Area Of Foramen Magnum Research Articles

Perioperative Segmentation of the Posterior Fossa and the Keel of Goodrich in Surgical Outcomes of Chiari Malformations

BackgroundChiari I malformation (CM- I) is defined as the extension of brain tissue into the spinal cord. This study aimed to refine the methodology for the acquisition of 3-dimensional measurements of the posterior fossa and introduce occipital keel size as a new marker and its impact in patients with CM. Materials and MethodsIn this retrospective study, all patients who underwent Chiari decompression surgery at Montefiore Medical Center from April 2012 to April 2022 were included. Perioperative clinical information was obtained in addition to maximal keel thickness (KT), foramen magnum area, and pre-and postoperative posterior fossa volumes for each patient and age-matched controls. Volumetric measurements were obtained using AI-based semiautomated segmentation. ResultsA total of 107 patients with CM including 37 males, and 70 females were studied with a mean age of 26.56±17.31 compared with 103 controls without CM. The comparison between the CM and the general population groups demonstrated a significantly increased keel size in Chiari patients. Keel size had a significant relationship with dysphagia, paresthesia, and intraoperative blood loss, while posterior volume change had a significant relationship with sex and early symptomatic improvement. The Foramen magnum area was related to tonsillar descent and more prominent in patients with spina bifida. ConclusionThe Keel of Goodrich is a new anatomical factor that should be taken into consideration when evaluating preoperative symptoms, and intraoperative complications in patients with CM-1. Volumetric analyses demonstrated that posterior fossa volume change had a significant impact on early symptom improvement in patients with Chiari, as did the choice of operative approach. The routine use of semi-automated segmentation of the posterior fossa may help stratify Chiari patients in the future and should be implemented in routine clinical care.

Surgical management of a foramen magnum tumor via a far-lateral approach using an oblique straight incision: a case series report and technique note.

To review our single-institution experience in the surgical management of foramen magnum tumors via a far-lateral approach using an oblique straight incision. From October 2023 to January 2024, four cases of tumors in the foramen magnum area treated at the Capital Medical University-affiliated XuanWu hospital neurosurgery department were involved in this study. All cases were managed with a far-lateral approach using an oblique straight incision. We retrospectively reviewed the clinical and imaging data, as well as the surgical strategies employed. Three cases of foramen magnum meningiomas and one case of glioma of the ventral medulla. All cases underwent a far-lateral approach using an oblique straight incision; all cases had a gross total resection, and the wounds healed well without cerebral fluid leakage or scalp hydrops. Except for one case of right foramen magnum meningioma, which had dysphagia and pneumothorax, the other cases were without any postoperative complications. A far-lateral approach using an oblique straight incision can preserve muscle integrity and minimize subcutaneous exposure, allowing for complete anatomical reduction of muscles. This craniectomy method is simple and replicable, making it worthy of further clinical practice.

Morphometric evaluation of the foramen magnum in the West African population: Implications for neurosurgical interventions

Background and objectivesWhile various pathologies affecting the foramen magnum region can have severe consequences, little research has been conducted on the unique morphological patterns in the West African subregion. The study aimed to assess these patterns and their implications for surgeries, comparing them with global standards. MethodsA descriptive study was conducted on 315 patients over a two-year period, excluding those with specific abnormalities. Measurements obtained from cranial 1.5T MRI scans included anteroposterior and transverse diameters of the foramen magnum. From these, the foramen magnum area and index were calculated. The data was analyzed by inferential, comparative and descriptive statistics, and a p value < 0.05 was regarded as statistically significant. ResultsOn average, the transverse and anteroposterior diameters were 28.51 mm and 33.02 mm for males and 28.39 mm and 33.47 mm for females, with a slightly smaller foramen magnum area in males (7.42 cm²) compared to females (7.47 cm²). Despite these differences, the variations were not statistically significant. However, the foramen magnum indices indicated medium size configuration for females and large size configuration for males, aligning with global trends. ConclusionThe study concluded that West Africans exhibited lower foramen magnum area and indices compared to other regions, with minor differences between sexes. Females tended to have a medium size configuration, while males tended to have a larger size configuration. These findings provide valuable insights for clinicians, highlighting the importance of considering ethno-regional variations in surgical approaches and interventions related to the craniocervical junction.

Sex determination from foramen magnum parameters in Thai cadaveric donor

The foramen magnum (FM) occupies a well-protected position, making it particularly intriguing for forensic research. The necessity for methods to estimate sex from cranial fragments becomes evident when only a partial skull is available for identification. The objective of this study was to assess sex differences in anthropometric measurements, including the length of the foramen magnum (FML), width of the foramen magnum (FMW), foramen magnum area (FMA), and circumference, with the aim of developing a binary logistic regression model in Thai cadaveric donors. Sixty adult dry skulls underwent both intraclass and interclass correlation analyses. Subsequently, 240 adult dry skulls of known sex (120 males and 120 females) were meticulously measured and analyzed to determine the optimal threshold for sex determination. Morphometric analysis of the FM was carried out using vernier calipers, and the area of the FM was precisely calculated. The FML, FMW, FMA, and circumference were all found to be significantly larger in males than in females. Furthermore, FM circumference exhibited an AUC (Area Under the Curve) value of 0.908, signifying it as an excellent parameter for sex discrimination. Lastly, binary logistic regression was executed. Significant sex differences in FM circumference were consistently observed, demonstrating an accuracy of 81.62% when validated in 120 dry skulls.

Low-dose infigratinib increases bone growth and corrects growth plate abnormalities in an achondroplasia mouse model.

Achondroplasia (ACH), the most common form of disproportionate short stature, is caused by gain-of-function point mutations in fibroblast growth factor receptor 3 (FGFR3). Abnormally elevated activation of FGFR3 modulates chondrocyte proliferation and differentiation via multiple signaling pathways, such as the MAPK pathway. Using a mouse model mimicking ACH (Fgfr3Y367C/+), we have previously shown that daily treatment with infigratinib (BGJ398), a selective and orally bioavailable FGFR1-3 inhibitor, at a dose of 2mg/kg, significantly increased bone growth. In this study, we investigated the activity of infigratinib administered at substantially lower doses (0.2 and 0.5mg/kg, given once daily) and using an intermittent dosing regimen (1mg/kg every 3days). Following a 15-day treatment period, these low dosages were sufficient to observe significant improvement of clinical hallmarks of ACH such as growth of the axial and appendicular skeleton and skull development. Immunohistological labeling demonstrated the positive impact of infigratinib on chondrocyte differentiation in the cartilage growth plate and the cartilage end plate of the vertebrae. Macroscopic and microcomputed analyses showed enlargement of the foramen magnum area at the skull base, thus improving foramen magnum stenosis, a well-recognized complication in ACH. No changes in FGF23 or phosphorus levels were observed, indicating that the treatment did not modify phosphate homeostasis. This proof-of-concept study demonstrates that infigratinib administered at low doses has the potential to be a safe and effective therapeutic option for children with ACH.

Morphometric analysis of posterior cranial fossa and foramen magnum and it’s clinical implications in craniovertebral junction malformations: a computed tomography based institutional study in a tertiary care hospital of northern part of India

BackgroundThe posterior cranial fossa (PCF) and the foramen magnum (FM) are the critical anatomical components of the craniovertebral junction region, which comprise and transmit numerous vital neurovascular structures. So, a fundamental knowledge of the basic radiological anatomy of PCF and FM is of paramount importance in the evaluation of associated pathologies and approaching these areas surgically. The aim of this study is to describe different linear and angular craniometric parameters of PCF, FM and surrounding territory based on reconstructed computed tomography (CT) images.Material and methodsThis study was conducted in our tertiary care hospital in northern India from the period of January 2023 to June 2023 on 120 patients, and CT screening was done for the head and spine region following a history of head injury.ResultsIn this study, 120 patients were included, of whom 50.83% (n = 61) were females and 49.17% (n = 59) were males. Age ranged from 18 to 70 years with mean age of 43.5 ± 14.08 years. The mean values for linear craniometric parameters of PCF were statistically nonsignificant for different age groups. Statistically significant differences were found for twinning line (TL) (p < 0.0001), McRae’s line (< 0.0001), clivus length (< p < 0.0001), internal occipital protuberence -opisthion line (p = 0.01), Klaus’ index (p < 0.0001), height of posterior fossa (h) (p < 0.0001), h/TL (p = 0.028), when these values were compared for the genders. The measurements of FM transverse diameter, anteroposterior diameter and area were 27.12 ± 1.42 mm (range 23.6–30.1 mm), 30.99 ± 2.23 mm (range 27.6–35.8 mm) and 691.32 ± 30.35 mm2 (range 632.7–777.7 mm2). The values of clivus canal angle (p = 0.038) and clivoodontoid angle (p = 0.012) were statistically significant when compared for different age groups. The values of Boogard’s angle (p = 0.021) and tentorial slope (p = 0.031) were statistically significant when these were compared for the genders.ConclusionsThis study described almost all the linear and angular craniometric parameters used in the morphometric analysis of PCF and FM. The findings of this study provide valuable data regarding linear and angular craniometric parameters of PCF and FM which can redefine reference values.

Anatomical assessment of foramen magnum among the South Indian population – A CT scan comparative study

Background: Foramen magnum (FM) is the most prominent opening in the floor of the posterior cranial fossa. Occipital condyle (OC) protrusion into the FM alters the measurements and produces an impact on the surgical access. Diagnostic modalities such as computed tomography (CT) and magnetic resonance imaging scan made revolutionary changes in assessing the skull base. Aims and Objectives: The aim of our study is to measure the morphometric measurements of FM, OC and assess the shapes of the FM. Materials and Methods: An observational descriptive study on morphometric measurements of FM and OC is conducted in dry skulls and CT scan images. Area, index, and shapes of FM were calculated and tabulated. Relationship between the FM dimensions was statistically analyzed using student t-test (P &lt; 0.05). Results: There was no significant difference of means (P &gt; 0.05) between the FM and OC parameters with respect to dry skulls and CT measurements. The study results showed that CT is good in predicting the measurements of FM. Our results on shapes of FM showed highest occurrence of the hexagonal (28.57%) followed by diamond shape (22.8%) in dry skulls and CT images. On applying the kappa statistics, there was no agreement in shapes of FM between dry skulls and CT images. Conclusion: Our study hopes to provide extensive knowledge of FM and OC for the operative surgeons and aids in the reduction of iatrogenic complications.

Clinical significance of morphological and morphometrical analysis of foramen magnum

Introduction: The foramen magnum is a transitional zone between cranial cavity and spinal canal, and it is related with the very important neuro-vascular structures like vertebral arteries, spinal accessory nerves and spinal arteries and terminal part of medulla oblongata. Therefore, thorough knowledge of morphometric and morphological variation of foramen magnum is important for authentic radiological diagnosis and surgeries in the area of cranio-cervical junction. Materials and Methods: This study was done on 70 dried human skulls taken from the Department of Anatomy, TS Misra Medical College &amp; Hospital, Era’s Lucknow Medical College &amp; Hospital, and KGMU, Lucknow. The shape of foramen magnum was observed and transverse and antero-posterior (AP) diameters of foramen magnum (FM) were measured with the help of vernier caliper. Foramen magnum index (FMI) and foramen magnum area (FMA) were also calculated. Results: The study showed six types of shapes of foramen magnum. The oval shaped foramen magnum was found in 47% (in 33 skulls), round 30% (in 30 skulls), tetragonal 10 % (in 10 skulls), triangular &amp; irregular 10% (in 5-5 skulls), pentagonal 2% (in 2 skulls), and hexagonal 1% (in single skull). The mean anteroposterior and transverse diameter were 34.3±2.90mm and 28.9±2.80 mm respectively. The mean foramen magnum index and Foramen magnum area were 77.80±27.80 and 845.90±87.50 mm2 respectively. Conclusions: The data obtained from the present study will be useful to the neurosurgeons prior to the surgeries in the area of cranio-cervical junction and posterior cranial fossa. The morphometric and morphological knowledge of the foramen Magnum has important clinical implications in the prognosis and treatment of various neurological pathologies like Arnold Chiari syndrome, Achondroplasia and posterior cranial fossa lesions. Keywords: Foramen magnum, Transcondylar approach, Foramen magnum index, Foramen magnum area, Transverse diameter (TD), Anteroposterior diameter, Trigonal.

Unravelling the pathogenesis of foramen magnum stenosis in patients with severe achondroplasia: a CT-based comparison with age-matched controls and FGFR3 craniosynostosis syndromes.

Foramen magnum(FM) stenosis can be responsible for acute and chronic damage to the cervicomedullary junction in children with achondroplasia. The bony anatomy and patterns of suture fusion of the FM in this context are incompletely understood, yet becoming increasingly important in the light of novel medical therapies for achondroplasia. The objective of this study was to describe and quantify bony anatomy and fusion patterns of FM stenosis in patients with achondroplasia using CT scans, comparing them to age-matched controls and other FGFR3 craniosynostosis patients. Patients with achondroplasia and severe FM stenosis, classified as achondroplasia foramen magnum score(AFMS) grades 3 and 4, were identified from a departmental operative database. All had pre-operative CT scans of the craniocervical junction. Measurements obtained comprised sagittal diameter (SD), transverse diameter (TD), foramen magnum area, and opisthion thickness. Anterior and posterior interoccipital synchondroses (AIOS and PIOS) were graded by the extent of fusion. These measurements were then compared with CT scans from 3 age-matched groups: the normal control group, children with Muenke syndrome, and children with Crouzon syndrome with acanthosis nigricans (CSAN). CT scans were reviewed in 23 cases of patients with achondroplasia, 23 normal controls, 20 Muenke, and 15 CSAN. Children with achondroplasia had significantly smaller sagittal diameter (mean 16.2 ± 2.4mm) compared to other groups (control 31.7 ± 2.4mm, p < 0.0001; Muenke 31.7 ± 3.5mm, p < 0.0001; and CSAN 23.1 ± 3.4mm, p < 0.0001) and transverse diameters (mean 14.3 ± 1.8mm) compared with other groups (control 26.5 ± 3.2mm, p < 0.0001; Muenke 24.1 ± 2.6mm, p < 0.0001; CSAN 19.1 ± 2.6mm, p < 0.0001). This translated into a surface area which was 3.4 times smaller in the achondroplasia group compared with the control group. The median grade of the AIOS fusion achondroplasia group was 3.0 (IQR 3.0-5.0), which was significantly higher compared with the control group (1.0, IQR 1.0-1.0, p < 0.0001), Muenke group (1.0, IQR 1.0-1.0, p < 0.0001), and CSAN (2.0, IQR 1.0-2.0, p < 0.0002). Median PIOS fusion grade was also highest in the achondroplasia group (5.0, IQR 4.0-5.0) compared with control (1.0, IQR 1.0-1.0, p < 0.0001), Muenke (2.5, IQR 1.3-3.0, p < 0.0001), and CSAN (4.0, IQR 4.0-4.0, p = 0.2). Distinct bony opisthion spurs projecting into the foramen magnum were seen in achondroplasia patients but not others, resulting in characteristic crescent and cloverleaf shapes. Patients with AFMS stages 3 and 4 have significantly reduced FM diameters, with surface area 3.4 times smaller than age-matched controls. This is associated with premature fusion of the AIOS and PIOS in comparison with controls and other FGFR3-related conditions. The presence of thickened opisthion bony spurs contributes to stenosis in achondroplasia. Understanding and quantifying bony changes at the FM of patients with achondroplasia will be important in the future quantitative evaluation of emerging medical therapies.

Measurement of Foramen Magnum Dimensions in Computed Tomography of Head

Introduction: Dimensions of the foramen magnum are clinically important because of the vital structures passing through it and for sex determination of the skull. The objective of this study was to measure various dimensions of the foramen magnum in Computed Tomography (CT) and correlate them with sex. Methods: Descriptive cross-sectional study was done on 120 CT head images in the Department of Radiology and Imaging, from July to October 2019. The shape of the foramen magnum (FM), anteroposterior diameter (APD), transverse diameter (TD), FM area and FM index were calculated. Statistical analysis was done with SPSS 25 and Excel 2016. Discriminant function analysis and binary logistic regression analysis were used for gender verification. RESULTS: The mean values of the APD, TD, area and FM index in males and females were 33.56 ± 4.30 mm, 29.76 ± 4.10 mm, 792.94 ± 191.60 mm2, 85.01 ± 8.67 and 30.01 ± 2.04 mm, 25.33 ± 4.6 mm, 599.63± 128.13 mm2, 83.17 ± 7.78 respectively. All dimensions were significantly greater in males (r = 0.906, P&lt;0.001). The most common shape of the foramen magnum was oval (40.8%). The accuracy of sex identification was 68.3% using dimensions of the foramen magnum. Conclusion: There was sexual dimorphism in the diameter and area of the foramen magnum which can be used for sex determination.

Evaluating Foramen Magnum Surface Area in Males and Females for Morphological Differences Using 3D Computed Tomography Among Maharashtrian Population

resist decomposition for a long period. The foramen magnum, which is located at the cranial base, is also a good parameter for identifications with reasonable accuracy. The surface area of the foramen magnum can be calculated using 3D reconstructed computer tomography of the head to assess the morphological differences in males and females, which is useful in forensic sciences.Objectives: To measure the antero-posterior length of the foramen magnum, the transverse diameter of the foramen magnum, the surface area of foramen magnum in males and females and to compare surface area of male and female foramen magnum to find morphological difference.Method: CT scan was performed in 40 patients (20+20) in two groups consist male and female, using SIEMENCE SOMATOM 16 SLICE machine, in patients referred to Acharya Vinoba Bhave Rural Hospital for CT head scan with 3D skull. Scan will include the vertex to C3, received images then reconstructed into 3D images. From the 3D images the foramen magnum was measured; anterior-posterior, transverse and surface area in two groups of patients includes males and female. Teixeria’s and Radinsky’s formulae was used. Descriptive analysis to measure area of foramen magnum. Independent sample T test to determine any significant difference between male and female foramen magnum area and Discriminant analysis.Result: 70% of original group cases were correctly classified using the derived dataConclusion: foramen magnum can be used in forensic science as gender determination tool in the case where other identifying methods are inconclusive and modern imaging technology can be very useful.

Morphometric Evaluation of Foramen Magnum and its Shape Variations using Computed Tomographic Images of Normal Adults

Background and aims Skull morphology plays a key role in determining gender in medico-legal cases. Computed Tomography CT measurements of foramen magnum are useful in estimating gender. In this study sagittal diameter transverse diameter and area of foramen magnum were correlated. Also different variations in the shape of foramen magnum were evaluated using computed tomography.Methods This study was conducted using CT Brain Scan images of individuals belonging to both the genders in the age group of 18 to 85 years. Morphometry of foramen magnum sagittal diameter transverse diameter area of foramen magnum measurements and different shapes of foramen magnum were estimated on CT images using a 3D program on the CT workstation and were correlated against gender.Result In this study sagittal diameter of foramen magnum was 33.5 plusmn 2.9 mm among males and 31.4 plusmn 3.2 mm among females. Transverse diameter was found to be 29.1 plusmn 3.3 mm in males and 26.7plusmn3.7 mm in females. Area of foramen magnum was measured to be 642 plusmn 94.2 mm in males and 559.9 plusmn 115.5 mm in females. All the variables showed significant higher values in males than in females.Conclusion Based on the findings of this study conducted using CT scan images the foramen magnums diameter and area demonstrated a high degree of precision in gender identification. The results of this study could be used to identify human remains if other identifying techniques were unsuccessful.

Foramen Magnum as a Tool for Sexual Dimorphism

Background: Gender determination by skeletal relies predominantly on the skeletal radiology. Foramen magnum is in a favorable anatomic position, protected by soft tissue and skeleton of the head protecting the area for forensic examination. Foramen magnum being a relatively indestructible structure becomes an important tool in identification of gender. Objective: To study the vagueness and reliability of the foramen magnum (FM) in gender classification through the use of reconstructed computed tomography (CT) images. Materials and Method: A total of 200 patients (100 males and 100 females; age range, 18–60 years) were selected for the study. The FM measurements (sagittal, transverse, circumference, and area) were obtained from reformatted axial sections using a CT scan. Results: It was found that the mean FM sagittal diameter was 35.09 ± 2.48 mm, the FM transverse diameter was 28.76 ± 2.82 mm, the FM circumference was 110.56 ± 8.84 mm, and the FM area was 746.20 ± 108.47 mm2. According to Student’s t-test results, in all measured parameters, there was a significant difference between the genders (P &lt; 0.001). Conclusion: In all of the measured variables, there is a statistically significant difference present in the mean values of various parameters between both genders, with males having higher dimensions than female, indicative of sexual dimorphism.

Morphometric Analysis of Posterior Fossa and Foramen Magnum among Pediatric Age Group 6 to 16 Years

Background Configuration and size of the foramen magnum and posterior cranial fossa plays an important role in the pathophysiology of various disorders like Chiari malformations, basilar invagination etc. Thus, a fundamental knowledge of normal anatomy of this region is important to the clinician for diagnosis and treatment. However, we couldn’t find any anatomical study related to the concerned topic among the pediatric population aged 6 to 16 years in Nepal to the best of our knowledge.&#x0D; Objective To attain the baseline results (volume of bony part of posterior cranial fossa and the surface area of foramen magnum) that will help in the better diagnosis, classification, and treatment of diseases related to posterior fossa and craniovertebral junction and serve as a future reference defining an anatomic range in our region.&#x0D; Method This is a retrospective prospective observational study conducted from 1st February 2021 to 31st January 2022 at Dhulikhel Hospital, Kathmandu University Hospital, Kavrepalanchowk, Nepal. We used convenient sampling technique to fulfil our sample size. We considered 68 patients, who got recruited either from our emergency and OPD departments and were fulfilling our criteria of inclusion. Upon the recruitment, 68 consecutive head CT scan of pediatric patients with normal reports (without any bony or soft-tissue abnormality) were studied. Volume of the posterior fossa was calculated with the help of inbuilt “advanced work station - 3D volume calculator” program in 128 slices - SOMATOM PERSPECTIVE CT Scanner from Siemens, Germany. The area of the foramen magnum was calculated using formula πr2, where r is average radius calculated from obtained antero-posterior and transverse diameter.&#x0D; Result The age of the patients ranged between 6 and 16 years with the mean age of 10.56 ± 3.38 years with male to female distribution of 1: 1.125. The mean volume of the posterior fossa was 165.61 ± 8.52 mm3. The mean AP diameter, transverse diameter, and the surface area of foramen magnum were 3.31 ± 0.12 mm, 2.72 ± 0.12 mm, and 28.60 ± 0.09 mm2 respectively.&#x0D; Conclusion Normal ranges of volume of posterior cranial fossa and various dimensions and surface area of foramen magnum of pediatric population were determined using CT scans, which could serve as future reference in Nepal.

Sexual dimorphism and biomechanical loading in occipital bone morphological variation.

We explore the contribution of biological sex and biomechanical activity from subsistence to occipital bone variation. Previous studies have used occipital bone traits to determine biological sex and identify ancestry to differing degrees of success. Biomechanical stress from variation in subsistence and gender-based divisions of labor could perhaps explain some of the noise in the signal for these grouping variables. To explore this possibility, we used metric (foramen magnum length and breadth, external occipital protuberance depth, lambda-inion length, bicondylar breadth) and nonmetric traits (general occipital form, presence of a nuchal crest, and nuchal line count). We collected original data and mined published data for our analysis using skeletal collections of Native American hunter-gatherers and horticulturalists, a historic military site, and contemporary study collections. We find that the foramen magnum area exhibits sexual dimorphism and is not influenced by subsistence, but the accuracy of sex estimation is only 71%, suggesting the chance of being correct at slightly more than two-thirds. All traits exhibited sex-based variation but only bicondylar breadth and lambda-inion metrics exhibited subsistence-based variation. Given the limited amount of variance explained by either sex or sex and subsistence, biomechanics may still play a role but not from the influence of subsistence practices in these datasets. Additional data from a wider array of skeletal samples, perhaps with known occupation, is warranted if we are to understand how occipital variation is shaped.

The foramen magnum in scaphocephaly

PurposeThe foramen magnum (FM) presents various alterations in craniosynostoses, such as brachycephaly or Crouzon syndrome. However, to date, no study has been devoted to its morphology and morphometry in scaphocephaly, which is the most common of cranial deformities resulting from premature fusion of cranial sutures.MethodsWe assessed the morphology and morphometry of FM using preoperative thin-cut CT scans of 107 children with non-syndromic sagittal craniosynostosis aged 1–12 months (mean age 5.38 months). A series of sagittal and transverse dimensions were taken and the FM area was calculated in each case. Obtained data were compared to the age-matched control group of 101 normocephalic children.ResultsDolichotrematous type of FM was dominant in the scaphocephaly group and observed in 63/107 cases (58.9%). The mean FM area in the scaphocephaly group was 519.64 mm2 and was significantly smaller compared to the control group (p = 0.0011). The transverse diameter and anterior sagittal diameter were also significantly smaller (p = 0.0112 and p = 0.0003, respectively).ConclusionThe area of FM in scaphocephaly is smaller compared to normal individuals. This is associated with a significant reduction of the width of FM in children with sagittal craniosynostosis. FM in scaphocephaly is larger than in other reported series of children with brachycephaly or Crouzon syndrome.

A different perspective on the dilemma of durotomy or duraplasty in Chiari type 1 malformation surgery

Purpose Symptomatic Chiari type 1 malformation (CIM) patients may elect to be treated; however, choosing the optimum surgical method remains problematic: posterior fossa decompression with duraplasty (PFDD) or without duraplasty (PFD). Many studies have compared these surgical methods from several perspectives. We looked at soft tissue density (STD) at the foramen magnum to add another perspective to the comparison of PFD with PFDD. Materials and methods Eighty-six patients who underwent surgery in our clinic were included in the study. We examined preoperative and postoperative MR images taken in the 1st year. We obtained the foramen magnum area (FMA) and soft tissue at the level of the foramen magnum. The STD within the foramen magnum was calculated as the percentage ratio of soft tissue area (STA) to FMA. Anteroposterior diameters of the syrinx cavities in sagittal T2 sections were measured preoperatively and at 1-year postoperatively. Measurements were double-blind and were performed by the neurosurgeon and by the neuroradiologist. Results There was no statistically significant difference between the postoperative FMA increases, STA changes, STD changes in patients who underwent PFD and PFDD. In this study, there was no statistically significant difference between PFD and PFDD in terms of syrinx changes. Conclusions The medium-term anatomical outcome following craniovertebral decompression for CIM, is no different whether performed PFD or PFDD.

Airways and craniofacial assessment in children affected by achondroplasia with and without sleep-disordered breathing: quantitative magnetic resonance study.

To identify MRI-based quantitative craniofacial variables linked to airways narrowing and obstructive sleep apnea (OSA) development in children with achondroplasia. We evaluated skull base and midface MRI in two cohorts of children affected by achondroplasia, with (group 1) or without OSA (group 2). 3DFSPGR-T1weighted images were used to assess airways volume (nasopharynx, oropharynx, and laryngopharynx), jugular foramina (JF) and hypoglossal foramina (HF) areas, foramen magnum area, cervical cord area, and maxillary retrusion (SNA angle). Nineteen out of 27 children with achondroplasia exhibited different degrees of obstructive respiratory impairment (n.4 mild, n.8 moderate, n.7 severe), while 8 children did not show OSA. Each group was compared with age-matched controls without neuroimaging abnormalities. Both groups showed reduced nasopharynx volume, JF areas, and SNA angle, while group 1 showed also reduced oropharynx volume, ratio of FM/cervical cord areas, and HF areas (p < 0.05). A positive correlation between nasopharynx volume and SNA angle was found in both groups, while a positive correlation among upper airways volume, JF and HF areas was found only in group 1. No correlation between upper airways volume and OSA severity was found. In children with achondroplasia, multifaced craniofacial abnormalities contribute to airways volume reduction predisposing to sleep disordered breathing. MRI-based quantitative assessment allows the appraisal of craniofacial variables linked to the development of sleep-disordered breathing such as FM stenosis, jugular and hypoglossal foramina stenosis, and retruded maxillary position and may be a valuable tool for clinical surveillance.

Area of foramen magnum as a tool for sex determination

Area of foramen magnum as a tool for sex determination

Impairment of motor skills in children with achondroplasia-usefulness of brain and cranio-cervical junction evaluation by quantitative magnetic resonance imaging: a case-control study.

Most infants and children with achondroplasia show delayed motor skill development; however, some patients may have clinical consequences related to cranio-cervical junction stenosis and compression. To assess, using brain magnetic resonance imaging (MRI), quantitative variables linked to neuromotor impairment in achondroplasic children. In total, 24 achondroplasic children underwent pediatric neurological assessment and were grouped in two cohorts according to relevant motor skill impairment. Achondroplasic children with (n=12) and without (n=12) motor symptoms were identified, and brain MRI scans were quantitatively evaluated. 3D fast spoiled gradient echo T1-weighted images were used to assess: supratentorial intracranial volumes (SICV); supratentorial intracranial brain volume (SICBV); SICV/SICBV ratio; posterior cranial fossa volume (PCFV); posterior cranial fossa brain volume (PCBFV); PCFV/PCFBV ratio; ventricular and extra-ventricular cerebrospinal fluid (CSF) volumes; foramen magnum (FM) area; and jugular foramina (JF) areas. In both groups, SICV/SICBV ratio, supratentorial ventricular and extra-ventricular space volumes were increased while SICBV was increased only in the asymptomatic group (P < 0.05). PCFV/PCFBV ratio, IV ventricle, infratentorial extra-ventricular spaces volumes were reduced (P < 0.05) in the symptomatic group while PCFBV was increased only in the asymptomatic group (P < 0.05). Foramen magnum (FM) area was more reduced in the symptomatic group than the asymptomatic group (P < 0.05) but no correlation between FM area and ventriculomegaly was found (P > 0.05). Evaluation of the FM area together with infratentorial ventricular and extra-ventricular space volume reduction may be helpful in differentiating patients at risk of developing motor skill impairment. Further investigation is needed to better understand the temporal profile between imaging and motor function in order to propose possible personalized surgical treatment.