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At least 163 records · Page 9Linked to original sources

PubMed1999

[Chronic hydrocephalus in an adult due to congenital membranous occlusion of the apertura mediana ventriculi quartii (foramen of Magendie). Report of two cases and review of the literature].

Congenital membranous obstruction of the apertura mediana ventriculi quartii (foramen of Magendie) is a rare entity, as only 8 adult cases are mentioned in all medical literature. We report here the cases of 2 patients (35 and 68 year-old) with chronic hydrocephalus due to congenital membranous obstruction of the foramen of Magendie. Both these two patients presented with headaches, nausea, and impairment of gait and memory. CT and MRI examination showed a communicating hydrocephalus, with particular enlargement of the fourth ventricle. Both patients were operated on for microsurgical exploration of the outlet of the fourth ventricle, which demonstrated membranous obstruction of the foramen of Magendie. Microsurgical perforation of the foramen of Magendie was performed, and a ventriculo-cisternal shunt was left in place. The two patients were cured, with a follow-up of 7 years in one case, and 5 years in the other case. Despite its rare occurrence, congenital imperforation or membranous obstruction of the foramen of Magendie must be considered as a possible etiology of chronic hydrocephalus in adult, especially in case of non proportioned enlargement of the fourth ventricle, associated to signs of increased intra-cranial pressure. According to us, the best surgical procedure consists in a microsurgical exploration of the foramen of Magendie associated to a ventriculo-cisternal shunting (from the fourth ventricle to the cisterna magna). Such a procedure can be considered as curative, and has more advantages than a simple ventriculo-peritoneal shunting.

Adult↗

PubMedDate not supplied

Imaging findings in schwannomas of the jugular foramen.

BACKGROUND AND PURPOSE: Tumors of the cranial nerve sheath constitute 5% to 10% of all intracranial neoplasms, yet few articles have described their CT and MR characteristics. We report the imaging findings in a relatively large series of schwannomas of the jugular foramen, contrasting them with other disease entities, especially vestibular schwannomas and tumors of the glomus jugulare. METHODS: CT and/or MR studies of eight patients who underwent surgery for histologically proved schwannomas were reviewed retrospectively. One additional patient with an assumed schwannoma of the jugular foramen, who did not have surgery, was also included. RESULTS: Surgical findings showed schwannomas of the glossopharyngeal nerve in seven patients and tumor involvement of both the glossopharyngeal and vagal nerves in one patient. All tumors were partially located within the jugular foramen. Growth extending within the temporal bone was typical. Tumor extended into the posterior cranial fossa in all nine patients and produced mass effect on the brain stem and/or cerebellum in seven patients; in five patients, tumor extended below the skull base. On unenhanced CT scans, tumors were isodense with brain in six patients and hypodense in two. In seven patients, CT scans with bone algorithm showed an enlarged jugular foramen with sharply rounded bone borders and a sclerotic rim. On MR images, T1 signal from tumor was low and T2 signal was high relative to white matter in all patients. Contrast enhancement on CT and/or MR studies was strong in eight patients and moderate in one. CONCLUSION: Schwannoma of the jugular foramen is characteristically a sharply demarcated, contrast-enhancing tumor, typically centered on or based in an enlarged jugular foramen with sharply rounded bone borders and a sclerotic rim. Intraosseous extension may be marked.

Adult↗

PubMed1996

Patent foramen ovale in underwater medicine.

The foramen ovale, between the right and left atria, exists in the foetal heart as a vital physiological communication. Haemodynamic closure occurs in the neonatal period with most people having permanent fusion of the foramen. In up to a third of adults the closure is functional only and a potential right to left atrial communication persists as a patent foramen ovale. Studies in patients with decompression illness after diving suggest a consistent increase in the prevalence of patent foramen ovale, as detected by transthoracic contrast echocardiography. The association is strongest for those patients with early onset of neurological decompression illness, particularly those cases occurring in the absence of other risk factors traditionally associated with decompression illness. However, patent foramen ovale is a common finding in the general population and the absolute risk of decompression illness, even in the presence of a patent foramen ovale, remains very low.

Decompression Sickness↗

PubMedDate not supplied

Percutaneous occlusion of patent foramen ovale in patients with paradoxical embolism.

INTRODUCTION: A patent foramen ovale can be found in about one quarter of adults and in a small percentage it is a wide opening and may be associated with aneurysmal formation. The association between a wide patent foramen ovale and paradoxical embolism is well established. In such cases percutaneous closure is indicated, as an alternative to life-long anticoagulant therapy or surgery. Percutaneous closure is an attractive technique and is more advantageous than other methods. METHODOLOGY: We describe the first cases of percutaneous occlusion of patent foramen ovale performed in Portugal, using the Amplatzer PFO occluder, in three female patients with documented cerebrovascular accidents due to paradoxical embolism. We also analyze the rationale for using this technique in such patients and its preliminary results. RESULTS: All three patients submitted to percutaneous occlusion of patent foramen ovale had a similar history of ischemic cerebrovascular accident. Transesophageal echocardiography showed a wide-open foramen ovale ranging from 9 to 12 mm, with spontaneous right-to-left shunt in all patients, and one of them also had an aneurysmal formation. Total procedure time ranged from 30 to 55 minutes and fluoroscopic time from 9 to 12 minutes. There were no complications and during the short follow up all patients are asymptomatic and free of recurrent events. CONCLUSIONS: Percutaneous closure of patent foramen ovale is a safe and promising technique in the prevention of recurrent systemic thromboembolism in appropriately selected patients. Prospective studies comparing antithrombotic therapy or surgery with percutaneous closure should clarify its efficacy and therapeutic value.

Adult↗

PubMed2001

Foramen jugulare: a local investigation and a review of the literature.

The jugular foramen varies in size and shape. Because of the variations and the surrounding structures, successful surgery is difficult in this region. For this reason, numerous studies have investigate the detailed anatomy of the foramen. The purpose of the present study is to investigate the possible local variations of the foramen jugulare. In this work, Eastern Anatolian skulls were examined in order to investigate the local variety. Extracranial opening of the foramen was only measured in diameters as maximum anteroposterior (AP) and mediolateral diameter (ML) of both right and left foramen. The height of the jugular fossa was taken as the dome height (DH). The results were in mm (right-left) as: AP (12.2-10.9); ML (13.7-12.3); DH (14-13.7). The present study suggested that local differences of the jugular foramen in relative size and shape might occur. These differences are probably peculiar to the region or probably the result of some particular clinical situation.

Cranial Nerves↗

PubMed2003

Studies on the location of the mental foramen in Turkish mandibles.

The position of the mental foramen was studied in 58 adult Turkish skulls which were divided into two groups according to age. A previously published method was used to determine the position of the mental foramen. The most common position of the mental foramen lies in line with the longitudinal axis passing between the first and second premolars. This result was in accordance with classical textbooks. Another measurement was also performed on the mental foramen in both groups. The distance between the mental foramen and the mandibular symphysis (A) and the distance between the mental foramen and the inferior border of the mandible (B) were measured. There was a significant difference between the two groups in B, but not in A.

Adult↗

PubMed1991

On the size of apical foramen in anterior teeth, bicuspids and molars.

The present authors have used a replica method to obtain area size measurements for the apical foramen in 4,613 human permanent teeth, and have obtained the following results: 1. The morphology of the apical foramen is rich in variety which make it difficult to express its accurate size using foramen diameter measurement. It is therefore more appropriate to determine its size as an area measurement. 2. Much variation was observed in the size of the apical foramen even for teeth of the same type. It was, however, also observed that the foramen is smaller in smaller types of teeth and larger in larger types of teeth. It was also observed that, in teeth of the same type, those with a greater number of roots have smaller foramen than those with a smaller number of roots.

Bicuspid↗

PubMed1989

[Studies on the position of the mandibular foramen].

Accurate investigation of the position of the mandibular foramen is important in anatomical and clinical studies, and there are a number of reports about such measurements. In this study, 140 Indian dry skulls, whose dental stages ranged from the stage before deciduous occlusion to the later phase of third molar eruption, were reproduced and the position of the mandibular foramen was measured using laser beams and three-direction photography. The position of the mandibular foramen was defined by the tip of the lingula mandibulae. 1. The angle of the lingula mandibulae was 45 degrees in children and it decreased with ageing. 2. At the later phase of the deciduous occlusion stage, the distance from the occlusal plane to the tip of the lingula mandibulae was high. 3. Each distance increased with the increasing age, height and width of the ramus mandibulae, the front and rear of the lingula mandibulae, and height of the lingula mandibulae. 4. There was little change with age in the ratio of the height of the ramus mandibulae to the height of the lingula mandibulae, and the ratio of the width of the ramus mandibulae to the distance of rear the lingula mandibulae. 5. The method for producing anesthesia in the mandibular foramen of children is as follows. The injection is aimed at the lingula mandibulae, which is 1/2 of the height and 1/2 of the width of the ramus mandibulae, from between the deciduous canine and the first molar on the opposite side, at a 10 angle to occlusal plane and at a 45 angle to the median line. In this manner it is possible to inject into the pterygomandibular space safely and expect certain anesthesia. In this study, the position of the mandibular foramen of children was accurately determined, as well as a safe clinical method for producing anesthesia to the mandibular foramen.

Child↗

PubMed1989

[A case of jugular foramen meningioma in a child].

The common tumors originating in the jugular foramen are chemodectoma and schwannoma. Jugular foramen meningioma is extremely rare. Review of the literature revealed only seven reported cases of this tumor. The authors present a child case of jugular foramen meningioma with intra and extracranial extension. A 9-year-old boy was admitted to the Department of Neurosurgery, Hiroshima University School of Medicine on March 20, 1985. Since the age of 3, the patient had hoarseness and was found to tilt his neck when he shouted. Since the age of 6, he was found to nod when he swallowed. At the age of 8, he developed swallowing difficulties. On admission, his general condition was unremarkable except for his lean build (126 cm in height and 23 kg in weight). An elastic hard and immobile mass was palpable in the left upper neck deep in the atrophic sternocleidomastoid muscle. Neurological examination revealed involvement of the ninth, tenth, eleventh, and twelfth cranial nerves. A plain skull roentgenogram and laminogram revealed hyperostosis around the left jugular foramen, and narrowing of the canal. CT with contrast enhancement revealed a high density mass in the left cerebellopontine angle extending through the jugular foramen to the left parapharyngeal space. Cerebral angiography did not show any abnormal findings except for complete blockage of the left sigmoid sinus. On April 4, 1985, subtotal removal of the intracranial tumor was performed using suboccipital craniotomy. Then, on July 3, 1985, the left parapharyngeal tumor was excised through a cervicofacial incision. Finally the residual tumor in the jugular foramen was excised using suboccipital approach on August 18, 1986.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain Neoplasms↗

PubMed1986

[Surgical approach for jugular foramen neurinoma--combined suboccipital and infralabyrinthine approach using a rotatable head holder].

A 36-year-old male with jugular foramen neurinoma was operated upon using a rotatable head holder, which enables the surgeon to rotate the patient's head at any time during the procedure and to gain access in multiple directions to the tumor. The tumor was situated primarily in the jugular foramen and showed partial extension into intracranial as well as into extracranial space. The patient was placed in the lateral position with a rotatable head holder, which allows rotation of the patient's head with the range of 10 degrees face up to 80 degrees face down from the horizontal plane. A linear skin incision was made, beginning behind the auricle and extending along the anterior margin of the sternocleidomastoid muscle, and the sternocleidomastoid muscle was divided just below the tip of the mastoid process. During mastoidectomy and suboccipital craniectomy, the patient's head was rotated 15 degrees face down and sigmoid sinus was exposed toward the jugular foramen, meanwhile the posterior fossa dura mater was opened and the intracranial portion of the tumor was removed with the head positioned 45 degrees-60 degrees face down. The patient's head is then turned 30 degrees face down and the facial canal was opened to displace the facial nerve forward. This oblique posterior approach minimized facial nerve displacement and provided excellent exposure of the large tumor rest which was situated mainly in the jugular foramen and partly extended extracranially. The rotatable head holder allows excellent access in multiple directions and is very helpful in approaching to jugular foramen neurinomas which grow primarily in the jugular foramen and extend both into intra- and extracranially.

Adult↗

PubMed1982

[An anatomical and technical note for neurosurgery of the jugular foramen tumor [author's transl)].

The basic anatomy of the jugular foramen, some diagnostic principles of the jugular foramen tumors with presentation of our experiences of the 13 cases (6 neurinomas, 6 chemodectomas and 1 meningioma), and the detailed surgical technique used in their removal and its result are described. According to the extension of the tumor, one of the following operative approaches can be selected. A) Transjugular approach consists of a retromastoideal craniectomy following a radical mastoidectomy. The posterior wall of the jugular foramen is scraped out and the sigmoid sinus and the internal jugular vein are resected with the tumor either confined in the jugular foramen or extending out of the skull. B) Transjugular-transpetrosal approach is suitable for the tumor in the jugular foramen extending out of the skull as well as into the CP angle. The petrosal bone is more scraped out for removal of the tumor extending into the CP angle than in the above transjugular approach. In the case of the tumor extending into the CP angle and the upper clivus, the upper petrosal bone medial to the C-5-C-6 segments of the internal carotid artery are also removed and an extensive exposure of the intracranial tumor is obtained. C) A suboccipital craniectomy with retrolabyrinthine removal of the petrosal bone is suitable for large glosso-pharyngeal neurinomas extending into the CP angle but not out of the floor of the skull. In such cases, after removal of the CP angle tumor in the usual way, resection of the remaining jugular foramen tumor is easily performed through opening the petrosal bone forming the medial portion of the dome of the jugular fossa.

Aged↗

PubMed1984

[A case of huge neurofibroma expanding extra- and intracranially through the enlarged jugular foramen--CT scan findings and surgical approach].

The surgical approach to the jugular foramen has been considered to be very difficult and troublesome, because of the location in which important structures, such as the internal jugular vein, internal carotid artery and lower cranial nerves, converge in the narrow deep space. A case of huge neurofibroma, which extended from the tentorium cerebelli through the dilated jugular foramen to the level of the vertebral body of C3 was presented. A 12-year-old girl was admitted with complaints of visual disturbance and palsy of the V-XII cranial nerves of the left side. Plain skull film showed prominent widening of the cranial sutures and enlargement of the sella turcica. Horizontal CT scan with contrast showed symmetrical ventricular dilatation and a heterogeneously enhanced mass, which was situated mainly in the left CP angle. Coronal CT scan with contrast revealed a huge mass and enlarged jugular foramen, through which the tumor extended to the level of the vertebral body of C3. Occlusion of the sigmoid sinus and the internal jugular vein of the left side was noticed in the vertebral angiography. Two-stage approach, the first one for removal of the intracranial tumor and the second one for extracranial tumor, was performed for its huge tumor. Several authors have reported excellent surgical approaches for the tumors situated in the jugular foramen. By our approach, modifying Gardner's original one, a wide operative field was obtained to remove the tumor around the jugular foramen with success. Our approach for the jugular foramen was described with illustrations.

Adolescent↗

PubMed1995

["Disproportionately large, communicating fourth ventricle" due to membranous obstruction of Magendie's foramen].

A case of disproportionately large, communicating fourth ventricle (DLCFV) with the entire ventricular system dilated symmetrically due to membranous obstruction of Magendie's foramen is reported. A 20-year-old female complained of headache and nausea. Slight papilledema was found in both eyes. CT scan and MRI showed that the entire ventricular system was dilated symmetrically, but we could not locate the cause of this disease, for example, tumor, arachnoid cyst, cerebellar malformation and so on. Although cinemode-MRI showed CSF pulsation as if CSF flowed through Magendie's foramen, we were not convinced that CSF flowed through it. We speculated that something obstructed CSF flow at Magendie's or Luschka's foramen, so surgery was performed by suboccipital craniectomy. As expected, a membranous obstruction was found at Magendie's foramen. After excision of the membrane, all symptoms improved. Postoperative cinemode-MRI clearly demonstrated CSF flow through Magendie's foramen. Ventriculoperitoneal shunting is generally effective for DLCFV, but we do not consider it the optimal treatment. The cause of DLCFV must be confirmed by suboccipital craniectomy if evidence of NPH, mass lesion or cerebellar malformation cannot be found anywhere especially around Magendie's foramen.

Adult↗

PubMed1997

Radiologic evaluation of the relation of the screw tip to the nerve root in the intervertebral foramen.

Eight cervical spines were used to evaluate the relation of the screw tip to the nerve root in the intervertebral foramen. The specimens were divided into two groups: (a) lateral placement without contact with the nerve root, and (b) lateral placement with penetration of the nerve root. Six screws were used for each specimen. After screw placement, oblique radiographs and axial computed tomography (CT) scans were taken. The results on oblique radiographs showed that 23 (95.8%) of 24 screws without contact with the nerve root were found in the upper zone or the junction between the upper and lower zones of the intervertebral foramen. Twenty (83.3%) of 24 screws with penetration of the nerve root were located in the junction between the lower zone of the intervertebral foramen and the pedicle zone. No definite diagnosis of screw penetration of the nerve root could be made on axial CT scans, although scans can show that the screw is violating the foramen. Whether or not a screw violating the intertransverse foramen and affects the nerve root depends on its position on the oblique radiograph. It may be not necessary to remove or change the screw immediately if a longer screw is found in the upper portion of the intervertebral foramen on the oblique view and angled laterally on axial CT scan in a patient without radicular symptoms.

Adult↗

PubMed1998

Quantitative anatomy of the transverse foramen and pedicle of the axis.

Forty dry C2 cervical vertebrae were obtained to evaluate quantitatively the anatomy of the C2 transverse foramen and pedicle. Computed tomography (CT) scans and plain radiographs were also obtained of 20 specimens to evaluate the internal structure of the transverse foramen and pedicle. The results of the measurements showed that differences between male and female specimens were found to be significant for four of seven linear parameters and for one of the two angular parameters. With regard to the sides, differences were found to be significant for two of the seven linear parameters and both of the angular parameters between right and left measurements. The variation of the foramen size between sexes was more significant than that between sides, and a remarkable variation between sides and between sexes was found in the transverse foramen horizontal angle and the pedicle width. The inferior pedicle width was approximately 3 mm less than the superior pedicle width. CT scans revealed that the lateral wall of the pedicle is very thin compared with the medial wall. Considering the greater variation of the C2 foramen orientation, smaller inferior pedicle dimension, and thinner lateral pedicle wall, a screw placement as close as possible to the mediosuperior cortex is recommended to avoid violation of the transverse foramen if transpedicular screw fixation in C2 is intended.

Adult↗

PubMed1997

The effect of condylectomy on extreme lateral transcondylar approach to the anterior foramen magnum.

The dorsolateral, suboccipital, transcondylar technique was used in this cadaveric study. The angle and distance measurements in the corridors were taken intradurally both superior and inferior of the foramen magnum level. In the first stage of this study, the findings which were gained from the standard lateral suboccipital approach were compared with the findings after condyle and lateral atlantal mass removal. After condylectomy, the approach to anterior foramen magnum via both corridors was found to be shorter and the lateral angle of the exposure of the anterior foramen magnum was found to be wider. The considerable shortening of the distances to the anterior foramen magnum, especially in the superior corridor, emphasises the necessity of combining standard approaches with condylectomy. In addition, it was found that after condylectomy, considerable widening of both transverse and longitudinal planes in the inferior corridor allows the surgeon greater access to work on lesions. Furthermore, the freed space between the superior corridor and the interior corridor, which was gained by condylectomy, shows that condylectomy provides a combined approach to the inferior and superior parts of the foramen magnum anteriorly.

Cadaver↗

PubMed2003

Anatomy of the clinoidal region with special emphasis on the caroticoclinoid foramen and interclinoid osseous bridge in a recent Turkish population.

In this study we present the incidence of caroticoclinoid foramen and interclinoid osseous bridge and some topographic aspects regarding the clinoidal internal carotid artery (ICA) in a recent Turkish population to provide a guide for neurosurgeons in any surgical approach, especially to the cavernous sinus. One hundred nineteen adult dry skulls and 52 adult cadaveric heads were used for this purpose. Caroticoclinoid foramen and the interclinoid osseous bridge were divided into three types based on the classification of Keyers [13]. Caroticoclinoid foramen was observed in 35.67% of the specimens, unilaterally in 23.98%, and bilaterally in 11.69%. The complete-type caroticoclinoid foramen was observed in 4.09% of the specimens, the contact type in 4.68%, and the incomplete type in 14.91%. Transverse diameter of the foramen was 5.32+/-0.52 mm for the incomplete type. The incidence of interclinoid osseous bridge was 8.18%. The middle clinoid process was prominent in 15.12% of cases and rudimental in 13.23%. The mean distance between the proximal and distal dural rings of the clinoidal ICA was 4.51+/-0.44 mm, and mean diameter of the distal ring was 5.25+/-0.59 mm. Right-left differences were assessed for each parameter, and populational differences are discussed.

Adult↗

PubMed2004

The pathogenesis of syringomyelia associated with lesions at the foramen magnum: a critical review of existing theories and proposal of a new hypothesis.

Syringomyelia is frequently accompanied by an extramedullary lesion at the foramen magnum, particularly a Chiari I malformation. Although syringomyelia associated with foramen magnum obstruction has characteristic clinical, radiological, and neuropathological features, its pathogenesis remains unclear. Currently prevalent hydrodynamical theories assert that obstruction of the subarachnoid space at the foramen magnum interferes with flow of cerebrospinal fluid (CSF) between the spinal and the intracranial subarachnoid compartments. As a result, spinal CSF is driven into the spinal cord through the perivascular spaces to form a syrinx. These theories are implausible biophysically because none postulates a pump adequate to drive fluid through these spaces. None of the theories can explain why syrinx pressure is higher than CSF pressure; why extensive gliosis, edema, and vascular wall thickening regularly occur; and why the composition of syrinx fluid is not identical with that of CSF. A new theory of pathogenesis is proposed to address these difficulties. In the presence of subarachnoid obstruction at the foramen magnum, a variety of activities, such as assuming the erect posture, coughing or straining, and pulsatile fluctuations of CSF pressure during the cardiac cycle, produce transiently higher CSF pressure above the block than below it. There are corresponding changes in transmural venous and capillary pressure favoring dilation of vessels below the block and collapse of vessels above the block. The spatially uneven change of vessel caliber produces mechanical stress on the spinal cord, particularly caudal to the block. The mechanical stress, coupled with venous and capillary dilation, partially disrupt the blood-spinal cord barrier, allowing ultrafiltration of crystalloids and accumulation of a protein-poor fluid. The proposed theory is consistent with the neuropathological findings in syringomyelia and with the pressure and composition of syrinx fluid. It also accounts for the prolonged course of syringomyelia and its aggravation by cough, strain, and assumption of an erect posture. It contributes to understanding the low incidence and the morphology of syringobulbia. It explains the poorly understood presentation of foramen magnum meningiomas with symptoms of a mid- to low-cervical myelopathy. The theory also affords an understanding of the late recurrence of symptoms in children with hydromyelia who are treated with a ventricular shunt.

Arnold-Chiari Malformation↗