Isolated Oculomotor Nerve Palsy after Mechanical Thrombectomy for Middle Cerebral Artery Occlusion: A Case Report.

Objective: Complications of mechanical thrombectomy (MT) should be identified and managed because they often worsen clinical outcomes. Here we present a case of post-MT embolization of the artery supplying the oculomotor nerve, which has not previously been reported as a complication of MT. Case Presentation: An 81-year-old woman visited our hospital within 2 hours of the sudden onset of left hemiparesis and impaired awareness. MRA showed right middle cerebral artery (MCA) M1 segment occlusion and a possibly salvageable penumbra. We performed thrombectomy for right MCA occlusion with successful recanalization. In the final angiography view, the marginal tentorial artery was almost invisible. Ten hours after thrombectomy, the patient developed complete right oculomotor nerve palsy. Subsequent MRI showed ischemic lesions, but none in the oculomotor nucleus, and there were no lesions compressing the oculomotor nerve. We presume that embolization of the marginal tentorial artery caused oculomotor nerve palsy. The intracranial middle and distal portions of the oculomotor nerve are supplied by the superior branches of the inferolateral trunk and by the marginal tentorial artery. Conclusion: Occlusion of the marginal tentorial artery can cause oculomotor nerve palsy, although this has not previously been reported. Our case suggests that neurointerventional surgeons should evaluate patency of branches of the inferolateral trunk and the meningohypophyseal trunk during the procedure of MT.

Endovascular Mechanical Thrombectomy with a Large-Bore Aspiration Catheter and Stent Retriever for Cerebral Venous Sinus Thrombosis in Pregnancy: A Case Report.

Objective: A case of cerebral venous sinus thrombosis (CVST) during pregnancy effectively recanalized by endovascular mechanical thrombectomy with the combined use of an aspiration catheter and a stent retriever is reported. Case Presentation: A 27-year-old woman at eight weeks' gestation developed sudden onset of right hemiparalysis and seizures and was referred to our hospital. Her National Institutes of Health Stroke Scale score on admission was 23. On MRI, diffusion-weighted imaging showed a hyperintensity area in the left frontal lobe, and T2* imaging showed hemorrhagic infarction in the same area. MR venography showed obstruction of the anterior two-thirds of the superior sagittal sinus (SSS). Anticoagulant therapy with heparin was started, but since the venous return was expected to be severely impaired, mechanical thrombectomy by endovascular surgery was selected, hoping to resolve symptoms early. Using a large-bore aspiration catheter in combination with a stent retriever, it was possible to safely guide the aspiration catheter into the anterior half of the SSS. The use of a large-bore aspiration catheter enabled retrieval of a large amount of thrombus in a short time, and complete recanalization was achieved. The patient's hemiplegia and aphasia improved significantly within a week after the procedure, and she was discharged without sequelae. Conclusion: Mechanical endovascular therapy of CVST performed with a combination of a large-bore aspiration catheter and a stent retriever should be considered particularly for patients with severe neurological symptoms or intracranial hemorrhage and for those who do not respond to anticoagulation therapy.

A case of intracranial myxoid mesenchymal tumor with EWSR1:CREM fusion in an adult female: Extensive immunohistochemical evaluation.

Intracranial myxoid mesenchymal tumor (IMMT) is a recently described, extremely rare group of neoplasms characterized by fusions between the female-expressed transcript (FET) family genes and the cAMP response element-binding protein (CREB) family genes. Controversy persists regarding whether the tumor is a myxoid variant of angiomatoid fibrous histiocytoma or a completely distinct clinicopathological entity. Here, we report a case of IMMT arising in the posterior fossa in a 65-year-old woman with a history of breast cancer. We performed total removal of the tumor, which histologically demonstrated features characteristic of IMMT but also bore a partial resemblance to conventional angiomatoid fibrous histiocytoma. Immunohistochemically, tumor cells were diffusely positive for desmin, vimentin, cluster of differentiation (CD) 99 (CD99), glucose transporter-1, and cytokeratin (CK) 8/18 (CK8/18), and focally positive for CK7, epithelial membrane antigen, mucin 4, anaplastic lymphoma kinase, calponin, and CD68. Molecular genetic analysis revealed a fusion between the Ewing sarcoma breakpoint region 1 (EWSR1) gene (EWSR1) and the cAMP-responsive element modulator (CREM) gene (CREM) called EWSR1:CREM fusion, which confirmed the diagnosis. The overlap of the pathological features of IMMTs and angiomatoid fibrous histiocytomas may support the recent theory that these tumors are two manifestations of a single entity. Moreover, our study indicated the broad spectrum of immunohistochemical phenotypes of these tumors, which should be noted during diagnosis. Further studies are needed to elucidate the histopathological concept, long-term prognosis, optimal treatment strategy, and factors associated with the prognosis and therapeutic options of this condition.