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At least 541 records · Page 30Linked to original sources

PubMed1987

Diagnostic potential of magnetic resonance in cases of foramen magnum meningiomas.

Meningioma is a histologically benign tumor that is second in frequency only to gliomas among primary intracranial tumors. Its extracerebral development and generally clear demarcation from the brain does not make it easier to detect on magnetic resonance (MR) scanning. Only 2 to 3% of meningiomas occur in the foramen magnum, and these tumors are often clinically misdiagnosed. We discuss four cases of foramen magnum meningioma, with emphasis on MR scanning.

Adult↗

PubMed2005

An extramedullary foramen magnum cavernous malformation presenting with acute subarachnoid hemorrhage: case report and literature review.

OBJECTIVE AND IMPORTANCE: This case summarizes our experience with the first described intradural extramedullary cavernous malformation at the foramen magnum and reminds the neurosurgical community to consider cavernous malformations in the differential diagnosis for subarachnoid hemorrhage. CLINICAL PRESENTATION: A 21-year-old man presented with an occipital headache, photophobia, nausea, neck stiffness, and fever of 10 days' duration. A lumbar puncture yielded a clear pink fluid with 300 leukocytes/mm3 (30% neutrophils and 65% lymphocytes) and 42,200 erythrocytes/mm3, a protein count of 243 mg/dl, and a glucose count of 56 mg/dl. Computed tomography revealed a 1.5-cm right-sided dural-based mass of high attenuation that spanned the foramen magnum and a segment of the upper spinal canal. Magnetic resonance imaging showed a loculated, heterogeneously enhancing mass with a cystic component that slightly displaced the medulla to the left. An angiogram was negative for aneurysms and vascular malformations but did show an area of early filling and slow washout of the epidural venous plexus at the posterior canal margin of C1 and C2. INTERVENTION: A suboccipital craniectomy and C1 laminectomy were performed. Upon opening of the dura, an encapsulated mass was visualized. The lesion was located on the right lateral surface of the cervicomedullary junction and was entirely extraparenchymal. The mass was microsurgically dissected, and its associated venous malformation was left intact. The patient's postoperative course was uneventful, with a return to baseline function. Pathological examination confirmed the diagnosis of cavernous malformation. CONCLUSION: Our report not only presents a unique combination of pathological lesion, location, and presentation but also demonstrates that such lesions may be treated surgically with excellent results.

Acute Disease↗

PubMed1991

Foramen magnum decompression for syringomyelia associated with basilar impression and Chiari I malformation--report of three cases.

Anterior or posterior decompression of the foramen magnum was performed in three patients with syringomyelia associated with basilar impression and Chiari I malformation. The operative results were evaluated using the pre- and postoperative magnetic resonance (MR) images. Two patients with combined anterior and posterior cervicomedullary compression due to basilar impression and tonsillar descent received suboccipital craniectomy, upper cervical laminectomy, and dural plasty without any intradural manipulations via the posterior approach. One patient with prominent anterior cervicomedullary compression due to basilar impression and a sharp clivoaxial angle was operated on by the transoral anterior approach. Postoperatively, all patients showed a sustained shrinkage of the syrinx and rounding of the flattened cerebellar tonsils. Two patients showed upward movement of the herniated tonsils. All patients had improved symptoms during 2-4 years follow-up. Treatment of syringomyelia associated with basilar impression and Chiari I malformation requires more efficient decompressive procedures at the foramen magnum based on neurological and MR findings.

Adult↗

PubMed1999

Cystic lesion at the foramen magnum disseminated from a pituitary adenoma--case report.

A 38-year-old male presented with a cystic lesion at the foramen magnum due to intracranial dissemination from a pituitary adenoma. The primary tumor had required reoperation for regrowth twice. The tumor at the foramen magnum was removed surgically. Two smaller solid tumors were located in the left parietal convexity and the right temporal lobe. The former tumor was also removed surgically and the latter was observed. Histological examination showed the typical characteristics of pituitary adenoma in both surgical specimens. Immunohistochemical staining with MIB-1 and p53 antibodies showed low (< 1%) and negative reaction. Patients with pituitary adenoma, even benign tumors, must be carefully followed up for signs of metastasis.

Adenoma↗

PubMed2001

Transcondylar fossa approach to treat ventral foramen magnum meningioma--case report.

A 41-year-old female presented with a meningioma of the craniocervical junction manifesting as tetraparesis and vesicourethral dysfunction. Neuroradiological examinations showed a homogeneous enhanced mass lesion extending from the foramen magnum to the upper aspect of the second vertebral body. The tumor was totally removed via the transcondylar fossa approach, which is one type of the lateral approach. She was discharged without neurological deficits. The transcondylar approach is often utilized for lesions that occupy the ventral portion around the foramen magnum. The transcondylar fossa approach, a variation of the transcondylar approach, is a refined technique which obtains a closely similar surgical working field. Use of the transcondylar fossa approach remains controversial when treating patients with little brain stem dislocation, a small condylar fossa, and a protruding occipital condyle, but the approach can easily be converted to the transcondylar approach. The transcondylar fossa approach could become a standard method to access the craniocervical junction.

Adult↗

PubMed2003

Foramen magnum meningiomas: concepts, classifications, and nuances.

Foramen magnum meningiomas represent a common histological tumor in a rare and eloquent location. The authors review the clinical presentation, relevant anatomical details of the foramen magnum region, neuroimaging features, the posterior and posterolateral surgical approaches for resection, and outcomes. Based the experiences of the senior author (M.D.C.) and a review of the literature, they introduce the concept of a "surgical corridor," discuss the classification of these tumors, and the nuances of care for patients with these challenging lesions.

Foramen Magnum↗

PubMed2003

Anatomical basis of approaches to foramen magnum and lower clival meningiomas: comparison of retrosigmoid and transcondylar approaches.

OBJECT: Meningiomas of the lower clivus and foramen magnum are among the most challenging of all neurosurgical lesions. Debate continues regarding the most appropriate approach to this eloquent anatomical region. This anatomical study was undertaken to measure and compare the area of surgical exposures of the lower clivus achieved using the retrosigmoid and the extreme-lateral transcondylar (ELT) approaches. METHODS: Thirteen embalmed cadaveric heads were dissected bilaterally via the retrosigmoid approach on one side and the ELT approach on the other. The circumference of the area of exposure was delineated using beaded pins placed into the dura. After removal of the brain, the longest longitudinal and transverse axes of the pinned areas were measured and surface area calculated. The area of surgical exposure was also expressed as a percentage of the total area of the lower clivus. Normalized and adjusted surface areas were calculated using the bimastoid diameter. The areas of exposure were compared using the two-tailed paired Student t-test. The mean area of exposure required using the retrosigmoid approach was 19.8 +/- 14.7 mm2 (range 6-49 mm2) and that using the ELT approach was 27.8 +/- 22.8 mm2 (range 10-90 mm2). The mean percentage of the lower clivus exposed by the retrosigmoid approach was 14.9 +/- 3.6% (range 10-22%) and that exposed by the ELT approach was 20.5 +/- 4.9% (range 10-25%). The ELT approach provided significantly greater area of operative exposure and allowed a significantly higher percentage of lower clivus and foramen magnum exposure than did the retrosigmoid approach (p < 0.05). Normalized and adjusted surface areas, taking into consideration the bimastoid diameter, were also statistically significant in favor of the ELT approach. CONCLUSIONS: The ELT approach provided a significantly greater area of exposure than did the retrosigmoid approach.

Cranial Fossa, Posterior↗

PubMed1978

Foramen magnum tumors. Analysis of 57 cases of benign extramedullary tumors.

This study involved 57 patients with benign extramedullary tumors of the foramen magnum (19 neurinomas, 37 meningiomas, and one teratoma), who were operated on between 1957 and 1976. The 37 meningiomas represented 3.2% of 1139 meningiomas of the neuraxis. The initial neurological examinations of about half of these patients were unremarkable. The clinical presentation of tumors of the foramen magnum frequently mimics multiple sclerosis, cervical spondylosis, intramedullary tumor, syrinx, carpal tunnel syndrome, and even normal-pressure hydrocephalus. All operations were performed through a posterior approach, and two surgical deaths (3.5%) were recorded. No surgery for recurring of tumor was recorded. The follow-up review of 56 patients (98.2%) showed good functional results if the tumor was detected before severe neurological deficits occurred. The possible mechanism of the sensory symptoms and muscle atrophy of the hands is discussed, and the electromyographic findings are reviewed.

Adolescent↗

PubMed2001

Recurrence of a neurenteric cyst with malignant transformation in the foramen magnum after total resection. Case report.

A 53-year-old man presented with recurrence of a neurenteric cyst with malignant transformation in the foramen magnum 3.5 years after total resection of the original tumor had been reported. For 2 years following the initial surgery, the patient had been in good condition, but then underwent ventriculoperitoneal shunt placement for intracranial hypertension. At the time there was no evidence of recurrence of the tumor on magnetic resonance (MR) images. One and one-half years later, he presented with headache and anorexia. A massive recurrent tumor was identified on MR images. The tumor was severely adhesive to the brainstem, cranial nerves, and vessels, allowing only partial resection. Histological examination of tumor specimens obtained during the first and second craniotomies indicated a malignant change from a typical neurenteric cyst with a one-layer epithelium in the first specimen to an adenocarcinoma with papillary proliferation in the second. The results of various immunohistochemical studies of the first specimen were typical of those of a neurenteric cyst. The second specimen displayed stronger staining of carbohydrate 19-9 and carcinoembryonic antigens than the initial specimen. The percentage of Ki-67 antigen (MIB-1)-positive cells increased from 0% in the first specimen to 6.7% in the second. To the authors' knowledge this is the first case in which malignant transformation has been demonstrated after total resection of a neurenteric cyst in the foramen magnum.

Adenocarcinoma, Papillary↗

PubMed2005

Age-related variations in peak cerebrospinal fluid velocities in the foramen magnum.

OBJECT: Measurements of cerebrospinal fluid (CSF) velocities in the foramen magnum are used to determine the functional significance of Chiari malformation Type I (CM-I). Significantly higher peak velocities are found in adult patients with CM-I than in adult control participants. In addition, it appears that higher CSF velocities are found in pediatric patients with CM-I than in adult patients. Variations in CSF velocities across age groups in healthy individuals, however, have not been systematically studied. METHODS: Phase-contrast magnetic resonance imaging was performed in 10 pediatric patients after induction of anesthesia to evaluate conditions thought not to affect CSF flow in the foramen magnum. The peak systolic and diastolic velocities were plotted with respect to age and compared with velocities obtained in a group of 10 healthy adult volunteers. Differences between the adult and pediatric groups were tested for significance by using the Student t-test. Peak velocities ranged from 1.9 to 19.9 cm/second in the pediatric group and from 1.2 to 4.5 cm/second in the adults. A trend line fitted to the data showed a decrease in velocity with age in the first two decades of life, and little change thereafter. Differences in the pediatric and adult groups were significant at a level of 0.05. CONCLUSIONS: Peak CSF velocities vary significantly with age. To determine the normalcy of a CSF flow measurement, it must be compared with age-appropriate normative data.

Adolescent↗

PubMed1999

Choroid plexus papilloma of cerebellopontine angle with extension to foramen magnum.

A case of choroid plexus papilloma resembling meningioma of cerebellopontine (CP) angle with its extension to foramen magnum is presented. Occurrence of this tumour in CP angle is very rare. Its extension towards foramen magnum is further rare. It was a real diagnostic enigma preoperatively as the tumour was resembling meningioma upto some extent on radiological study. Retromastoid craniectomy with microsurgical excision of tumour and its extension was achieved in toto. Tumour was attached to few rootlets of lower cranial nerves which were preserved. Attachment of the tumour with lower cranial nerves again caused diagnostic confusion with neurofibroma intraoperatively.

Adult↗

PubMed1999

Midline and far lateral approaches to foramen magnum lesions.

Twenty patients with foramen magnum lesions were operated upon in the last 5 years at Postgraduate Institute of Medical Education and Research, Chandigarh. The common presenting features were quadriparesis, quadriplegia, diminished sensations, neck pain and respiratory insufficiency. The lesions encountered were meningiomas, neurofibromas, posterior inferior cerebellar artery aneurysms, neurenteric cyst and chordoma. Patients with posterior or posterolaterally placed lesions were operated by the midline posterior approach while those with anterior or anterolateral lesions were managed by the far lateral approach. All mass lesions were excised completely and the aneurysms were clipped. Seventeen patients made good neurological recovery while three died. The latter three patients presented very late. The merits of various surgical approaches to the foramen magnum are discussed.

Adolescent↗

PubMed2003

Foramen magnum metastatic malignant melanoma.

The foramen magnum as a site for brain metastasis is extremely rare. We report the case of a 24-year-old male who presented with features of increased intracranial pressure and lower cranial nerve palsies. Imaging revealed a foramen magnum tumor with extension up to the cerebellar vermis superiorly and into the spinal canal inferiorly (craniospinal mass) with mild obstructive hydrocephalus. A malignant melanoma was completely excised. The patient continued to be tumor-free 24 months later.

Adult↗

PubMed2004

Microsurgery on foramen magnum meningioma with suboccipital.

OBJECTIVE: To analyze which factors influence the operative outcome, and compare advantages and disadvantages of relative surgical approaches. METHODS: Eleven cases with the foramen magnum meningioma were operated by using posterior approach with lateral extension. RESULTS: Complete removal of the tumor was performed in 7 patients (7/11, 64%), subtotal resection in 2 cases (2/11, 18%) and partial resection in 2 cases (2/11, 18%). There were no operative death and significant complication. CONCLUSION: The posterior approach with lateral enlargement is sufficient to expose and remove foramen magnum tumors without expensive bone resection.

Adolescent↗

PubMed2005

Estimation of sex by 3D CT measurements of the foramen magnum.

The purpose of this prospective study is to investigate the value and accuracy of the measurements of the foramen magnum (FM) by using three-dimensional computed tomography (3DCT). Cases were randomly selected among 100 patients (48 males, 52 females) who had temporal CT in the Radiology Department. Seven measurements of the foramen magnum on 3D images, modified from the nine lines previously defined by Giles and Elliot were made. Using Fisher's linear discriminant functions test, the length and width of right condyle and width of FM diameters were found to be statistically different in each sex (p < 0.001) with 81% accuracy. To our best knowledge, this is the first report studying 3DCT measurements of FM, resulting with a sex determination accuracy rate of 81%. CT/3DCT can be reliably used in further investigations to provide basis for anthropometric and forensic issues.

Adolescent↗

PubMed1989

[Tumor in the region of foramen magnum].

Twenty-five patients with tumors in the region of foramen magnum confirmed by pathology and surgery are presented. There were 19 males and 6 females. The ages ranged from 4-56 years. According to the clinical findings, the authors suggest that if a patient has occipitocervical pain or headache accompanied with neurological signs of medulla, cervical spinal cord or lower cranial nerves, tumors in the region of foramen magnum should be considered. The authors emphasize that a total removal of the extramedullary tumor is the best choice. The initial symptoms and signs, cases misdiagnosed and surgical treatment of this tumor are discussed.

Adolescent↗

PubMed1988

Variations in the shape of foramen magnum in Indian skulls.

200 skulls from anthropology museum of GSVM Medical College, Kanpur, U.P., India, were studied to note the variations in the shape of foramen magnum. Foramen magnum was found to be variable in shape: Shapes noted were oval (64%), hexagonal (24.5%), pentagonal (7.5%), irregular (3.5%) and round (0.5%). The findings are hitherto not reported.

Foramen Magnum↗

PubMed1988

[Lateral approach to the anterior foramen magnum tumor: report of two cases].

A procedure for lateral approach to the ventral portion of the foramen magnum and the upper cervical canal is described. The patient was placed in the lateral position and a curvilinear skin incision was made from the retoroauricular area down to the lateral neck across the sternocleidomastoid muscle, and underlying muscle layers were divided. A suboccipital hemicraniotomy and hemilaminectomies were performed with an air drill. Because the medulla and the cervical cord are displaced posteriorly by the tumor, there is no need to retract those structures and all the tumors can be removed under direct vision. This procedure was applied on the two patients with ventrally situated foramen magnum tumors; a neurenteric cyst and neurofibroma, and both of the tumors were successfully removed under direct vision. Major advantages of this approach are that there is no need for retraction of the spinal cord, and there is excellent exposure of an anteriorly located tumor, no postoperative cervical spine instability, no risk for CSF leak and infection, which effects are often found after the anterior approach. The procedure, like the posterior approach, is relatively simple.

Adult↗