Sumiyoshi Tanabe

Results of reoperation for failed microvascular decompression

SummaryAmong 64 patients with hemifacial spasm (HFS) and 60 with trigeminal neuralgia (TN) treated by microvascular decompression (MVD), repeated MVD performed on 3 cases with HFS resulted in the absence of spasm in all cases. In 7 cases with TN, this technique resulted in complete remission in 2, recurrence in 3, and no pain relief in 2 cases. MVD was more effective on HFS than on TN in repeated procedures as well as for initial treatment. The cause of recurrence of HFS was attributed to the inadequate cushion effect of muscle as a prosthesis, while that for TN was suspected to be related more to post-operative fibrotic adhesions formed around the fifth nerve.

Cervical dural arteriovenous malformation presenting with right-sided occipitalgia: Before and after successful treatment by embolization

SYNOPSIS

Vascularized omentum graft for the reconstruction of the skull base after removal of a nasoethmoidal tumor with intracranial extension: case report.

A 16-year-old boy with rhabdomyosarcoma occupying the nasal cavities and the ethmoid sinus with intracranial extension underwent transcranial surgery. The intradural tumor was resected first with the affected dura of the anterior skull base, and the dural defect was repaired with fascia harvested from the sheath of the rectus abdominis muscle. The remaining tumor contiguous to the nasal cavities was completely extirpated. The cranial cavity was then exposed to the opened nasal cavities, where a revascularized omental graft was used to separate these compartments. Lyophilized dura was placed beforehand beneath the omental graft, as a roof to the nasal cavity, and was removed 3 weeks later through the nostril. A bony skull base repair was performed over the omentum using the inner table of the bone flap. Subcutaneous fat from the abdomen was placed on the bone graft for fixation and as an additional seal for the dural defect. Reconstruction of the anterior skull base with a vascularized omental transfer provides an efficient barrier to the nasal cavity. It also serves as an excellent supporting structure for regeneration of the mucosal epithelium of the nasal cavities.

Significant Improvement of Visual Functions after Removal of an Intracranial Giant Optic Nerve Glioma Revealing Exophytic Growth: Case Report

Received, April 6, 2005. Accepted, November 29, 2005. OBJECTIVE AND IMPORTANCE: Intracranial giant optic nerve gliomas, usually presumed as optic chiasmatic gliomas, are much less common. The architectural tumor form of optic nerve glioma without neurofibromatosis type 1 is usually the expansileintraneural pattern. The exophytic optic nerve gliomas without neurofibromatosis type 1 are relatively uncommon. Surgical decompression for intracranial optic gliomas frequently leads to clinical improvement, but obvious improvement of vision is rare. We report a case that demonstrated significant recovery of visual function after removal of the intracranial giant optic nerve glioma, revealing exophytic growth. CLINICAL PRESENTATION: A 13-year-old boy presented with visual impairment in both eyes. Magnetic resonance images (MRI) disclosed a 6 cm diameter mass in the suprasellar area. On heavily T2-reversed MRIs, it was obvious that the intracranial portion of right optic nerve was enlarged, and optic tracts were shifted to the left by the tumor. The relationship of the tumor to the chiasma could not be affirmed on MRIs. INTERVENTION: A right frontotemporal craniotomy for decompression of the optic apparatus was performed. After the majority of the tumor was resected, it became clear that the tumor originated in the right optic nerve. The tumor exophytically grew and dislocated the optic chiasma and optic tracts. Significant improvement of visual functions began from the first week after surgery and continued gradually thereafter. The histological diagnosis was pilocytic astrocytoma. A follow-up MRI taken 4 years after surgery showed no regrowth of the residual tumor. CONCLUSION: Giant exophytic gliomas without neurofibromatosis type 1 may arise from the intracranial portion of an isolated optic nerve. Direct visualization of optic component by heavily T2-reversed MRI could more precisely delineate the relationship of the intracranial optic nerve glioma to the optic apparatus. Surgery may be indicated in giant exophytic intracranial optic nerve gliomas and preoperative postulated optic chiasmatic gliomas. Microsurgical resection can induce postoperative visual improvement without regrowth of the residual tumor.OBJECTIVE AND IMPORTANCE:Intracranial giant optic nerve gliomas, usually presumed as optic chiasmatic gliomas, are much less common. The architectural tumor form of optic nerve glioma without neurofibromatosis type 1 is usually the expansile-intraneural pattern. The exophytic optic nerve gliomas without neurofibromatosis type 1 are relatively uncommon. Surgical decompression for intracranial optic gliomas frequently leads to clinical improvement, but obvious improvement of vision is rare. We report a case that demonstrated significant recovery of visual function after removal of the intracranial giant optic nerve glioma, revealing exophytic growth. CLINICAL PRESENTATION:A 13-year-old boy presented with visual impairment in both eyes. Magnetic resonance images (MRI) disclosed a 6 cm diameter mass in the suprasellar area. On heavily T2-reversed MRIs, it was obvious that the intracranial portion of right optic nerve was enlarged, and optic tracts were shifted to the left by the tumor. The relationship of the tumor to the chiasma could not be affirmed on MRIs. INTERVENTION:A right frontotemporal craniotomy for decompression of the optic apparatus was performed. After the majority of the tumor was resected, it became clear that the tumor originated in the right optic nerve. The tumor exophytically grew and dislocated the optic chiasma and optic tracts. Significant improvement of visual functions began from the first week after surgery and continued gradually thereafter. The histological diagnosis was pilocytic astrocytoma. A follow-up MRI taken 4 years after surgery showed no regrowth of the residual tumor. CONCLUSION:Giant exophytic gliomas without neurofibromatosis type 1 may arise from the intracranial portion of an isolated optic nerve. Direct visualization of optic component by heavily T2-reversed MRI could more precisely delineate the relationship of the intracranial optic nerve glioma to the optic apparatus. Surgery may be indicated in giant exophytic intracranial optic nerve gliomas and preoperative postulated optic chiasmatic gliomas. Microsurgical resection can induce postoperative visual improvement without regrowth of the residual tumor.

Diagnosis of cerebral arteriovenous malformations with three-dimensional CT angiography

High speed spiral computed tomography (CT) is well known to be a good tool to visualize cerebrovascular lesions; this technique is called three-dimensional CT angiography (3D-CTA). Although 3D-CTA is widely accepted to diagnose cerebral aneurysms because it is less invasive and more useful than digital subtraction angiography, little is known about its diagnostic potential for arteriovenous malformation (AVM). In this study, the efficacy of 3D-CTA in diagnosis and surgical planning was investigated in 21 patients with AVMs. AVMs located in the cerebral hemisphere, the cerebellum, the basal ganglia, the brain stem, the corpus callosum, the optic chiasm and the lateral ventricle. 3D-CTA clearly demonstrated the three-dimensional feature of the feeding artery, the nidus, the draining vein and the surrounding normal structures. We conclude that 3D-CTA is essential to preoperative planning for the appropriate surgical approach toward the AVM.

Diagnosis of unruptured intracranial aneurysms with three-dimensional CT angiography

The usefulness of three-dimensional CT angiography (3D-CTA) for the diagnosis of unruptured cerebral aneurysms was compared with that of MR angiography (MRA) and digital subtraction angiography (DSA).

Effects of bromocriptine for prolactin-secreting adenomas: analysis by CT scan

Effects of bromocriptine on the size of adenomas in CT scans were examined in eight patients with prolactin-secreting adenomas. The changes on CT scans were classified into three types: Type I showed a reduction of enhanced area, Type II showed a decrease of enhanced density and Type III showed no change on CT scans.

54. The New Operative Procedure for the Carotid-Cavernous Fistula without any Interference to Blood Circulation of Internal Carotid Artery

gradually and the patient was confused or stuporous. Six days after admission, the right frontal ventricular tap with closed system drainage was performed. Seven days after admission, the pneumoventriculographic study showed a defect in the rhomboid fossa with displacement of the fourth ventricle to the left. A suboccipital craniectomy was carried out. We found a bluish-colored elevation in the right and middle lower portion of the floor of the fourth ventricle, and a hematoma, semifluid collection of 18 cc black blood, was evacuated. No tumor tissue was found, and the biopsies from the hematoma cavity were also negative. Recovery was very satisfactory with slightly right-sided cerebellar disturbance and he was discharged two months after the operation. At the time of this report, improvement has been maintained for approximately one year and eleven months. The pathogenesis of these primary hemorrhages of the pontien-medeullary part is, as shown by others, possibly related to a microaneurysm of a branch of the basilar artery.