We report five patients with odontoid invagination, in which the odontoid process bulges upward into the foramen magnum and compresses the brainstem without deformity of the occipital bone. Two patients had a craniovertebral abnormality associated with Chiari malformation without instability of the craniovertebral junction (stable odontoid invagination). The other three patients had dislocation of the craniovertebral junction due to iatrogenic destruction of the occipital condyle, rheumatoid arthritis or an anomaly of C2 (unstable odontoid invagination).
View Article and Find Full Text PDFWe present a rare case of a solitary dumbbell intra- and extramedullary schwannoma of the thoracic spine in a 54-year-old man without signs of von Recklinghausen's disease. The patient presented with motor weakness in the left lower extremity, bilateral sensory impairment below the T9 dermatome and rectovesical dysfunction. Preoperative magnetic resonance imaging was suspicious for an intradural extramedullary tumor.
View Article and Find Full Text PDFThis study was conducted to determine the incidence, severity, and causes of delayed vasospasm after clipping of unruptured paraclinoid aneurysms of the internal carotid artery (ICA). A retrospective analysis was made of 30 patients, who underwent clipping of unruptured paraclinoid aneurysms in our institution between 1991 and 1998. We compared angiograms before and after operation and classified them into two groups: vasospasm group and non-vasospasm group.
View Article and Find Full Text PDFWe performed 8 operations on 7 patients with benign intramedullary astrocytomas and ependymomas in the cervical and cervicothoracic region. All patients initially underwent gross total tumor resection en bloc. One patient with an astrocytoma showed tumor recurrence postoperatively, and underwent a second operation resulting in subtotal removal.
View Article and Find Full Text PDFBackground: Ganglioneuromas are rare benign tumors arising most commonly from the sympathetic nervous system. They occasionally grow in a dumbbell fashion extending into the spinal canal extradurally. However, ganglioneuromas of the cervical spine with intradural extension or multiple locations or in association with von Recklinghausen's disease are rare.
View Article and Find Full Text PDFWe present our surgical experience of 20 patients with syringomyelia, who were divided into two groups based on the findings of magnetic resonance (MR) imaging: a "non-visible cisterna magna" group, in which MR imaging did not reveal cerebrospinal fluid (CSF) in the cisterna magna, and a "visible cisterna magna" group. Patients with non-visible cisterna magna were associated with Chiari malformation (14 patients) or tight cisterna magna (4 patients) and underwent craniocervical decompression. Intradural exploration was performed when CSF movement in the cisterna magna or CSF outflow from the fourth ventricle appeared to be insufficient.
View Article and Find Full Text PDFSurgery was performed on the medulla oblongata of two adult patients with malignant glioma. Gross total resection of the tumors, located laterally or medially in the upper half of the medulla respectively, was achieved. The patient with the medially located tumor experienced significant postoperative neurological deterioration including sleep apnea.
View Article and Find Full Text PDFSome chordomas have a very poor prognosis because of their aggressive growth nature, but the efficacy of repeat operations for these cases has not been well documented. This report concerns 3 patients with aggressive chordoma of the clivus, who underwent operations 6 to 12 times over a period of 8 to 17 years because of symptomatic regrowth. Overall mean interval between repeat operations was 18 months with a range from 5 to 57 months and survival times were 9 to19 years after the first surgery.
View Article and Find Full Text PDFObjective And Importance: The natural history of syringomyelia is highly unpredictable, and some patients experience improvement or stabilization without surgery. However, the mechanisms of the formation and spontaneous resolution of syringomyelia remain controversial. This report concerns two patients with syringomyelia who demonstrated spontaneous reductions in syrinx size, accompanied by symptomatic improvement.
View Article and Find Full Text PDFObjective And Importance: Intradural-extradural dumbbell C2 schwannomas are rare. This report concerns two such cases with the intradural compartment located ventral to the spinal cord and involving both sensory and motor rootlets.
Clinical Presentation: One patient was a 57-year-old woman with sensory disturbances in the right extremities and hyperreflexia in the left extremities.
Background: En bloc removal of soft tumors within the brain parenchyma has rarely been performed. We describe a safe technique for en bloc removal of the tumors using a spoon retractor, which enables retraction while holding the soft mass upward.
Methods: Dissection of a tumor mass is performed under traction of the surrounding brain tissue by retracting the mass using a spoon retractor.
Background: A halo vest apparatus, commonly used for external immobilization and protection of the cervical spine, offers several advantages. We present here a simple, accurate, easy, and safe cervical traction technique using a halo vest apparatus.
Methods: The distinguishing feature of our technique is that, after application of a halo vest apparatus, the halo crown is distracted gradually and stepwise by turning the bilateral screw bolts that hold the halo crown over a period of one to several weeks.
Idiopathic syringomyelia, which is not associated with any definite pathogenic lesions, has been treated mainly by shunting of the syrinx and rarely by craniocervical decompression. The authors report four cases of syringomyelia thought to be idiopathic syringomyelia but treated by craniocervical decompression with favorable results. Syringomyelia was present without hindbrain herniation.
View Article and Find Full Text PDFBackground: When the surgeon's approach is from behind the patient's shoulder via the infratentorial supracerebellar approach in the prone position (Concorde position), the patient's shoulder nearest the surgeon occasionally interferes with the visual route and surgical manipulation. To avoid this difficulty the author developed a modified Concorde position.
Methods: In the prone position, the patient's arm at the surgeon's side hangs down over the head end of the operating table, with elbow flexion supported by an arm-holder.
We present a case of malignant astrocytoma of the conus medullaris in a 48-year-old man treated by spinal cordectomy. Preoperative examination revealed a tumor at the T12 to L1 level, and intraparenchymal invasion up to T8. The spinal cord was amputated caudally to the root entry zones of the T9 sensory roots.
View Article and Find Full Text PDFObjective: We present surgical results obtained with the use of an alternative transfacial approach to the central cranial base.
Methods: A degloving transfacial approach, which is a combination of the midface degloving procedure, the Le Fort I osteotomy with a pediculated cartilaginous septum, and a nasomaxillary osteotomy, was used in 13 procedures for 8 patients. The lower clivus and upper cervical spine were approached via a submucosal route, without opening of the oropharyngeal mucosa.