The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
Aaron A Cohengadol - One of the best experts on this subject based on the ideXlab platform.
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morphometry of the outlet of the Foramen Magnum in crania with atlantooccipital fusion laboratory investigation
Journal of Neurosurgery, 2011Co-Authors: Shane R Tubbs, Joshua J. Chern, Marios Loukas, Mohammadali Mohajel Shoja, Jeffrey R Lancaster, Martin M Mortazavi, Aaron A CohengadolAbstract:Object Assimilation of the atlas to the occiput may result in symptoms that are often compressive in nature around the outlet of the Foramen Magnum. The aim of the present study was to elucidate the morphological features of the bone through this Foramen. Methods Thirteen adult skulls with atlantooccipital fusion underwent morphometrical analysis of the outlet of the Foramen Magnum. Results All specimens but one were found to have a decreased area of the outlet of the Foramen Magnum. In those 12 specimens, a decrease of 15%–35% was seen. Fusions of the atlas that were based primarily along the anterior rim of the Foramen Magnum resulted in more obstruction of its outlet. In general, the horizontal diameters of the outlet of these foramina were more decreased from the normal range. Conclusions These findings demonstrate that in the majority of cases, assimilation of the atlas to the occiput results in a compromised outlet of the Foramen Magnum.
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morphometric analysis of the Foramen Magnum an anatomic study
Neurosurgery, 2010Co-Authors: Shane R Tubbs, Marios Loukas, Mohammadali Mohajel Shoja, Christoph J Griessenauer, Aaron A CohengadolAbstract:OBJECTIVE: To further elucidate the importance of anatomic variations in morphology of the Foramen Magnum and associated clinical implications, we conducted a morphometric study. METHODS: Seventy-two dry skulls were used for this study. Digital images were obtained of the Foramen Magnum from an inferior view.These images were studied using a computer-assisted image analysis system. Next, an image processor was used to calculate pixel differences between 2 selected points, which allowed accurate translation of pixel differences into metric measurements. RESULTS: We found that the mean surface area of the Foramen Magnum was 558 mm 2 , the mean anteroposterior diameter was 3.1 cm, and the mean horizontal diameter was 2.7 cm. For comparison, surface areas were classified into 3 types based on size. Type I foramina were identified in 20.8% of the dry skulls (15 skulls) and exhibited a surface area of less than 500 mm 2 . Type II (66.6%,48 skulls) was applied to foramina of an intermediate size with surface areas ranging between 500 to 600 mm 2 . Type III (12.5%, 9 skulls) was applied to large foramina with surface areas of more than 600 mm 2 . CONCLUSION: These data may be of use as a morphometric database for description of "normal" variants of Foramen Magnum morphology.
Shane R Tubbs - One of the best experts on this subject based on the ideXlab platform.
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morphometry of the outlet of the Foramen Magnum in crania with atlantooccipital fusion laboratory investigation
Journal of Neurosurgery, 2011Co-Authors: Shane R Tubbs, Joshua J. Chern, Marios Loukas, Mohammadali Mohajel Shoja, Jeffrey R Lancaster, Martin M Mortazavi, Aaron A CohengadolAbstract:Object Assimilation of the atlas to the occiput may result in symptoms that are often compressive in nature around the outlet of the Foramen Magnum. The aim of the present study was to elucidate the morphological features of the bone through this Foramen. Methods Thirteen adult skulls with atlantooccipital fusion underwent morphometrical analysis of the outlet of the Foramen Magnum. Results All specimens but one were found to have a decreased area of the outlet of the Foramen Magnum. In those 12 specimens, a decrease of 15%–35% was seen. Fusions of the atlas that were based primarily along the anterior rim of the Foramen Magnum resulted in more obstruction of its outlet. In general, the horizontal diameters of the outlet of these foramina were more decreased from the normal range. Conclusions These findings demonstrate that in the majority of cases, assimilation of the atlas to the occiput results in a compromised outlet of the Foramen Magnum.
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morphometric analysis of the Foramen Magnum an anatomic study
Neurosurgery, 2010Co-Authors: Shane R Tubbs, Marios Loukas, Mohammadali Mohajel Shoja, Christoph J Griessenauer, Aaron A CohengadolAbstract:OBJECTIVE: To further elucidate the importance of anatomic variations in morphology of the Foramen Magnum and associated clinical implications, we conducted a morphometric study. METHODS: Seventy-two dry skulls were used for this study. Digital images were obtained of the Foramen Magnum from an inferior view.These images were studied using a computer-assisted image analysis system. Next, an image processor was used to calculate pixel differences between 2 selected points, which allowed accurate translation of pixel differences into metric measurements. RESULTS: We found that the mean surface area of the Foramen Magnum was 558 mm 2 , the mean anteroposterior diameter was 3.1 cm, and the mean horizontal diameter was 2.7 cm. For comparison, surface areas were classified into 3 types based on size. Type I foramina were identified in 20.8% of the dry skulls (15 skulls) and exhibited a surface area of less than 500 mm 2 . Type II (66.6%,48 skulls) was applied to foramina of an intermediate size with surface areas ranging between 500 to 600 mm 2 . Type III (12.5%, 9 skulls) was applied to large foramina with surface areas of more than 600 mm 2 . CONCLUSION: These data may be of use as a morphometric database for description of "normal" variants of Foramen Magnum morphology.
Benedicto Oscar Colli - One of the best experts on this subject based on the ideXlab platform.
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surgical management of Foramen Magnum meningiomas
Neurosurgical Review, 2009Co-Authors: Luis A B Borba, Jean G De Oliveira, Miguel Giudicissifilho, Benedicto Oscar ColliAbstract:The objective of the study is to describe our experience in the surgical management of Foramen Magnum meningiomas with regard to the clinical–radiological findings, the surgical approach and the outcomes after mid-term follow up. Over a 5-year period, 15 patients presenting with meningiomas of the Foramen Magnum underwent surgical treatment. The medical records were reviewed in order to analyze the clinical–radiological aspects, as well as the surgical approach and the outcomes. Based on the preoperative magnetic resonance imaging exams, the tumors were classified as anterior or anterolateral in the axial slices and clivospinal or spinoclival in the sagittal slices. The lateral approach was used in all cases. However, the extent of bone removal and the management of the vertebral artery were tailored to each patient. Fourteen patients were females, and one was male, ranging in age from 42 to 74 years (mean 55,9 years). The occipital condyle was partially removed in eight patients, and in seven patients, removal was not necessary. Total removal of the tumor was achieved in 12 patients, subtotal in two, and partial resection in one patient. Postoperative complications occurred in two patients. Follow-up ranged from 6 to 56 months (mean 23.6 months).There was no surgical mortality in this series. The extent of the surgical approach to Foramen Magnum meningiomas must be based on the main point of dural attachment and tailored individually case-by-case. The differentiation between the clivospinal and spinoclival types, as well as anterior and anterolateral types, is crucial for the neurosurgical planning of Foramen Magnum meningiomas.
Mohammadali Mohajel Shoja - One of the best experts on this subject based on the ideXlab platform.
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Lateral compression of the Foramen Magnum with the Chiari I malformation: case illustrations.
Childs Nervous System, 2012Co-Authors: R. Shane Tubbs, Joshua J. Chern, Mitchel Muhleman, Marios Loukas, Mohammadali Mohajel Shoja, W. Jerry OakesAbstract:The morphometry and size of the Foramen Magnum play an important role in the pathophysiology of various disorders of the skull base. Elongation of the clivus and hence the anterior aspect of the Foramen Magnum results from, for example, growth of the spheno-occipital synchondrosis. Descent of the occiput via growth from the petro-occipital and sphenopetrosal junctions is important in the formation of the bone around the Foramen Magnum while the primary determinants of Foramen Magnum size and area are the basiexoccipital and exo-supraoccipital synchondroses and the three enchondral parts of the basiocciput, exocciput, and supra-occiput [22]. In contrast to the majority of cranial and facial bones, which develop from intramembranous ossification, the cranial base takes the intermediate step of calcification of a cartilaginous model [9]. We review the literature regarding anomalies of the Foramen Magnum related to various disease processes and present two illustrative cases demonstrating lateral compression of the Foramen Magnum that resulted in complications related to posterior fossa decompression procedures in children with Chiari I malformation.
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morphometry of the outlet of the Foramen Magnum in crania with atlantooccipital fusion laboratory investigation
Journal of Neurosurgery, 2011Co-Authors: Shane R Tubbs, Joshua J. Chern, Marios Loukas, Mohammadali Mohajel Shoja, Jeffrey R Lancaster, Martin M Mortazavi, Aaron A CohengadolAbstract:Object Assimilation of the atlas to the occiput may result in symptoms that are often compressive in nature around the outlet of the Foramen Magnum. The aim of the present study was to elucidate the morphological features of the bone through this Foramen. Methods Thirteen adult skulls with atlantooccipital fusion underwent morphometrical analysis of the outlet of the Foramen Magnum. Results All specimens but one were found to have a decreased area of the outlet of the Foramen Magnum. In those 12 specimens, a decrease of 15%–35% was seen. Fusions of the atlas that were based primarily along the anterior rim of the Foramen Magnum resulted in more obstruction of its outlet. In general, the horizontal diameters of the outlet of these foramina were more decreased from the normal range. Conclusions These findings demonstrate that in the majority of cases, assimilation of the atlas to the occiput results in a compromised outlet of the Foramen Magnum.
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morphometric analysis of the Foramen Magnum an anatomic study
Neurosurgery, 2010Co-Authors: Shane R Tubbs, Marios Loukas, Mohammadali Mohajel Shoja, Christoph J Griessenauer, Aaron A CohengadolAbstract:OBJECTIVE: To further elucidate the importance of anatomic variations in morphology of the Foramen Magnum and associated clinical implications, we conducted a morphometric study. METHODS: Seventy-two dry skulls were used for this study. Digital images were obtained of the Foramen Magnum from an inferior view.These images were studied using a computer-assisted image analysis system. Next, an image processor was used to calculate pixel differences between 2 selected points, which allowed accurate translation of pixel differences into metric measurements. RESULTS: We found that the mean surface area of the Foramen Magnum was 558 mm 2 , the mean anteroposterior diameter was 3.1 cm, and the mean horizontal diameter was 2.7 cm. For comparison, surface areas were classified into 3 types based on size. Type I foramina were identified in 20.8% of the dry skulls (15 skulls) and exhibited a surface area of less than 500 mm 2 . Type II (66.6%,48 skulls) was applied to foramina of an intermediate size with surface areas ranging between 500 to 600 mm 2 . Type III (12.5%, 9 skulls) was applied to large foramina with surface areas of more than 600 mm 2 . CONCLUSION: These data may be of use as a morphometric database for description of "normal" variants of Foramen Magnum morphology.
Marios Loukas - One of the best experts on this subject based on the ideXlab platform.
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Lateral compression of the Foramen Magnum with the Chiari I malformation: case illustrations.
Childs Nervous System, 2012Co-Authors: R. Shane Tubbs, Joshua J. Chern, Mitchel Muhleman, Marios Loukas, Mohammadali Mohajel Shoja, W. Jerry OakesAbstract:The morphometry and size of the Foramen Magnum play an important role in the pathophysiology of various disorders of the skull base. Elongation of the clivus and hence the anterior aspect of the Foramen Magnum results from, for example, growth of the spheno-occipital synchondrosis. Descent of the occiput via growth from the petro-occipital and sphenopetrosal junctions is important in the formation of the bone around the Foramen Magnum while the primary determinants of Foramen Magnum size and area are the basiexoccipital and exo-supraoccipital synchondroses and the three enchondral parts of the basiocciput, exocciput, and supra-occiput [22]. In contrast to the majority of cranial and facial bones, which develop from intramembranous ossification, the cranial base takes the intermediate step of calcification of a cartilaginous model [9]. We review the literature regarding anomalies of the Foramen Magnum related to various disease processes and present two illustrative cases demonstrating lateral compression of the Foramen Magnum that resulted in complications related to posterior fossa decompression procedures in children with Chiari I malformation.
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morphometry of the outlet of the Foramen Magnum in crania with atlantooccipital fusion laboratory investigation
Journal of Neurosurgery, 2011Co-Authors: Shane R Tubbs, Joshua J. Chern, Marios Loukas, Mohammadali Mohajel Shoja, Jeffrey R Lancaster, Martin M Mortazavi, Aaron A CohengadolAbstract:Object Assimilation of the atlas to the occiput may result in symptoms that are often compressive in nature around the outlet of the Foramen Magnum. The aim of the present study was to elucidate the morphological features of the bone through this Foramen. Methods Thirteen adult skulls with atlantooccipital fusion underwent morphometrical analysis of the outlet of the Foramen Magnum. Results All specimens but one were found to have a decreased area of the outlet of the Foramen Magnum. In those 12 specimens, a decrease of 15%–35% was seen. Fusions of the atlas that were based primarily along the anterior rim of the Foramen Magnum resulted in more obstruction of its outlet. In general, the horizontal diameters of the outlet of these foramina were more decreased from the normal range. Conclusions These findings demonstrate that in the majority of cases, assimilation of the atlas to the occiput results in a compromised outlet of the Foramen Magnum.
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morphometric analysis of the Foramen Magnum an anatomic study
Neurosurgery, 2010Co-Authors: Shane R Tubbs, Marios Loukas, Mohammadali Mohajel Shoja, Christoph J Griessenauer, Aaron A CohengadolAbstract:OBJECTIVE: To further elucidate the importance of anatomic variations in morphology of the Foramen Magnum and associated clinical implications, we conducted a morphometric study. METHODS: Seventy-two dry skulls were used for this study. Digital images were obtained of the Foramen Magnum from an inferior view.These images were studied using a computer-assisted image analysis system. Next, an image processor was used to calculate pixel differences between 2 selected points, which allowed accurate translation of pixel differences into metric measurements. RESULTS: We found that the mean surface area of the Foramen Magnum was 558 mm 2 , the mean anteroposterior diameter was 3.1 cm, and the mean horizontal diameter was 2.7 cm. For comparison, surface areas were classified into 3 types based on size. Type I foramina were identified in 20.8% of the dry skulls (15 skulls) and exhibited a surface area of less than 500 mm 2 . Type II (66.6%,48 skulls) was applied to foramina of an intermediate size with surface areas ranging between 500 to 600 mm 2 . Type III (12.5%, 9 skulls) was applied to large foramina with surface areas of more than 600 mm 2 . CONCLUSION: These data may be of use as a morphometric database for description of "normal" variants of Foramen Magnum morphology.