Significant improvement of visual functions after removal of an intracranial giant optic nerve glioma revealing exophytic growth: case report.

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.

[A case of sinonasal carcinoma with intracranial invasion treated by a multidisciplinary team].

We report a case of a 66-year-old male with diffuse infiltration of neoplasm from the paranasal sinuses to the orbit and left cerebral hemisphere, associated with prominent edema. Initial complaints were headache and swelling of the forehead, which were followed by progressive symptoms, such as epistaxis, dacryops, and severe pains. Neuroimaging showed marked invasion of a neoplasm from the left paranasal sinuses into the intracranial space and to the frontal skull. Radical removal of the neoplasm and left orbital content with reconstruction of the anterior skull base using musculocutaneous flap was carried out by a multidisciplinary team. The pathological diagnosis was "poorly differentiated carcinoma from the paranasal sinus". Postoperatively the patient received radiation and chemotherapy. He is still alive with mild right hemiparesis and mild dysphasia, more than 2 years after surgery.

[111In-DTPA cisterno SPECT for the diagnosis of CSF rhinorrhea: case report].

The authors report on a patient with postoperative CSF (cerebrospinal fluid) leakage subsequent to transsphenoidal surgery where cisterno SPECT (single photon emission computed tomography) demonstrated the precise location of a CSF fistula. Seven months after surgery, the patient suffered from CSF rhinorrhea and headache. MRI (Magnetic Resonance Imaging) revealed significant contrast on T1-weighted images resulting from measurements in the right sphenoid sinus, which were hyperintense relative to CSF. On the basis of signal intensity differences, MRI could not distinguish between CSF leakage and postoperative scarring. Therefore, we performed cisterno SPECT at the same time as RI cisternography with intrathecal lumbar injection of 111In-DTPA which revealed dramatic accumulation of the tracer in the right sphenoid sinus. The patient underwent re-operation via a transsphenoidal approach, and the CSF leakage was repaired using fat-in-fibrin glue and the sella floor was reconstructed by hydroxyapatite platinge. These results suggest that cisterno SPECT may be useful in identifying the precise location of CSF fistulae, while other techniques fail to show evidence of CSF leakage.

[Evaluation of three-dimensional enhanced brain surface imaging using CT (3D surface CT angiography) and magnetic resonance imaging (3D surface MR angiography)].

The optimal imaging conditions for 3D brain surface imaging by magnetic resonance imaging (MRI) and multi-slice CT were investigated. Visualization of the sulci, gyri, and veins on the brain's surface was also compared between 3D surface images acquired using multi-slice CT and conventional single-slice CT and MRI. Various imaging parameters, including slice thickness, dose, and matrix size, were evaluated using our original brain surface phantom and longitudinal direction evaluation phantom as well as images obtained from healthy volunteers. Subjects of the clinical study were patients with arteriovenous malformations and brain tumors who underwent CT-angiography at the same time as MR-angiography. The quality of 3D images of the brain surface is most strongly influenced by partial volume effects related to slice thickness. In multi-slice CT, a slice thickness of 0.5 mm can be employed to minimize the partial volume effect, providing results that are far superior to those that can be achieved by conventional single-slice 3D-CT. In addition, the excellent S/N of multi-slice CT permits the veins on the brain's surface to be clearly visualized without the use of contrast medium. With regard to visualization of the sulci and gyri, although some problems remain to be overcome, multi-slice CT was found to be equivalent to 3D surface imaging using MRI.

T2 reversed fast spin-echo image and enhanced three-dimensional surface MR angiography for the diagnosis of cerebral arteriovenous malformations.

Although conventional neuro-imaging of cerebral arteriovenous malformation (AVM) supports preoperative evaluation, it is still difficult to visualise the detailed anatomical conformation of the AVM, the point of nidus, the feeding arteries or draining veins, and the three-dimensional configuration of nidus in the sulcus or gyrus. In the present study, we investigated the efficacy of enhanced three-dimensional surface MR angiography (surface MRA) and T2 reversed imaging (T2R imaging) in diagnosis and surgical planning for cerebral AVMs. Surface MRA clearly demonstrated nidus adjacent to eloquent area and three-dimensional figures of feeding arteries and draining veins. T2R imaging was useful to differentiate sulcal AVM from gyral AVM, and to estimate the depth of the nidus in the parenchyma. Although it has generally been assumed that nidus is present in the gyrus, T2R imaging clearly demonstrates that most of the nidus is in the sulcus and is possible to be dissected and removed without damaging parenchyma. Indeed, these imaging methods supply clinically relevant data that is difficult to obtain with conventional neuro-imaging and provide better details of lesions, informing surgical planning and decision-making.