Objective: There are few detailed reports on abducens nerve palsy due to a ruptured vertebral artery dissecting aneurysm (VADA). We investigated the clinical characteristics and long-term course of abducens nerve palsy in ruptured VADA patients treated by endovascular surgery.

Methods: Of the 51 cases of ruptured VADA treated by endovascular intervention from 2011 to 2019, 31 with a good/fair outcome, in which ocular motility disorder was able to be followed, were included and investigated.

Results: In all, 11 patients (35.5%) had abducens nerve palsy, and the World Federation of Neurological Surgeons (WFNS) grade and Hunt & Hess (H&H) grade at the time of arrival of patients with abducens nerve palsy were significantly higher than those of patients without abducens nerve palsy. Of the 10 patients who were able to be followed, abducens nerve palsy in 3 completely recovered in 7–180 days. Abducens nerve palsy improved in five patients and remained in two patients.

Conclusion: More severe neurological findings on admission reflect a higher rate of abducens nerve palsy. Diplopia induced by abducens nerve palsy is one of the most important sequelae of ruptured VADA, which impairs the daily activities of the patients. Some cases of abducens nerve palsy improve over a long period. Therefore, appropriate diagnosis and follow-up should be concerned.

Objective: Endovascular treatment (EVT) for large vessel occlusion in acute ischemic stroke patients during the SARS-CoV-2 epidemic requires the implementation of an in-hospital system to guard against infection. Changes to this system may be needed upon aggravation of the epidemic in a particular region. The objective of this study was to clarify the present state of infection protection and the effects of a change in the in-hospital system in EVT at a single institution.

Methods: The subjects were consecutive patients treated by EVT under the protocol of infection protection using medical history and chest CT at our hospital between April 2020 and February 2021. For the subjects, background factors, time metrics, including door-to-puncture time (D2P), clinical outcome, and success of infection protection for medical staff were examined. The patients were divided into a group of those with PCR measurement after EVT (Group C; from April 2020 to November 2020) and a group of all with PCR measurement before EVT (Group P; from December 2020 to February 2021). Time metrics and clinical outcome were compared between the groups.

Results: There were 69 subjects, including 40 and 29 patients in groups C and P, respectively. The median age was 82, which was higher in group P. The median D2P was 70 min, which did not differ significantly between the two groups, but it was slightly longer in group P than in group C by multivariate analysis. A favorable outcome (modified Rankin Scale 0–2 at 3 months) was observed in 23 patients (38%), which did not differ significantly between the two groups, but the rate of a favorable outcome was slightly lower in group P than in group C by multivariate analysis. Although medical staff wearing full personal protection equipment were needed for 15 patients (22%), 12 of whom were suspected of being positive and three (4%) were confirmed positive for SARS-CoV-2 by PCR, no staff member who participated in EVT was infected.

Conclusion: The median D2P was 70 min and 38% had a favorable outcome of EVT under the present state of infection protection. After a change in the in-hospital system for clinical settings during the SARS-CoV-2 epidemic, the D2P increased and the rate of a favorable clinical outcome slightly decreased, but both were not significantly affected and infection protection for medical staff was effective. Therefore, the effects of a change were acceptable considering the circumstances.

Objective: To meet the new standard of the annual dose limit for the eye lens recommended by the International Commission on Radiation Protection, radiation doses of neuroendovascular procedures in Japanese institutions were investigated.

Methods: Radiation doses to operators involved in 304 neuroendovascular procedures at 30 Japanese institutions were prospectively surveyed. The institutions recruited at an annual meeting of the Japanese Society for Neuroendovascular Therapy participated voluntarily. A maximum of 10 wireless dosimeters were attached to the radiation protection (RP) goggles, the ceiling-mounted RP shielding screen, and the operators’ forehead and neck over the protective clothing. Doses recorded inside the goggles were defined as eye lens doses for operators who wore RP goggles, while doses to the forehead were defined as eye lens doses for those who did not. The shielding effect rates of the protection devices were calculated, and statistical analysis was performed for the comparison of radiation doses.

Results: From 296 analyzed cases, mean eye lens radiation doses per procedure were 0.088 mGy for the left eye and 0.041 mGy for the right eye. For the left eye, that dose without RP equipment was 0.176 mGy and that with RP goggles plus an RP shielding screen was 0.034 mGy. Four parameters, including left eye dose, air kerma at the patient entrance reference point, fluoroscopic time, and the total number of frames, were assessed for five types of neurovascular procedures. Of them, transarterial embolization for dural arteriovenous fistula was associated with the highest eye lens dose at 0.138 mGy. The shielding effect rates of protection goggles were 60% for the left and 55% for the right RP goggle. The mean doses to the inner and outer surfaces of the RP shielding screen were 0.831 mGy and 0.040 mGy, respectively, amounting to a shielding effect rate of 95%.

Conclusion: To meet the new standard, both RP goggles and RP shielding screens are strongly recommended to be used effectively. Without proper use of radiological protection devices, the number of neuroendovascular procedures that one operator performs per year will be limited under the new guideline.

Objective: We report a rare case of pterygopalatine fossa arterial venous shunt disease with venous congestion of the superior ophthalmic vein (SOV) that was treated by transarterial balloon-assisted embolization.

Case Presentation: A 57-year-old man presented with congestion of the right bulbar conjunctiva, protrusion, and swelling of the right eyelid was admitted to our hospital. Angiography demonstrated an arteriovenous fistula (AVF) forming small congregated vessels in the pterygopalatine fossa fed by the branch of the ophthalmic artery (OA) and artery of the superior orbital fissure, draining into the SOV via the inferior ophthalmic vein (IOV). From the artery of the superior orbital fissure, transarterial embolization (TAE) with ONYX using a dual-lumen balloon catheter was performed. The patient was treated without complications.

Conclusion: TAE using transarterial balloon-assisted embolization with ONYX is effective for periorbital arteriovenous shunts, although special care is necessary to prevent the migration of ONYX into the OA.

Objective: This report highlights a case of a de novo aneurysm assumed to be caused by hemodynamic stress resulting from proximal basilar artery stenosis.

Case Presentation: A 76-year-old woman presented at our hospital with tinnitus. Although MRI did not reveal the cause of her tinnitus, it did uncover an incidental finding of basilar artery stenosis. The patient reported a history of cerebral infarction, diabetes, and hypertension. Six years following the initial discovery of basilar artery stenosis, a saccular aneurysm was detected at the bifurcation of the basilar artery and the right anterior inferior cerebellar artery, corresponding to the distal portion of the basilar artery stenosis. Upon revelation of an enlarged aneurysm on the subsequent two-year follow-up MRI, the patient received coil embolization treatment. No signs of recurrence were observed on the next two-year follow-up MRI.

Conclusion: It was assumed that proximal basilar artery arteriosclerotic stenosis had caused hemodynamic stress on the distal vessel wall, and that this was responsible for the formation and growth of a de novo aneurysm. This case suggests that cerebrovascular arteriosclerotic changes may be associated with de novo aneurysm formation and therefore requires careful follow-up.

Objective: We report a case of contrast-induced encephalopathy (CIE) after repeated percutaneous transluminal angioplasty (PTA) for acute middle cerebral artery (MCA) occlusion.

Case Presentation: An 88-year-old woman with left hemiparesis was transferred to our hospital by ambulance. MRI revealed acute MCA M1 occlusion. We performed intravenous tissue plasminogen activator therapy and PTA for right MCA occlusion, leading to complete recanalization and improvement in hemiparalysis. After approximately one week, restenosis of right MCA developed and PTA was performed again on day 11. However, her left hemiparesis exacerbated shortly thereafter. CT demonstrated leakage of contrast medium, and an extensive high-intensity area (HIA) on the white matter in the right cerebral hemisphere was noted on MRI FLAIR. The HIA on MRI and neurological deficits gradually improved after conservative treatment, but diffuse atrophy of the right cerebral hemisphere occurred and higher brain dysfunction remained.

Conclusion: Repeated ischemia and reperfusion, and the frequent use of contrast media were considered the causes of CIE.

Objective: We report a case of subarachnoid hemorrhage (SAH) that occurred at 30 weeks of pregnancy and was treated by coil embolization in a woman with middle cerebral artery (MCA) aplasia.

Case Presentation: A 40-year-old woman who was 30 weeks pregnant presented to the emergency department with a half-day history of headache and nausea. She had sudden onset headache and her symptom did not improve. There was no neurological deficit. Head CT at the referring hospital revealed SAH. The fetal state was stable. There was no sign of threatened premature delivery. Head MRA revealed aplasia of the left MCA and aneurysm with a daughter sac at the A1 segment of the anterior cerebral artery (ACA). Head DSA revealed that the A1 aneurysm with a daughter sac arose from the anomalous collateral artery leading to a plexiform network. The diagnosis was SAH due to rupture of an A1 aneurysm. Performance of less invasive coil embolization seemed to be possible and was carried out under general anesthesia. The operation was completed after placing one coil and confirming that most of the aneurysmal dome was embolized, including the daughter sac. There was no cerebral vasospasm and no obvious neurological deficit. Antiplatelet drugs were only required for 10 days after the operation. Pregnancy was stable and the patient delivered a baby by cesarean section at 38 weeks of pregnancy.

Conclusion: A rare case of aneurysmal SAH in a pregnant woman with MCA aplasia was successfully treated by endovascular surgery.

Objective: Although the presence of leptomeningeal anastomosis is known as a predictor of favorable outcome in patients with acute large vessel occlusion, the efficacy of enhancing leptomeningeal collateral flow has rarely been demonstrated.

Case Presentation: A 73-year-old man previously diagnosed with asymptomatic bilateral carotid stenosis was admitted to our emergency department 2 hours after the onset of fluctuating symptoms, including aphasia, left conjugate deviation, and right hemiparesis. CT demonstrated no hemorrhagic lesion. Considering the history of the patient, emergent angiography was performed and demonstrated tandem occlusion of the left cervical internal carotid artery (ICA) with left common carotid injection, leptomeningeal flow compensating for distal territory of occluded segment of left middle cerebral artery (MCA) via the left anterior cerebral artery through severe cervical ICA stenosis with right common carotid injection, and the proximal segment of the left MCA through the posterior communicating artery and occlusion of the M2 segment with left vertebral injection. Given the results of angiography and fluctuating symptoms, hemodynamic insufficiency was considered the underlying stroke mechanism for this case. Although recanalization of tandem lesions was initially considered, the risk of distal clot migration was a concern, so the patient underwent right carotid artery stenting (CAS) to enhance leptomeningeal collateral flow. This resulted in immediate resolution of symptoms after right CAS.

Conclusion: Stenting for carotid artery stenosis contralateral to tandem occlusive lesion may offer an effective alternative when both Willisian and leptomeningeal collaterals are robust.