Acute large-vessel occlusion due to an infected thrombus formation induced by invasive sphenoid sinus aspergillosis: illustrative case.

BACKGROUND: The authors describe a rare case of acute large-vessel occlusion due to an infected thrombus formation that was induced by invasive sphenoid sinus aspergillosis. OBSERVATIONS: An 82-year-old man with a history of immunoglobulin G4-related disease and long-term use of steroids and immunosuppressants was admitted to the authors' hospital with severe right hemiparesis. Cerebral angiography revealed occlusion of the left internal carotid artery (ICA). He underwent thrombectomy, resulting in successful recanalization. However, severe stenosis was evident in the left ICA cavernous segment. Pathological analysis of the retrieved thrombus identified Aspergillus. Postoperative magnetic resonance imaging revealed sinusitis in the left sphenoid sinus as a possible source of the infection. The patient's general condition deteriorated during the course of hospitalization due to refractory aspiration pneumonia, and he died 46 days after thrombectomy. Pathological autopsy and histopathological investigation of the left ICA and the left sphenoid sinus showed that Aspergillus had invaded the wall of the left ICA from the adjacent sphenoid sinus. These findings indicate a diagnosis of acute large-vessel occlusion due to infected thrombus formation induced by invasive sphenoid sinus aspergillosis. LESSONS: Pathological analysis of a retrieved thrombus appears useful for identifying rare stroke etiologies such as fungal infection.

Successful carotid stenting of a carotid arterial dissection after straightening the tortuosity using an inflated balloon guiding catheter and the delivery wire of an anchored stent retriever.

The authors present a patient with carotid dissection in a tortuous arterial segment who successfully underwent carotid artery stenting (CAS) by straightening the tortuosity using an inflated balloon guiding catheter (BGC) and a stent retriever (SR). A 56-year-old man was transferred to our institute with right hemiparesis and a National Institutes of Health Stroke Scale score of 9. Magnetic resonance imaging showed left internal carotid artery (ICA) occlusion and ischemic change in the parietal lobe. Emergent angiography revealed tapered extracranial ICA occlusion sugg carotid artery dissection (CAD). CAS was attempted for CAD due to a mismatch of the motor area on clinical imaging. However, several attempts to navigate the stent delivery system over a guidewire failed. Therefore, we deployed a Trevo NXT ProVue SR (3 × 32 mm) in the middle cerebral artery, inflated a BGC, and then pulled on both to straighten the tortuous carotid artery, which resulted in successful navigation of the stent delivery system. The patient's symptoms improved after the recanalization. This case demonstrates the utility of a technique for navigation of a stent delivery system through a tortuous carotid artery in which the tortuosity is straightened by pulling on an inflated BGC and the delivery wire of the SR.

A case of intracerebral hemorrhage due to cerebral hyperperfusion after stenting for acute cervical carotid artery dissection.

Urgent carotid artery stenting (CAS) is effective for treatment-resistant cervical internal carotid artery dissection (CICAD). We experienced a 37-year-old woman who presented with sudden onset of cervical pain, blurred vision in the right eye, and numbness in the left upper and lower extremities. Due to neurological deterioration resulting from hemodynamic impairment, urgent CAS was performed under general anesthesia. Brain perfusion single-photon emission computed tomography performed immediately after CAS showed increased blood flow in the right hemisphere despite no evidence of hemorrhage or ischemic lesion on brain computed tomography (CT). Systolic blood pressure was therefore strictly controlled below 110 mm Hg perioperatively. However, the day after CAS, a follow-up CT showed intracerebral hemorrhage in the right temporal lobe. Urgent CAS in patients with progressive deterioration of hemodynamic impairment caused by CICAD may induce intracerebral hemorrhage due to cerebral hyperperfusion. Care should be taken to recognize and manage this phenomenon during the perioperative period.

Using a low-metal-density stent for thrombectomy-resistant vertebrobasilar occlusion due to thrombus migration from a thrombosed vertebral artery aneurysm: illustrative case.

BACKGROUND: Thrombosed intracranial aneurysms can lead to large vessel occlusion as a result of spontaneous thrombosis. Although mechanical thrombectomy is likely effective, recurrent thromboembolism can occur if the thrombotic source remains untreated. The authors describe a case of recurrent vertebrobasilar artery occlusion due to thrombus migration from a large thrombosed vertebral artery (VA) aneurysm that was successfully treated with mechanical thrombectomy followed by stenting. OBSERVATIONS: A 61-year-old male previously diagnosed with a large, thrombosed VA aneurysm presented with right hypoesthesia. Imaging on admission showed left VA occlusion and an acute ischemic lesion in the left medial medulla. His symptoms worsened, with complete right hemiparesis and tongue deviation occurring 3 hours after admission, and mechanical thrombectomy was performed to recanalize the left-dominant VA. Despite several attempts, reocclusion of the vertebrobasilar system occurred after each mechanical thrombectomy because of repeated thrombus formation in the thrombosed aneurysm. Therefore, a low-metal-density stent was deployed to prevent thrombus migration into the parent artery, which resulted in complete recanalization and rapid improvement of the symptoms. LESSONS: Stenting with a low-metal-density stent for recurrent embolism secondary to thrombus migration from a large thrombosed aneurysm was feasible in the acute stroke setting.

Ruptured Aneurysm at the Origin of an Anomalous Callosomarginal Artery Arising from the A1 Segment of the Anterior Cerebral Artery-A Case Report.

Aneurysms of the A1 segment of the anterior cerebral artery tend to develop in combination with various vascular anomalies of the A1 segment. Arterial branches that originate from the A1 segment and perfuse cortical regions are known to be rare. In this report, we describe a 48-year-old woman who presented with a ruptured aneurysm at the origin of an anomalous cortical artery arising from the A1 segment, for which microsurgical neck clipping was performed. Intraoperatively, the anomalous artery was seen to originate from the A1 segment, running into the interhemispheric fissure. An aneurysm was located at the bifurcation of the anomalous artery and the A1 segment. Postoperative angiography showed that the anomalous artery has branched into the fronto-orbital artery and the frontopolar artery and terminated as the anterior internal frontal arteries. We report a rare case of an aneurysm arising from an anomalous callosomarginal artery that arose from the A1 segment and perfused the cortical region. It is of significance to recognize that an aneurysm can develop at the origin of an anomalous artery that arises from the A1 segment.

Dipyridamole inhibits intracellular calcium transients in isolated rat arteriole smooth muscle cells.

Dipyridamole, an inhibitor of adenosine uptake as well as a cGMP phosphodiesterase inhibitor, is commonly used in prophylactic therapy for patients with angina pectoris. However, the effects of dipyridamole on systemic blood vessels, especially on the peripheral vascular system, are not well understood. Therefore, the effect of dipyridamole on ATP-induced arteriole contraction was examined with special reference to intracellular Ca(2+) concentration ([Ca(2+)](i)) using real-time confocal microscopy. In cases of 0.1-10microM range, dipyridamole induced only slight [Ca(2+)](i) decreases in smooth muscle cells of both testicular and cerebral arterioles. However, 100microM dipyridamole induced substantial [Ca(2+)](i) decreases in the cells. In the presence of 10microM dipyridamole, changes in ATP-induced [Ca(2+)](i) were found to be inhibited in smooth muscle cells of testicular arterioles but not in those of cerebral arterioles. In addition, alpha, beta-methylene ATP-induced [Ca(2+)](i) increases in testicular arteriole smooth muscle cells were also partially inhibited in the presence of dipyridamole. When testicular arterioles were perfused with dipyridamole, no increases in nitric oxide levels were detected. High levels of K(+) induced a [Ca(2+)](i) increase in testicular arterioles that was also partially inhibited by dipyridamole. In the presence of substances that affect protein kinase A or G, ATP-induced [Ca(2+)](i) was not completely inhibited. These findings suggest that dipyridamole may act not only as an inhibitor of adenosine uptake and as a cGMP phosphodiesterase inhibitor, but also as a calcium channel blocker in arteriole smooth muscle cells.

Immunohistochemical localization of protease-activated receptors in cerebral and testicular arterioles of rats: their dependence on arteriole size and organ-specificity.

Protease-activated receptors (PARs) expressed in the endothelia and smooth muscles of vessels may play important roles in blood vessel function. Using intracellular calcium ion concentration ([Ca2+]i) imaging, we recently observed that small - but not large - arterioles of the brain responded to proteases, while testicular arterioles showed no response. The purpose of the present study was to examine the heterogeneity of the localization of PARs in arterioles using immunohistochemistry. Consistent with the [Ca2+]i imaging results, neither the thrombin receptor nor PAR2 were evident in large arterioles of the brain. However, the small arterioles of the brain, vascular smooth muscles, and endothelia showed a distinct immunoreactivity against the thrombin receptor and PAR2. The immunoreactivity of PARs in testicular arterioles was faint. In conclusion, size-dependent and/or organ-specific responses of arterioles to proteases are due to the heterogeneous localization of PARs.

The role of protease-activated receptors on the intracellular calcium ion dynamics of vascular smooth muscles, with special reference to cerebral arterioles.

Protease-activated receptors (PARs) mediate cellular responses to various proteases in numerous cell types, including smooth muscles and the endothelium of blood vessels. To clarify whether the stimulation of PARs induces responses in smooth muscle cells of cerebral arterioles, intracellular Ca2+([Ca2+]i) dynamics and nitric oxide (NO) production during PARs stimulation were investigated in the rat cerebral arterioles by real-time confocal microscopy, since [Ca2+]i and NO are both key factors in the maintenance of strain in blood vessels. Testicular arterioles were also investigated for comparison. In smooth muscle cells of small cerebral arterioles (< 50 microm in diameter), thrombin and PAR1-activating peptide (AP) induced an increase in [Ca2+]i and contraction. The response to PAR1 activation was caused by Ca2+ mobilization from intracellular Ca2+ stores. Trypsin and PAR2-AP induced a decrease in [Ca2+]i in the cells which was considered to be mediated by endothelium-derived NO and/or by promoting a Ca2+ sequestration mechanism. PAR3- and 4-AP had little effect. In contrast to small cerebral arterioles, [Ca2+]i dynamics in smooth muscle cells of large cerebral arterioles (< 150 microm in diameter) or testicular arterioles remained unchanged during PARs activation. The effects of PARs activation on the [Ca2+]i dynamics and the contraction/relaxation of cerebral arterioles are also discussed in relation to the role of proteases in the regional tissue circulation of the brain.

Use of fractional anisotropy value by diffusion tensor MRI for preoperative diagnosis of astrocytic tumors: case report.

The fractional anisotropy (FA) value calculated by diffusion tensor MRI can indicate the degree of directionality of water diffusion in astrocytic tumors. Here, we report a case of anaplastic astrocytoma in which FA proved invaluable for the preoperative differential diagnosis. A 60-year-old man complained of headache, and underwent routine neuroimaging and DTI. The routine images suggested a low-grade glioma in the left temporal lobe, based on lack of enhancement on MRI with contrast medium and lack of tumor staining on angiograms, whereas FA value was very high. Based on these findings, a preoperative diagnosis of high-grade glioma was suspected. The surgical specimen exhibited the histological features of anaplastic astrocytoma with a high density of spindle shaped cells and low vascularity. In this report, we discuss the relationship between FA and other characteristics of the present tumor, and discuss the utility of FA measurement in astrocytic tumors.