Search

BACKGROUND A craniocervical junction arteriovenous fistula (CCJAVF) is a rare vascular malformation, and its etiology remains unclear. Here, to the best of the authors’ knowledge, they present the first case of CCJAVF associated with thrombus formation in the ipsilateral internal jugular vein. OBSERVATIONS An 80-year-old man presented with a sudden occipital headache. Computed tomography revealed a subarachnoid hemorrhage surrounding the brainstem and upper cervical cord. Digital subtraction angiography showed a CCJAVF fed by the left C2 radiculomeningeal artery with ascending intracranial drainage and epidural plexus. After endovascular treatment, the authors retrospectively found that his ipsilateral internal jugular vein and innominate vein were occluded with a huge thrombus at admission. LESSONS This case suggested a restricted antegrade venous flow due to thrombus-induced progressive retrograde intracranial drainage causing hemorrhage. Venous hypertension should be considered one of the causes of hemorrhage due to CCJAVF as well as intracranial arteriovenous fistulas.

Bow hunter's stroke is a rare cause of vertebrobasilar infarction. There is no consensus regarding the optimal treatment. We herein report a case of bow hunter's stroke successfully treated by endovascular treatment. A 70-year-old man presented with central vertigo. Magnetic resonance imaging (MRI) showed posterior circulation infarcts. Dynamic angiography revealed thrombus formation and hypoperfusion of the right vertebral artery upon head rotation to the left. Endovascular parent artery occlusion of the right vertebral artery was performed, and there was no recurrence at follow-up MRI. Endovascular parent artery occlusion might be a useful treatment for bow hunter's stroke.

Background Diagnosis of hemangioblastoma by magnetic resonance imaging (MRI) can sometimes be difficult when the tumor is a solid mass in the posterior fossa. We therefore evaluated perfusion images and diffusion-weighted images as brain function images to diagnose hemangioblastoma in order to obtain the most useful quantitative features. Methods Forty-five posterior fossa tumors whose pathological diagnosis was confirmed by surgery were included in groups A (18 hemangioblastomas) and B (non-hemangioblastoma 27 cases: metastatic brain tumor 8 cases, pilocytic astrocytoma 6 cases, and other 13 cases). All cases were imaged by 3.0-Tesla MRI, with arterial spin labeling (ASL) as the relative value from the CBF map to the region of interest (ROI) in the contralateral hemisphere as perfusion image. Among 45 cases, 27 cases were evaluated with both ASL and dynamic susceptibility contrast (DSC) as rCBF, rCBV, corrected CBV, and K2. The ROI was set to match the contrast-enhanced part, and the two groups were compared and examined. Results The relative ASL value of group A and the corrected CBV in DSC were significantly higher than group B (p < 0.001). In contrast, the ADC showed no marked difference between the two groups. In the distinction between the two groups, the receiver operating characteristic (ROC) analysis showed that the area under the curve (AUC) of the relative ASL value was significantly higher than the other parameters (AUC 0.995, cut-off value 2.34, sensitivity 100%, specificity 99.5%). Conclusions The non-contrast ASL method was extremely useful for diagnosing hemangioblastoma in posterior fossa tumors. Non contrast ASL can be used instead of contrast-enhanced DSC in diagnosing posterior fossa hemangioblastoma.

Background: Carotid endarterectomy (CEA) is a conventional surgical technique to prevent ischemic stroke and the effectiveness for advanced lesions is established in many large studies. The vagus nerve is one of the cranial nerves that we usually encounter during CEA manipulation, which is identified as located posterior to the vessels in a position posterolateral to the carotid artery and posteromedial to the internal jugular vein. Case Description: We experienced an extremely rare case of the vagus nerve passing anterior to the internal carotid artery during CEA. Conclusion: We should be careful not to accidentally cut off because the variation of the vagus nerve can be mistaken for an ansa cervicalis. A delicate and complete dissection to understand the variation of the vagus nerve is crucial to minimize the risk of cranial nerve injury during CEA.

We report a rare case of asymptomatic aplastic or twig-like middle cerebral artery (Ap/T-MCA) with small unruptured aneurysms at the origin (A1) of the anomalous collateral artery containing plexiform (twig-like) networks and in the anterior communicating artery. In Ap/T-MCA, other cerebrovascular systems are usually considered to exhibit normal findings not associated with atherosclerosis. At first admission, atherosclerotic M1 occlusion was suspected because of the patient's risk factors and multiple stenoses in major intracranial arteries. Cerebral blood flow (CBF) studies revealed reduction of resting CBF and vascular reserve in the ipsilateral MCA territory. After 5 years, a diagnosis of Ap/T-MCA was reached based on detailed image examination and intraoperative findings during aneurysm clipping in combination with extracranial-intracranial (EC-IC) bypass. It should be noted that atherosclerosis can coexist with Ap/T-MCA, which is considered a congenital anomaly in which bleeding often occurs due to a ruptured aneurysm within the fragile collateral vessels. In previous reports, A1 aneurysms at the origins of the collateral arteries ruptured even when they were small. Aggressive radical surgery using EC-IC bypass can be considered for the treatment of unruptured aneurysms associated with Ap/T-MCA, but further research is needed. (Received September 14, 2020; Accepted November 4, 2020; Published 1 April, 2021).

Background: Mechanical thrombectomy (MT) is standard treatment for acute ischemic stroke (AIS) with large-vessel occlusion within 6 h of symptom onset to treatment initiation (OTP). Recent trials have extended the therapeutic time window for MT to within 24 h. However, MT treatment remains low in remote areas. Nagasaki Prefecture, Japan has many inhabited islands with no neurointerventionalists. Our hospital on the mainland is a regional hub for eight island hospitals. We evaluated clinical outcomes of MT for patients with AIS on these islands versus on the mainland. Methods: During 2014–2019, we reviewed consecutive patients with AIS who received MT at our hospital. Patients comprised the Islands group and Mainland group. Patient characteristics and clinical outcomes were compared between groups. Results: We included 91 patients (Islands group: 15 patients, Mainland group: 76 patients). Seven patients (46.7%) in the Islands group versus 43 (56.6%) in the Mainland group achieved favorable outcomes. Successful recanalization was obtained in 11 patients (73.3%) on the islands and 67 (88.2%) on the mainland. The median OTP time in the Islands was 365 min. In both the Islands and Mainland groups, the OTP time and successful recanalization were associated with functional outcome. The modified Rankin Scale (mRS) score at 90 days ≤2 was obtained in two patients and mRS = 3 in four patients among eight patients with OTP time >6 h. Conclusions: Few patients with AIS on remote islands have received MT. Although patients who underwent MT on the islands had longer OTP, the clinical outcomes were acceptable. OTP time on remote islands must be shortened, as this is related to functional outcome. In some cases with successful recanalization, a favorable outcome can still be obtained even after 6 h. Even if OTP exceeds 6 h, it is desirable to appropriately select patients and actively perform MT., PLOS ONE, 16(1), e0245082; 2021

A 58-year-old woman underwent left frontotemporal craniotomy for clipping of an unruptured cerebral aneurysm. A small defect was accidentally created in the orbital roof intraoperatively. The patient developed left eyelid edema and ocular pain after recovery from anesthesia. The following day, the eyelid edema worsened, and she had difficulty opening her eyes. On the 9

A 69-year-old woman presented on an emergency basis, with headache and left hemiparesis. Initial head CT at the time of admission revealed a large subcortical hematoma with perihematomal edema extending from the right parietal to the occipital lobe. A small part of the hematoma extended toward the trigone of the right lateral ventricle. CT angiography revealed no vascular abnormalities. Emergency craniotomy was erformed, and the patient's initial postoperative course was unremarkable. However, the patient's neurological symptoms worsened 10 days postoperatively, and CT revealed a new low-density cystic lesion with perifocal edema at the site of hematoma removal, in addition to severe cerebral compression. We performed a reoperation, and intraoperatively we observed hematoma fluid mixed with cerebrospinal fluid without any abnormal blood vessels or neoplastic lesions in the hematoma cavity. We identified the choroid plexus deep within the surgical field, and slight leakage of cerebrospinal fluid was detected from the ventricular aspect, indicating the formation of a small passage between the hematoma cavity and the ventricle. After the second operation, her postoperative course was uneventful without recurrent cyst formation. An early symptomatic expanding porencephalic cyst in the hematoma cavity after removal of an intracerebral hematoma is rare, and only a few cases have been reported in the literature. Based on literature review and considering the likely mechanism of cyst development, we speculated that progressive cyst expansion could be attributed to a check valve mechanism between the ventricle and the cavity from which the hematoma was removed, as observed in the present case.

Cervical carotid disease is typical atherosclerosis, which is responsible for ischemic stroke. The effectiveness of carotid endarterectomy (CEA) for advanced carotid stenosis has been established in many large studies, and CEA is the gold standard in surgical treatment. On the other hand, endovascular carotid artery stenting (CAS) has become increasingly popular recently. It is very important to avoid any complications to maintain the effectiveness of CEA. The retractor device is important for the exposure of carotid arteries and for the safe surgical manipulation. We have started to use lone star retractor system (LSRS) to deploy the surgical field. LSRS provides the usability to handle and a shallower surgical field without the disturbance of surgical manipulation. And it can facilitate exposure of the distal internal carotid artery because surgeon can retract freely in whole circumference by towing with moderate strength. LSRS may bring the smoother and easier surgical manipulations in CEA.

Background: Middle cerebral artery (MCA) has a significantly lower incidence of anatomical variations than other intracranial arteries. We present an extremely rare case of unruptured aneurysms with the segmental duplicated MCA (d-MCA) formed a fenestrated structure at origin. Case Description: A 55-year-old female underwent direct surgery for the unruptured aneurysms at the top of the right internal cerebral artery with d-MCA. The d-MCA branches separated at the right internal cerebral artery top and had comparable with that of the main MCA trunk. Moreover, there was an anastomosis between the d-MCA branches. We diagnosed this anastomosis as segmental d-MCA. Two aneurysmal domes were identified during surgery at the origin of the d-MCA, which the main dome protruding backward was wide necked and another small one was collapsed or thrombosed protruding forward. We used a fenestrated clip for the posterior projecting dome, and the aneurysms were successfully obliterated. Conclusion: Although cerebral aneurysms associated with d-MCA are rare, there are technical difficulties in the surgical management. A fenestrated clip might be most reasonable to obtain patency of the parent arteries for the posterior projecting aneurysms if the perforators can be avoided.

We report a rare case of the endovascular treatment of a ruptured aneurysm of the right vertebral artery with an aberrant right subclavian artery(ARSA). A 60-year-old woman was urgently admitted because of consciousness disturbance. Brain CT showed subarachnoid hemorrhage, and CT angiography showed a right vertebral ruptured aneurysm. Endovascular treatment of the aneurysm was performed via a transfemoral approach. During the endovascular treatment, the right subclavian artery was found to diverge from the descending aorta on the periphery of the left subclavian artery. An ARSA was detected, and the right vertebral artery(VA)originated from the ARSA. The guiding catheter was passed through the right VA via an ARSA, and the aneurysm was completely embolized. The patient was transferred to another hospital on day 44 without any motor weakness. To our knowledge, this is the first case of an ARSA with a ruptured aneurysm in the right VA for which endovascular treatment was successfully performed via the ARSA. In patients with an ARSA or aberrant left subclavian artery, the artery could merge with Kommerell's diverticulum(KD)at its origin and be histologically fragile. Thus, in patients with an ARSA, attention should be paid to catheterization to avoid injuring the KD. CT angiography of the aortic arch might be considered before endovascular treatment.

We report a rare case of reversible cerebral vasoconstriction syndrome(RCVS)with cortical subarachnoid hemorrhage(cSAH)associated with a fresh cortical infarction beneath the sulcus with thick cSAH. A 34-year-old woman presented with history of thunderclap headache. She was transferred to our hospital for further examination of a cSAH in the left frontal lobe. Results of the cerebrospinal fluid examination were unremarkable, but three-dimensional rotational angiography revealed multiple instances of narrowing of the cortical branches of the anterior and middle cerebral arteries, suggesting the diagnosis of RCVS. Diffusion weighted imaging(DWI)demonstrated a small cortical area with high-signal intensity around the sulcus , where a thick cSAH clot was observed. This cortical lesion appeared as low-signal intensity on the apparent diffusion coefficient maps, and the follow-up T2-weighted images(obtained 3 months after onset)demonstrated a residual lesion that was smaller than the initial DWI abnormality with high-signal intensity;thus indicating the presence of a coincident fresh cortical infarction. The position of the infarct next to the thickest portion of cSAH suggested that it was the bleeding source of the cSAH. Ten days after onset, the cerebral blood flow and volume in the cortex around the cSAH increased as compared to the same area on the contralateral side. These findings suggested that at least one of the bleeding mechanisms of the cSAH was related to the hemorrhagic infarction or subpial hemorrhage resulting from the "ischemia-reperfusion injury" due to the acute disturbance of the pial vessel microcirculation with subsequent rapid resolution of the blood flow during the early phases of RCVS. These dynamics could not be demonstrated with contemporary angiographic imaging.

We report an extremely rare case of dural arteriovenous fistula(DAVF)involving the superior sagittal sinus(SSS)that presented as a primary intraventricular hemorrhage(PIVH). A 79-year-old man who presented with disturbance of consciousness and vomiting was transferred to our hospital. The initial head CT revealed an intraventricular hemorrhage in the lateral, third, and fourth ventricles, predominantly involving the right lateral ventricle associated with obstructive hydrocephalus. CT angiography and three-dimensional rotational angiography(3D-RA)revealed SSS-DAVF with retrograde venous drainage from the cortical venous system to the subependymal venous system through engorged superficial/anastomotic/deep medullary or transcerebral veins, showing a pseudophlebitic pattern. A severe stenosis of the SSS was observed at the site just proximal to the shunting point. A varix of the right transvers caudate vein(TCV)was observed within the thickest portion of the hematoma in close contact with the wall of the right lateral ventricle. A stenosis of the branching point of the right TCV was detected on the 3D-RA image. The DAVF was completely cured after transarterial embolization. The varix gradually shrank and finally disappeared after 2 months. This is the first report of a case of PIVH due to SSS-DAVF with a subependymal varix considered as the bleeding point. Serial gadolinium-enhanced MR images clearly showed the shrinking of the varix. Our case is the second reported case of spontaneous resolution of the varix after embolization of the DAVF. The obstructive changes of the two venous outflow pathways(SSS/TCV)might further worsen the state of venous congestion in the deep medullary venous system and eventually lead to formation and rupture of the varix.

We report an extremely rare case of a fenestration in the infracallosal(A2)segment of the right anterior cerebral artery(ACA)associated with an unruptured aneurysm at the proximal end of the fenestrated portion. A 70-year-old man was referred to our hospital for further examination and treatment of unruptured aneurysms at the A1/A2 junction of the right ACA and the distal end of the right vertebral artery that were incidentally detected on MR angiography. CT angiography and 3D-rotational angiography revealed a fenestration in the proximal A2 segment of the right ACA with a small(3.6×3.8mm)aneurysm arising from the proximal end of the fenestration. The dome of the aneurysm projected to the left anterior/inferior direction. He underwent aneurysm neck clipping surgery via the right pterional approach without complications, while the vertebral artery aneurysm was managed conservatively. An extensive review of the literature revealed that only a small number of cases of A2 fenestration have been reported to date. To our knowledge, this is the first report of an A2 fenestration associated with an aneurysm at the fenestrated segment. Embryologically, the A2 fenestration may represent a remnant of plexiform arterial channels that constitute the primitive ACA system including the primitive olfactory artery, median artery of the corpus callosum and anterior communicating plexus.

A persistent primitive olfactory artery (PPOA) is a rare anomaly of anterior cerebral artery (ACA), which generally arises from the internal carotid artery (ICA), runs along the olfactory tract, and makes a hairpin bend to supply the territory of the distal ACA. PPOA is also associated with cerebral aneurysms. An accessory MCA is a variant of the middle cerebral artery (MCA) that arises from either the proximal or distal portion of the A1 segment of the ACA, which runs parallel to the course of the MCA and supplies some of the MCA territory. We experienced a rare case of coexistence of PPOA with an unruptured aneurysm and accessory MCA. Three-dimensional computed tomographic angiography (3D-CTA) has an excellent picture of the spatial relationship of the surrounding bony and vascular structure.

A 67-year-old man with a high position carotid plaque presented with severe pain in ipsilateral parotid region several days after carotid endarterectomy (CEA). The pain occurred at the first bite of each meal and resolved as further bite. We diagnosed the pain as first bite syndrome (FBS). FBS is infrequent but known as a complication associated with parapharyngeal space surgery. The pain is characterized by sharp pain in the parotid region associated with mastication. The cause is unclear but thought to the result from sympathetic denervation of the parotid gland, followed by parasympathetic nerve hypersensitivity. Only five cases associated with carotid endarterectomy (CEA) have been reported. We should be in mind that CEA for high position plaque is one of the risk factors to cause FBS associated with CEA. Neurologists and vascular surgeons as well as otolaryngologists should all be informed FBS as one of the complications after carotid endarterectomy.

We report an extremely rare case of a fenestration in the cavernous segment of the left internal carotid artery(ICA)associated with an unruptured aneurysm at the proximal end of the fenestrated portion. A 44-year-old woman with a dull headache was referred to our hospital for further evaluation of a suspected aneurysm in the right ICA on MR angiography(MRA). CT angiography and 3D-rotational angiography revealed no aneurysm in the right ICA;however, an intracavernous fenestration with an incidental aneurysm was observed in the left ICA. The aneurysm was small(5×3mm)with a wide neck arising from the origin of the ventral limb of the duplicated vessels, in association with a tiny bulge projecting medially. She requested conservative management and periodic follow-up with MRA. After 18 months, no structural change in the aneurysm was observed. To our knowledge, including our patient, only three cases of this type of ICA fenestration have been published, and this is the first report of an ICA fenestration with an unruptured aneurysm at the fenestrated segment. It is presently unknown whether the intracavernous fenestration has the potential to form an aneurysm within the proximal end of the duplicated segment, as reported in cases of supraclinoid ICA fenestrations.

Of all brain metastases, the most common primary lesion is derived from the lung. These types of metastases enlarge aggressively with unfavorable prognoses. We report the case of a 75-year-old male patient who had a history of pulmonary resection for Stage IA non-small cell lung cancer(NSCLC), and received chemotherapy. One year after NSCLC surgery, he experienced a cardiogenic cerebral infarction, and anticoagulant therapy was initiated. Mass lesions with hemorrhage were detected bilaterally in the frontal lobes through magnetic resonance imaging three years after the NSCLC surgery. The lesions slowly enlarged during follow-up. However, there were no clinical symptoms. There was no finding indicating a local recurrence or metastasis through positron emission tomography(PET). Two and a half years after the detection of the lesion, left hemiplegia was observed. Massive hemorrhage from the right frontal lobe lesion was observed on computed tomography(CT). Craniotomy and evacuation of the hematoma were performed. The histopathological findings showed adenocarcinoma and the diagnosis was brain metastasis of the lung cancer. This case reveals brain metastasis of lung cancer that progressed without extracranial metastases for three years. The brain tumor enlarged, accompanied by hemorrhage, extremely slowly without any symptoms. It was difficult to differentiate between metastasis and cavernous hemangioma, considering the extremely slow progress and image analyses. Of the reported prognostic factors associated with postoperative brain metastasis from surgically resected NSCLC, three factors were applicable to this case:adenocarcinoma, a small number of brain metastases, and the absence of extracranial metastases at the diagnosis of brain metastasis. We should consider the possibility of a metastatic brain tumor secondary to lung cancer even long after thoracic surgery.