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BACKGROUND Limb-shaking transient ischemic attacks (LS-TIAs) are a rare form of TIAs that present as involuntary movements of the limbs and indicate severe cerebral hypoperfusion. LS-TIAs are often reported in patients with carotid artery stenosis but can also affect patients with intracranial artery stenosis and moyamoya disease (MMD). OBSERVATIONS A 72-year-old woman presented with repeated episodes of involuntary shaking movements of the right upper limb. Cerebral angiography revealed complete occlusion of the M1 segment of the left middle cerebral artery (MCA), and the left hemisphere was supplied by moyamoya vessels. She was treated with left direct revascularization without complications, and her involuntary movements subsided. However, she demonstrated involuntary shaking movements of the right lower limb 2 months postoperatively. Cerebral angiography revealed complete occlusion of the A1 segment of the left anterior cerebral artery (ACA). The multiple burr hole opening (MBHO) procedure was performed to improve perfusion in the left ACA territory and after 3 months, the patient’s symptoms resolved. LESSONS This case demonstrated that LS-TIAs can also develop as ischemic symptoms due to MMD. Moreover, instances of LS-TIA of the upper and lower limbs developed separately in the same patient. The patient’s symptoms improved with direct revascularization and MBHO.

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OBJECTIVE Carotid stenosis can lead to both cognitive impairment (CI) and ischemic stroke. Although carotid revascularization surgery, which includes carotid endarterectomy (CEA) and carotid artery stenting (CAS), can prevent future strokes, its effect on cognitive function is controversial. In this study, the authors examined resting-state functional connectivity (FC) in carotid stenosis patients with CI undergoing revascularization surgery, with a particular focus on the default mode network (DMN). METHODS Twenty-seven patients with carotid stenosis who were scheduled to undergo CEA or CAS between April 2016 and December 2020 were prospectively enrolled. A cognitive assessment, including the Mini-Mental State Examination (MMSE), Frontal Assessment Battery (FAB), and Japanese version of the Montreal Cognitive Assessment (MoCA), as well as resting-state functional MRI, was performed 1 week preoperatively and 3 months postoperatively. For FC analysis, a seed was placed in the region associated with the DMN. The patients were divided into two groups according to the preoperative MoCA score: a normal cognition (NC) group (MoCA score ≥ 26) and a CI group (MoCA score < 26). The difference in cognitive function and FC between the NC and CI groups was investigated first, and then the change in cognitive function and FC after carotid revascularization was investigated in the CI group. RESULTS There were 11 and 16 patients in the NC and CI groups, respectively. The FC of the medial prefrontal cortex with the precuneus and that of the left lateral parietal cortex (LLP) with the right cerebellum were significantly lower in the CI group than in the NC group. In the CI group, significant improvements were found in MMSE (25.3 vs 26.8, p = 0.02), FAB (14.4 vs 15.6, p = 0.01), and MoCA scores (20.1 vs 23.9, p = 0.0001) after revascularization surgery. Significantly increased FC of the LLP with the right intracalcarine cortex, right lingual gyrus, and precuneus was observed after carotid revascularization. In addition, there was a significant positive correlation between the increased FC of the LLP with the precuneus and improvement in the MoCA score after carotid revascularization. CONCLUSIONS These findings suggest that carotid revascularization, including CEA and CAS, might improve cognitive function based on brain FC in the DMN in carotid stenosis patients with CI.

Cerebral aneurysms rupture at a thin-walled region; however, mechanisms underlying aneurysmal wall thinning and thickening remain unclear. In this study our objective was to uncover the biological basis for these findings. Cerebral aneurysmal wall samples were collected between August 2020 and March 2022 for proteomic analysis and immunohistology. We examined the co-localization of myoglobin expression within smooth muscle cells, identified by α-smooth muscle actin (α-SMA) staining, and myofibroblasts, identified by periostin staining. Furthermore, we measured collagen density in the samples using Sirius Red staining and investigated its correlation with myoglobin density. Analysis of proteins extracted from aneurysmal walls detected expression of myoglobin only in the thickened wall. Among 24 formalin-fixed aneurysmal wall samples, 19 expressed myoglobin. Myoglobin was scattered or clustered within the vascular smooth muscle layer and tended to be expressed at sites other than where inducible nitric oxide synthase was identified. Double-label immunofluorescence staining confirmed that the myoglobin-positive rate within α-SMA-positive cells and α-SMA-positive areas was 33.2 ± 23.8% and 31.3 ± 37.8%, respectively, whereas within periostin-positive cells and periostin-positive areas, it was 92.2 ± 13.7% and 79.8 ± 29.5, respectively. A moderate correlation was observed between the density of myoglobin and collagen in the same sample field, with a Spearman's rank correlation coefficient of 0.593 (p = 0.036). Cerebral aneurysmal walls express myoglobin, which may be produced by myofibroblasts in the wall. Areas with high myoglobin levels retain high levels of collagen fibers, and myoglobin may be involved in wall thickening by suppressing destructive changes in the extracellular matrix collagen fibers.