Background: Meningiomas presenting with acute subdural hematomas are extremely rare. To the best of our knowledge, only 45 cases have been reported to date. We report on a case of a meningioma mimicking an acute subdural hematoma as well as a thorough literature review. Case Description: A 67-year-old man with no history of trauma was referred to our hospital with sudden onset of decreased level of consciousness and left hemiplegia. Computed tomography revealed an acute convexity subdural hematoma. Emergency surgery to remove the hematoma was performed. The hematoma was found to exist in the extra-axial space and the attached dura mater and pia mater remained intact. Pathological examination revealed a transitional meningioma, the World Health Organization Grade 1. Detailed medical history taken postoperatively revealed that a convexity meningioma had been diagnosed incidentally at another facility 1 year earlier. Conclusion: Acute subdural hematomas due to meningiomas are rare, and establishing the cause is challenging. Prompt and precise diagnosis of such entities may afford patients a better prognosis.

We describe three cases with acute middle cerebral artery (MCA) occlusion. From the preoperative MRI, including three-dimensional turbo spin-echo sequences using T1WI and T2WI, we assessed both thrombus configuration and arterial anatomy at the MCA bifurcations. For efficient endovascular thrombectomy, we identified the applied MCA segment 2 (M2) branch, in which the main thrombus was buried. Sufficient recanalization after a single pass was achieved and the patients made a marked recovery. Although mechanical thrombectomy for M2 occlusion has not been of proven benefit, the endovascular procedure based on three-dimensional turbo spin-echo imaging is useful for more complete thrombus removal at MCA bifurcations.

Background: Nontraumatic true superficial temporal artery aneurysm (STAA) is rare, and its characteristics and pathogenesis are unclear. Methods: We report a case of STAA and performed a systematic review of PubMed, Scopus, and Web of Science using the keyword “superficial temporal artery aneurysm” to include studies on STAA reported through July 2022. We excluded studies on STAA associated with trauma, arterial dissection, infection, or vasculitis. Results: A 63-year-old woman who underwent left superficial temporal artery (STA)-middle cerebral artery bypass surgery 8 years previously was diagnosed with an aneurysm located at the left STA. The blood flow volume estimated by ultrasonography was higher in the left STA than in the contralateral counterpart (114 mL/min vs. 32 mL/min). She underwent clipping surgery to prevent aneurysmal rupture without sequela. The lesion was diagnosed as a true aneurysm by histology. The systematic review identified 63 cases (including the present case) of nontraumatic true STAA. The median age of the patients was 57 (interquartile range [IQR]: 41–70) years. Most (90.5%) cases were detected as a palpable mass. Aneurysmal rupture occurred in only 1 (1.6%) case, despite the large size of aneurysms (median size: 13 [IQR: 8–20] mm) and the high frequency (33.3%) of aneurysmal growth during observation. Most (93.7%) patients underwent surgical resection of STAA without sequela. Conclusion: Our findings suggest that the pathogenesis of true STAA is promoted by hemodynamic stress. The systematic review clarified patients’ and aneurysmal characteristics and treatment outcomes, providing further insight into the pathogenesis of nontraumatic true STAA.

Acute cerebral infarction due to basilar artery occlusion (BAO) has a poor prognosis and is characterized by a high mortality rate. Moreover, the efficacy of mechanical thrombectomy (MT) and its indications for BAO have yet to be established. In the present study, we retrospectively investigated the prognostic factors of MT for BAO at our hospital. Patients and Methods: This study included 13 consecutive patients (eight men, mean age 76 years) who underwent acute-stage revascularization at our hospital for cerebral infarction associated with basilar artery occlusion over a 66-month period from January 2014 to June 2019. Background and treatmentassociated factors of each patient were retrospectively identified, and patient outcomes after 90 days (modified Rankin Scale [mRS] score) were investigated by assigning post-operative patients to the good outcome group (mRS score 0-2) or the poor outcome group (mRS score 3-6) and examining their respective associations with each potential prognostic factor. The following six factors were selected: pre-operative National Institutes of Health Stroke Scale (NIHSS) score, posterior circulation Alberta Stroke Program Early CT Score on diffusion-weighted imaging, time from disease onset or final confirmation of good health to recanalization, thrombolysis in cerebral infarction (TICI) classification, collateral blood circulation from the anterior circulation, and basilar artery occlusion site.Results: The recanalization rate in patients with a TICI grade ≥ 2B was 91%. The good outcome group included 31% of study participants, and the mortality rate was 23%. The mean time to recanalization was 332 min (range: 140-720 min), and the mean pre-operative NIHSS score was 17 (range: 3-30). Associations between background factors and outcomes after 90 days were investigated using the Student's t-test, and the results showed that a pre-operative NIHSS score ≤ 13 was a significant indicator of a good outcome (p=0.029). None of the other factors was associated with the outcome. Conclusion:The findings of this study revealed that proactive therapeutic interventions in patients with BAO with an NIHSS score ≤13 significantly improved outcomes.

Here, we describe a case of a 67-year-old man who was transferred to our hospital with complaints of sudden upper right limb weakness and ataxia. Scattered acute cerebral infarction was found in the watershed zone between the left anterior cerebral artery and the middle cerebral artery territories. A shelf-like structure at the origin of the left carotid artery and a vulnerable plaque distal to the lesion was found. Symptomatic atherosclerotic plaque with concomitant carotid web was diagnosed. Carotid endarterectomy resulted in good revascularization. Hemodynamic changes associated with vascular stenosis are involved in atherosclerosis. The current case is valuable and shows that carotid web can cause not only embolic infarction but also cerebral thrombosis due to atheroma formation in the carotid artery.