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Purpose: To investigate how different presentations of posterior fossa arachnoid cysts (PFACs) influence surgical indication and strategies and their impact on clinical and radiological outcome in children, proposing a treatment flow-chart. Methods: In this retrospective study, children < 14 years old with PFAC diagnosed at IRCCS Giannina Gaslini Hospital from 2008 to 2023 were identified Patients showing a mega cisterna magna (MCM), Dandy-Walker syndrome (DWS), Blake's pouch cyst (BPC), neuroenteric cysts or multiple cysts were excluded. Data regarding type of treatment, age at surgery, surgical complications were collected and analyzed. Clinical and radiological outcomes were considered at 1-, 3- and 5-years follow-up. Results: A "wait and see" strategy in asymptomatic showed better clinical outcomes at 1-year follow-up (p = 0.047). No significant difference in clinical outcome or risk of re-surgery were observed between microsurgical fenestration, endoscopical fenestration or shunting were reported, while location of the cyst influenced surgical strategy (p = 0.015). Age < 12 months at surgery (p = 0.008), hydrocephalus (p = 0.001), especially when associated with macrocephaly (p = 0.004), and the placement of a shunt (p = 0.006) resulted as risk factors of re-surgery. An association between radiological and clinical outcomes was observed at 1-year follow-up. Conclusion: Treatment decision should be based on clinical presentation rather than radiological presentation. While a "wait and see" strategy is suggested in asymptomatic patients, when surgery is indicated, several factors should be considered, such as presence of hydrocephalus, location of the cyst and age of the patient, to improve clinical outcomes, reducing complications. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to investigate the use of image-guided volumetry in cerebellar infarction during the decision-making process for surgery. Particular emphasis was placed on the ratio of the infarction volume to the cerebellar volume or cranial posterior fossa volume. Methods: A retrospective, multicenter, multidisciplinary study design was selected. Statistical methods such as regression analysis and ROC analysis included the volumetric data of the infarction, the posterior fossa and the cerebellum itself as new factors. Results: Thirty-eight patients (mean age 75 (SD: 13.93) years, 16 (42%) female patients) were included. The mean infarction volume was 37.79 (SD: 25.24) cm3. Patients treated surgically had a 2.05-fold larger infarction than those managed without surgery (p ≤ 0.001). Medical and surgical treatment revealed a significant difference in the ratio of the cranial posterior fossa volume to the infarction volume (medical 12.05, SD:9.09; surgical 5.14, SD: 5,65; p ≤ 0.001) and the ratio of the cerebellar volume to the infarction volume (medical 8.55, SD: 5.97; surgical 3.82, SD: 3.39; p ≤ 0.001). Subsequent multivariate regression analysis for surgical therapy showed significant results only for the posterior fossa volume to infarction volume ratio ≤/> 4:1 (OR: 1.162, CI: 1.007–1.341, p = 0.04). Younger (≤60 years) patients also had a significantly better outcome at discharge (p ≤ 0.017). A cut-off value for the infarction volume of 31.35 cm3 (sensitivity = 0.875, specificity = 0.2) was determined for the necessity of surgery. Conclusions: Volumetric data on the infarction, the posterior fossa and the cerebellum itself could be meaningful in decision-making towards surgery. [ABSTRACT FROM AUTHOR]

Purpose: This study presents the morphological variation of falx cerebelli, which helps to identify the possible variations in the presence of the occipital sinus in the posterior margin of the fold whose damage during midline incision of posterior cranial fossa surgeries may lead to internal hemorrhage. Method: The study was conducted on 48 cranial cavities exploring the falx cerebelli. Variations in the number of folds, its proximal and distal attachments, and the drainage pattern of the occipital sinus were evaluated by histological processing of the upper 1/3rd section of the falx fold. Results: The variation in the number of folds recorded are single folds in 87.5%, double folded in 8.3%, and multiple folds (five and seven folded) in 4.2% of the cases. The variation in the proximal and distal attachments in single falx folds showed three combinations: Ramified triangular in 66.7%, both ramified type in 12.5%, and both triangular type in 8.3% of the cases. Double and multiple folds showed ramified and triangular types of variation in their attachments. Histological findings showed the presence of occipital venous sinuses in most of the single falx fold. Two aberrant venous sinuses were seen in a double and five-folded falx cerebelli. Conclusions: This study records the variations in the morphology of falx cerebelli. The histological data of this study sheds light on the drainage pattern of venous sinuses in the area whose negligence during midline incisions of brain surgeries may increase the possibility of hemorrhage. [ABSTRACT FROM AUTHOR]

Background: Hemangioblastoma (HB) is a highly vascularized tumor most commonly occurring in the posterior cranial fossa, requiring accurate preoperative diagnosis to avoid accidental intraoperative hemorrhage and even death. Purpose: To accurately distinguish HBs from other cerebellar‐and‐brainstem tumors using a convolutional neural network model based on a contrast‐enhanced brain MRI dataset. Study Type: Retrospective. Population: Four hundred five patients (182 = HBs; 223 = other cerebellar‐and brainstem tumors): 305 cases for model training, and 100 for evaluation. Field Strength/Sequence: 3 T/contrast‐enhanced T1‐weighted imaging (T1WI + C). Assessment: A CNN‐based 2D classification network was trained by using sliced data along the z‐axis. To improve the performance of the network, we introduced demographic information, various data‐augmentation methods and an auxiliary task to segment tumor region. Then, this method was compared with the evaluations performed by experienced and intermediate‐level neuroradiologists, and the heatmap of deep feature, which indicates the contribution of each pixel to model prediction, was visualized by Grad‐CAM for analyzing the misclassified cases. Statistical Tests: The Pearson chi‐square test and an independent t‐test were used to test for distribution difference in age and sex. And the independent t‐test was exploited to evaluate the performance between experts and our proposed method. P value <0.05 was considered significant. Results: The trained network showed a higher accuracy for identifying HBs (accuracy = 0.902 ± 0.031, F1 = 0.891 ± 0.035, AUC = 0.926 ± 0.040) than experienced (accuracy = 0.887 ± 0.013, F1 = 0.868 ± 0.011, AUC = 0.881 ± 0.008) and intermediate‐level (accuracy = 0.827 ± 0.037, F1 = 0.768 ± 0.068, AUC = 0.810 ± 0.047) neuroradiologists. The recall values were 0.910 ± 0.050, 0.659 ± 0.084, and 0.828 ± 0.019 for the trained network, intermediate and experienced neuroradiologists, respectively. Additional ablation experiments verified the utility of the introduced demographic information, data augmentation, and the auxiliary‐segmentation task. Data Conclusion: Our proposed method can successfully distinguish HBs from other cerebellar‐and‐brainstem tumors and showed diagnostic efficiency comparable to that of experienced neuroradiologists. Evidence Level: 3 Technical Efficacy: Stage 2 [ABSTRACT FROM AUTHOR]

To evaluate the necessity of performing whole spine magnetic resonance imaging (MRI) as opposed to solely lumbosacral MRI for detecting high-level spinal lesions (in the brain, cervical, or thoracic spine) in patients with anorectal malformations (ARM). This retrospective cohort study included 69 patients treated for ARM at a medical center between January 2011 and January 2022. Before March 2021, lumbosacral MRI was used for patients with ARM. Since March 2021, anomalies in the posterior cranial fossa and whole spine were assessed using routine MRI. Both male (n = 30, 43.4%) and female patients were included in the study. Out of the 69 patients, 19 (27.5%) underwent whole spine MRI, and 50 (72.5%) underwent lumbosacral MRI. In the whole spine group, 4 patients had anomalies beyond the lumbosacral area. In the lumbosacral group, 4 patients subsequently underwent whole spine MRI due to symptoms, with 3 revealing higher-level anomalies.High-level spinal and brain anomalies, although infrequent, are present in patients with ARM. The findings suggest considering routine whole spine MRI in screening ARM patients to avoid missing high-level anomalies. [ABSTRACT FROM AUTHOR]

Arnold Chiari syndrome, also known as Chiari malformation, is a group of deformations of the posterior cranial fossa and hindbrain, consisting in the lowering of the cerebellum or its tonsils towards the occipital foramen. This leads to a reduction in the volume reserve within the foramen magnum, pressure on surrounding structures and obstruction of the flow of cerebrospinal fluid. The process is most often asymptomatic. Symptoms include headaches, neck pain, but also fainting, sinus bradycardia, coordination disorders and many others. Chiari malformation is often diagnosed incidentally. The basis of diagnosis is the detection of characteristic morphological features in magnetic resonance imaging. Surgical treatment is successfully used among patients with severe Arnold-Chiari syndrome and progression of clinical symptoms. Materials and methods Literature included in the PubMed, BioMed Central and Polish Medical Platform databases searched by means of the words such as Gamma Knife, CyberKnife, radiosurgery, stereotactic radiotherapy. Sources quoted in selected works were also used. Summary Arnold-Chiari malformation is often discovered incidentally. If the features observed on MRI suggest the above diagnosis, the patient should be referred to a neurologist. After excluding other possible causes of the imaged morphological features and performing a dedicated magnetic resonance imaging examination, the neurosurgeon decides whether to qualify for the procedure. In a selected group of patients, significant improvement can be expected after surgical treatment. [ABSTRACT FROM AUTHOR]

Chiari malformation has been classified as a group of posterior cranial fossa disorders characterized by hindbrain herniation. Chiari malformation type I (CM-I) is the most common subtype, ranging from asymptomatic patients to those with severe disorders. Research about clinical manifestations or medical treatments is still growing, but cognitive functioning has been less explored. The aim of this systematic review is to update the literature search about cognitive deficits in CM-I patients. A literature search was performed through the following electronic databases: MEDLINE, PsychINFO, Pubmed, Cochrane Library, Scopus, and Web of Science. The date last searched was February 1, 2023. The inclusion criteria were as follows: (a) include pediatric or adult participants with a CM-I diagnosis, (b) include cognitive or neuropsychological assessment with standardized tests, (c) be published in English or Spanish, and (d) be empirical studies. Articles that did not report empirical data, textbooks and conference abstracts were excluded. After the screening, twenty-eight articles were included in this systematic review. From those, twenty-one articles were focused on adult samples and seven included pediatric patients. There is a great heterogeneity in the recruited samples, followed methodology and administered neurocognitive protocols. Cognitive functioning appears to be affected in CM-I patients, at least some aspects of attention, executive functions, visuospatial abilities, episodic memory, or processing speed. However, these results require careful interpretation due to the methodological limitations of the studies. Although it is difficult to draw a clear profile of cognitive deficits related to CM-I, the literature suggests that cognitive dysfunction may be a symptom of CM-I. This suggest that clinicians should include cognitive assessment in their diagnostic procedures used for CM-I. In summary, further research is needed to determine a well-defined cognitive profile related to CM-I, favoring a multidisciplinary approach of this disorder. [ABSTRACT FROM AUTHOR]

This article presents a case report on a patient who underwent a surgical procedure to repair a pseudomeningocele and tympanoplasty. The patient had symptoms of ear discharge and hearing loss. The surgical approach involved repairing a bony defect in the tegmen tympani using septal cartilage and fascia lata. The article emphasizes the importance of surgical treatment to prevent complications and discusses different surgical approaches for repairing tegmen defects. The combined middle cranial fossa approach is highlighted as a minimally invasive procedure that preserves hearing. [Extracted from the article]

The rhomboid lip is a neural tissue encountered during cerebellopontine angle surgery, with differing shape and extent among individuals. This study aimed to investigate the variation of rhomboid lips during posterior fossa surgery. In this retrospective study, we examined posterior cranial fossa surgeries performed using a retrosigmoid approach. Rhomboid lips were classified according to thickness, extent, and appearance, with some subjected to histological analysis. T2-weighted magnetic resonance imaging of rhomboid lips was conducted. Among 304 surgeries, rhomboid lips were observed in 75 patients who underwent schwannoma or meningioma resection, facial spasm-related neurovascular decompression, and other surgeries (37, 2, 32, and 4 patients, respectively). Rhomboid lips were categorized based on apparent thickness: thin membranous type, resembling an arachnoid membrane, and thick parenchymal type. Rhomboid lip extension was classified by position relative to the choroid plexus: nonextension, lateral extension, and jugular foramen (41, 22, and 12 patients, respectively). Veins were observed on the rhomboid lip surface in 37 cases. The rhomboid lip was visible in only 1 case (parenchymal jugular foramen type) on magnetic resonance imaging. Histologically, the rhomboid lip comprised an ependymal cell layer, a glial layer, and connecting tissue. The glial layer thickness determined the rhomboid lip thickness, which was greater in the parenchymal type than in the membrane type. In 42 patients, the rhomboid lip was dissected with no complications observed. Morphological classification of the rhomboid lip and understanding of its anatomical details contribute to safe surgical field development for neurosurgeons. [ABSTRACT FROM AUTHOR]

Trigeminal neuralgia (TN) due to venous compression is far less common than that due to arterial compression, and its pathogenesis is less clear. We investigated the clinical and imaging features of TN caused by solely venous compression by measuring the morphologies of the posterior cranial fossa (PCF) and the trigeminal nerve. We retrospectively reviewed records of TN patients who underwent microvascular decompression at our institution and extracted cases with solely arterial or solely venous compression. Preoperative magnetic resonance imaging was used to find the length (Y), width (X), height (Z), and volume (V) of the PCF, the angle between the trigeminal nerve and pons, and the distance between Meckel's cave and the root entry zone of the trigeminal nerve. Of 152 patients, 24 had TN caused solely by venous compression. The value of Y was significantly smaller in the venous group than the arterial group (P < 0.01). The trigeminal nerve and pons was significantly smaller in the venous group (P < 0.01). We hypothesized that TN patients with solely venous compression had a characteristic PCF morphology with a short anteroposterior diameter (Y), such that age-related changes in brain morphology could alter the course of the trigeminal nerve and cause compression by a vein. The morphological features of the PCF differed between patients with TN of venous and those with TN of arterial etiology. Age-related changes in brain morphology and changes of course of the trigeminal nerve may also add to the possibility of developing TN, especially of venous etiology. [ABSTRACT FROM AUTHOR]

The potential advantages of exoscopy have been discussed theoretically for a long time. Such a concept holds significance, especially in the specific setting of the posterior cranial fossa (PCF), characterized by complex anatomy and long and narrow surgical corridors with relatively extreme working angles. We aimed to: 1) analyze the institutional preliminary case-based data on the use of the Robotic 3D Exoscope AEOS Aesculap in three different PCF approaches: retrosigmoid (RSA), midline suboccipital (MSA), and supracerebellar infratentorial via feedbacks was collected using a 20-point questionnaire, and 2) perform a comprehensive review of the literature concerning the use of EX in PCF surgery. A total of 38 patients with neurosurgical pathologies underwent a neurosurgical procedure using the EX (Robotic 3D exoscope AEOS Aesculap) at our institution between January and March 2022. 21 surgeons were involved in the abovementioned PCF surgeries and answered the questionnaire. The main perceived advantages were in terms of ergonomics (67%), magnification (52%), and visualization of extreme angles. The main reported disadvantage was color vision (16, 76%), followed by manual mobility (24%). Concerning the review, the search of the literature yielded a total of 177 results. Upon full-text review, 17 articles were included, including 153 patients. In conclusion, our study provides a comprehensive evaluation of the advantages and challenges associated with using the exoscope in posterior fossa surgery, setting a precedent as the first to report on a questionnaire-based analysis of exoscope utilization in this specific domain. [ABSTRACT FROM AUTHOR]

Introduction: Most myelomeningocele (MMC) cases present with ventriculomegaly or hydrocephalus, yet a comprehensive volumetric assessment of MMC intracranial structures is lacking. This study aimed to provide baseline data on intracranial structural volumes immediately after birth in MMC infants who underwent repair surgeries after birth (postnatal repair). Methods: In this retrospective single-center study, we analyzed 52 MMC infants undergoing postnatal repair, utilizing head computed tomography scans at birth for volumetric assessment. Intracranial volume (ICV), lateral ventricles volume (LVV), choroid plexus volume (CPV), and posterior cranial fossa volume (PCFV) were measured. Hydrocephalus was classified into no hydrocephalus, progressive hydrocephalus, and hydrocephalus at birth. Comparative analysis employed the Wilcoxon rank-sum test. Receiver operating characteristic (ROC) analysis discriminated cases with and without ventriculoperitoneal shunt (VPS). Results: The median values were 407.50 mL for ICV, 33.18 mL for LVV, 0.67 mL for CPV, and 21.35 mL for PCFV. Thirty-seven cases (71.15%) underwent VPS. ROC analysis revealed an LVV cut-off value of 6.74 mL for discriminating cases with and without VPS. Progressive hydrocephalus showed no significant difference in ICV but significantly larger LVV compared to no hydrocephalus. Hydrocephalus at birth demonstrated statistically larger ICV and LVV compared to the other two types. Conclusion: Baseline volumetric data were provided, and volumetric analysis exhibited statistical differences among three hydrocephalus types. These findings enhance our understanding of intracranial volumetric changes in MMC, facilitating more objective assessments of MMC cases. [ABSTRACT FROM AUTHOR]

Background: Foramen magnum (FM) is a crucial aperture situated in the occipital bone and connects the brain to the spinal cord. Its size and dimensions are crucial in understanding a range of disorders, with implications for clinical, surgical, radiological, and forensic fields. We undertook the present study to analyze the morphometry of FM in detail and to compare this data with other similar studies. Methodology: This study analyzed 51 dry human skulls from Northern India of unspecified gender. Morphometric assessments of the FM were conducted, encompassing measurements of its shape, anteroposterior diameter (APD), transverse diameter (TD), FM index (FMI), size, and surface area using digital Vernier calipers. Minimum, maximum, and mean values and standard deviations (SDs) were calculated for each parameter. A comparison with previous studies was conducted. Results: The study established that the most common shape of FM as calculated by the ratio of AP diameter to TD was round (58.8% of specimens) and the majority of FM (41.1%) were narrow according to Martin and Saller classification. Mean APD was 33.71 ± 2.53, and TD was 27.88 ± 1.92; AP diameter was significantly greater than TD (P < 0.05). FMI ranged from 70.54 to 93.55 (mean: 82.92 and SD: 5.63). The mean surface area as calculated by Teixeira’s method was higher compared to Radinsky’s formula; 747.51 ± 96.25 mm2 and 739.93 ± 94.85 mm2, respectively. This difference was not statistically significant (P = 0.68). Conclusion: This study furnishes data on detailed morphometry of FM, a complete knowledge of which is essential for planning surgical procedures for optimal preoperative and postoperative results. It provides an objective definition of the FM’s morphology and highlights the ambiguous role of visual assessment which needs to be reconsidered. The comparison of present morphometric data with other national and international studies further highlights the ethnic and genetic variation of FM.

Abstract To evaluate the necessity of performing whole spine magnetic resonance imaging (MRI) as opposed to solely lumbosacral MRI for detecting high-level spinal lesions (in the brain, cervical, or thoracic spine) in patients with anorectal malformations (ARM). This retrospective cohort study included 69 patients treated for ARM at a medical center between January 2011 and January 2022. Before March 2021, lumbosacral MRI was used for patients with ARM. Since March 2021, anomalies in the posterior cranial fossa and whole spine were assessed using routine MRI. Both male (n = 30, 43.4%) and female patients were included in the study. Out of the 69 patients, 19 (27.5%) underwent whole spine MRI, and 50 (72.5%) underwent lumbosacral MRI. In the whole spine group, 4 patients had anomalies beyond the lumbosacral area. In the lumbosacral group, 4 patients subsequently underwent whole spine MRI due to symptoms, with 3 revealing higher-level anomalies.High-level spinal and brain anomalies, although infrequent, are present in patients with ARM. The findings suggest considering routine whole spine MRI in screening ARM patients to avoid missing high-level anomalies.

Introduction The development of endoscopic techniques has made endoscopic endonasal approaches (EEAs) to the anterior cranial fossa (ACF) increasingly popular. Still, the steps and nuances involved in the approach may be difficult to understand for trainees. Thus, we aim to didactically describe the EEAs to the ACF in an anatomically based, step-by-step manner with supplementary clinical cases. Methods Six cadaveric head specimens were dissected. Endoscopic endonasal Draf I, IIA, IIB, and III frontal sinusotomies, endoscopic endonasal superior ethmoidectomy, and endoscopic endonasal transcribriform and transplanum approaches were modularly performed. The specimens were photodocumented with endoscopic techniques. Results Draf I frontal sinusotomy started with the complete removal of the anteromedial portion of the agger nasi cell, exposing the medial orbital wall, cranial base, and anterior cribriform plate. Draf II frontal sinusotomy proceeded with the removal of the floor of the frontal sinus between the lamina papyracea and the middle turbinate (IIa), and the nasal septum (IIb) until the first olfactory filaments were exposed. Draf III proceeded by creating a superior septal window just below the floor of the frontal sinus. The bone of the ACF bounded by the limbus sphenoidale posteriorly, frontal sinus anteriorly, and the medial orbital walls bilaterally was removed; the cribriform plate was removed; and the crista galli was dissected free from the dural leaflets of the falx cerebri and removed. Conclusion We provide a step-by-step dissection describing basic surgical steps and anatomy of the EEAs to the ACF to facilitate the learning process for skull base surgery trainees. [ABSTRACT FROM AUTHOR]

Background and Objective: Primary hemifacial spasm (HFS) is caused by neurovascular conflict (NVC) at the root entry zone of the facial nerve. Whether reduction of posterior cranial fossa (PCF) cerebrospinal fluid (CSF) volume is a risk factor for HFS is not clear. The study aims at the radiologic assessment of PCF CSF volume and its clinical correlation. Methods: A cross-sectional, hospital-based, case–control study was conducted, in which 50 cases of primary HFS and 50 age- and sex-matched controls were recruited. PCF CSF volume was quantified in 3-T brain magnetic resonance imaging. Results: The mean age at presentation of cases was 50.7 ± 10.7 years (42–69 years) and controls was 52.4 ± 8.7 years (45–68 years). The mean duration of symptoms was 3.5 ± 1.3 years (1.5–8 years). About 52% of patients had grade 2 (mild) severity of HFS. The mean PCF CSF volume of patients was 13,725.1 ± 909.5 mm3 and controls was 14,458.5 ± 973.5 mm3 (P < 0.001). The mean PCF CSF volume of females with HFS was 13,714.8 ± 852.5 mm3 and female controls was 14,521.8 ± 973.5 mm3 (P = 0.006). PCF CSF volume was significantly associated with the presence of HFS (P = 0.007), the severity of HFS (P < 0.001), and the presence of NVC (P = 0.02). Conclusion: PCF CSF volume was lesser in HFS patients and was associated with the presence of HFS, the severity of HFS, and the presence of NVC. Females with HFS had smaller PCF CSF volume. Small PCF CSF volume is a risk factor for HFS, particularly in females with HFS.

Surgery of meningiomas of the posterior cranial fossa, due to its small volume and close anatomical relationship of neoplasms with the brain stem, cranial nerves, main arteries and venous collectors, remains one of the urgent problems of neurooncology. Despite the improvement of microsurgical techniques and neurophysiological control, maintaining a high level of quality of life after radical removal of meningiomas is still far from desired. Purpose of the study. Retrospective analysis and generalization of clinical results of surgical treatment of patients with meningiomas of the posterior cranial fossa. Material and methods. The paper analyzes the results of surgical treatment of 101 patient with meningiomas of the posterior cranial fossa of various localization (80 women (79.2 %) and 21 men (20.7 %), age 58.26 ± 1.00 years). According to the localization of meningiomas, they were distributed as follows: convexital – 49 (48.5 %), cerebellopontine angle – 22 (21.8 %), jugular foramen – 4 (4 %), petroclival – 16 (15.8 %), foramen magnum – 10 (9.9 %). Results. All patients underwent surgical removal of the formation. In 99 (98 %) one-stage and in 2 (1.9 %) cases of additional surgical intervention, in the form of external drainage according to Arendt and ventriculoperitoneal shunting, due to frolicking liquorodynamic disorders. Radical removal of meningioma (grade I according to Simpson scale) was achieved in 72 (71.3 %) of cases, tumor resection with coagulation of the tumor matrix zone (Simpson II) – in 21 (20.8 %), removal without resection and coagulation of the matrix, or leaving the extradural component of meningiomas (Simpson III) – in 8 (7.9 %). Conclusions. The results obtained on the basis of the complex use of modern neuroimaging diagnostic tools, microneurosurgery, optimal surgical approaches in combination with the mandatory intraoperative physiological control of the function of the brain stem and cranial nerves in the early postoperative period indicate an improvement in the functional state, and sometimes complete regression of the neurological symptoms in 58 (57.4 %) of operated patients. Complete regression of symptoms and restoration of the functional state was achieved in 30 (29.7 %) of cases, deterioration was noted in 17 (16.8 %) of the operated patients, mortality was 4.95 % (n = 5).

Study Design A descriptive, quantitative cross-sectional study of the atlantic part (V3) of the vertebral artery (VA). Purpose This study aimed to bridge the research gap in the morphometry of the V3 segment of the VA in the South Indian population. Overview of Literature The microsurgical anatomy of this segment of the VA has been explored in various populations, and a thorough understanding of the anatomy and course of the VA, particularly the V3 segment, is essential to prevent iatrogenic complications. Several computed tomography studies but a few cadaveric studies have explored the V3 segment of the VA in the South Indian population. Methods This study examined 40 VAs from 20 embalmed cadavers that were obtained from the voluntary donation program, and Institutional Ethical Clearance was obtained before the study. The length, diameter, and angle of the vertical, horizontal, and exit parts of the V3 segment of the VA were documented after its exposure. Results The mean lengths of the right and left VAs on each part were nearly similar, except for the mean length of the horizontal part (right: 38.937 mm, left: 40.237 mm) and total length of the V3 segment (right: 66.870 mm, left: 70.350 mm). Conclusions These morphometric parameters are essential to spine surgeons who intend to operate on a small part (vertical, horizontal, or exit part) of the V3 segment of the VA. The mean values of the parameters obtained in this study give average measurements or safe limits to surgeons for safe surgical procedures such as the occipital condyle screw technique and C1 laminectomy.

Objective Imaging parameters of Chiari malformation type I (CMI) development are not well established. This study aimed to collect evidence of general or specific imaging measurements in patients with CMI, analyze indicators that may assist in determining the severity of CMI, and guide its diagnosis and treatment. Methods A comprehensive search was conducted across various databases including the Cochrane Library, PubMed, MEDLINE, Scopus, and Embase, covering the period from January 2002 to October 2023, following predefined inclusion criteria. Meta-analyses were performed using RevMan (ver. 5.4). We performed a quantitative summary and systematic analysis of the included studies. This study was registered in the PROSPERO (International Prospective Register of Systematic Reviews) prior to initiation (CRD42023415454). Results Thirty-three studies met our inclusion criteria. The findings indicated that out of the 14 parameters examined, 6 (clivus length, basal angle, Boogard’s angle, supraocciput lengths, posterior cranial fossa [PCF] height, and volume) exhibited significant differences between the CMI group and the control group. Furthermore, apart from certain anatomical parameters that hold prognostic value for CMI, functional parameters like tonsillar movement, obex displacement, and cerebrospinal fluid dynamics serve as valuable indicators for guiding the clinical management of the disease. Conclusion We collated and established a set of linear, angular, and area measurements deemed essential for diagnosing CMI. However, more indicators can only be analyzed descriptively for various reasons, particularly in prognostic prediction. We posit that the systematic assessment of patients’ PCF morphology, volume, and other parameters at a 3-dimensional level holds promising clinical application prospects.

Background: The semi-sitting position offers advantages for surgeries in the posterior cranial fossa. However, data on its safety and effectiveness for clipping aneurysms in the posterior cerebral circulation are limited. This retrospective cohort study evaluates the safety and effectiveness of using the semi-sitting position for these surgeries. Methods: We conducted a retrospective study of 17 patients with posterior cerebral circulation aneurysms who underwent surgical clipping in the semi-sitting position in the Department of Neurosurgery at Hannover Medical School over a 10-year period. Results: The mean age at surgery was 62 years (range, 31 to 75). Fourteen patients were admitted with subarachnoid hemorrhage and 3 patients had incidental aneurysmas. Fifteen patients had PICA aneurysms, and two had aneurysms of the vertebral artery and the superior cerebellar artery, respectively. The median diameter of the aneurysms was 5 mm (range 3–17 mm). Intraoperative venous air embolism (VAE) occurred in 4 patients, without affecting the surgical or clinical course. VAE was associated with a mild decrease of EtCO2 levels in 3 patients and in 2 patients a decrease of blood pressure occurred which was managed effectively. Surgical procedures proceeded as planned in all instances. There were no complications secondary to VAE. Two patients died secondary to respiratory problems (not related to VAE), and one patient was lost to follow-up. Eleven of fourteen patients were partially or completely independent (Barthel index between 60 and 100) at a median follow-up duration of 13.5 months (range, 3–103 months). Conclusion: The semi-sitting position is a safe and effective technique for the surgical clipping of aneurysms in the posterior cerebral circulation. The incidence of VAE is comparable to that seen in tumor surgery. However, it is crucial for the surgical and anesthesiological team to be familiar with potential complications and to react immediately in case of an occurrence of VAE. [ABSTRACT FROM AUTHOR]

Background: Chiari I malformation (CMI) is characterized by inferior descent of the cerebellar tonsils through the foramen magnum and is associated with headache and neck pain. Many morphometric research efforts have aimed to describe CMI anatomy in the midsagittal plane using classical measurement techniques such as linear dimensions and angles. These methods are less frequently applied to parasagittal features and may fall short in quantifying more intricate anatomy with fewer distinct homologous landmarks. Methods: Landmark-based geometric morphometric techniques were used to asses CMI morphology in five anatomical planes of interest. Results: Significant shape differences between CMI and age/sex-matched controls were found in the midsagittal (Pseudo-F=5.4841, p = 0.001) and axial planes through the rostral medulla (Pseudo-F=7.6319, p=0.001). In addition to tonsillar descent, CMI principal component 1 (PC1) scores in the midsagittal protocol were associated with marked anterior concavity of the brainstem and generalized verticality of the cerebellum with anterior rotation of its anterior lobe. In the axial medulla/cerebellum protocol, CMI PC1 scores were associated with greater anterior-posterior (A-P) dimension with loss of medial-lateral (M-L) dimension. Discussion: These results suggest that CMI is associated with greater curvature of the brainstem and spinal cord, which may perturb normal neural activities and disrupt cerebrospinal fluid movements. Previous reports on the A-P diameter of the posterior fossa in CMI have conflicted; our findings of greater A-P cerebellar dimensionality with concomitant loss of width alludes to the possibility that more caudal aspects of the posterior cranial fossa are more bowl-like (homogenous in axial dimensions) and less trough-like or elongated in the M-L direction. [ABSTRACT FROM AUTHOR]

The cerebellum, a major feature of the hindbrain, lies posterior to the pons and medulla and inferior to the posterior part of the cerebrum. It lies beneath the tentorium cerebelli in the posterior cranial fossa and consists of two lateral hemispheres connected by the vermis. The cerebellum is primarily supplied by three arteries originating from the vertebrobasilar system: the superior cerebellar artery (SCA), the anterior inferior cerebellar artery (AICA), and the posterior inferior cerebellar artery (PICA). However, variations of the cerebellar arteries may occur, such as duplication of the SCA, SCA creating a common trunk with the posterior cerebral artery, triplication of the AICA, and agenesis of PICA, amongst others. Knowledge of the arterial anatomy of the cerebellum is crucial, as inadequate blood supply to this region can result in diminished motor functioning, significantly impacting the quality of life for patients. The present study demonstrated the importance of adequate anatomical knowledge of the arteries supplying the cerebellum. The PubMed and Embase databases were searched to gather articles on the anatomical characteristics and variations of the arterial supply of the cerebellum. It is the most comprehensive and up-to-date review available in the literature. The possible variations of these vessels may be clinically silent or present with clinical symptoms such as neurovascular compression syndromes of the cranial nerves and aneurysms. With a comprehensive understanding of the cerebellar arterial system, physicians can enhance their diagnostic and treatment capabilities, ultimately leading to more effective management of cerebellar vascular-related issues and other neurological deficits. [ABSTRACT FROM AUTHOR]

The retrolabyrinthine approach provides shorter working distance and less cerebellar retraction compared with the retrosigmoid approach to the internal acoustic canal (IAC) and cerebellopontine angle cistern. However, exposure of the ventral surface of the brainstem and petroclival region may be restricted. Trautmann's triangle (TT), an area intimately related to this region, demonstrates significant anatomical variability, which may adversely affect the ease of the approach. The aim of this study is to evaluate anatomic parameters of the posterior fossa that may anticipate a challenging situation in approaching the IAC and the petroclival region through the retrolabyrinthine approach. It was performed a radioanatomic analysis of 75 cerebral angiotomography exams to identify parameters that could potentially reduce areas of surgical exposure. Large variations were observed in the area of exposure of the TT (553%) and the height of the jugular bulb (234%). Shorter distances from the sigmoid sinus to the posterior semicircular canal and high-riding jugular bulb were associated with smaller areas of exposure. Dominant and laterally positioned sigmoid sinuses and less pneumatized mastoids were associated with potentially unfavorable conditions, including a narrower angle of attack to the IAC. Increased petrous slopes and petroclival angles were associated with smaller petroclival areas and shallower clival depths. This study of the posterior fossa reveals remarkable anatomic variation in the region. These findings should be taken into consideration during the preoperative planning of retrolabyrinthine approaches in order to offer safer and more effective surgical procedures. [ABSTRACT FROM AUTHOR]

Study Design: A descriptive, quantitative cross-sectional study of the atlantic part (V3) of the vertebral artery (VA). Purpose: This study aimed to bridge the research gap in the morphometry of the V3 segment of the VA in the South Indian population. Overview of Literature: The microsurgical anatomy of this segment of the VA has been explored in various populations, and a thorough understanding of the anatomy and course of the VA, particularly the V3 segment, is essential to prevent iatrogenic complications. Several computed tomography studies but a few cadaveric studies have explored the V3 segment of the VA in the South Indian population. Methods: This study examined 40 VAs from 20 embalmed cadavers that were obtained from the voluntary donation program, and Institutional Ethical Clearance was obtained before the study. The length, diameter, and angle of the vertical, horizontal, and exit parts of the V3 segment of the VA were documented after its exposure. Results: The mean lengths of the right and left VAs on each part were nearly similar, except for the mean length of the horizontal part (right: 38.937 mm, left: 40.237 mm) and total length of the V3 segment (right: 66.870 mm, left: 70.350 mm). Conclusions: These morphometric parameters are essential to spine surgeons who intend to operate on a small part (vertical, horizontal, or exit part) of the V3 segment of the VA. The mean values of the parameters obtained in this study give average measurements or safe limits to surgeons for safe surgical procedures such as the occipital condyle screw technique and C1 laminectomy. [ABSTRACT FROM AUTHOR]

Objective: To quantitatively study the measurement data related to the bony posterior cranial fossa and explore the correlation between bony posterior cranial fossa morphology and the occurrence of hemifacial spasm. Methods: A total of 50 patients with hemifacial spasm who attended the Department of Neurosurgery of China-Japan Friendship Hospital from October 2021 to February 2022 were included, and 60 patients with minor head trauma excluding skull fracture and intracranial abnormalities were included as controls. Cranial multilayer spiral CTs (MSCTs) were performed in both groups, and multiplanar reconstruction (MPR) was used as a postprocessing method to measure data related to the posterior cranial fossa in both groups. Results: Compared with the control group, the anteroposterior diameter (labeled AB) and the height (labeled BE) of the bony posterior cranial fossa, the anteroposterior diameter of the foramen magnum (labeled BC), the length of the clivus (labeled AB), and the length of the posterior occipital (labeled CD) in the HFS group were all reduced, and the differences were statistically significant. BE is positively correlated with AB and CD, with a stronger correlation observed between BE and AB (r = 0.487, p < 0.01). AB is negatively correlated with AD (r = -0.473, p < 0.01). The remaining correlations between the data were not statistically significant. There was no overlap in the 95% confidence interval for any of the measurements between the hemifacial spasm group and the control group. Conclusion: There is a correlation between the posterior cranial fossa and hemifacial spasm. [ABSTRACT FROM AUTHOR]

Background and Objective: Primary hemifacial spasm (HFS) is caused by neurovascular conflict (NVC) at the root entry zone of the facial nerve. Whether reduction of posterior cranial fossa (PCF) cerebrospinal fluid (CSF) volume is a risk factor for HFS is not clear. The study aims at the radiologic assessment of PCF CSF volume and its clinical correlation. Methods: A cross-sectional, hospital-based, case--control study was conducted, in which 50 cases of primary HFS and 50 age- and sex-matched controls were recruited. PCF CSF volume was quantified in 3-T brain magnetic resonance imaging. Results: The mean age at presentation of cases was 50.7 ± 10.7 years (42-69 years) and controls was 52.4 ± 8.7 years (45-68 years). The mean duration of symptoms was 3.5 ± 1.3 years (1.5-8 years). About 52% of patients had grade 2 (mild) severity of HFS. The mean PCF CSF volume of patients was 13,725.1 ± 909.5 mm3 and controls was 14,458.5 ± 973.5 mm³p (P < 0.001). The mean PCF CSF volume of females with HFS was 13,714.8 ± 852.5 mm³ and female controls was 14,521.8 ± 973.5 mm³ (P = 0.006). PCF CSF volume was significantly associated with the presence of HFS (P = 0.007), the severity of HFS (P < 0.001), and the presence of NVC (P = 0.02). Conclusion: PCF CSF volume was lesser in HFS patients and was associated with the presence of HFS, the severity of HFS, and the presence of NVC. Females with HFS had smaller PCF CSF volume. Small PCF CSF volume is a risk factor for HFS, particularly in females with HFS. [ABSTRACT FROM AUTHOR]

Background: Augmentative and Alternative Communication (AAC) improved communicative skills in adults with post-stroke aphasia demonstrating the effectiveness in speech disorders and consequent improvement of patients' communication skills. This study aimed to report the efficacy of AAC in the rehabilitation of cognitive disorders and to estimate how the changes in cognitive and communicative functions could enhance the quality of life in patients affected by severe acquired brain injury. Methods: Three patients with pontine cerebral ischemia, traumatic brain injury (TBI), and meningioma expressed in the posterior cranial fossa, respectively, were submitted to rehabilitative training with AAC for 6 months. Patients underwent to neuropsychological and mood evaluations at the beginning of AAC treatment (T0) and after rehabilitative training (T1). Results: The results support the efficacy of AAC in the improvement of cognitive functions, particularly in memory, attention, and language domains. In addition, we described also an improvement in the quality of life and a decrease in depressive symptoms. Conclusions: The AAC seems to be an important rehabilitative technique for the recovery of cognitive functions with a consequent effect in improvement of psychological aspects and quality of life in patients with Acquired Brain Injury (ABI). [ABSTRACT FROM AUTHOR]

Simple Summary: Numerous diagnostic-imaging-based studies (computed tomography (CT) and magnetic resonance imaging (MRI)) have focused on the shape and size of the skull and neck of small- and toy-breed dogs in relation to disorders of the skull, vertebral column, and spinal cord. No such studies have particularly focused on associations with Chiari-like malformation and syringomyelia (CM/SM) in the Pomeranian dog breed. The aim Part II of this two-part study was to describe and analyze various aspects and measurements of the skull and neck region of Pomeranians in relationship to CM/SM by means of CT and MRI. Classifications of CM/SM and measurements on CT and MRI images were performed for 99 Pomeranians. Among other significant findings, we found that dogs with SM had a shorter skull base based on both MRI and CT measurements, and a significantly smaller skull in the area of the hindbrain. These results provide further insights into the development of CM/SM in Pomeranians. Background: The aim of Part II of this two-part study is to describe and analyze the association of various aspects and measurements related to the morphometry of the skull and craniocervical region to CM/SM status of Pomeranians, by means of computed tomography (CT) and magnetic resonance imaging (MRI). Methods: Prospectively, Pomeranians were included that underwent both CT and MRI studies of the head and cervicothoracic vertebral column. For those cases where qualitative classifications differed between observers, the experienced observer re-evaluated the studies and decided on a final classification that was used for further analysis. For quantitative measurements, the means of the observers' measurements were used for analysis. Results: Among statistically significant differences in measurements, we found that dogs with SM had a significantly shorter clivus length based on both MRI (p = 0.01) and CT measurements (p = 0.01), and a significantly smaller caudal cranial fossa area based on both MRI (p = 0.02) and CT measurements (p = 0.02). Conclusions: Significant morphometrical differences were identified between dogs with or without CM/SM. The findings in this study add to those already described in other breeds and provide further insight into factors that may play a role in the pathogenesis of CM/SM in Pomeranians. [ABSTRACT FROM AUTHOR]

Objectives: The aim of our study to contribute to the field of morphometrics by including measurements of the SAC and SAF and their distances from surrounding structures, particularly for surgeons involved in retrosigmoid approach for internal acoustic meatus tumor surgery and cerebellopontine angle surgery. Although there is limited information in the literature regarding the role of the subarcuate fossa (SAF) and subarcuate canal (SAC), it has been suggested that the SAC may be a potential pathway for infection from the middle ear to the posterior cranial fossa, and cerebellar abscesses may have this origin. Methods: For the images of our study, computerized tomography images of 118 individuals (59 females and 59 males) between the ages of 18–65 who applied to Bayındır Health Group. Results: The width of the cranial opening of the subarcuate canal was determined as 44 ± 0.54 mm, width of the labyrinth opening of the subarcuate canal was determined as 60 ± 0.42 mm, Length of the subarcuate canal was determined as 8.79 ± 2.31 mm, width of the subarcuate canal was determined as 5.54 ± 1.75 mm, and depth of subarcuate fossa was determined as 1.67 ± 0.69 mm. The distance of the cranial opening of the subarcuate canal to the superior semicircular canal (SSC–SAC/C) was measured as 5.33 ± 1.81 mm, The distance of the labyrinth opening of the subarcuate canal to the superior semicircular canal (SSC–SAC/L) was measured as 3.90 ±.98 mm, length of the petrous part of the temporal bone medial to the anterior semicircular canal measured from the apex to the SSCD (PLM) was measured as 33.56 ± 0.42 mm. No statistically significant differences were found between the right and left sides. Conclusions: The morphometric measurements obtained in this study can provide useful information for neurosurgeons, neurotologist and otolaryngologists involved in retrosigmoid approach for internal acoustic meatus tumor surgery and cerebellopontine angle surgery, and for patients undergoing cochlear implant planning with a retrofacial approach. [ABSTRACT FROM AUTHOR]

Embolomeres have been considered candidate stem-amniotes by many authors, but recent work has shown that anatomical and phylogenetic support for this hypothesis may be ambiguous. Newer phylogenetic approaches focus on the anatomy of the endochondral bones surrounding the brain (neurocranium) and associated dermal investing bones, so accurate description of the neurocranium of tetrapods, and particularly embolomeres, is critical to assess the phylogenetic context of amniote origins. I here amend prior descriptions of the neurocranium of the abundant Early Permian embolomere, Archeria crassidisca , with a description of a previously unreported partial braincase. This specimen reveals features broadly associated with stem-tetrapods of the fin-to-limb transition and recently described in aïstopod stem-tetrapods, including a cranial notochordal remnant, a possible buccohypophyseal canal, and anteroventrally projecting saccular fossae that extend deep into the basioccipital. I present an amended description and reconstruction of the neurocranium and a phylogenetic analysis integrating these codings, which recovers embolomeres more robustly within the tetrapod stem. I review characters previously used to assign embolomeres to the amniote stem and find this evidence is ambiguous or incorrect. I then outline strong character support for a stem-tetrapod position of embolomeres, and implications for the ancestral body plan of crown-group tetrapods. [ABSTRACT FROM AUTHOR]

Background: The most dangerous and least curable type of stroke is spontaneous intracerebral hemorrhage (ICH), and prognosis is highly correlated with location and size in the posterior fossa. The objective of this work was to estimate the frequency of posterior fossa hemorrhage (PFH) in Tanta University Hospitals, as well as identify functional outcomes and mortality in PFH. Methods: This study was performed on 33 posterior fossa hemorrhagic patients and 119 posterior ischemic stroke patients (PCIS) submitted to the CT brain and the MRI brain, using the following scales: GCS and NIHSS, and the intracerebral hemorrhage scale (ICH score). Results: Posterior fossa hemorrhage (PFH) represents 16.83% of total hemorrhagic stroke in the ER. Vertigo and DCL are more common in PFH (60.6%, 48.4%) than in PCIS. 82% of PFH patients had hypertension (HTN) hemorrhage. The cerebellum is the most common site for PFH (48%), pontine (24%), thalamic (18%), and midbrain (9%). PFH had unfavorable outcomes in 55% of the studied patients; the MRS mean was 4; and 39% died in the follow-up. Conclusion: Posterior fossa hemorrhage is a potentially serious neurovascular emergency associated with complex symptomatology. PFH demonstrates diverse prognoses depending on the location of the intracerebral hemorrhage and the size of the hematoma. [ABSTRACT FROM AUTHOR]

The article focuses on Chiari malformation type 1 (CM1), discussing both congenital and acquired forms of the condition. It details the anatomical characteristics where the cerebellar tonsils descend below the foramen magnum, leading to potential obstruction of cerebrospinal fluid (CSF) flow and compression of the brainstem and upper spinal cord. It emphasizes the clinical manifestations such as headaches, neurological symptoms, and the diagnostic criteria involving MRI imaging.

Background: Chiari malformation type 1 (CM-1) involves the cerebellar tonsils' descent below the foramen magnum. In Chiari malformation type 1.5 (CM-1.5), both the cerebellar tonsils and the brainstem are herniated. Common symptoms include headaches and cervical pain, often associated with conditions like syringomyelia and hydrocephalus. Surgical treatment is not performed in asymptomatic patients, while the presence of syringomyelia represents an indication for surgery. Methods: This study retrospectively examined pediatric patients with CM-1 and CM-1.5 at Giannina Gaslini Hospital from 2006 to 2020, analyzing demographics, radiological findings, surgical interventions, and outcomes. Results: Out of 211 patients who underwent surgery, 83.9% were diagnosed with CM-1 and 16.1% with CM-1.5. Headaches were prevalent (69%) and cerebellar signs were noted in 29% of patients. Syringomyelia and hydrocephalus were present in 28.4% and 8% of cases, respectively. Intraoperative ultrasonography guided interventions, with 59.8% requiring bony and ligamentous decompression, and 27.1% undergoing duraplasty. Conclusions: The surgical treatment of CM-1/CM-1.5 involves posterior cranial fossa decompression. Choosing between bony decompression alone and its combination with duraplasty has always been controversial in the pediatric population. If we consider as surgical endpoint the restoration of cerebrospinal fluid (CSF) flux, intraoperative ultrasound may be a real-time helpful tool in orienting the surgical strategy, yet refinement with quantitative measures is needed. [ABSTRACT FROM AUTHOR]

Neuronavigation systems coupled with previously reported external anatomical landmarks assist neurosurgeons during intracranial procedures. We aimed to verify whether the posterior auricularis muscle (PAM) could be used as an external landmark for identifying the sigmoid sinus (SS) and the transverse-sigmoid sinus junction (TSSJ) during posterior cranial fossa surgery. The PAM was dissected in 10 adult cadaveric heads and after drilling the underlying bone, the relationships with the underlying SS and TSSJ were noted. The width and length of the PAM, and the distance between the muscle and reference points (asterion, mastoid tip, and midline), were measured. The PAM was identified in 18 sides (9 left, 9 right). The first 20 mm of the muscle length (mean 28.28 mm) consistently overlay the mastoid process anteriorly and the proximal half of the SS slightly posteriorly on all sides. The superior border was a mean of 2.22 mm inferior to the TSSJ and, especially when the muscle length exceeded 20 mm, this border extended closer to the transverse sinus; it was usually found at a mean of 3.11 mm (range 0.0–13.80 mm) inferior to the distal third of the transverse sinus. Superficial landmarks give surgeons improved surgical access, avoiding overexposure of deep neurovascular structures and reducing brain retraction. On the basis of our cadaveric study, the PAM is a reliable and accurate direct landmark for identifying the SS and TSSJ. The PAM could potentially be used for guiding the retrosigmoid approach. [ABSTRACT FROM AUTHOR]

Venous sinus thromboses (VSTs) are rare complications of neurosurgical procedures in the proximity of the dural sinuses. Surgery of the posterior cranial fossa (PCF) and particularly of the cerebellopontine angle (CPA) shows increased risk of VST. VST management is challenging because anticoagulant therapy must be balanced with the risk of postoperative bleeding. We performed a systematic review and meta-analysis to summarize the most important neuroradiologic and clinical aspects of VST after PCF/CPA surgery. We performed a comprehensive literature search to identify articles reporting data on VST after PCF/CPA surgery. We selected only comparative studies providing adequate neuroimaging assessing VST and a control group. We included 13 articles reporting 1855 patients. VST occurred in 251/1855 cases (estimated incidence, 17.3%; 95% confidence interval [CI], 12.4%–22.2%). Only presigmoid approach (odds ratio [OR], 2.505; 95% CI, 1.161–5.404; P = 0.019) and intraoperative sinus injury (OR, 8.95; 95% CI, 3.43–23.34; P < 0.001) showed a significant association with VST. VST-related symptoms were reported in 12/251 patients with VST (pooled incidence, 3.1%; 95% CI, 1%–5.2%). In particular, we found a significantly increased OR of cerebrospinal fluid leak (OR, 3.197; 95% CI, 1.899–5.382; P < 0.001) and cerebrospinal fluid dynamic alterations in general (OR, 3.625; 95% CI, 2.370–5.543; P < 0.001). Indications for VST treatment were heterogeneous: 58/251 patients underwent antithrombotics, with 6 treatment-related bleedings. Recanalization overall occurred in 56.4% (95% CI, 40.6%–72.2%), with no significant difference between treated and untreated patients. However, untreated patients had a favorable outcome. VST is a relatively frequent complication after PCF/CPA surgery and a presigmoid approach and intraoperative sinus injury represent the most significant risk factors. However, the clinical course is generally benign, with no advantage of antithrombotic therapy. [ABSTRACT FROM AUTHOR]

Objective: Imaging parameters of Chiari malformation type I (CMI) development are not well established. This study aimed to collect evidence of general or specific imaging measurements in patients with CMI, analyze indicators that may assist in determining the severity of CMI, and guide its diagnosis and treatment. Methods: A comprehensive search was conducted across various databases including the Cochrane Library, PubMed, MEDLINE, Scopus, and Embase, covering the period from January 2002 to October 2023, following predefined inclusion criteria. Meta-analyses were performed using RevMan (ver. 5.4). We performed a quantitative summary and systematic analysis of the included studies. This study was registered in the PROSPERO (International Prospective Register of Systematic Reviews) prior to initiation (CRD42023415454). Results: Thirty-three studies met our inclusion criteria. The findings indicated that out of the 14 parameters examined, 6 (clivus length, basal angle, Boogard's angle, supraocciput lengths, posterior cranial fossa [PCF] height, and volume) exhibited significant differences between the CMI group and the control group. Furthermore, apart from certain anatomical parameters that hold prognostic value for CMI, functional parameters like tonsillar movement, obex displacement, and cerebrospinal fluid dynamics serve as valuable indicators for guiding the clinical management of the disease. Conclusion: We collated and established a set of linear, angular, and area measurements deemed essential for diagnosing CMI. However, more indicators can only be analyzed descriptively for various reasons, particularly in prognostic prediction. We posit that the systematic assessment of patients' PCF morphology, volume, and other parameters at a 3-dimensional level holds promising clinical application prospects. [ABSTRACT FROM AUTHOR]

Objective: Identify the benefits and caveats of combining minimal access approaches to the infratemporal fossa (ITF), such as the endoscopic transnasal, endoscopic transorbital, endoscopic transoral, and endoscopic sublabial transmaxillary approaches to address extensive lesions not amenable to a single approach. The study provides anatomical metrics including area of exposure and degree of surgical freedom. Methods: Five human cadaveric specimens (10 sides) were dissected to expose and methodically analyze the anatomical intricacies of the ITF using the following minimal access approaches: endoscopic transnasal transpterygoid (EETA), endoscopic sublabial transmaxillary, endoscopic transorbital via infraorbital foramen, and endoscopic transoral techniques. Area of exposure at the pterygopalatine fossa and surgical freedom at the ITF were obtained for each approach. Results: The endoscopic sublabial transmaxillary sinus and the combined approach afford a significantly greater exposure than an isolated EETA. The difference in exposure (mean) between the endoscopic sublabial transmaxillary and EETA was 1.62 ± 0.85 cm2 (p < 0.001), and the difference between the combined approach and EETA was 4.25 ± 0.85 cm2 (p < 0.001). Conclusions: Combining minimal access endoscopic approaches to the ITF can provide significantly greater exposure than an isolated EETA; thus, providing enhanced access to address lesions with extensive involvement of the ITF, especially those with superolateral and inferolateral extensions. In addition, some approaches may have an adjunctive role to the resection, such as the endoscopic transoral approach offering the potential for early control of the internal maxillary artery and its branches, some of which may be supplying the tumor in the ITF; or the endoscopic transorbital approach yielding a direct line of sight to the superior ITF and middle cranial fossa. Level of Evidence: NA. [ABSTRACT FROM AUTHOR]

This article discusses the identification of partial hydatidiform mole (PHM) using non-invasive single-cell sequencing of fetal circulating extravillous trophoblasts (cEVTs) isolated from maternal blood. PHM is a condition that is typically triploid and associated with risks such as pre-eclampsia and gestational trophoblastic disease. The article presents a case study where a novel cell-based non-invasive prenatal testing (CB-NIPT) platform was used to accurately diagnose PHM. The study found that the number of cEVTs recovered from maternal blood was significantly higher in the PHM case compared to healthy controls, suggesting the potential for cEVTs as an early marker for associated hypertensive disorders and pre-eclampsia. Early diagnosis of PHM is crucial for optimal management and this study demonstrates the potential of CB-NIPT technology for early blood-based detection of PHM. [Extracted from the article]

The topographic anatomy of the abducens nerve has been the subject of research for more than 150 years. Although its vulnerability was initially attributed to its length, this hypothesis has largely lost prominence. Instead, attention has shifted toward its intricate anatomical relations along the cranial base. Contrary to the extensive anatomical and neurosurgical literature on abducens nerve anatomy in humans, its complex anatomy in other species has received less emphasis. The main question addressed here is why the human abducens nerve is predisposed to injury. Specifically, we aim to perform a comparative analysis of the basicranial pathway of the abducens nerve in mammals and primates. Our hypothesis links its vulnerability to cranial base flexion, particularly around the sphenooccipital synchondrosis. We examined the abducens nerve pathway in various mammals, including primates, humans (N = 40; 60% males; 40% females), and human fetuses (N = 5; 60% males; 40% females). The findings are presented at both the macroscopic and histological levels. To associate our findings with basicranial flexion, we measured the cranial base angles in the species included in this study and compared them to data in the available literature. Our findings show that the primitive state of the abducens nerve pathway follows a nearly flat (unflexed) cranial base from the pontomedullary sulcus to the superior orbital fissure. Only the gulfar segment, where the nerve passes through Dorello's canal, demonstrates some degree of variation. We present evidence indicating that the derived state of the abducens pathway, which is most pronounced in humans from an early stage of development, is characterized by following the significantly more flexed basicranium. Overall, the present study elucidates the evolutionary basis for the vulnerability of the abducens nerve, especially within its gulfar and cavernous segments, which are situated at the main synchondroses between the anterior, middle, and posterior cranial fossae--a unique anatomical relation exclusive to the abducens nerve. The principal differences between the pathways of this nerve and those of other cranial nerves are discussed. The findings suggest that the highly flexed human cranial base plays a pivotal role in the intricate anatomical relations and resulting vulnerability of the abducens nerve. [ABSTRACT FROM AUTHOR]

In this report, we described the clinical, ultrasound, contrast-enhanced T2-weighted brain magnetic resonance imaging (MRI), and histopathological findings of a retinoblastoma-like tumor with brain metastasis in a 3-year-old male Border Collie. Ophthalmoscopic and ultrasonographic examination revealed leukocoria associated with a solid mass of retinal origin in the left eye. Simultaneous contrast-enhanced T2-weighted brain MRI evaluation revealed solid masses at three different locations: the first one at the levels of the suprasellar cistern, third ventricle and chiasma opticum; the second one in the medulla oblongata adjacent to the caudal cranial fossa; and the third one in the left intraocular region. Histopathological examination of the extracted mass in the globe revealed a retinoblastoma-like tumor. The patient died before receiving radiotherapy treatment. In conclusion: this report highlights the importance of early diagnosis through ophthalmoscopic and ultrasonographic examinations. Emphasizing the brain as a potential secondary metastatic site, the report underscores the critical need to create a window for timely radiotherapy. Furthermore, the recommendation is made to evaluate dogs with leukocoria during ophthalmoscopic examination for both retinoblastoma and potential brain metastasis. [ABSTRACT FROM AUTHOR]

The transorbital approach (TOA) is gaining popularity in skull base surgery scenarios. This approach represents a valuable surgical corridor to access various compartments and safely address several intracranial pathologies, both intradurally and extradurally, including tumors of the olfactory groove in the anterior cranial fossa (ACF), cavernous sinus in the middle cranial fossa (MCF), and the cerebellopontine angle in the posterior cranial fossa (PCF). The TOA exists in many variants, both from the point of view of invasiveness and from that of the entry point to the orbit, corresponding to the four orbital quadrants: the superior eyelid crease (SLC), the precaruncular (PC), the lateral retrocanthal (LRC), and the preseptal lower eyelid (PS). Moreover, multiportal variants, consisting of the combination of the transorbital approach with others, exist and are relevant to reach peculiar surgical territories. The significance of the TOA in neurosurgery, coupled with the dearth of thorough studies assessing its various applications and adaptations, underscores the necessity for this research. This extensive review delineates the multitude of target lesions reachable through the transorbital route, categorizing them based on surgical complexity. Furthermore, it provides an overview of the different transorbital variations, both standalone and in conjunction with other techniques. By offering a comprehensive understanding, this study aims to enhance awareness and knowledge regarding the current utility of the transorbital approach in neurosurgery. Additionally, it aims to steer future investigations toward deeper exploration, refinement, and exploration of additional perspectives concerning this surgical method. [ABSTRACT FROM AUTHOR]

Postoperative pediatric cerebellar mutism syndrome (CMS) may occur following a process affecting the posterior cranial fossa. Recent evidence demonstrates disabling and potentially lasting motor components of this syndrome, including ataxia, hemiparesis, and oculomotor dysfunction. These impairments may contribute to vestibular deficits. This case series contributes data to quantify vestibular dysfunction in postoperative CMS. The pair consisted of one female and one male. Vestibular testing demonstrated both peripheral and central dysfunction. Given these findings, a thorough vestibular assessment may be indicated as part of a comprehensive evaluation following a postoperative CMS diagnosis. Further research is needed to understand the pathophysiology, treatment, and long-term outcomes of postoperative pediatric CMS. [ABSTRACT FROM AUTHOR]

The prominent retrocerebellar cerebrospinal fluid (CSF) space can be frequently encountered on paediatric neuroimaging studies. In cases involving abnormal vermian development where imaging does not align with the established criteria of Dandy–Walker malformation (DWM), the term "Dandy–Walker variant or continuum" has been historically employed to describe the aberrant posterior fossa development. Instead, the emphasis is on a more elaborate description of the findings in the posterior fossa. Moreover, combining the findings in the supratentorial brain can occasionally predict certain neurogenetic disorders that mimic Dandy–Walker phenotype. The present review demonstrates and differentiates the imaging features of various entities that result in an enlarged retrocerebellar CSF space, such as inferior vermian hypoplasia (IVH) and several neurogenetic conditions. [ABSTRACT FROM AUTHOR]

Medulloblastoma is the most common malignant brain tumor in childhood. Initial treatment generally includes surgery, irradiation, and chemotherapy. Approximately 20–30% of patients will experience a recurrence, which portends a very poor prognosis. The current standard of care for evaluation for relapse includes radiographic surveillance with magnetic resonance imaging at regular intervals. The presence of circulating tumor DNA in the cerebrospinal fluid has been demonstrated to be a predictor of a higher risk of progression in a research setting for patients with medulloblastoma treated on a prospective single institution clinical trial. We have previously published and clinically validated a liquid-biopsy-based genetic assay utilizing low-pass whole genome sequencing to detect copy number alterations in circulating tumor DNA. Here, we present two teenage patients with posterior fossa medulloblastoma with recurrent disease who have been monitored with serial liquid biopsies showing tumor evolution over time, demonstrating the clinical utility of these approaches. [ABSTRACT FROM AUTHOR]

This article presents a comparative study on the anatomical assessment of the foramen magnum (FM) among the South Indian population using CT scans. The study found that the most common shape of the FM in both dry skulls and CT scan images was hexagonal. There were no significant differences in measurements between the two methods. The study provides valuable information for surgeons and medical professionals. The document is a list of references to various studies and articles related to the anatomical assessment of the foramen magnum and spinal cord, which can be useful for researchers studying these features in different populations. [Extracted from the article]

Background: Segmentation tools continue to advance, evolving from manual contouring to deep learning. Researchers have utilized segmentation to study a myriad of posterior fossa-related conditions, such as Chiari malformation, trigeminal neuralgia, post-operative pediatric cerebellar mutism syndrome, and Crouzon syndrome. Herein, we present a summary of the current literature on segmentation of the posterior fossa. The review highlights the various segmentation techniques, and their respective strengths and weaknesses, employed along with objectives and outcomes of the various studies reported in the literature. Methods: A literature search was conducted in PubMed, Embase, Cochrane, and Web of Science up to November 2023 for articles on segmentation techniques of posterior fossa. The two senior authors searched through databases based on the keywords of the article separately and then enrolled joint articles that met the inclusion and exclusion criteria. Results: The initial search identified 2205 articles. After applying inclusion and exclusion criteria, 77 articles were selected for full-text review after screening of titles/abstracts. 52 articles were ultimately included in the review. Segmentation techniques included manual, semi-automated, and fully automated (atlas-based, convolutional neural networks). The most common pathology investigated was Chiari malformation. Conclusions: Various forms of segmentation techniques have been used to assess posterior fossa volumes/pathologies and each has its advantages and disadvantages. We discuss these nuances and summarize the current state of literature in the context of posterior fossa-associated pathologies. [ABSTRACT FROM AUTHOR]

The primary aim of this study was to estimate the incidence of posterior fossa anomalies (PFA) and assess the associated outcomes in King Abdulaziz Medical City (KAMC), Riyadh. All fetuses diagnosed by prenatal ultrasound with PFA from 2017 to 2021 in KAMC were analyzed retrospectively. PFA included Dandy–Walker malformation (DWM), mega cisterna magna (MCM), Blake's pouch cyst (BPC), and isolated vermian hypoplasia (VH). The 65 cases of PFA were 41.5% DWM, 46.2% MCM, 10.8% VH, and 1.5% BPC. The annual incidence rates were 2.48, 2.64, 4.41, 8.75, and 1.71 per 1000 anatomy scans for 2017, 2018, 2019, 2020, and 2021, respectively. Infants with DWM appeared to have a higher proportion of associated central nervous system (CNS) abnormalities (70.4% vs. 39.5%; p-value = 0.014) and seizures than others (45% vs. 17.9%; p-value = 0.041). Ten patients with abnormal genetic testing showed a single gene mutation causing CNS abnormalities, including a pathogenic variant in MPL, C5orf42, ISPD, PDHA1, PNPLA8, JAM3, COL18A1, and a variant of uncertain significance in the PNPLA8 gene. Our result showed that the most common PFA is DWM and MCM. The autosomal recessive pathogenic mutation is the major cause of genetic disease in Saudi patients diagnosed with PFA. [ABSTRACT FROM AUTHOR]

Background: The posterior cranial fossa and the foramen magnum are the key anatomical components of the craniovertebral junction, which contain and transmit numerous vital neurovascular structures. Through foramen magnum important neural elements, the 7th to 12th cranial nerves, the cervical spinal nerves, the brainstem, the rostral aspect of the spinal cord, the cerebellum and the vermis, as well as various vascular structures such as the vertebral artery and its branches, the meningeal vessels and the venous sinuses. Materials and Methods: The present study conducted with 154 adult dry skull. We have observed the shapes of foramen magnum and classified as oval, round, tetragonal, pentagonal, hexagonal and irregular in shape. We have recorded morphometric measurements like anterior-posterior diameter and transverse diameter of foramen magnum. Values of each measurement were expressed in the form of Mean+SD. Results: Oval shape foramen magnum was observed in 52 number of skulls and the incidence was 33.76%, tetragonal shape was observed in 31 number of skulls and the incidence was 20.12%, hexagonal shape was observed in 18 number of skulls and the incidence was 11.68%, round shape was observed in 26 number of skulls and the incidence was 16.88%, pentagonal shape was observed in 13 number of skulls and the incidence was 8.44% and pear shape was observed in 14 number of skulls and the incidence was 9.12%. The Anterior - Posterior diameter (mm) Foramen Magnum was 36.84+4.62mm. The transverse diameter (mm) foramen magnum 30.45+2.82mm. Conclusion: In present study findings concludes hat the results may be helpful to the neurosurgeon in analysing the morphological anatomy of craniovertebral junction. The findings are also assisting in their pracice for the anthropologists, morphologists and clinical anatomists. [ABSTRACT FROM AUTHOR]

Introduction: Posterior fossa extradural hematoma (PFEDH) is an infrequent occurrence in traumatic brain injuries, constituting approximately 4-7% of all extradural hematomas (EDHs). Despite its rarity, PFEDH demands urgent attention as it can swiftly lead to a fatal outcome unless promptly identified and addressed. The posterior fossa's confined space means that even a relatively small hematoma volume can result in clinical deterioration. Early detection through cranial computed tomography is imperative, and immediate evacuation is essential for a positive prognosis. The critical nature of PFEDH underscores the necessity for rapid intervention to prevent irreversible neurological damage and reduce the risk of mortality. Materials and methods: This study was conducted at Department of Neurosurgery, Gajra Raja Medical College, Gwalior, Madhya Pradesh, India from a period of July 2021 to June 2023 of 23 cases of PFEDHs. Records of patients with PFEDHs were reviewed for the mode of injury, Glasgow Coma Scale (GCS) at admission, imaging, type of intervention, outcome, and follow-up. GCS was assessed at 6 months. Results: Of these 23 patients, 17 were males and 6 females. The mean age of patients was 25 year .12 patients had GCS 15 at admission, and only 4 of them had GCS <8. Mean EDH volume was 25 ml. 20 patients were operated, 3 managed conservatively. 21 patients were discharged, Two patients died. At 6 months follow-up, 20 patients had good reovery (Glasgow Outcome Score [GOS] 5). Conclusions: Posterior fossa extradural hematomas (PFEDH) are uncommon occurrences often linked with occipital bone fractures and occasionally accompanied by supratentorial hematomas. The rapid fatality of PFEDH results from hematoma expansion, which compromises the limited space in the posterior cranial fossa. This compression can lead to severe consequences such as brainstem compression, tonsillar herniation, and obstructive hydrocephalus. Timely identification and urgent evacuation through medical intervention are pivotal for a positive outcome in PFEDH cases. [ABSTRACT FROM AUTHOR]