Two Cases of Mechanical Thrombectomy in Patients with Fenestration of the M1 Segment of the Middle Cerebral Artery.

M1 fenestration of the middle cerebral artery is rare. We present two patterns of acute thromboembolic conditions in M1 fenestrations treated with mechanical thrombectomy. Case 1 was a male in his 60s presenting with right hemiparesis and aphasia. Angiography showed acute left M1 proximal occlusion; the first direct aspiration revealed two parallel routes, and the second aspiration achieved complete recanalization of the left M1 fenestration. Case 2 was a male in his 70s presenting right hemiparesis and aphasia. Angiography revealed a sudden stair-like narrowing of the left M1 in the intermediate part, and a retrograde blood flow cavity was observed on the upper side of the distal part. Mechanical thrombectomy was performed to diagnose the upper limb occlusion of the left M1 fenestration, and successful recanalization was achieved through direct aspiration. Anatomical variations, such as fenestration, should be considered to reduce complication risks.

A posterior inferior cerebellar artery of C2 transverse foramen level origin that entered the spinal canal via the C1/2 intervertebral space demonstrated by computed tomography angiography.

PURPOSE: To describe a case of a posterior inferior cerebellar artery (PICA) of C2 transverse foramen level vertebral artery (VA) origin that entered the spinal canal via the C1/2 intervertebral space. CASE REPORT: A 48-year-old man with posterior neck pain underwent computed tomography (CT) angiography and selective left vertebral angiography. Arterial dissection was found at the distal V2 segment of the left VA on subtracted CT angiography. The left PICA arising from the VA at the level of C2 transverse foramen was identified on CT angiography with bone imaging. This PICA of extracranial origin entered the spinal canal via the C1/2 intervertebral space, just like a PICA of C1/2 level origin. DISCUSSION: The origins of PICAs show several variations. PICAs originating at the extracranial C1/2 level VA are relatively rare, with a reported prevalence of approximately 1%. Our patient had a left PICA arising from the VA at the level of the C2 transverse foramen. No similar cases have been reported in the relevant English-language literature. We speculated that the proximal short segment of the PICA arising from the C1/2 level VA regressed incidentally and that the distal segment of the PICA was supplied by the muscular branch of the VA arising from the level of the C2 transverse foramen. CONCLUSION: We reported the first case of PICA arising from the C2 transverse foramen level VA. CT angiography with bone imaging is useful for identifying a PICA arising from the extracranial VA.

Duplicated posterior inferior cerebellar arteries one of which was supplied by the jugular branch of the ascending pharyngeal artery.

PURPOSE: To describe a case of duplicated posterior inferior cerebellar arteries (PICAs), one of which was supplied by the jugular branch of the ascending pharyngeal artery (APA). CASE REPORT: A 62-year-old man with cerebral infarction underwent cranial magnetic resonance (MR) imaging and MR angiography. MR angiography showed a hyperplastic left APA, that was found to enter the posterior cranial fossa and continue to the PICA. Another left PICA arising from the V4 segment of the left vertebral artery (VA) and a tiny left anterior inferior cerebellar artery (AICA) were also identified. The source images of MR angiography revealed that the anomalous artery was passing through the medial side of the jugular foramen pars vascularis. The two left PICAs did not fuse to each other. DISCUSSION: There are four types of the PICA arising from the carotid system: (1) the PICA arises from the cavernous segment of the internal carotid artery (ICA) (persistent trigeminal artery variant); (2) the PICA arises from the cervical segment of the ICA (persistent hypoglossal artery variant); (3) the PICA arises from the APA via the hypoglossal canal; and (4) the PICA arises from the APA via the jugular foramen. Two PICAs sometimes arise from the V4 segment of the VA. In this common variation, the AICA is usually absent. This is the first reported case involving the association of (4) and a duplicated PICA with a tiny AICA. CONCLUSION: To identify this variation, careful observation of source images and creation of partial maximum-intensity-projection images of MR angiography are important.

Endovascular Treatment for Acute Ischaemic Stroke Caused by Vertebral Artery Dissection: A Report of Three Cases and Literature Review.

Vertebrobasilar artery dissection is an uncommon cause of acute ischaemic stroke (AIS). Optimal endovascular management has not been established. This study aimed to share our experience with endovascular reperfusion therapy for vertebrobasilar artery occlusion due to vertebral artery dissection (VAD). We retrospectively reviewed 134 consecutive patients with AIS who received urgent endovascular reperfusion therapy between November 2017 and November 2019. Three patients diagnosed with VAD were investigated. The evaluation included mechanisms of vertebrobasilar artery occlusion due to VAD, variations in endovascular procedures, and functional outcomes. Dissections at the V3, V4 and extension of V3 to V4 segments were seen in one patient each. The mechanism of AIS was different in each patient: occlusion of the distal non-dissected artery due to an embolus from the dissection site (distal occlusion), haemodynamic collapse of the entire vertebrobasilar artery system due to the arterial dissection itself (local occlusion), or coexistence of distal occlusion and local occlusion (tandem occlusion). The endovascular reperfusion therapy was performed corresponding to the abovementioned mechanisms: mechanical thrombectomy for distal occlusion, stenting for local occlusion, and a combination of thrombectomy and stenting for tandem occlusion. In all three patients, effective recanalization and functional independence (modified Rankin Scale scores of 0-2 at 90 days after the onset) were achieved. Endovascular treatment corresponding to the individual mechanism of AIS may improve patient outcomes.

A dural metastatic small cell carcinoma of the gallbladder as the first manifestation: a case report.

BACKGROUND: A dural metastasis is one of the essential differential diagnoses of meningioma. In general, carcinomas of the breast and lung in females and prostate in males have been the most commonly reported primary lesions of dural metastases. However, dural metastasis of gallbladder carcinoma is extremely rare. Here, we report a unique case of a dural matter metastasis of gallbladder carcinoma as the first manifestation, which was autopsy-defined as small cell carcinoma. CASE PRESENTATION: A 78-year-old man came to our hospital complaining of left hemianopia. Brain computed tomography (CT) revealed a sizeable parasagittal dural-based extra-axial tumor. However, the findings for meningioma were atypical by magnetic resonance imaging, suggesting a meningioma mimic. A contrast-enhanced CT scan of the abdomen revealed a large gallbladder carcinoma. The patient opted for the best supportive care and died 2 months later. The post-mortem examination revealed small cell carcinoma in gallbladder carcinoma. Moreover, an immunologically similar carcinoma was detected in the dural metastasis. CONCLUSIONS: To the best of our knowledge, this is the first case of a dural metastasis of gallbladder small cell carcinoma. A systemic examination is essential for clinicians when atypical findings of meningioma are observed, suggesting a meningioma mimic. We present this rare case with a review of the literature.

Pathologic Findings of Symptomatic Carotid Artery Stenosis Several Decades after Radiation Therapy: A Case Report.

Improved long-term survival of malignancy has drawn increased attention to late cerebrovascular toxicity after neck radiotherapy. Recently, neck radiotherapy has been found as a significant risk factor of carotid artery stenosis and ischemic stroke; however, long-term adverse effects of radiation in large arteries remain unknown. Here, we described an autopsied case with recurrent ischemic stroke associated with ipsilateral carotid artery stenosis several decades after neck radiation therapy. Pathologically, there were intima-media fibrosis, endothelial cell loss, and decreased expression of thrombomodulin in irradiated carotid artery stenosis. Our findings support the hypothesis that long-term radiation-induced vascular injury in large arteries is morphologically different from atherosclerotic change. Furthermore, endothelial cell injury may promote fibrin thrombus formation through decreased expression of thrombomodulin, which may cause ischemic stroke associated with radiation-induced carotid artery stenosis.

[Usefulness of Bilateral rSO2 Monitoring for Predicting Cerebral Hyperperfusion Syndrome after Carotid Artery Stenting].

OBJECTIVE: Cerebral hyperperfusion syndrome(CHS)and cerebral hyperperfusion phenomenon(CHP)induce intracranial hemorrhage and can become critical complications after carotid artery stenting(CAS). The purpose of the present study was to predict and avoid CHS after CAS using bilateral rSO2 intraoperative monitoring. METHODS: We retrospectively analyzed 100 consecutive patients who underwent CAS between January 2012 and May 2014 in our institution. We performed continuous bilateral rSO2 monitoring from anesthetic induction to the day following CAS. CHS was defined as the deterioration of neurological conditions post-CAS, no ischemic changes on post-CAS head CT or brain MRI, an increase in cerebral blood flow(CBF)and cerebral blood volume(CBV), and shortening of the mean transit time(MTT)or time to peak(TTP)on CT perfusion. To compare the CHS/CHP group and non-CHS/CHP group, we defined four parameters:rSO2 difference(rSO2 at the endpoint of the procedure-baseline rSO2), ΔrSO2 difference(affected side rSO2 difference-unaffected side rSO2 difference), rSO2 ratio(rSO2 at the endpoint of the procedure/baseline rSO2), and ΔrSO2 ratio(affected side rSO2 ratio/unaffected side rSO2 ratio). RESULTS: There were 2 CHS cases(2.2%)and 3 CHP cases(3.3%). In the CHS/CHP group, the ΔrSO2 difference and ΔrSO2 ratio were significantly higher than those in the non-CHS/CHP group(p value<0.05);however, no significant differences were found in the affected side rSO2 difference(p value=0.063)and affected side rSO2 ratio(p value=0.054)between the groups. CONCLUSION: We could promptly detect CHS and CHP in all cases by using continuous bilateral rSO2 monitoring and analysis of the ΔrSO2 difference and ΔrSO2 ratio.

Takotsubo-like Myocardial Dysfunction in a Patient with Botulism.

Botulinum toxin A (BTXA) can disrupt the neuromuscular and autonomic functions. We herein report a case of autonomic system dysfunction that manifested as Takotsubo-like myocardial dysfunction in a patient with botulism. Takotsubo syndrome results in acute cardiac insufficiency, another fatal complication of botulism in addition to respiratory muscle paralysis, particularly in patients with cardiovascular disease.

A case of hemifacial paresis in a patient with Lyme neuroborreliosis treated with antibiotics in whom Borrelia meningitis developed.

A 38-year-old man visited our hospital because of hemifacial paresis that developed 2 months after being bit by a tick. We diagnosed idiopathic peripheral facial palsy and gave the patient oral prednisolone and valacyclovir. Although the symptoms completely resolved in about 2 weeks, there was a risk of Lyme neuroborreliosis. The patient therefore received doxycycline (100 mg twice daily) and amoxicillin (1,000 mg 3 times daily) for 14 days. Two months later, he had symptoms of meningitis such as headache and fever accompanied by lymphocytic cerebrospinal fluid pleocytosis. Viral meningitis was diagnosed and treated with parenteral acyclovir. The symptoms of meningitis improved. Tests for serum IgG antibodies against borrelia were positive. We gave the patient a diagnosis of Lyme neuroborreliosis. The patient received intravenous ceftriaxone and had no relapse. It is a rare for meningitis to develop in a patient with cranial neuropathy who received doxycycline. Lyme neuroborreliosis is a rare disease in Japan. Care should therefore be exercised in the diagnosis of Lyme neuroborreliosis and evaluation of the response to treatment.

The safety and efficacy of preoperative embolization of meningioma with N-butyl cyanoacrylate.

OBJECTIVE: Preoperative embolization of meningioma is commonly performed; however, there is no consensus on the best embolic material to reduce intraoperative blood loss and surgery time. METHOD: We retrospectively assessed the safety and efficacy of 56 cases of preoperative embolization of the middle meningeal artery with N-butyl cyanoacrylate (NBCA) in 105 cases of surgery for meningioma. We also defined a blood loss to tumor volume ratio to compensate for bias caused by tumor volume, and analyzed limited cases (the embolized group n = 52, the non-embolized group n = 21) of the convexity, the parasagittal region, the falx, and the sphenoidal ridge. RESULT: The blood loss to tumor volume ratio was significantly less in the embolized group (p < 0.007). Preoperative embolization could be useful for cases with the external carotid artery as the dominant feeder vessel (p < 0.02); however, the efficacy decreased for cases with an internal carotid artery feeder. Transient complications occurred in four cases (hemiparesis secondary to edema: two cases; intratumoral bleeding: one case; trigeminal nerve disorder: one case). The cases that showed a postoperative increase in edema or intratumoral bleeding were large tumors with the early filling of veins. For such cases, surgeons should pay close attention to slow injection speed and higher NBCA viscosity, not to cause the occlusion of draining vessels. CONCLUSION: Tumor embolization with NBCA can be safely performed, and the procedure significantly reduces intraoperative blood loss.

Risk factors for coil protrusion into the parent artery and associated thrombo-embolic events following unruptured cerebral aneurysm embolization.

OBJECTIVE: Advances in vascular reconstruction devices and coil technologies have made coil embolization a popular and effective strategy for treatment of relatively wide-neck cerebral aneurysms. However, coil protrusion occurs occasionally, and little is known about the frequency, the risk factors and the risk of thrombo-embolic complications. METHOD: We assessed the frequency and the risk factors for coil protrusion in 330 unruptured aneurysm embolization cases, and examined the occurrence of cerebral infarction by diffusion-weighted magnetic resonance imaging (DW-MRI). RESULT: Forty-four instances of coil protrusion were encountered during coil embolization (13.3% of cases), but incidence was reduced to 33 (10% of cases) by balloon press or insertion of the next coil. Coil protrusion occurred more frequently during the last phase of the procedure, and both a wide neck (large fundus to neck ratio) (OR = 1.84, P = 0.03) and an inadequately stable neck frame (OR = 5.49, P = 0.0007) increased protrusion risk. Coil protrusions did not increase the incidence of high-intensity lesions (infarcts) on DW-MRI (33.3% vs 29% of cases with no coil protrusion). However, longer operation time did increase infarct risk (P = 0.0003). Thus, tail or loop type coil protrusion did not increase the risk of thrombo-embolic complications, if adequate blood flow was maintained. CONCLUSION: Coil protrusion tended to occur more frequently in cases of wide-neck aneurysms with loose neck framing. Moderate and less coil protrusion carries no additional thrombo-embolic risk, if blood flow is maintained, which can be aided by additional post-operative antiplatelet therapy.

Aberrant internal carotid artery associated with occipital artery arising from the internal carotid artery.

We present an extremely rare case of an aberrant course of the petrous internal carotid artery (ICA) associated with the ipsilateral occipital artery arising from the cervical ICA, a combination not previously reported by magnetic resonance (MR) angiography. The patient was a 53-year-old woman with no symptoms related to the anomalous ICA. Source images and partial maximum-intensity-projection images of MR angiography are useful in diagnosing these variations. Source images and curved multiplanar reconstruction images of computed tomography angiography are important for the accurate evaluation of reduced arterial diameter and the relationship between the anomalous artery and petrous bone.

Risk factors and prevention of guiding catheter-induced vasospasm in neuroendovascular treatment.

Mechanically-induced vasospasm often occurs during guiding catheter insertion, occasionally preventing catheter advancement to the desired location. Delicate manipulation would be impossible without the proper positioning of guiding catheters, and vasospasm-induced cerebral hypoperfusion may cause thrombotic complications. From June 2012 to December 2013, we prospectively analyzed 150 endovascular treatment cases, excluding acute cases, for the frequency of vasospasm, risk factors, and countermeasures. The associated risk factors such as the Japanese-style State-Trait Anxiety Inventory (STAI) score; anatomy and devices; and the efficacies of warm compresses, intra-arterial lidocaine/nicardipine, and tranquilizers were analyzed. Groups 1, 2, and 3 comprised 50 patients each with controls, tranquilizer administration, and prophylactic warm compresses/intra-arterial drug injection, respectively. Moderate or severe vasospasm was seen in approximately 40% patients in each group; however, severe vasospasm was absent in Group 3. Mild vasospasm-induced cerebral infarction occurred in one patient each in Groups 1 and 2. Vasospasm during diagnostic angiography [odds ratio (OR) = 10.63; P = 0.01], many ≥ 30° vessel curves [OR = 4.21; P = 0.01], and the high STAI score [OR = 1.84; P = 0.01] were risk factors for severe vasospasm. Although the relationship between anxiety and sympathetic tone remained unclear, tranquilizer administration relieved vasospasm. Warm compresses and the intra-arterial drug infusion were also useful for relieving vasospasm. Prophylactic measures such as a tranquilizer and warm compresses are expected to alleviate vasospasm; in addition, countermeasures such as the intra-arterial injection of lidocaine/nicardipine are effective.

Contrast-induced encephalopathy after coil embolization of an unruptured internal carotid artery aneurysm.

A 58-year-old woman developed agraphia and mild right hemiparesis approximately one month after undergoing coil embolization of an unruptured left internal carotid artery aneurysm. MRI performed on day 39 post-coil embolization showed multiple lesions in the white matter with signal hyperintensity on T2-weighted and FLAIR images in the left middle cerebral artery territory. The patient's cerebrospinal fluid exhibited an elevated protein level at 46 mg/dL; however, no other findings suggested another underlying disease. Corticosteroids were administered, and, by day 50 post-coil embolization, the clinical findings and abnormal features on MRI had improved. The patient was therefore diagnosed with contrast-induced encephalopathy after coil embolization.

Subdural and intracerebral hemorrhage caused by spontaneous bleeding in the middle meningeal artery after coil embolization of a cerebral aneurysm.

Nontraumatic acute subdural hemorrhage (SDH) with intracerebral hemorrhage (ICH) is rare and is usually caused by severe bleeding from aneurysms or arteriovenous fistulas. We encountered a very rare case of spontaneous bleeding from the middle meningeal artery (MMA), which caused hemorrhage in the temporal lobe and subdural space 2 weeks after coil embolization of an ipsilateral, unruptured internal cerebral artery aneurysm in the cavernous portion. At onset, the distribution of hematoma on a computed tomography scan led us to believe that the treated intracavernous aneurysm could bleed into the intradural space. Emergency craniotomy revealed that the dura of the middle fossa was intact except for the point at the foramen spinosum where the exposed MMA was bleeding. Retrospectively, angiography just before and after embolization of the aneurysm did not show any aberrations in the MMA. Although the MMA usually courses on the outer surface of the dura and is unlikely to rupture without an external force, physicians should be aware that the MMA may bleed spontaneously and cause SDH and ICH.

Fusiform dilatation of the outer contour of a dissected anterior cerebral artery revealed by magnetic resonance cisternography in a patient with simultaneous cerebral infarction and subarachnoid hemorrhage.

A 46-year-old man presented with right hemiparesis. Cranial magnetic resonance (MR) imaging revealed both an acute cerebral infarction in the territory of the left anterior cerebral artery (ACA) and a thin subarachnoid hemorrhage in the left superior frontal sulcus. MR angiography revealed stenosis at the A2 segment of the left ACA. MR cisternography was, therefore, performed on day 12 after admission using sagittal, 3-dimensional, heavily T2-weighted images. Fusiform dilatation of the outer contour was confirmed by MR cisternography at the region of narrowing identified by MR angiography. This case indicates that the combination of MR cisternography and angiography can be useful for detecting ACA dissection.