Dural Arteriovenous Fistula Mimicking Acute Encephalitis.

We herein report a case of acute neurological symptoms and a fever initially suspected of being encephalitis but later revealed to be dural arteriovenous fistula (dAVF). An 84-year-old woman had a fever and cerebral edema and was initially treated for encephalitis. A review of her magnetic resonance imaging findings revealed abnormal blood flow signals. After cerebral angiography, the patient was finally diagnosed with left transverse-sigmoid sinus dAVF. The present case showed that dAVF can also present with an acute onset and a fever, mimicking acute encephalitis. Because the treatments for encephalitis and dAVF differ greatly, the possibility of dAVF should also be considered when diagnosing encephalitis.

New Cortical Spot Cerebral Infarction Out of Border Zone in ICA Occlusion Suggests Recanalization: A Case Report.

Internal carotid artery occlusion rarely recanalizes spontaneously. Awareness of signs of recanalization is important, as it may necessitate changing the treatment strategy. We report a case of new cortical infarction outside the border zone, which led to the realization of internal carotid artery recanalization and revascularization. A 76-year-old woman presented with mild dysarthria. Magnetic resonance imaging showed cerebral infarction in the left-hemispheric border zone and occlusion of the internal carotid artery origin. Cerebral angiography performed showed complete occlusion of the internal carotid artery origin and intracranial collateral blood flow from the external carotid artery through the ophthalmic artery. She was diagnosed with infarction due to a hemodynamic mechanism caused by internal carotid artery occlusion and was treated with supplemental fluids and antithrombotic drugs. Four days after hospitalization, the right paralysis worsened and a new cerebral infarction was observed in the cortex, outside the border zone. This infarction appeared to be embolic rather than hemodynamic; thus, we suspected recanalization of the internal carotid artery. The patient underwent emergency cerebral angiography again, which revealed slight recanalization. Thus, emergency revascularization and carotid artery stenting were performed. New cortical infarcts outside the border zone in patients with complete internal carotid artery occlusion is an important finding, suggesting spontaneous recanalization of the occluded internal carotid artery.

Direct Advancement of Balloon-Guide Catheter Distal to the Carotid Free-Floating Thrombus Achieves Smart Mechanical Thrombectomy.

A 68-year-old man with bladder cancer developed sudden dysarthria and left hemiplegia. MRI revealed occlusion of the right middle cerebral artery (MCA). Cerebral angiography revealed a large carotid free-floating thrombus (CFFT) at the origin of the right internal carotid artery (ICA) and right M1 occlusion. A balloon-guide catheter (BGC) was directly guided distal to the CFFT. Mechanical thrombectomy (MT) was performed on the M1 occlusion while the balloon was inflated to block antegrade blood flow, and good recanalization was achieved. To continue processing the CFFT, the deflated BGC was pulled to the common carotid artery, and the thrombus dispersed into the external carotid artery (ECA). Subsequently, the patient's symptoms improved. Directly advancing a BGC distally to a CFFT may be a useful treatment strategy for tandem lesions with carotid free-floating thrombi.

Successful Mechanical Thrombectomy for Acute Middle Cerebral Artery Occlusion in a Centenarian.

Clinical trials have proven the efficacy and beneficial therapeutic outcomes of endovascular therapy in patients with major arterial occlusion. However, its efficacy for very elderly patients, such as nonagenarians or centenarians, is not well established. In this case report, we describe the successful use of mechanical thrombectomy for the management of stroke in a centenarian. The 100-year-old woman with severe right-sided paralysis and total aphasia was admitted to our hospital approximately 30 min from the onset of symptoms. The National Institutes of Health Stroke Scale score was 24 at admission, and three-dimensional computed tomography angiography revealed occlusion in the M1 segment of left middle cerebral artery. She had persistent atrial fibrillation and was diagnosed with colon cancer one month prior to the admission. The modified Rankin Scale score before the stroke was 1, and she was generally independent. The patient successfully underwent mechanical thrombectomy, and recanalization with thrombolysis in cerebral infarction grade 3 was accomplished 129 minutes after the onset. The patient made a remarkable recovery with a National Institutes of Health Stroke Scale score of 4 at 48 h and was discharged home with a modified Rankin Scale score of 2 on day 8. Thus, mechanical thrombectomy can be performed with a good outcome even in centenarians.

Penumbra Detection With Oxygen Extraction Fraction Using Magnetic Susceptibility in Patients With Acute Ischemic Stroke.

BACKGROUND: The oxygen extraction fraction (OEF) has been applied to identify ischemic penumbral tissue, but is difficult to use in an urgent care setting. This study aimed to investigate whether an OEF map generated via magnetic resonance quantitative susceptibility mapping (QSM) could help identify the ischemic penumbra in patients with acute ischemic stroke. MATERIALS AND METHODS: This prospective imaging study included 21 patients with large anterior circulation vessel occlusion who were admitted <24 h after stroke onset and 21 age-matched healthy controls. We identified the ischemic penumbra as the region with a Tmax of >6 s during dynamic susceptibility contrast-magnetic resonance imaging (DSC-MRI) and calculated the perfusion-core mismatch ratio between the ischemic penumbra and infarct core volumes. The OEF values were measured based on magnetic susceptibility differences between the venous structures and brain tissues using rapid QSM acquisition. Volumes with increased OEF values were compared to the ischemic penumbra volumes using an anatomical template. RESULTS: Eleven patients had a perfusion-core mismatch ratio of ≥1.8, and reperfusion therapy was recommended. In these patients, the volumes with increased OEF values of >51.5%, which was defined using the anterior circulation territory OEF values from the 21 healthy controls, were positively correlated with the ischemic penumbra volumes (r = 0.636, 95% CI: 0.059 to 0.895, P = 0.035) and inversely correlated with the 30-day change in the National Institutes of Health Stroke Scale scores (r = -0.624, 95% CI: -0.891 to -0.039, P = 0.041). CONCLUSION: Tissue volumes with increased OEF values could predict ischemic penumbra volumes based on DSC-MRI, highlighting the potential of the QSM-derived OEF map as a penumbra biomarker to guide treatment selection in patients with acute ischemic stroke.

Aplastic or twig-like middle cerebral artery and cardiogenic cerebral embolism mimicking moyamoya disease with RNF213 polymorphism: A case report.

Progressive stenosis and occlusion of the bilateral internal carotid artery terminals and circle of Willis are typical features of Moyamoya disease. However, aplastic or twig-like middle cerebral artery (Ap/T-MCA)-wherein the unilateral main trunk of the middle cerebral artery (MCA) is not depicted, and a plexiform arterial network is formed-is similar to the findings of Moyamoya disease. Here, we describe a 78-year-old man who presented with mild right paralysis and aphasia. Magnetic resonance angiography (MRA) at admission did not show the bilateral MCAs. The findings were similar to those of Moyamoya disease, and his symptoms worsened after hospitalization. Endovascular treatment was performed, and the left MCA was completely recanalized. Later, paroxysmal atrial fibrillation was detected, and we finally determined that left MCA occlusion had occurred due to embolism. The right MCA was completely occluded at its origin, indicating an Ap/T-MCA. Embolic occlusion of the unilateral MCA and contralateral Ap/T-MCA made this case resemble Moyamoya disease in the acute stage. Even when chronic occlusion is suspected on MRA in acute cerebral infarction, endovascular treatment should be considered. Additionally, a heterotypic R4810K polymorphism was later found in the RNF213 gene. To our knowledge, this is the second report of Ap/T-MCA with the RNF213 gene polymorphism; however, their association remains unclear and requires further analyses.

The Feasibility of Mechanical Thrombectomy on Single-Plane Angiosuite: An In-Depth Analysis of Procedure Time.

INTRODUCTION: Mechanical thrombectomy (MT) is usually performed on biplane (BP) angiosuites. When the BP angiosuite is not available, the single-plane (SP) angiosuite may be a substitute. However, the feasibility of MT performed on the SP angiosuite is yet to be elucidated. Therefore, we investigated the alternative effect of the SP angiosuite on the detailed division of procedure time, recanalization rate, and outcome in patients with anterior circulation infarction. METHODS: The subjects included 80 consecutive patients with anterior circulation infarction who underwent MT at our hospital between May 2015 and December 2020. Demographics and characteristics of the BP and SP groups were assessed and compared. The time from puncture to guiding catheter placement (P-G), time from guiding catheter placement to recanalization (G-R), and time from puncture to recanalization (P-R) were also extracted. A good outcome was defined as a modified Rankin scale score ≤2 at 3 months. RESULTS: Of the 80 patients, 67 and 13 were treated with BP and SP angiosuites, respectively. There were no differences in age, sex, complications, Alberta Stroke Program Early CT Score, National Institutes of Health Stroke Scale score at onset, occlusion site, rate of recombinant tissue-type plasminogen activator administration, stroke subtype, recanalization rate, and complications between the 2 groups. The rate of a good outcome was not different between the 2 groups. P-G was significantly longer in the SP group than in the BP group, whereas there was no significant difference in G-R and P-R between the 2 groups (P-G: BP 29.9 ± 21.8 vs. SP 48.5 ± 43.6 min, p = 0.04). CONCLUSION: MT performed on the SP angiosuite tended to prolong the time for guiding catheter placement. However, there was no difference in the overall procedure time, recanalization rate, or outcome between BP and SP angiosuites. Therefore, if the BP angiosuite is not available, the use of the SP angiosuite should be encouraged.

Reproducible Presyncope Due to Osteophyte Compression Into Transverse Foramen of the C5 Vertebra.

Beauty parlor stroke syndrome is characterized by the development of various neurological symptoms during cervical hyperextension, followed by inadequate blood flow through the posterior circulation of the brain. However, there are few reports of beauty parlor stroke syndrome wherein the cause of the posterior circulatory inadequacy has been directly identified. Here we report a case where we could directly detect the origin of the posterior circulatory inadequacy. A 76-year-old Japanese man with hypertension presented with presyncope following cervical retroflexion. Head magnetic resonance angiography revealed that the vertebrobasilar circulation was exclusively supplied by the right vertebral artery. Cervical spine computed tomography showed compression of the osteophytes on the right superior articular process of C6 into the right transverse foramen of C5. Moreover, computed tomography angiography and carotid duplex ultrasonography showed decreased blood flow in the right vertebral artery on gradual retroflexion of the neck. Based on the above findings, we speculate that the right vertebral artery was compressed by the osteophytes, with the decreased blood flow being the cause of presyncope following cervical retroflexion.

Development of Internal Carotid Artery Dissection During Masturbation.

Sexual intercourse is known as one of the daily activities triggering spontaneous cervicocephalic artery dissection (sCAD), however, it has been unclear if masturbation can trigger the development of sCAD. Herein, we report a case of sCAD in association with masturbation. A 51-year-old right-handed man developed subarachnoid hemorrhage during masturbation. The dissection of the left internal carotid artery was evident on the 9th hospital day. Finally, he was treated with stenting and coiling and discharged with a good prognosis.

Importance of Chronological Changes on High-Resolution Vessel Wall Imaging for Diagnosis of Isolated Anterior Cerebral Artery Dissection.

INTRODUCTION: The accurate diagnosis of isolated anterior cerebral artery dissection (iACA-D) is made difficult by the spatial resolution on conventional magnetic resonance imaging (MRI) techniques including time-of-flight magnetic resonance angiography that is too limited to detect minute arterial wall abnormalities. Recent advances in high-resolution vessel wall imaging (HRVWI), which can detect intramural hematomas (IMH), have improved the noninvasive diagnostic accuracy of iACA-D. However, despite the risk of overlooking minute IMH and aneurysmal dilations especially at the early disease stage, the utility of T1-weighted and T2-weighted HRVWI at each disease stage (i.e., acute, early subacute, late subacute and chronic) has not been evaluated thoroughly enough. This prompted us to undertake the present study to determine the diagnostic value of chronological changes of IMHs on T1-weighted HRVWI and arterial dilations on T2-weighted HRVWI to achieve the earliest possible and most accurate diagnosis of iACA-D. METHODS: In addition to six patients with iACA-D, five previously reported iACA-D patients from three institutions for whom reliable information on HRVWI and its examination date was available were enrolled in this study. IMHs on T1-weighted HRVWI and aneurysmal dilations on T2-weighted HRVWI and their chronological changes were visually evaluated. RESULTS: Either or both of IMHs on T1-weighted HRVWI and aneurysmal dilations on T2-weighted HRVWI were detected in all our six patients and the five previously reported ones. The disease stage showed a notable influence on the degree of their visualization. In contrast to IMHs which are regarded as the gold standard for the diagnosis of intracranial dissections, aneurysmal dilations were identified in 80% of cases even at the acute stage, reaching 100% at the early subacute stage. Despite the excellent detection rate of IMHs at the late subacute stage (100%), their detectability is poor at the acute and early subacute stages (0 and 40%, respectively). CONCLUSION: The results of this study highlighted the importance of aneurysmal dilations on T2-weighted HRVWI as a diagnostic marker to raise suspicion of iACA-D at the acute and early subacute stages, and similarly IMHs on T1-weighted HRVWI to confirm the diagnosis of iACA-D at the late subacute stage. These stage-dependent detectability changes in IMHs and aneurysmal dilations make an understanding of the chronological changes of these abnormal imaging findings mandatory to achieve an early and accurate diagnosis of iACA-D.

Direct Brachial Approach for Acute Basilar Artery Occlusion: Technical Note and Preliminary Clinical Experience.

In mechanical endovascular thrombectomy (MET) for acute basilar artery occlusion (ABAO) in the elderly, navigating a guide catheter via the femoral artery may be difficult due to the approach route's significant tortuosity. To resolve this problem, we have been performing a technique that uses a direct brachial approach (DiBA) with a large-bore aspiration catheter. We reported our preliminary clinical experience with this technique. MET for ABAO using the DiBA technique was performed on 4 consecutive patients between August 2017 and December 2018. In all patients, thrombolysis in cerebral infarction 2B or 3 recanalization was achieved, but the modified Rankin Scale at 90 days was ≥4. There were no technical difficulties or complications with this technique. The DiBA technique is an effective and feasible approach in MET for ABAO. Although excellent clinical outcomes could not be achieved, the angiographic outcomes were excellent with no technical complications. This approach can be an alternative to the femoral artery approach, particularly for tortuous arteries in the elderly.

Miller Fisher Syndrome Mimicking Tolosa-Hunt Syndrome.

We herein report a patient with Miller Fisher syndrome mimicking Tolosa-Hunt syndrome. A 47-year-old man presented with right orbital pain and diplopia. On a neurological examination, he had right oculomotor nerve palsy and diminished deep tendon reflexes. Brain magnetic resonance imaging failed to show any parenchymal lesions; however, the bilateral oculomotor nerves were gadolinium-enhanced. The presence of a triad of orbital pain, ipsilateral oculomotor nerve palsy, and a rapid response to steroid therapy met the diagnostic criteria for Tolosa-Hunt syndrome. After discharge, antibodies against GQ1b and GT1a were reported to be positive only with phosphatidic acid. The present case was ultimately diagnosed as an incomplete phenotype of Miller Fisher syndrome.

Utility of T1- and T2-Weighted High-Resolution Vessel Wall Imaging for the Diagnosis and Follow Up of Isolated Posterior Inferior Cerebellar Artery Dissection with Ischemic Stroke: Report of 4 Cases and Review of the Literature.

BACKGROUND: An accurate diagnosis of isolated posterior inferior cerebellar artery dissection (iPICA-D) is difficult due to the limitation of spatial resolution on conventional magnetic resonance imaging (MRI) techniques to detect subtle vessel wall abnormalities. The recent development of MRI techniques, including high-resolution vessel wall imaging (HRVWI), has resulted in the improved diagnostic accuracy and efficiency of iPICA-D. In fact, T1-weighted HRVWI, which can reveal intramural hematomas in the posterior inferior cerebellar artery (PICA), is useful for the diagnosis of iPICA-D. However, the utility of T2-weighted HRVWI has not been previously reported. The aim of this study was to investigate the diagnostic utility of T1- and T2-weighted HRVWI for the diagnosis of iPICA-D. METHODS: We retrospectively evaluated MRI findings including intramural hematomas, dilations, and chronological changes in 4 patients with iPICA-D admitted to our hospital and related facility from January 2015 to August 2016. In addition to T1-weighted HRVWI, T2-weighted HRVWI was performed on isovoxel three-dimensional (3D) fast spin-echo or 3D sampling perfection with application-optimized contrast using different flip-angle evolution. We also reviewed cases of nonhemorrhagic iPICA-D with ischemic onset in which the MRI findings were described. RESULTS: In all 4 patients, in addition to the intramural hematomas on T1-weighted HRVWI, T2-weighted HRVWI clearly showed the fusiform dilation of the external diameter of the PICA. T2-weighted HRVWI was more useful than other techniques, including T1-weighted HRVWI, for the evaluation of arterial shape changes. CONCLUSIONS: Like T1-weighted HRVWI, T2-weighted HRVWI is useful for the diagnosis and assessment of chronological changes in vessel wall abnormalities during the follow-up period.

Cerebral infarction due to cardiac myxoma developed with the loss of consciousness immediately after defecation-a case report.

A 74-year-old man lost consciousness immediately after defecation. The loss of consciousness lasted for several minutes, and he experienced difficulty in walking when he regained consciousness. He was transferred to our hospital via an ambulance. Upon neurological examination, nystagmus and ataxia in the left arm and leg were noted. An MRI of the brain revealed multiple acute infarcts mainly in the bilateral cerebellum. Intravenous thrombolytic therapy with alteplase was initiated 3 h and 20 min after the onset of symptoms, and an improvement in neurological symptoms was observed. Echocardiography displayed a mobile mass in the left atrium, suggesting myxoma. After 14 days from the onset of symptoms, the tumor was surgically resected, and a pathological diagnosis of myxoma was established. Because of the unique event surrounding the onset in this case, we considered that there was a potential detachment of myxoma and/or thrombi fragments triggered by an increase in intrathoracic pressure induced by the action of defecation. This present case suggests that clinicians should consider cardiac myxoma in patients with cerebral infarction if the stroke is preceded by a Valsalva maneuver-like action and accompanied by the loss of consciousness.

Carotid Artery Stenting Successfully Prevents Progressive Stroke Due to Mobile Plaque.

We report a case of progressive ischemic stroke due to a mobile plaque, in which carotid artery stenting successfully prevented further infarctions. A 78-year-old man developed acute multiple infarcts in the right hemisphere, and a duplex ultrasound showed a mobile plaque involving the bifurcation of the left common carotid artery. Maximal medical therapy failed to prevent further infarcts, and the number of infarcts increased with his neurological deterioration. Our present case suggests that the deployment of a closed-cell stent is effective to prevent the progression of the ischemic stroke due to the mobile plaque.

Fatal Intraperitoneal Bleeding after Intravenous Administration of Tissue Plasminogen Activator.

We report a case of acute ischemic stroke, which developed fatal intraperitoneal bleeding after intravenous administration of alteplase. An 86-year-old woman developed acute infarction of the right middle cerebral artery during admission for chronic heart failure. Two days before the stroke, liver biopsy was performed; the result was benign. Although rivaroxaban was prescribed for atrial fibrillation, the rivaroxaban had been discontinued for liver biopsy until the time when she developed the stroke. A condition of recent biopsy required careful determination of eligibility of intravenous alteplase; however, we considered that the benefit of intravenous alteplase outweighed the hemorrhagic adverse effects. Alteplase (0.6 mg/kg) was started 2 hours after the stroke onset, however, no clinical improvement was obtained. One hour after the completion of alteplase, she suddenly developed a shock state. Emergent computed tomography disclosed massive intraperitoneal hemorrhage. She died 8 hours after the completion of alteplase. In the present case, mechanical thrombectomy without intravenous alteplase can be an alternative therapeutic option.

Transbrachial carotid artery stenting can prevent renal cholesterol embolism.

A 78-year-old man was admitted for the treatment of internal carotid artery stenosis. The left internal carotid artery was occluded and stenosis of the right internal carotid artery was progressive. The patient had a history of renal cholesterol embolism associated with percutaneous peripheral intervention. Stenting of the right internal carotid artery was successfully performed via the right brachial artery, and cholesterol embolism was not noted after the procedure. This case suggests that carotid artery stenting (CAS) performed via a brachial approach is less likely to elicit cholesterol embolism than CAS performed via a femoral approach.

Intravascular lymphomatosis mimicking primary central nervous system lymphoma: a case report and literature review.

We herein report a 75-year-old female patient with intravascular lymphomatosis (IVL) who presented with fever of unknown origin. Examination, including contrast-enhanced CT and (67)Ga scintigraphy, failed to show any lesions. Her blood levels of lactate dehydrogenase and soluble interleukin-2 receptors were high, suggesting a lymphomatous tumor. A bone marrow puncture was negative, and a random skin biopsy revealed a monoclonal proliferation of naked, large lymphocytes in the vascular space of the subcutaneous tissue, confirming the diagnosis of IVL. MRI, performed 7 weeks after admission, showed a brain mass mimicking primary central nervous system lymphoma. The mass was considered to be a collection of malignant lymphocyte cells invading from the vessels. Without the random skin biopsy, this case may have been misdiagnosed as primary central nervous system lymphoma.