrain, each component of the brain stem, and vermis and hemispheres of the cerebellum were analyzed visually on magnetic resonance (MR) images of 110 microcephalic patients. A disproportionally large cerebellum, compared with the cerebrum, was found in 50 cases (45.5%), a proportional cerebellum in 49 cases (44.5%), and a disproportionally small cerebellum in 11 cases (10%). Proportional cerebella were most common in mild (86%) and moderate (55%) microcephaly patients, whereas disproportionately large cerebella were most common in severe (57%) and moderate (32%) microcephaly. Disproportionately small cerebella were seen only in moderate (13%) and severe (9%) microcephaly. As genes are expressed at different times in cerebral and cerebellar development, it is postulated that analysis of relative cerebellar and brain stem size may be useful in the initial analysis of microcephaly by MR images both to categorize and to help determine likely genetic causes.

Occipital pressure ulcers and wound gaping may occur in unconscious and malnourished patients. Most of the time, a large defect requires wound coverage by scalp flaps. This video describes a rotational occipital scalp flap for occipital pressure ulcer and wound gaping in a patient of operated midline posterior fossa mass & ventriculoperitoneal shunt. The defect measured 2.25 × 2.5 cm with exposed inion. The wound was included in an imaginary triangle, and the horizontal and vertical incision lengths were about four times the base of the triangle. The flap was based on the left occipital artery and raised in an avascular plane above the periosteum. The wound margins were freshened and undermined. The flap was rotated to bring it over the defect, and suturing was done in the standard manner. The flap had good healing, and the patient continued to be under care for his cerebellar medulloblastoma. [ABSTRACT FROM AUTHOR]

Introduction. Intracranial epidermoid cysts are the most frequent congenital intracranial lesion. They rare and benign tumors that can present in different clinical situations depending on location and extension of the disease. Diagnosis is obtained with radiological imaging with RM and non-enhanced TC as elective investigating methods. Elective treatment is surgery, based on total/subtotal excision sparring healthy neurovascular structures, considering the benign nature of this lesion. Case Report. In this study we present the case of a 79-year-old woman affected by recidivist epidermal cyst of the posterior fossa. Clinical presentation was characterized by positional subjective vertigo, intense headache localized in the right part of the head increased by Valsalva maneuver and retroarticular subcutaneous swelling. Radiological investigation found a giant epidemoid cyst of the posterior fossa (8,4 x 4,8 x 5,8 cm), treated with surgery. In the postoperative, the patient was fine and no neurological deficit has been encounterd. REVIEW. In this study, we present a review of the literature regarding giant epidermoid cysts of posterior fossa. Only 11 cases were reported before ours, which actually is one of the largest ever described. [ABSTRACT FROM AUTHOR]

ObjectiveTo determine postoperative hearing outcomes after surgical plugging via middle cranial fossa approach for superior semicircular canal dehiscence syndrome (SCDS).Study designClinical review.SettingTertiary care medical center.PatientsForty-three cases of SCDS based on history, physical examination, vestibular function testing, and computed tomography imaging confirming the presence of a dehiscence. All patients underwent surgical plugging of the superior semicircular canal via middle cranial fossa approach.InterventionPure tone audiometry was performed preoperatively and at 7 days and at least 1 month postoperatively.Main outcome measuresChange in air-bone gap (ABG) and pure tone average (PTA).ResultsPreoperative average ABG across 0.25, 0.5, 1, and 2 kHz was 16.0 dB (standard deviation [SD], 7.5 dB). At 7 days postoperatively, average ABG was 16.5 dB (SD, 11.1; p = 0.42), and at greater than 1 month was 8.1 dB (SD, 8.4; p < 0.001). 53% (95% confidence interval, 33-69) of affected ears had greater than 10 dB increase in their 4-frequency (0.5, 1, 2, and 4 kHz) PTA measured by bone-conduction (BC) threshold 7 days postoperatively and 25% (95% confidence interval, 8-39) at greater than 1 month postoperatively. Mean BC PTA of affected ears was 8.4 dB hearing loss (HL) (SD, 10.4) preoperatively. Compared with baseline, this declined to 19.2 dB HL (SD, 12.6; p < 0.001) at 7 days postoperatively and 16.4 dB HL (SD, 18.8; p = 0.01) at greater than 1 month. No significant differences in speech discrimination score were noted (F = 0.17).ConclusionLow-frequency air-bone gap decreases after surgical plugging and seems to be due to both increased BC thresholds and decreased AC thresholds. Surgical plugging via a middle cranial fossa approach in SCDS is associated with mild high-frequency sensorineural hearing loss that persists in 25% but no change in speech discrimination.

Background Deep-seated clival varied malignancies represent a surgical challenge because of complex anatomy and surgical procedures posing great risks to adjacent neurovascular structures. To investigate effects of diagnosis and treatment of clival region lesions, review experience of individualized surgical procedures and comprehensive therapy. Methods and Results A total of 56 patients with clival malignancies from July 2007 to December 2018 were included. The patients mainly presented with headache and cranial nerve paresis. After multidisciplinary consultation, radical resection were performed in 45 cases different kinds of surgical approaches including endonasal (15 cases, 33.33% ), intraoral accompanied by intraoral and endonasal combined (7 cases, 15.56%), Derome (8 cases, 17.78%), maxillary swing (9 cases, 20%), and infratemporal (6 cases, 13.33%) approaches were chosen according to clinical and radiographic findings, and biopsies were performed in 11 patients to confirm the pathological diagnosis. The primary pathological finding was chordoma (28 cases, 50%). Total resection was achieved in 21 cases (46.67%), and 17 cases (37.78%) underwent subtotal resection. Besides, partial resection was performed in 7 cases (15.56%). The complications developed in 28 patients, including cranial nerve deficits (13 cases, 23.21%), cerebrospinal fluid leakage (14 cases, 25%), intracranial infection (8 cases, 14.29%), pneumonitis (2 cases, 3.57% ), postoperative hematoma (2 cases, 3.57% ), and mental disorder (1 cases, 1.79% ). Adjuvant chemoradiotherapy was provided by the oncologists depending on the pathological findings. The average follow-up was 59.90 months, but 8 patients (14.29%) were lost. The progression-free survival was achieved in 16 patients (28.57%), whereas the disease progression occurred in 13 patients (23.21%). The mortality was 33.93% (19/56). Conclusions Although malignancies occupy a larger subset of clival tumors, not all are needed to be radically resected. Our preliminary results suggest that multidisciplinary consultation is indispensable to clarify the therapeutic purpose and provide individualized surgical approaches. Postoperative comprehensive therapy may reduce the surgical complications and improve the outcomes of patients. [ABSTRACT FROM AUTHOR]

We conducted a randomized, triple-blinded home drinking water intervention trial to determine if a large study could be undertaken while successfully blinding participants. Households were randomized 50:50 to use externally identical active or sham treatment devices. We measured the effectiveness of blinding of participants by using a published blinding index in which values >0.5 indicate successful blinding. The principal health outcome measured was "highly credible gastrointestinal illness" (HCGI). Participants (n=236) from 77 households were successfully blinded to their treatment assignment. At the end of the study, the blinding index was 0.64 (95% confidence interval 0.51-0.78). There were 103 episodes of HCGI during 10,790 person-days at risk in the sham group and 82 episodes during 11,380 person-days at risk in the active treatment group. The incidence rate ratio of disease (adjusted for the clustered sampling) was 1.32 (95% CI 0.75, 2.33) and the attributable risk was 0.24 (95% CI -0.33, 0.57). These data confirm that participants can be successfully blinded to treatment group assignment during a randomized trial of an in-home drinking water intervention.

Ultrasound diagnosis of posterior fossa malformations in the prenatal period is a challenge, having major implications for the counseling and follow-up of pregnant women. The purpose of this study was to review aspects of the ultrasound evaluation of the fetal posterior fossa, as well as to describe the most relevant ultrasound findings of the main posterior fossa malformations that can affect the fetus in the prenatal period. [ABSTRACT FROM AUTHOR]

Cerebellar mutism is a rare finding associated with resection of posterior fossa tumors or cerebellar hemorrhages. We reviewed the medical records of six children, aged 6 to 12 years, who developed cerebellar mutism after resection of a posterior fossa mass or as a result of posterior fossa trauma. From 1989 to 1994, 210 children underwent posterior fossa resection at our institution, and four developed mutism (an incidence of 1.6%). All four patients had primitive neuroectodermal tumors. The fifth patient experienced trauma, and another patient had an arteriovenous malformation (AVM). In four children, hydrocephalus developed as a result of their tumor or AVM. Four developed cerebellar mutism 24 to 48 hours after surgery or trauma, and one developed cerebellar mutism 5 days after surgery, coincident with hydrocephalus. In one, mutism occurred after a second resection was performed for a recurrence of his posterior fossa tumor. Cerebellar mutism lasted 10 days in one patient and 2 to 8 weeks in the other four. Dysarthria was apparent in four patients during the recovery phase. We suggest trauma to the dentate nucleus and/or its outflow tract, the superior cerebellar peduncle, as a cause of reversible mutism. Because posterior fossa tumors are common in children, mutism should be recognized as an important side effect of surgery.

Background: Superior semicircular canal dehiscence (SSCD) is a disorder of the skull base that is gaining increasing recognition among neurosurgeons. Traditionally, the middle cranial fossa (MCF) approach has been used for the surgical repair of SSCD. However, the transmastoid (TM) approach is an alternative strategy that has demonstrated promising results.Methods: We performed independent searches of a popular database to identify studies that described outcomes following the surgical repair of SSCD through MCF and TM approaches. The primary outcome was symptom resolution.Results: Our analysis included 24 studies that described 230 patients that underwent either an MCF (n = 148, 64%) approach or a TM (n = 82, 36%) approach for primary surgical repair of SSCD. A greater percentage of patients in the MCF group experienced resolution of auditory symptoms (72% vs 59%, p = 0.012), aural fullness (83% vs 55%, p = 0.049), hearing loss (57% vs 31%, p = 0.026), and disequilibrium (75% vs 44%, p = 0.001) when compared to the TM group. The MCF approach was also associated with higher odds of symptom resolution for auditory symptoms (odds ratio [OR] 1.79, 95% confidence interval [CI] 1.14-2.82), aural fullness (OR 4.02, 95% CI 1.04-15.53), hearing loss (OR 2.91, 95% CI 1.14-7.42), and disequilibrium (OR 3.94, 95% CI 1.78-8.73). The mean follow-up was 9 months.Conclusions: The literature suggests that the MCF approach for the repair of SSCD is associated with greater symptom resolution when compared to the TM approach. This information could help facilitate patient discussions. [ABSTRACT FROM AUTHOR]

Background Very few studies have examined vestibular schwannoma (VS) management trends across centers and between providers. The objective of this study is to examine current practice trends, variance in treatment philosophies, and nuanced or controversial aspects of VS care across North America. Methods This is a cross-sectional survey of North American Skull Base Society (NASBS) members who report regular involvement in VS care. Results A total of 57 completed surveys were returned. Most respondents claimed to have over 20 years of experience and the majority reported working in an academic practice with an affiliated otolaryngology and/or neurosurgery residency program. Sixty-three percent of respondents claimed to evaluate VS patients in clinic with both an otolaryngologist and neurosurgeon involved. Eighty-six percent of respondents claimed to operate on VS with both an otolaryngologist and neurosurgeon involved, while only 18% of neurosurgeons and 9% of otolaryngologists performed surgery alone. There was a wide range in the number of cases evaluated at each center annually. Similarly, there was wide variation in the number of patients treated with microsurgery and radiation at each center. Additional details regardingmanagement preferences for microsurgery, stereotactic radiosurgery, stereotactic radiotherapy, and conservative observation are presented. [ABSTRACT FROM AUTHOR]

The skull base provides a platform for supporting the brain while serving as a conduit for major neurovascular structures. In addition to malignant lesions originating in the skull base, there are many benign entities and developmental variants that may simulate disease. Therefore, a basic understanding of the relevant embryology is essential. Lesions centered in the skull base can extend to the adjacent intracranial and extracranial compartments; conversely, the skull base can be secondarily involved by primary extracranial and intracranial disease. CT and MRI are the mainstay imaging methods and are complementary in the evaluation of skull base lesions. Advances in cross-sectional imaging have been crucial in the management of patients with skull base pathology, as this represents a complex anatomical area that is hidden from direct clinical exam. Furthermore, the clinician must rely on imaging studies for therapy planning and to monitor treatment response. It is crucial to have a thorough understanding of skull base anatomy and its various pathologies, as well as to recognize the appearance of treatment-related changes. In this review, we aim to describe skull base tumors and tumor-like lesions in an anatomical compartmental approach and present imaging methods that aid in diagnosis, management, and follow-up.

The morphology of the brain and skull are important in the evaluation of the aging human; however, little is known about how the skull may change with age. The objective of this study was to evaluate the morphological changes of the adult skull using three-dimensional geometric morphometric analysis of thousands of landmarks with the focus on anatomic regions that may be correlated with brain atrophy and head injury. Computed tomography data were collected between ages 20 and 100. Each scan was segmented using thresholding techniques. An atlas image of a 50th percentile skull was registered to each subject scan by computing a series of rigid, affine, and non-linear transformations between atlas space and subject space. Landmarks on the atlas skull were transformed to each subject and partitioned into the inner and outer cranial vault and the cranial fossae. A generalized Procrustes analysis was completed for the landmark sets. The coordinate locations describing the shape of each region were regressed with age to generate a model predicting the landmark location with age. Permutation testing was performed to assess significant changes with age. For the males, all anatomic regions reveal significant changes in shape with age except for the posterior cranial fossa. For the females, only the middle cranial fossa and anterior cranial fossa were found to change significantly in shape. Results of this study are important for understanding the adult skull and how shape changes may pertain to brain atrophy, aging, and injury. [ABSTRACT FROM AUTHOR]

We report on a rare case of connecting rod migration into the posterior cranial fossa after posterior cervical decompression and lateral mass screw fixation. A 55-year-old male patient who was operated on for ossification of posterior longitudinal ligament complained of sudden-onset giddiness followed by loss of consciousness one and half year following surgery. CT scan showed migration of left-sided connecting rod into the right cerebellum through foramen magnum. The patient was operated on for rod removal but he sustained a cardiorespiratory arrest and died on the eighth postoperative day. Autopsy confirmed damage to the right cerebellum due to rod migration. The clinician should be aware that superior rod migration is a rare but potentially disastrous complication. Regular follow-up with radiological evaluation should be done to look for implant loosening, migration, and non-union even in asymptomatic patients. The implant should be subsequently removed after it has served its purpose. [ABSTRACT FROM AUTHOR]

Clivus fractures are a rare pathology, frecuently associated tohigh power trauma. Such injuries may be associated with vascular and cranial nerves lesions. The abducens nerve is particularly vulnerable to traumatic injuries due to its long intracranial course, since their real origin until the lateral rectus muscle. The unilateral abducens nerve palsy of 1-2-7% occurs in patients with cranial trauma, bilateral paralysis is rare. We report a patient who presented bilateral abducens nerve palsy associated with a clivus fracture.

Objective The article analyzed the curative effect of different surgical treatments for non-solid hemangioblastoma in posterior cranial fossa to explore reasonable operation method. Methods Clinical data of 61 patients with non-solid hemangioblastoma who underwent surgeries in Tianjin Huanhu Hospital during July 2007 and June 2014 were retrospectively analyzed. According to surgical approaches and the situation of foramen magnum and atlas, these patients were divided into 5 groups: midline approach opening foramen magnum and atlas (Group A), midline approach without opening foramen magnum and atlas (Group B), paramedian approach opening foramen magnum and atlas (Group C), paramedian approach without opening foramen magnum and atlas (Group D), retrosigmoid approach (Group E). By collecting clinical symptoms, imaging findings, surgical records and postoperative complications, the surgical results and occurrence of postoperative complications were summarized and reasonable operation method was discussed. Results Among 61 patients, total resection was achieved in 56 cases (91.80%), and partial resection was achieved in 5 cases (8.20% ). The postoperative remission rate of 43 cases with hydrocephalus was 79.07% (34/43). Intracranial infection was the most common postoperative complication, accounting for 22.95% (14/61). There was significant difference in occurrence rate of intracranial infection among 4 subgroups: opening or not opening the foramen magnum and atlas with or without restoring bone flap (Z = 16.269, P = 0.001). In the subgroup of not opening foramen magnum and atlas with restoring bone flap, the infection rate, which accounted for 6.90% (2/29), was the lowest. Conclusions The surgical treatment options for non-solid hemangioblastoma in posterior fossa should be done according to patients' condition, and performed by a professional group. If conditions allow, not to open the foramen magnum and atlas, as well as intraoperative restoring bone flap should be chosen as far as possible, so as to reduce the occurrence of postoperative complications. [ABSTRACT FROM AUTHOR]

Aim: Trigeminocardicac reflex (TCR), a brainstem reflex, can be manifested in almost all types of surgery in the head and neck region. Patients & methods: Retrospective review of 125 patients operated on cerebellopontine angle (CPA) tumors according to strict inclusion/exclusion criteria. Results: A total of 14 out of 125 patients showed TCR during CPA tumor operation. In total, 29% of those patients presented with a meningioma located exclusively premeatal, but not retromeatal in the CPA. There was significant relationship between meningiomas subgroups and TCR (Barnard test; p < 0.05). Conclusion: Anatomical location may represent an important, but not yet described risk factor for the TCR having therefore an important role in the understanding of the TCR. [ABSTRACT FROM AUTHOR]

This study describes the microsurgical anatomy of the middle cranial fossa approach using temporal bone three-dimensional (3D) computed tomography (CT) reconstruction, which should contribute to determining the drilling point for the internal auditory meatus (IAM) when bony landmarks are absent. Thirty temporal bone CT scans were reviewed retrospectively. We measured the shortest and longest distances to IAM from the petrous ridge, and measured the angle between the facial nerve and various labyrinth structures. Three-dimensional reconstructed images were obtained using high-resolution axial temporal bone CT (0.7-mm-thick slices, FOV 90 × 90, KVp 120, 305 mA, width 2,800, and level 800). The mean shortest and longest distances to IAM from the petrous ridge were 5.22 and 10.1 mm, respectively. The mean distance to the IAM from the cochlea was 9.91 mm. The mean angle between the IAM and superior semicircular canal was 47.21°, which was more acute than previously reported. The mean angle between the IAM and geniculate ganglion (GG) and external auditory canal was 113.8°, and the mean distance from the GG to the IAM was 15.44 mm. Understanding the 3D relationships among the microsurgical structures will help to decide the drilling point for the IAM when bony landmarks are absent. A preoperative evaluation might be useful for preserving important neurovascular structures while approaching the middle fossa. [ABSTRACT FROM AUTHOR]