Application of Ion-beam Implanted Expanded Polytetrafluoroethylene to Microvascular Decompression and the Surgical Outcome.

Accurate and long-term transposition of offending vessels is required in microvascular decompression (MVD) for the treatment of hemifacial spasm (HFS) and trigeminal neuralgia (TN). We created ion-beam implanted of an expanded-polytetrafluoroethylene (i-ePTFE) surface to transpose offending vessels in MVD. In 13 patients with MVD, we concealed and transposed offending vessels with tape-shaped i-ePTFE, and relieved facial and trigeminal nerve compression by attaching the i-ePTFE to the dura with fibrin glue. After surgery, none of the patients reported further symptoms or experienced recurrence of symptoms up to 12 months post-surgery. Favorable surgical outcomes are obtainable, since i-ePTFE has high tissue affinity and is easy to manipulate, even under a narrow and deep operative field. Our results suggested that i-ePTFE is very useful for transposition in MVD.

[A Case of a Solitary Plasmacytoma Extending into the Extradural Space].

Plasmacytomas are characterized by a monoclonal proliferation of plasma cells, and constitute the bulk of multiple myeloma. A solitary plasmacytoma is a rare entity, and is even more unlikely to occur intracranially. Here we present a 62-year-old man with an intracranial tumor. Magnetic resonance imaging revealed a large mass on the surface of the right fronto-parieto-temporal region, with extradurally directed growth. The tumor was enhanced homogenously by gadolinium, with dural tail-like findings, which resembled a meningioma. Head computed tomography scan showed osteolytic changes of the calvarium. Tumor removal following intravascular embolization was performed. The tumor seemed to have developed from the dura mater because it was firmly adhered to the dura but not to the calvarium. Histopathological analysis revealed monoclonal proliferation of plasma cells, which were positive for CD56, CD138, and lambda chain, on immunostaining. Since a systemic examination showed no evidence of other lesions, we diagnosed the tumor as a solitary dural plasmacytoma. There was no recurrence after postoperative radiotherapy. Rare entities, such as a solitary plasmacytoma, should be considered when an intracranial lesion with atypical radiological features is observed. If the lesion is anatomically resectable, histopathological evaluation is essential.

[A Case of Bilateral Traumatic Carotid-Cavernous Fistula].

Bilateral traumatic carotid-cavernous fistula(CCF)is rare. It is most commonly caused by a direct head or face injury involving the cavernous sinus and develops immediately after trauma. We report a case of bilateral traumatic CCF that occurred as an intracerebral hematoma(ICH)mimicking apoplexy 5 months later. We treated the patient with point occlusion of venous reflux causing an ICH using coil embolization to remove the hematoma. Three days after we performed trans-venous occlusion of the intercavernous connection and right cavernous sinus using coil embolization through the right inferior petrosal vein, it was identified that the left CCF was occluded after first embolization into the left sylvian vein. The mechanism of delayed development of traumatic CCF and spontaneous disappearance of CCF after occlusion of venous reflux are discussed.

Brain metastasis from a lung mucoepidermoid carcinoma mimicking a brain abscess.

BACKGROUND: Mucoepidermoid carcinoma (MEC) is a rare tumor of the lung that accounts for 0.1-0.2% of all pulmonary tumors. To the best of our knowledge, brain metastasis from lung MEC is rare and magnetic resonance imaging (MRI) findings of this lesion have not been documented. CASE DESCRIPTION: We herein report the case of a 72-year-old male. MRI revealed a left parietal tumor showing ring enhancement with medium gadolinium contrast and an evident high intensity area in the nonenhanced central portion on diffusion-weighted images (DWI) mimicking a brain abscess. Histologically, MEC is composed of a mixture of different cell types including mucin-secreting glandular cells and squamous cells. Accordingly, we suggest that the high DWI signal can be explained by the development of intracellular and intraluminal mucin, which have a high viscosity. CONCLUSION: Further accumulation of cases with brain metastasis from MEC is needed to establish the characteristic image findings, which would lead to prompt and adequate treatment.

[Hypertrophic pachymeningitis associated with autoimmune pancreatitis examined for IgG4 related disease: a case report].

Hypertrophic pachymeningitis is a rare disease, and the fibrosing inflammatory process causes a thickening of the dura mater. A 62-year-old male undergoing corticosteroid therapy for autoimmune pancreatitis presented with headache and right facial numbness. Brain CT and MRI revealed thickened mass lesion around the tentorium. The specimen obtained by biopsy showed a small number of immunostain areas positive for IgG and IgG4. Systemic IgG4 related disease entity is proposed and analyzed from Japan, and pachymeningitis is also included in the examination. Some autoimmune mechanism is related to pachymeningitis, however, it is necessary to consider well if only the IgG4 has responsibility for the disease.

[Radiation-induced fibrosarcomas rapidly appeared more than 20 years after radiation therapy for germ cell tumors: report of two cases].

Radiation-induced brain tumor is a rare but serious and potentially fatal complication. We report two cases of radiation-induced fibrosarcomas which occurred more than 20 years after whole brain radiation therapy (60 Gy) for intracranial germinomas. Although both of them underwent imaging examination every year, the symptomatic sarcomas developed rapidly within a year. Eight months after total removal, the tumor recurred in the one case. Second surgery and gamma knife surgery could not prevent the tumor progression. In the other case, tumor regrowth was not observed during the five months follow-up after total removal surgery. It is important to keep in mind the possibility of a postradiation sarcoma that might have developed very aggressively after a long latent period.

Inflammatory myofibroblastic tumor of the cerebellar hemisphere--case report.

A 60-year-old man presented with a rare cerebellar inflammatory myofibroblastic tumor (IMT) manifesting as gait disturbance and dysarthria. Brain magnetic resonance imaging demonstrated an intra-axial round-shaped isointense mass homogeneously enhanced with gadolinium in the right cerebellar hemisphere, as well as perifocal edema extending to the brain stem and right thalamus. The tumor was elastic hard and was resected en bloc with a clear margin. Histological examination revealed IMT with spindle cells and collagen, but negative for anaplastic lymphoma kinase expression. IMT most commonly affects the lung, but may involve many other parts of the body. There is some debate regarding the disease entity of IMT in the central nervous system (IMT-CNS) because of its rarity and high frequency of recurrence. IMT-CNS is an important differential diagnosis among tumor-like intracranial lesions and total resection is required.

Subarachnoid hemorrhage caused by pilocytic astrocytoma--case report.

A 20-year-old woman presented with subarachnoid hemorrhage (SAH) in the frontal interhemispheric fissure, and a cystic lesion in the left frontal lobe. Cerebral angiography demonstrated no aneurysm or vascular abnormalities. T(1)-weighted magnetic resonance imaging with contrast medium revealed an enhanced lesion along the falx. The lesion and cyst were removed, and histological examination revealed a pilocytic astrocytoma. Spontaneous intracranial hemorrhage from pilocytic astrocytoma is rare, with only 15 reported cases mostly involving intratumoral hemorrhage in the parenchyma of hypothalamic and cerebellar tumors. SAH caused by cerebral hemisphere pilocytic astrocytoma is extremely rare. This case suggests that interhemispheric fissure SAH, not associated with aneurysm or abnormal vascularity, could originate from small, low-grade glioma in the superficial cerebral hemisphere.

[Basilar artery occlusion with benign outcome--two case reports and a review on the role of collateral circulation and therapeutic time window].

We reported two cases of acute basilar artery occlusion (BAO) with favorable prognosis and discussed the role of collateral circulation. Patient 1 presented with minor brainstem dysfunction for 24 hours due to a short-segment embolic BAO at the mid-pontine level. Carotid angiogram demonstrated reversed basilar flow through the posterior communicating artery distal to the occlusion. Subsequently, the patient suddenly went into coma and developed tetraplegia due to spontaneous displacement and lodging of the embolus to the top of the basilar artery. Immediate recanalization was achieved by intra-arterial thrombolysis, and she recovered and was independent at 3 months after onset. Patient 2 developed progressive brainstem and cerebellar dysfunction due to thrombotic occlusion of the intracranial vertebral and the proximal basilar artery. Angiographic studies demonstrated that reversed basilar flow from the carotid system and meningeal anastomosis arising from the proximal vertebral artery filled the basilar artery distal to the occlusion. The patient recovered after conservative treatment leaving only residual signs of lateral medullary infarction. Recent case series show varied prognosis of BAO. Individual differences in the effectiveness of collateral circulation may be one of the reasons that accounts for this variability. The interval of reversible brainstem ischemia supported by the collaterals may widen the therapeutic time window up to recanalization following acute basilar artery occlusion.