Extradural Component Research Articles

Nonvascular Lesions of the Jugular Foramen: The Gruppo Otologico Experience

Tumors other than paragangliomas in the jugular foramen are uncommon. Of these, schwannomas and meningiomas predominate. Little clinical data are available in the literature on these tumors at this site. The purpose of this article is to review our experience at the Gruppo Otologico of the management of these tumors. A retrospective series is presented of 32 consecutive patients affected by jugular foramen schwannomas and meningiomas in which their clinical and radiological signs, together with surgical techniques and outcomes, were reviewed. A single-stage resection was possible for the majority of patients when the petro-occipital trans-sigmoid (POTS) approach was used. This allowed resection of both intra- and extradural components of the tumor with hearing preservation and avoidance of facial nerve transposition. No deaths occurred. Lower cranial nerve palsies constituted the major cause of morbidity, but none of the patients required an adjunctive procedure such as vocal cord medialization, tracheostomy, or percutaneous gastrostomy.

Primary Cervical PNET mimicking as neurofibroma. A case report

Primitive Neuro Ectodermal tumor (PNET) are the lesions commonly occurring in intracranial locations, more often in children and young adult. These are aggressive and highly malignant tumors which may spread through CSF to the spinal cord. Occurrence of primary spinal PNET is rare. In the cord these can arise at any level and may be intramedullary, extramedullary or extradural in location. The appearance on MR studies may mimic a neurofibroma with intra and extradural components. The management includes surgical excision, radiotherapy and adjuvant chemotherapy. Despite good surgical excision, due to the aggressive nature of the tumor recurrence is likely and the life expectancy remains poor. An 18 year old right handed male presented with the complaint of pain in the neck and progressive weakness in both the upper and lower limbs more on left then right side of 4 month duration. Examination revealed wasting of the deltoid, supraspinatus and infraspinatus muscles on left side. Tone was increased in both lower limbs and the reflexes were brisk. Power was grade IV/V in RUL and RLL and III/V in LUL and LLL. Contrast MRI showed an extramedullary intradural mass of 3.4x1.2x1.7 cms in the spinal canal at C2 – C3 level compressing the cord and was extending to the C2 C3 neural foramen and thought to be neurofibroma with a major extradural component arising from the nerve root foramen. The patient was operated via C1-C4 laminectomy. Intra operative inspection revealed a large, vascular and firm tumor which had a major extradural component and was adherent to the left vertebral artery. The dura was opened and the intra and extradural components were excised. The intra foraminal portion of the tumor, which was adherent to the left vertebral was left. Histopathological examination revealed a highly cellular tumor which was infiltrating the surrounding meningeal and fibrocollagenous tissue with tumor cells arranged in small sheets suggestive of Primitive Neuro Ectodermal tumor (PNET). The patient did well after surgery and his power in upper and lower limbs improved to grade V on both the sides. A contrast CT scan of brain did not reveal any primary lesion in the brain thus ruling this out as a secondary lesion in the spine. The patient was advised adjuvant radiotherapy and chemotherapy, but was unable to take the treatment due to financial constraints. On follow up at the end of 4 months he was doing well. 6 months later he presented to us again with recurrence of progressive weakness in upper and lower limbs, as well as difficulty in breathing. A recurrence of the tumor was suspected and MRI of the cervical spine was repeated. This time it revealed two lesions; one at the previous (C2-3) level and the second lesion at the foramen magnum, which was compressing the cervico medullary junction anteriorly and encasing both vertebral arteries, which was a new development. The patient was re operated and both the lesions were excised by a posterior midline approach. The patient showed improvement post operatively with improvement in power and respiration. He was referred to the medical oncology department for chemotherapy. Primary Cervical PNET mimicking as neurofibroma. A case report

Convexity dural cavernous malformation with intradural and extradural extension mimicking a meningioma: a case report

Dural-based cavernous malformations are rare and have been more commonly described in the middle fossa. Fewer than 20 cases outside of the middle fossa have been reported and they often mimic more commonly found lesions such as meningiomas or hemangiopericytomas. We describe the unusual case of a right frontal convexity dural cavernous malformation with intradural and extradural components as well as erosion through the calvarium. The patient underwent a right frontal craniotomy and en-bloc resection of the mass. Final pathologic interpretation confirmed a cavernous malformation that had eroded through the calvarium. Dural-based cavernous malformations are a rare entity, but should be considered in the differential diagnosis of atypical appearing dural-based lesions and soft subgaleal masses. If atypical features are present, further radiographic investigations should be undertaken. To our knowledge, this is the only reported case of a dural-based cavernous malformation eroding through the calvarium and presenting initially as a soft scalp mass.

CT angiography and perfusion imaging in patients with subarachnoid hemorrhage: correlation of vasospasm to perfusion abnormality

We retrospectively evaluated computed tomography angiography (CTA) and perfusion imaging (CTP) of patients with aneurysmal subarachnoid hemorrhage (SAH) for any correlation between degree of vasospasm and perfusion deficit. Sequentially performed CTP and CTA of 41 patients at least at the third day of postbleeding were reviewed for vasospasm and perfusion deficit throughout the anterior and middle cerebral arteries and corresponding territories. Vasospasm was noted comparing the contralateral normal ones or extradural components of the vessel itself and graded to negative, mild, moderate, and severe as luminal narrowing none, <25%, between 25% and 50%, and >or=50%, respectively. CTP abnormality was noted using cerebral blood flow and volume and mean transit time maps. Of 41 patients, 20 had no vasospasm; 15 had mild to moderate and six had severe vasospasm. Three of 20 patients with no vasospasm (15%), four of 15 patients with mild to moderate vasospasm (26%), and five of six patients with severe vasospasm (83%) had perfusion abnormality. Perfusion abnormalities noted were ischemia, infarction, and hyperperfusion. Perfusion abnormality without vasospasm was observed in the watershed areas and adjacent to sulcal clots. In SAH patients, if there is a macrovascular vasospasm with luminal narrowing >or=50%, there is a high likelihood (83%) of perfusion abnormality in the territory of the vasospastic vessel. There may also be perfusion abnormality without macrovascular vasospasm in the watershed areas or in the vicinity of sulcal clots.

Dumbbell-shaped intrathoracic-extradural haemangioma of the thoracic spine

Spinal haemangiomas are benign vasoproliferative lesions that are typically intra-osseous and generally asymptomatic, although localized pain can be a symptom. Capillary and cavernous variants have been described. We describe a rare case of a dumbbell-shaped haemangioma of the thoracic spine with both an intraspinal – extradural and intrathoracic component.

Typical magnetic resonance features of a haemangioblastoma, an uncommon nerve root lesion: Case report and literature review

Haemangioblastomas are uncommon tumours of the central nervous system. Nerve root haemangioblastomas with both intradural and extradural components are extremely rare. We present a case of a C2 nerve root haemangioblastoma in a 64-year-old man where the preoperative diagnosis was a spinal meningioma. An unexpectedly vascular tumour was found at initial procedure. Urgent catheter angiography was performed and the tumour was embolized prior to complete excision at a subsequent procedure.

Anterolateral approach to the craniocervical junction

The authors present the surgical results obtained using the anterolateral approach to the craniocervical junction (CCJ) to resect a lesion with an extradural component located anterolateral to the foramen magnum and upper cervical spine. The anterolateral approach, which is a presternomastoid retrojugular route to the CCJ, was performed in 14 patients. The skin incision follows the anterior edge of the sternomastoid muscle. The vertebral artery (VA) was exposed at C-1. This approach was extended either down to the cervical spine or anteriorly to the jugular foramen, according to specific requirements. Two patients had previously undergone other surgical procedures. The follow-up period ranged from 4 months to 6.2 years. The tumor resection was complete in 11 cases and subtotal in two. In a case of vertebral coiling, a vein graft was interposed between the V1 and the V3 segments of the VA, and the bypass was still patent at the 2-year follow-up examination. In two cases involving a glomus tumor, there was a transitory postoperative seventh cranial nerve deficit. The aforementioned technique allows for sufficient access to lesions located anterolateral to the CCJ. It is indicated in cases in which lesions exhibit a significant extradural component, and it provides good control of the VA, the cervical portion of the internal carotid artery, sigmoid-jugular complex, and lower cranial nerves. This approach can easily be combined with a posterolateral approach and can be extended anteriorly toward the jugular foramen and inferiorly toward the lower cervical spine.

The filum terminale externum

The filum terminale externum (FTE) is the extradural component of the filum terminale internum and little attention has been dedicated to this structure in the literature. The authors theorized that the rare intrasacral ependymomas may originate from ependymal cell collections within the FTE. To address this hypothesis, the FTE was dissected and analyzed histologically in 15 adult cadavers. None of the specimens was found to harbor ependymal or other glial cell collections. The authors found previously undescribed smooth-muscle cells within the FTE. Furthermore, histological analysis identified adipose, nerve, bone, and cartilage cells.

Management of a Sporadic Malignant Subfrontal Peripheral Nerve Sheath Tumor

Malignant subfrontal (olfactory) peripheral nerve sheath tumors (MPNSTs) are exceedingly rare. Although meningiomas are the most common subfrontal extra-axial lesions, it is important to recognize that MPNSTs, which are radiographically similar to meningiomas, can also be present in this location. MPNSTs require more aggressive surgical and postoperative management than meningiomas. In this paper, we describe a patient with a subfrontal MPNST with unusual histological characteristics and present a review of the literature. A 49-year-old woman presented with chronic sinusitis and progressive headaches. A neurological examination revealed left-sided anosmia. Brain-imaging studies revealed a large left subfrontal mass with extension into the frontal and ethmoid sinuses and the nasal cavity. The patient underwent both a bifrontal transbasal craniotomy and a transnasal approach for an attempt at total resection of both the intradural and extradural components of the MPNST. The patient was treated postoperatively with radiation therapy, and had no evidence of recurrence at her follow-up examination 1-year after treatment. Subfrontal PNSTs are extremely rare and usually benign. The specific cell and nerve of origin for these tumors remains unknown. Our case shows that these rare lesions can present as a malignant variant and thus require aggressive surgical and postoperative management to provide long-term tumor control.

Cervical Dumbbell Intra-extradural Hemangioblastoma: Total Removal through the Lateral Approach: Technical Case Report.

Extradural hemangioblastomas account for 8 to 12% of all spinal hemangioblastomas. Among them, intra-extradural forms with a dumbbell extension are extremely rare. We report a case of intra-extradural hemangioblastoma involving the C6 cervical nerve root. The patient was a 31-year-old woman presenting with signs of myelopathy and C6 radiculopathy on the right side. A computed tomographic scan and magnetic resonance imaging demonstrated a dumbbell tumor that had developed through the C5-C6 intervertebral foramen. Angiography revealed a well-circumscribed mass with feeders from the vertebral artery and the deep cervical artery. The tumor was totally removed through the lateral approach, with control of the vertebral artery and sacrifice of the C6 cervical nerve root. Limited bone drilling to enlarge the foramen permitted us to reach and resect the intradural component. Histopathological examination confirmed the diagnosis of hemangioblastoma. Follow-up was uneventful. This is the sixth reported case of a cervical dumbbell hemangioblastoma investigated by computed tomographic scanning and MRI but the first one resected via the lateral approach. The lateral approach seems appropriate for surgical resection because it provides primary control of the vascular feeders and access to the extradural and intradural components.

Juxtaposition of an Epidural Intraforaminal Cavernous Hemangioma and an Intradural Schwannoma

A case of juxtaposition of a purely extradural cavernous hemangioma and an intradural schwannoma in the thoracic spine is reported. The objectives of this study were to present a rare and before-surgery unexpected combination of spinal tumors, which may complicate surgical removal; and to discuss the radiologic features and the possible pathogenesis of this combination of tumors and its implications on surgical therapy. Juxtaposition of different spinal tumors is exceedingly rare in patients without neurofibromatosis. To the authors' knowledge, no combination of a purely epidural spinal cavernous hemangioma with an intradural schwannoma has been previously reported. A 47-year-old woman presented with progressive paraparesis. Magnetic resonance imaging revealed a partly cystic intradural mass at the T6-T7 level and a solid extradural intraforaminal component that demonstrated slightly different signal characteristics. An intra-/extradural schwannoma was assumed. Surgical exposure displayed a highly vascularized lobulated mass within the left neuroforamen at T6-T7. There was no continuity with the larger intradural, cystic, and mildly vascularized lesion. Histologic examination diagnosed an extradural cavernous hemangioma and an intradural schwannoma. The segmental juxtaposition of lesions should be considered in the differential diagnosis of spinal pathology.

Multiple subpial lipomas with dumb-bell extradural extension through the intervertebral foramen without spinal dysraphism

BACKGROUND Intradural subpial lipomas not associated with spinal dysraphism, account for less than 1% of spinal cord tumors. The simultaneous existence of multiple intradural subpial lipomas with dumb-bell extradural extension through the intervertebral foramen in the same patient without any evidence of spinal dysraphism has not been previously reported. CASE DESCRIPTION A 38-year-old man presented with progressive spastic paraparesis, and weakness of right elbow extension and opposition of the medial three fingers. He also had ascending paraesthesia from the C6 dermatome to the saddle region and loss of joint and position sense of both lower limbs with hesitancy and precipitancy of micturition. There was no spinal tenderness, deformity, neurocutaneous markers, or spinal dysraphism. The total duration of illness was 11 years. The oblique views of the plain radiographs of the cervical spine revealed an enlarged right C7-D1 intervertebral foramen. The T1- and T2-weighted magnetic resonance (MR) images showed two intradural, hyperintense lesions (with extensive loss of signal on fat suppression sequences), one extending from C5 to D2 and the other opposite the C3–4 disc space. The parasagittal and axial images showed the extradural component of the lesion emerging from the right C7-D1 intervertebral foramen. At surgery, a C2 to D2 laminectomy was performed. The lipoma, enclosed in a fine pial membrane, was situated on the right posterolateral aspect of the cord. The right-sided nerve roots from the C6 to D1 levels were completely enmeshed by the lipoma. There was a separate superficial subpial lipoma adherent to the posterior aspect of the cord at the C3–4 level. A distinct area of normal cord was present between the two lesions. A subtotal decompression of the lesions including the component emerging through the right C7-D1 intervertebral foramen and a duraplasty were performed. At follow-up after 18 months, the posterior column impairment, lower limb hypoaesthesia, and right upper limb paraesthesia had improved. However, residual elbow extension and lower limb weakness, mild lower limb spasticity and sphincteric dysfunction persisted. CONCLUSIONS The multiplicity of intradural subpial lipomas without spinal dysraphism points to a dysembryogenetic basis similar to that seen in patients with spinal dysraphism that results in lipomas, but in which the defect is not severe enough to give rise to coexisting vertebral and soft tissue anomalies. The dumb-bell extradural extension through the intervertebral foramen is extremely rare. The magnetic resonance imaging and surgical principles are discussed.

傍床状突起部外側型動脈りゅう

We present a small series of 3 surgical cases with lateral paraclinoid carotid aneurysms. Since the lateral wall of the internal carotid artery in the vicinity of dural ring is uncommon as a site of aneurysmal origin, little experience has been reported in the literature. Discrepancies were encountered between preoperative prediction and operative findings regarding the location of dural ring. On preoperative angiogram, 2 aneurysms were diagnosed as totally intradural and 1 as partially intradural. At surgery, 1 aneurysm was purely intradural, another 1 had both intra- and extradural component, and the other was located completely proximal to the dural ring.Difficulties in specifying the location of dural ring, especially the lateral margin, on preoperative imaging studies arise in the fact that the dural ring intersects the internal carotid artery at an oblique angle, which varies from case to case. The origin of the ophthalmic artery on lateral angiogram was an unreliable landmark for the lateral margin of dural ring. One of more useful landmarks is the anterior clinoid process visualized on angiogram before subtraction or 3D-CT. Lateral paraclinoid aneurysms that have a component above the anterior clinoid process are likely to be located entirely or at least partially intradural. Surgery should be preserved for those aneurysms because they are at risk of causing subarachnoid hemorrhage.

Spinal Metastasis from Eccrine Adenocarcinoma of the Neck

We report a rare case of spinal metastasis from eccrine carcinoma of the nape of the neck four years after resection of the primary lesion. There was local recurrence at the same site apart from the spinal metastasis. The spinal lesion involved the pedicle and body of the D-9 vertebra with an extradural component compressing the cord. MR appearance was that of any metastatic deposit, hypointense on T1 and hyperintense on T2.

Cervical neuromas with extradural components: surgical management in a series of 57 patients.

Cervical neuromas with extradural components (intraextradural or strictly extradural forms) are rare. Their resection raises the problems of nerve root preservation, vertebral artery (VA) control, and spinal stability. A series of 57 patients with neuromas (29 neurofibromas, 23 schwannomas, 4 neurofibrosarcomas, and 1 plexiform neurofibroma) was treated during the period of 1980 to 1995, using one of the lateral approaches (antero- or posterolateral approach). The VA was always controlled before resection of the tumor. In cases of intraextradural forms, the intradural component was removed by a complementary laminectomy (three patients) in the early period and then by an oblique corpectomy through the same lateral approach (five patients) in the late period. A laminectomy had been performed in 15 other patients (11 patients with intraextradural neuromas) before they were referred to us. These patients included seven with recurrent neuromas, occurring after an average period of 4.1 years (1-9 yr). Complete resection was achieved in all except two patients, in whom the nerve root reacted positively to intraoperative stimulation and could not be separated from the tumor. One of the patients was subsequently operated on after 2 years. Another recurrence was observed in another patient at 1 year. The four patients with sarcomas died from recurrence within 2 years. The rate of root preservation included an average of 28%, including 43.5% for schwannomas, 18% for neurofibromas, 44% for lower cervical neuromas (C4-C8), and 4.5% for upper cervical neuromas (C1-C3). Worsening of preoperative neurological deficits was observed in only two patients. The VA was always preserved, except in one patient with a sarcoma that was preoperatively occluded. No instability was observed in any of the patients. Complete resection with good neurological results can be achieved in most patients harboring cervical neuromas each with an extradural component by using a lateral approach and VA control. If the root cannot be separated from the tumor, especially in patients with neurofibromas, intraoperative stimulation can help decide whether the root may be divided without incurring postoperative deficit. The lateral approach permits the resection of the extradural as well as the intradural component by a complementary oblique corpectomy. There was no morbidity in relation to VA control as well as no postoperative instability.

Meningioma of the foramen magnum: A series of 40 cases

Surgical treatment of foramen magnum meningiomas (FM meningiomas) has been improved by the recently developed posterolateral and anterolateral approaches. The choice of these approaches and the extent of bone resection, however, need to be defined according to the tumor location. Over a short period (1980-1993), 40 cases of FM meningiomas were treated either by the posterolateral (N = 31), the anterolateral (N = 5), or the midline posterior approaches (N = 4). The choice of surgical technique (surgical approach, extent of bone drilling, and dural opening) was made according to the tumor location, which is defined by three parameters: the horizontal plane (anterior N = 18, lateral N = 21, and posterior N = 1); the vertebral artery (above N = 4, below N = 20, and on both sides N = 16); the dura mater (intradural N = 24, extradural N = 2, and intraextradural N = 4). Intradural anterior and lateral FM meningiomas were operated by the posterolateral approach. The bone drilling was limited either to the occipital condyle or to the lateral mass of the atlas, depending on whether the tumor location is above or below the vertebral artery, respectively. Intradural posterior meningiomas were treated by the midline posterior approach. FM meningiomas with an extradural component were resected by the anterolateral approach alone or combined with a midline posterior approach. The rate of complete resection was 94% for intradural FM meningiomas and 50% for the extradural ones. FM meningiomas with an extradural component generally have aggressive features invading the adjacent bone and soft tissues; this explains the difficulty of performing a complete resection. The clinical condition improved in 90%, worsened in 7.5%, and did not change in 2.5%. The worsened group consisted of three deaths (one case of air embolism, one case of pulmonary embolism, and one case with preoperative coma and tetraplegia). Similar results were obtained in both anterior and lateral locations. FM meningiomas can be completely and safely removed in most cases, using an appropriate surgical technique. The technique must be chosen after precise and correct analysis of the tumor location. The lateral approaches are very effective in the treatment of lateral and anterior FM meningiomas.

Paralysis of the arm after posterior decompression of the cervical spinal cord

An anatomical study of the cervical spinal cord and root to investigate the mechanism of paralysis of the arm after posterior decompression was performed using 14 cadavers of Japanese adults. It revealed that in the intervertebral foramen, extradural portions of the anterior and posterior roots of the cervical spinal cord lay separately in caudal-rostral relation, and the anterior root passed through the narrowest portion of the foramen isolatedly, i.e. the superior notch of the superior articular process. After laminectomy, a posteromedial shift of the dura-root junction occurred in combination with the posterior enlargement of the dual tube, and it showed two effects on the roots, one a relaxing effect on rootlets and the other, a traction effect on the extradural portion of a root. Through these effects, the anterior and posterior rootlets did not lose their laxities even when there was maximal posterior shift of the spinal cord in the maximally enlarged dural tube, and conversely, extradural portions of both roots were laid under traction by the posteriorly expanded dural tube. This traction force to the extradural portion of the roots disappeared with a longitudinal incision to the posterior aspect of the bulging dural membrane, suggesting that it was the posteriorly expanded dural membrane that exerted the traction force on the extradural components of the anterior and posterior roots. From these anatomical findings, mechanisms of paralysis were deduced as follows. The posteriorly expanded dural tube exerts traction force on the extradural portions of the anterior and posterior roots. With the impingement of the medial facet edge on the posterior root, a traction-compression injury of the posterior rootlets or extradural portion of the posterior root occurs. With anchoring of the anterior root inside the foramen, a traction injury of the anterior root develops. The predominance of paralysis at the middle cervical level could be explained by the higher degree of anterior protrusion of the superior articular process and the more frequent degenerative changes here than at other levels. These factors might inhibit the gliding abilities of the roots inside the foramina, with the formation of perineural fibrosis, predisposing the roots to damage by the traction force.

MR imaging of the sacral plexus: normal findings.

Imaging of the sacral plexus requires evaluation of both intradural and extradural components with cross-sectional techniques. Although CT is useful, individual extradural sacral nerves and the sacral plexus usually cannot be distinguished from adjacent structures. The higher contrast resolution provided by MR imaging allows the region of the sacral plexus to be examined in greater detail. With MR imaging, the constant relationship of the neural components to one another, and the gluteal vessels in their course from the sacrum to the greater sciatic foramen, can be shown consistently. An understanding of the anatomy of this area in multiple planes can aid in more accurate localization of abnormalities involving the sacral plexus. This pictorial essay reviews the MR appearance of the region of the sacral plexus.

Membranous nephropathy associated with spinal schwannoma

Clinical cure was effected in a patient with biopsy-proven membranous nephropathy associated with spinal schwannoma. The renal manifestation of nephrotic syndrome antedated the clinical presentation of the spinal tumor. The proteinuria and edema subsided 4 mths after the complete resection of the intradural component and partial removal of the extradural component of the schwannoma. Careful workup in patients with membranous nephropathy should include not only malignant but also benign tumors.

Intradural herniation of thoracic disc: CT metrizamide myelography

A case of intradural herniation of a thoracic (T12-L1) intervertebral disc is reported. On metrizamide myelography, this lesion resembled an intradural extramedullary tumor with an extradural component. A computed tomographic (CT) scan taken immediately after the myelogram, showed gas in the spinal anal and in the intervertebral disc. In addition, it showed a high-density mass located in the ventral epidural space and also intradurally. The density of this soft-tissue mass was identical to that of the intervertebral disc. CT provided very important information regarding the precise location and probable etiology of the lesion, and the success of surgery.