Management of traumatic dislocation of the mandibular condyle into the middle cranial fossa. (1/44)

Dislocation of the mandibular condyle into the middle cranial fossa is a rare complication of facial trauma that can have neurological and life-threatening implications. This article discusses the anatomic features that predispose patients to this type of injury, as well as the clinical features and mechanism of injury for this rare type of condylar deformity, to help practitioners recognize this easily overlooked injury and avoid disastrous complications. The article summarizes previously published case reports of this rare complication of condylar trauma and presents a case for which initial diagnosis and a management protocol are described.  (+info)

Orbit deformities in craniofacial neurofibromatosis type 1. (2/44)

BACKGROUND AND PURPOSE: The possible relationship of orbit deformities in neurofibromatosis type 1 (NF1) to plexiform neurofibromas (PNFs) have not been fully elucidated. Our purpose was to review orbital changes in patients with craniofacial NF1. METHODS: We retrospectively reviewed CT and MR imaging abnormalities of the orbit in 31 patients (18 male, 13 female; mean age, 14 years; age range 1-40 years) with craniofacial NF1. RESULTS: Orbital abnormalities were documented in 24 patients. Six had optic nerve gliomas with enlarged optic canals. Twenty had PNFs in the orbit or contiguous to the anterior skull. The posterior orbit was distorted by encroachment from an expanded middle cranial fossa in 13 patients, and 18 had enlargement of the orbital rim. Other changes included focal decalcification or remodeling of orbital walls adjacent to PNFs in 18 patients and enlargement of cranial foramina resulting from tumor infiltration of sensory nerves in 16. These orbital deformities were sometimes progressive and always associated with orbital infiltration by PNFs. CONCLUSION: In our patients with craniofacial neurofibromatosis, bony orbital deformity occurred frequently and always with an optic nerve glioma or orbital PNF. PNFs were associated with orbital-bone changes in four patterns: expansion of the middle cranial fossa into the posterior orbit, enlargement of the orbital rim, bone erosion and decalcification by contiguous tumor, and enlargement of the cranial foramina. Orbital changes support the concept of secondary dysplasia, in which interaction of PNFs with the developing skull is a major component of the multifaceted craniofacial changes possible with NF1.  (+info)

The sphenoparietal sinus of breschet: does it exist? An anatomic study. (3/44)

BACKGROUND AND PURPOSE: The termination of the superficial middle cerebral vein is classically assimilated to the sphenoid portion of the sphenoparietal sinus. This notion has, however, been challenged in a sometimes confusing literature. The purpose of the present study was to evaluate the actual anatomic relationship existing between the sphenoparietal sinus and the superficial middle cerebral vein. METHODS: The cranial venous system of 15 nonfixed human specimens was evaluated by the corrosion cast technique (12 cases) and by classic anatomic dissection (three cases). Angiographic correlation was provided by use of the digital subtraction technique. RESULTS: The parietal portion of the sphenoparietal sinus was found to correspond to the parietal portion of the anterior branch of the middle meningeal veins. The sphenoid portion of the sphenoparietal sinus was found to be an independent venous sinus coursing under the lesser sphenoid wing, the sinus of the lesser sphenoid wing, which was connected medially to the cavernous sinus and laterally to the anterior middle meningeal veins. The superficial middle cerebral vein drained into a paracavernous sinus, a laterocavernous sinus, or a cavernous sinus but was never connected to the sphenoparietal sinus. All these venous structures were demonstrated angiographically. CONCLUSION: The sphenoparietal sinus corresponds to the artificial combination of two venous structures, the parietal portion of the anterior branch of the middle meningeal veins and a dural channel located under the lesser sphenoid wing, the sinus of the lesser sphenoid wing. The classic notion that the superficial middle cerebral vein drains into or is partially equivalent to the sphenoparietal sinus is erroneous. Our study showed these structures to be independent of each other; we found no instance in which the superficial middle cerebral vein was connected to the anterior branch of the middle meningeal veins or the sinus of the lesser sphenoid wing. The clinical implications of these anatomic findings are discussed in relation to dural arteriovenous fistulas in the region of the lesser sphenoid wing.  (+info)

MR imaging of orbital inflammatory pseudotumors with extraorbital extension. (4/44)

OBJECTIVE: To demonstrate a variety of MR imaging findings of orbital inflammatory pseudotumors with extraorbital extension. MATERIALS AND METHODS: We retrospectively reviewed the MR features of five patients, who were diagnosed clinically and radiologically as having an orbital inflammatory pseudotumor with extraorbital extension. RESULTS: The types of orbital pseudotumors were a mass in the orbital apex (n = 3), diffuse form (n = 2), and myositis (n = 1). The extraorbital extension of the orbital pseudotumor passed through the superior orbital fissure in all cases, through the inferior orbital fissure in two cases, and through the optic canal in one case. The orbital lesions extended into the following areas: the cavernous sinus (n = 4), the middle cranial fossa (n = 4), Meckel's cave (n = 2), the petrous apex (n = 2), the clivus (n = 2), the pterygopalatine fossa and infratemporal fossa (n = 2), the foramen rotundum (n = 1), the paranasal sinus (n = 1), and the infraorbital foramen (n = 1). On MR imaging, the lesions appeared as an isosignal intensity with gray matter on the T1-weighted images, as a low signal intensity on the T2-weighted images and showed a marked enhancement on the post-gadoliniumdiethylene triamine pentaacetic acid (post-Gd-DTPA) T1-sequences. The symptoms of all of the patients improved when they were given high doses of steroids. Three of the five patients experienced a recurrence. CONCLUSION: MR imaging is useful for demonstrating the presence of a variety of extraorbital extensions of orbital inflammatory pseudotumors.  (+info)

Rapidly growing microcystic meningioma of the middle fossa floor. Case report. (5/44)

A 74-year-old woman presented with a microcystic meningioma which manifested as mental disturbance. A rapidly growing tumor in the left middle fossa had not been detected by examination 10 months before. The tumor was remarkably enhanced by contrast medium on both computed tomography and magnetic resonance imaging and was associated with massive perifocal edema. Cerebral angiography revealed that the tumor was mainly fed by the left middle meningeal artery, which was embolized preoperatively. The tumor was completely removed and no postoperative adjuvant therapy was administered. The histological diagnosis was microcystic meningioma with many mitotic figures and a MIB-1 labeling index of 12.8%. Four months later, the tumor recurred and invaded the paranasal sinus. Focal irradiation successfully controlled further regrowth. This case suggests that microcystic meningioma may have aggressive features, and close observation is necessary even after gross total removal.  (+info)

Synovial chondromatosis of the temporomandibular joint with extension to the middle cranial fossa. (6/44)

A rare case of synovial chondromatosis with extension to the middle cranial fossa is reported. Synovial chondromatosis, a benign disorder characterized by multiple cartilaginous, free-floating nodules that originate from the synovial membrane is not exclusive to the temporomandibular joint (TMJ). This condition is commonly seen in the axial skeleton and can involve multiple joints. In this case, synovial chondromatosis of the TMJ led to complete bony erosion of the glenoid fossa extending into the middle cranial fossa. Although plain radiographs showed the involvement of the joint, Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) provided more detailed information about the lesion in all three dimensions. This case demonstrates the value of CT and MRI in both the diagnosis and treatment planning. A review of previously reported cases of synovial chondromatosis with cranial extensions is included.  (+info)

Assessment of the anatomical relationship between the arcuate eminence and superior semicircular canal by computed tomography. (7/44)

The anatomical relationship between the arcuate eminence (AE) and the superior semicircular canal (SSC) was examined by computed tomography (CT) in 52 petrous bones of 26 patients. After acquiring volume data by multidetector CT, 1-mm thick oblique bone window images perpendicular to the SSC were obtained from the axial images. The distances between the AE and the SSC, and the SSC and the superior surface of the petrous bone were measured. The AE corresponded exactly with the SSC in only 2/52 petrous bones, and corresponded well in 7/52. The AE was lateral to the SSC in 25/52 cases, medial to the SSC in 6/52 cases, intersected in 3/52 cases, and was indiscernible in 9/52 cases. The distance between the SSC and the petrous surface was 0 mm in 45/52 petrous bones, 1 mm in 5/52, 2 mm in 1/52, and 3 mm in 1/52. The SSC typically does not correspond exactly with the AE, and is generally located just under the surface of the petrous bone. Planning of the middle cranial fossa approach requires location of the SSC by CT.  (+info)

Dura-based giant intracranial schwannoma in the middle fossa. (8/44)

A 49-year-old female presented with a rare giant schwannoma arising from the dura mater of the middle fossa manifesting as loss of left visual acuity. Magnetic resonance imaging revealed a heterogeneously enhanced giant mass in the left middle fossa. Surgery via the transsylvian approach confirmed the origin of the tumor between the left internal carotid artery and the trigeminal nerve in the lateral wall of the cavernous sinus. Elongated abducens nerve was confirmed, but no tumor adhesion to the abducens nerve was found. The tumor was closely attached to the dura mater of the middle fossa and the lateral wall of the cavernous sinus. The histological diagnosis was schwannoma. Both left oculomotor and abducens nerve pareses occurred immediately after the operation but gradually resolved over 3 months. The operative findings indicated that this schwannoma may have arisen from the meningeal branch of the trigeminal nerve in the dura mater of the middle fossa.  (+info)