[Evaluation of cerebral hemodynamics using arterial spin labeling perfusion MR imaging in a patient with cervical internal carotid artery vasospasm].

57-year-old woman with sequelae of cerebral infarction was admitted to our hospital because her left-sided hemiparesis was worsened. The right internal carotid artery (ICA) was not visualized by carotid duplex sonography and brain MRA. Arterial spin labeling (ASL) perfusion MR images showed reduced signals in the bilateral ICA territories at post labeling delay 1,525 ms. Her neurological symptoms improved on the day after hospitalization. On day 3, the bilateral ICAs were well visualized on MRA, while cerebral perfusion in the ICA territories appeared to be normalized on ASL. We diagnosed cervical ICA vasospasm, based on the findings of cervical MRA and cerebral angiography. Three months later, the recurrence of ICA vasospasm occurred. ASL was useful for the serial non-invasive evaluation of cerebral hemodynamics from the onset to improvement in a patient with ICA vasospasm.

A Case of Huge Scrotal Hematoma during Mechanical Thrombectomy.

Objective: We report a case of huge scrotal hematoma during emergency mechanical thrombectomy. Case Presentation: An 85-year-old man presented with sudden aphasia and right-sided hemiplegia. He was diagnosed with cerebral infarction due to left M1 occlusion and underwent an emergency mechanical thrombectomy. The treatment was completed with full recanalization, but when replacing the long sheath in the right femoral artery with a short sheath, the patient flexed his leg. The sheath could not be replaced, resulting in a massive scrotal hematoma. Shortly after, the patient went into cardiopulmonary arrest but recovered spontaneous circulation after cardiopulmonary resuscitation. The puncture site was treated hemostatically with manual compression, and the scrotal hematoma was not enlarged. He was transferred to another hospital with a modified Rankin Scale score of 5. Conclusion: Scrotal hematoma is a rare but potentially fatal puncture site complication that should be considered during neuro-endovascular treatment.

Multiple Thrombectomies for Cerebral and Coronary Artery Occlusion in Trousseau Syndrome.

Objective: Trousseau syndrome (TS) is a condition of systemic thrombosis generally associated with an underlying malignancy. An ischemic stroke is a representative thrombotic event. Thrombectomy is a useful procedure for the treatment of cerebral large vessel occlusion, and anticoagulation therapy is the main preventive treatment for TS. This case report describes a woman with terminal pancreatic tumor presenting with repeated occlusions of cerebral and coronary arteries necessitating multiple thrombectomies. Case Presentation: A 67-year-old woman was admitted to our hospital with severe right hemiplegia and global aphasia. MRI revealed left M1 occlusion; therefore, a thrombectomy was performed. Her symptoms recovered completely. Body contrast CT revealed pancreatic cancer with multiple metastases, and she was diagnosed with TS. On day 4 after thrombectomy, the same neurological symptoms occurred and re-occlusion of the left M1 was confirmed. Endothelial injury was suspected, and thrombectomy was repeated. Despite continuing anticoagulation therapy, the coronary artery was occluded and she underwent percutaneous coronary intervention on day 13. To treat the primary pancreatic lesion, she was transferred to the Surgery unit on day 20. Conclusion: Hypercoagulability associated with TS and endothelial damage due to rough procedure resulted in repeated vessel occlusions in this case. Careful thrombectomy and anticoagulation therapy with strict monitoring are needed in TS patients.

Subtraction of arterial spin-labeling magnetic resonance perfusion images acquired at dual post-labeling delay: Potential for evaluating cerebral hyperperfusion syndrome following carotid endarterectomy.

Arterial spin-labeling magnetic resonance perfusion imaging is a promising tool for the diagnosis of cerebral hyperperfusion syndrome after carotid endarterectomy. However, arterial spin-labeling with a single post-labeling delay has been reported to show a higher incidence of increased arterial spin-labeling signals in the bilateral hemisphere, probably due to a shortening of the arterial transit time or an arterial transit artifact caused by intravascular stagnant magnetically-labeled spin. To overcome these shortcomings, we used two post-labeling delay settings (1.0 and 1.5 s) in 8 patients who had undergone carotid endarterectomy. In addition, we created a subtraction image between the mean perfusion maps at post-labeling delays of 1.0 and 1.5 s. This also decreased arterial transit artifacts, as these appeared in nearly the same configuration in both post-labeling delay settings. In all eight cases examined, increased arterial spin-labeling signals were observed bilaterally on both dual post-labeling delay settings. Subtraction images revealed that these increased signals were attributable to arterial transit artifacts in seven cases. However, in one patient who developed clinical symptoms, the subtraction method demonstrated post-carotid endarterectomy hyperperfusion. This preliminary study demonstrates that the subtraction method might decrease arterial transit artifacts and yield a map that can better represent true perfusion, thus enabling the detection of post-carotid endarterectomy hyperperfusion.

[Ruptured Dissecting Aneurysm of the Fenestrated Vertebral Artery:A Case Report].

Fenestration of a vertebral artery(VA)is a rare anomaly that has occasionally been associated with the formation of saccular aneurysms, whereas dissection of a limb of the fenestrated artery is an extremely rare occurrence. We report the case of a ruptured dissecting aneurysm of a fenestrated VA. A 56-year-old man presented with acute-onset headache followed by respiratory failure. Computed tomography(CT)revealed diffuse subarachnoid hemorrhage, and CT angiography(CTA)demonstrated fenestration of the left VA and a fusiform aneurysm of the dorsolateral limb of the fenestrated VA. CT after injection of contrast medium revealed dissection of a limb of the fenestrated VA. A comparison of the 3-dimensional digital subtraction angiogram obtained 2 days later with the initial CTA showed that the dissecting aneurysm had shrunk. Coil embolization of the dissecting limb of the fenestrated VA was achieved, and the patient was discharged without neurologic deficit. Further advancements in neuroimaging modalities will provide more opportunities to treat dissecting aneurysms of fenestrated VAs. The relevant clinical characteristics of VA fenestration and the treatment options for a dissecting aneurysm of a limb of the fenestrated VA are also discussed in this report.

Interaction between the stent strut and thrombus characterized by contrast-enhanced high-resolution cone beam CT during deployment of the Solitaire stent retriever.

BACKGROUND: The mechanism by which a stent retriever removes intraluminal thrombus from an occluded vessel in humans has not previously been studied. This study performed contrast-enhanced high-resolution cone beam CT (CE-HRCBCT) during deployment of the stent retriever to observe the interaction between the strut and intraluminal thrombus intraoperatively. We also discuss the mechanism by which the thrombus is retrieved. METHODS: In 11 patients, mechanical thrombectomy was performed with a Solitaire stent retriever. The presence or absence of flow restoration (FR) was evaluated immediately and at least 5 min after deployment. Stent retriever findings on CE-HRCBCT were divided into two groups: (1) complete expansion; and (2) incomplete expansion. RESULTS: FR was observed in all 11 cases (100%) immediately after deployment of the Solitaire stent retriever. Complete expansion was observed in only one case and incomplete expansion was observed in 10 cases. The thrombus was observed mainly near to or outside the strut of the stent retriever by CE-HRCBCT. Loss of FR was seen in only one of the 11 cases. Regardless of this, successful recanalization was achieved with only the stent retriever in nine cases. CONCLUSIONS: CE-HRCBCT showed that the Solitaire stent retriever rarely expanded fully and the thrombus was mainly near to or outside the strut. It may not be necessary to wait a long time to allow the stent to expand fully into the thrombus because the main capture mechanism seems to be engagement of the clot between the crossings of the struts of the Solitaire.

[Repeated Cerebellar Hemorrhage Related to Rivaroxaban and Apixaban: A Case Report].

We report a case of repeated cerebral hemorrhage associated with administration of rivaroxaban and apixaban. A 74-year-old man had undergone catheter ablation for non-valvular paroxysmal atrial fibrillation in 2 years prior. Warfarin treatment was continued after successful catheter ablation, and was then changed to rivaroxaban in 1 year prior. Three months later, he developed subcortical cerebral hemorrhage in the right occipital lobe and pharmacotherapy was changed to apixaban. At the current presentation, he complained of headache and left visual field defect, and was admitted to our hospital. Computed tomography of the head revealed recurrent hematoma at the same site as the previous hemorrhagic lesion. Administration of apixaban was subsequently stopped. Magnetic resonance imaging of the head revealed no vascular anomalies around the hemorrhagic lesion, except for two microbleeds in the left cerebral cortex, suggesting amyloid angiopathy. We report the current case from the perspective of whether anticoagulation should be continued after successful catheter ablation, and whether anticoagulation is appropriate in patients with microbleed signals in the cerebral cortex.

Impact of Metformin on the Severity and Outcomes of Acute Ischemic Stroke in Patients with Type 2 Diabetes Mellitus.

BACKGROUND: Diabetes mellitus (DM) is a major risk factor for cardiovascular disease. Metformin therapy reportedly decreases the risk of stroke, but the associations between metformin treatment and neurological severity or patient prognosis have not been investigated in clinical studies. This study evaluated the effects of metformin on stroke severity and outcomes in acute ischemic stroke patients with type 2 DM. METHODS: We examined 355 stroke patients with type 2 DM without severe renal impairment or prestroke impairment of activities of daily living who were admitted to Kyushu Medical Center between April 2010 and September 2014. Neurological severity was assessed according to the National Institutes of Health Stroke Scale (NIHSS) score on admission. Mild neurological severity was defined as an NIHSS score lower than 3 on admission, and favorable functional outcome was defined as a modified Rankin Scale score of 2 or lower at discharge. RESULTS: On logistic regression analysis with adjustments for multiple confounding factors, pretreatment with metformin was independently associated with mild neurological symptoms (odds ratio [OR], 2.12; 95% confidence interval [CI], 1.09-4.10; P = .026). In contrast, functional outcomes showed no significant associations. Nevertheless, a benefit of prior metformin use was observed in patients with a prior history of stroke (OR, 11.3; P = .046) and in patients after excluding those with mild stroke severity (OR, 5.64; P = .042). CONCLUSIONS: Administration of metformin in DM patients prior to stroke onset may be associated with reduced neurological severity and improved acute-phase therapy outcomes.

[Impact of comprehensive stroke team combined with vascular neurologist, neurosurgeon and endovascular interventionist for acute stroke].

The stroke center with endovascular intervention has been developed with advances in acute stroke therapy. Vascular neurologists who intend to perform endovascular intervention should receive advanced clinical training in a neurosurgical department, as well as experience in cardiovascular medicine for a prescribed period. A stroke team combined with vascular neurologists, neurosurgeons, and endovascular interventionists would be essential for a regional core comprehensive stroke center in the future.

Increase in the Size of an Intracardiac Thrombus during Dabigatran Therapy (110 mg b.i.d.) in an Acute Cardioembolic Stroke Patient.

We report a case of atrial fibrillation in a patient in whom a mobile thrombus in the left atrial appendage increased in size after low-dose dabigatran therapy. A 74-year-old man was admitted to our hospital because of sudden onset of right hemiplasia and dysarthria. On admission, his National Institutes of Health Stroke Scale score was three. Axial diffusion-weighted magnetic resonance images and magnetic resonance angiography images showed hyperintense signals in the left front-parietal cerebral cortex without any intracranial stenotic lesions, and acute cardioembolic stroke associated with nonvalvular atrial fibrillation was diagnosed. Transesophageal echocardiography revealed a mobile thrombosis (1.0 × 2.2 cm) in the left atrial appendage, and dabigatran therapy (110 mg b.i.d.) was initiated to prevent stroke recurrence. Transesophageal echocardiography performed 6 days later revealed that the size of the thrombus had increased to 1.5 × 3.0 cm. Medication was changed to warfarin, and the thrombosis subsequently decreased in size. The patient did not have a recurrent stroke and was discharged with a National Institutes of Health Stroke Scale score of zero. This case demonstrates that low-dose dabigatran may not be effective in reducing the size of a thrombus.