Ruptured aneurysm in collateral arteries with blood-flow impairment of posterior inferior cerebellar artery: a report of three cases.

Herein, we report three cases of cerebellar hemorrhage due to a ruptured small aneurysm located on a collateral artery compensating for one or more stenotic or occluded major cerebellar arteries. In each case, endovascular distant parent artery occlusion of both the collateral artery and aneurysm was performed to prevent rebleeding. A ruptured small aneurysm in a collateral artery may be observed in patients with hemorrhage in an atypical cerebellar region, especially in cases of stenosis or occlusion of the vertebral artery or posterior inferior cerebellar artery. Thus, cerebral angiography is recommended to rule out collateral artery aneurysm.

Frequency and Characteristics of Paraclinoid Aneurysm in Ruptured Cerebral Aneurysms.

OBJECTIVE: This study aimed to determine the frequency of paraclinoid aneurysms among ruptured cerebral aneurysms and compare paraclinoid aneurysms with other aneurysms to clarify the characteristics of ruptured paraclinoid aneurysms. METHODS: This study included 970 ruptured cerebral aneurysms treated at our hospital between 2003 and 2020. RESULTS: There were 15 cases (1.3%) of paraclinoid aneurysms with maximum diameters of 5-22 mm (mean±standard deviation [SD], 11.6±5.4 mm). Treatment consisted of clipping in four patients and endovascular treatment in 11. Factors significantly different in multivariate analysis for paraclinoid aneurysms compared with those for other aneurysms were a history of hypertension (odds ratio [OR], 1.2-9.8; p=0.021) and aneurysm ≥10 mm (OR, 7.5-390.3; p<0.001). The sites of paraclinoid aneurysm were ophthalmic artery type in nine patients, anterior wall type in five, medial wall type in one, and ventral wall type in zero. The medial wall type (22 mm) was significantly larger than the ophthalmic artery type (mean±SD, 7.2±2.0 mm) (p=0.003), and the anterior wall type (mean±SD, 12.2±4.8 mm) was significantly larger than the ophthalmic artery type (p=0.024). CONCLUSION: This study showed a low frequency of paraclinoid aneurysms among ruptured cerebral aneurysms. Most were upward-facing with relatively large aneurysms, and no aneurysms were smaller than 5 mm. With recent advances in endovascular treatment devices, paraclinoid aneurysms are easily treatable. However, the treatment indication of each paraclinoid aneurysm should be carefully considered.

Superiority of Endovascular Coiling Over Surgical Clipping for Clinical Outcomes at Discharge in Patients With Poor-Grade Subarachnoid Hemorrhage: A Registry Study in Japan.

BACKGROUND AND OBJECTIVES: The differences in clinical outcomes between endovascular coiling (EC) and surgical clipping (SC) in patients with poor-grade aneurysmal subarachnoid hemorrhage (aSAH) are controversial. Therefore, this study aimed to evaluate whether EC is superior to SC and identify risk factors in patients with poor-grade aSAH. METHODS: We used data from the "Predict for Outcome Study of aneurysmal SubArachnoid Hemorrhage." World Federation of Neurological Societies (WFNS) grade III-V aSAH was defined as poor-grade aSAH, and unfavorable clinical outcomes (modified Rankin Scale scores 3-6) were compared between SC and EC after propensity score matching (PSM). In-hospital mortality was similarly evaluated. Predictors of unfavorable clinical outcomes were identified using multivariable analysis. RESULTS: Ultimately, 1326 (SC: 847, EC: 479) and 632 (SC: 316, EC: 316) patients with poor-grade aSAH were included before and after PSM, respectively. Unfavorable clinical outcomes at discharge were significantly different between SC and EC before (72.0% vs 66.2%, P = .026) and after PSM (70.6% vs 63.3%, P = .025). In-hospital mortality was significantly different between groups before PSM (10.5% vs 16.1%, P = .003) but not after PSM (10.4% vs 12.7%, P = .384). Predictors of unfavorable clinical outcomes in both SC and EC were WFNS grade V, older than 70 years, and Fisher computed tomography (CT) grade 4. Predictors of unfavorable clinical outcomes only in SC were WFNS grade IV (odds ratio: 2.46, 95% CI: 1.22-4.97, P = .012) and Fisher CT grade 3 (4.90, 1.42-16.9, P = .012). Predictors of unfavorable clinical outcome only in EC were ages of 50s (3.35, 1.37-8.20, P = .008) and 60s (3.28, 1.43-7.52, P = .005). CONCLUSION: EC resulted in significantly more favorable clinical outcomes than SC in patients with poor-grade aSAH, without clear differences in in-hospital mortality. The benefit of EC over SC might be particularly remarkable in patients with WFNS grade IV and Fisher CT grade 3.

The necessity of gait evaluation on the 7th day after tap tests for the idiopathic normal pressure hydrocephalus patients.

BACKGROUND: A tap test is established as an evaluation method to indicate shunt surgery for hydrocephalus, especially idiopathic normal pressure hydrocephalus (iNPH). The timing of gait assessment after the test is still controversial, while some studies reported the effectiveness of the gait evaluation up to 2nd day after tap tests. Our study explored whether the gait evaluation on the 7th day after a tap test is necessary. METHODS: We retrospectively evaluated 129 consecutive cases with possible iNPH who performed gait assessment on all 1st, 3rd, and 7th days after tap tests between May 2020 and February 2022. We reviewed the following items of the patients: age, sex, modified Rankin scale, iNPH grading scale, Mini-Mental State Evaluation (MMSE), and neurological imaging. The number of probable iNPH patients who improved their gait each day after the test was analyzed. We also assessed the number of definite iNPH patients and revealed the background characteristics of the patients who showed gait improvement on the 7th day after the tests. RESULTS: Of the 129 patients who met our inclusion criteria, 57 were judged as probable iNPH on the 1st day, 28 were new on the 3rd, and 23 were new on the 7th. The number of probable iNPH patients up to the 7th day after tests was significantly more extensive than that of those up to the 3rd (108 [83.7%] vs. 85 [65.9%]; 95% confidence interval [CI], p < 0.0001). The number of definite iNPH patients was also significantly more prominent when the evaluation after the tests was performed on all of the 1st, the 3rd, and the 7th days than just on the 1st (72 vs. 42; 95% CI, p = 0.00016) or both of the 1st and the 3rd (72 vs. 61; 95% CI, p = 0.00074). No statistically significant difference existed in the patients' backgrounds except for the pre-tap test MMSE. CONCLUSION: Gait evaluation on the 7th day after tap tests, in addition to the first few days, may reduce the number of iNPH patients who miss the opportunity of getting beneficial treatment.

A Case of Iatrogenic Dural Artery-Pial Vein Shunt Treated with Endovascular Treatment.

Objective: A few cases of postsurgical iatrogenic arteriovenous shunts have been reported, with the arterial blood flow directly entering the pial veins. Herein, we reported a patient with a dural artery-pial vein shunt found 1 year after aneurysmal clipping. Case Presentation: A 64-year-old male presented with generalized convulsion 1 year after cerebral aneurysmal clipping. A CT showed intracerebral hemorrhage in the temporo-occipital cortex and a dural artery-pial vein shunt in proximity to the previous craniotomy center. The arterial blood flow from the deep temporal artery, the middle meningeal artery, and the anterior auricular branch of the superficial temporal artery shunted into the superficial middle cerebral vein, with evident cortical venous reflux. Embolization was performed with n-butyl-2-cyanoacrylate and completely occluded the shunt. The patient was discharged without neurological deficits. Conclusion: Endovascular liquid embolization may be an effective treatment for iatrogenic dural artery-pial vein shunt.

Modified Unilateral Approach for Ventrally Located Spinal Tumors.

Surgery on spinal tumors becomes challenging when the tumor is ventral to the spinal cord. Conventionally, we approach it posteriorly through bilateral laminectomy and rotate the cord after sectioning the dentate ligament and nerve roots. However, manipulating the cord can be hazardous, and a long bilateral laminectomy can be invasive. Meanwhile, a narrow operative field and a limited lateral viewing angle in a unilateral approach constrained the surgeon. To overcome these problems, we previously reported a technique of modified unilateral approach where we incised the skin and the fascia horizontally and placed a pair of retractors longitudinally.The current article reports our experience applying this approach in 15 patients with ventrally located spinal tumors. The approach was performed on 10 schwannomas, 2 meningiomas, and 3 others. We evaluated paraspinal muscle atrophy on postoperative magnetic resonance imaging.The modified unilateral approach provided an excellent surgical field for removing ventrally located tumors. Gross total removal was achieved in 11 patients (92% of benign tumors). No neurological complications occurred except for one case of transient weakness. We encountered no wound-related late complications such as pain or deformity. The reduction of the cross-sectional area of the paraspinal muscles on the approach side (compared to the nonapproach side) was 0.93 (95% confidence interval: 0.72-1.06), indicating 7% atrophy (statistically nonsignificant, p = 0.48).We believe this simple technique can be useful for removing spinal tumors located ventral to the spinal cord.

Temperature measurement of intracranial cerebrospinal fluid using diffusion tensor imaging after revascularization surgery in Moyamoya disease.

OBJECTIVE: Brain temperature monitoring using a catheter thermometer has been reported to be a useful technique to predict prognosis in neurosurgery. To investigate the possibility of measuring intracranial cerebrospinal fluid temperature for postoperative monitoring in patients with Moyamoya disease (MMD) after bypass surgery. MATERIALS AND METHODS: This study evaluated fifteen patients with MMD who were indicated for bypass surgery. Diffusion tensor imaging for brain thermometry were performed on a 1.5-T MR scanner. Intracranial cerebrospinal fluid temperature with/without considering the fractional anisotropy component, body temperature, C-reactive protein levels, white blood cell count, and cerebral blood flow measured by 123I-IMP single-photon emission computed tomography were obtained before surgery and 1-3 days after surgery. Pixel values considered to be signal outliers in fractional anisotropy processing were defined as cerebrospinal fluid noise index and calculated. Wilcoxon signed-rank test and effect size were performed to compare the changes before and after revascularization. Spearman's rho correlation coefficient was used to analyze the correlations between each parameter. Statistical significance was defined as p < 0.05. RESULTS: All parameter values became significantly higher compared to those measured before revascularization (p < 0.01 in all cases). The effect sizes were largest for the cerebrospinal fluid temperature with fractional anisotropy processing and for C-reactive protein levels (Rank-biserial correlation = 1.0). The cerebrospinal fluid noise index and cerebrospinal fluid temperatures with fractional anisotropy processing (r = 0.84, p < 0.0001) or without fractional anisotropy processing (r = 0.95, p < 0.0001) showed highly significant positive correlations. Although no significant correlation was observed, cerebrospinal fluid temperatures with fractional anisotropy had small or moderately positive correlations with cerebral blood flow, body temperature, C-reactive protein levels, and white blood cell count (r = 0.37, 0.42, 0.41, and 0.44, respectively; p > 0.05). CONCLUSION: Our findings suggest the possibility of postoperative monitoring for MMD patients by measuring intracranial cerebrospinal fluid temperature with fractional anisotropy processing. Intracranial cerebrospinal fluid temperature might be considered as combined response since cerebrospinal fluid, body temperature, and inflammation are equally correlated.

Analysis of Factors Influencing Delayed Presentation in Japanese Patients with Subarachnoid Hemorrhage.

OBJECTIVE: Some aneurysmal subarachnoid hemorrhage (SAH) patients are delayed in their presentation. This can cause a washout of the subarachnoid hematoma and a potential misdiagnosis. As a result, they may suffer rerupture of the aneurysm and preventable deterioration. We investigated the factors that influence delayed SAH presentation. METHODS: Aneurysmal SAH patients treated at 9 stroke centers from 2002 to 2020 were included. Age, gender, pre-SAH modified Rankin scale, World Federation of Neurological Surgeons grade, Fisher group, day of presentation, aneurysm treatment method, past history of cerebral stroke, comorbidity of hypertension and/or diabetes mellitus, and modified Rankin scaleat discharge were assessed retrospectively. We formed 2 groups based on the day of presentation after the onset of SAH: day 0-3 (early) and other (delayed). Logistic regression analyses detected the factors that influenced the day of presentation and outcome for SAH. A P- value <0.05 was considered significant. RESULTS: Delayed presentation comprised 282 cases (6.3%) of 4507 included cases. Logistic regression analyses showed that patients in an urban area, of male gender, low WFNS grade and low Fisher group correlated significantly with a delayed presentation. But delayed presentation did not influence outcome at discharge. CONCLUSIONS: Area of residency and gender correlated with delayed presentation after SAH in Japan. Urbanization, male gender, and mild SAH lead patients to delay presentation. The factors underlying these tendencies will be analyzed in a future prospective study.

Magnetic Resonance Imaging/Gadolinium-enhanced Vessel Wall Image after Bypass Surgery in Moyamoya Disease.

OBJECTIVE: After bypass surgery in patients with moyamoya disease, several changes on magnetic resonance imaging (MRI)/fluid attenuated inversion recovery (FLAIR) have been recognized, while findings on MRI/gadolinium-enhanced (Gd) vessel wall imaging (VWI) have never been reported. The purposes of this study were to investigate postoperative changes on MRI/Gd VWI and to clarify the relationship between the MRI/Gd VWI and MRI/FLAIR findings. METHODS: Consecutive patients who underwent bypass surgery at our hospital from September 2020 to March 2022 were candidates. RESULTS: In 20 patients with moyamoya disease, 25 operated hemispheres were investigated. In all hemispheres, hyperintensities in the cortical sulci on MRI/FLAIR and enhancement in the cortical sulci on MRI/Gd VWI appeared after bypass surgery. The maximum appearance of sulci enhancement on MRI/Gd VWI occurred earlier than the maximum appearance of the sulci hyperintensity on MRI/FLAIR, and this difference was significant (p = 0.001). CONCLUSIONS: MRI/Gd VWI demonstrated that the peak of the enhancement changes preceded the peak of hyperintensity changes on MRI/FLAIR. These MRI changes may reflect alterations in blood-brain barrier permeability after bypass surgery in patients with moyamoya disease.

Cerebrovascular Reserve Impairment in the Anterior Cerebral Artery Territory Predicts Deep Temporal Artery Enlargement After Combined Revascularization Surgery in Moyamoya Disease.

OBJECTIVE: A combined surgery of direct and indirect revascularization has been frequently performed in patients with moyamoya disease, though the efficacy of indirect revascularization surgery in adult patients with moyamoya disease has not been established. This study aimed to evaluate superficial temporal artery (STA) and deep temporal artery (DTA) diameters 1 day and 3 months after combined revascularization surgery in patients with moyamoya disease. We also investigated clinical factors related to DTA enlargement after surgery. METHODS: We examined 78 cerebral hemispheres in 57 adult and pediatric patients with moyamoya disease who underwent combined revascularization surgery [STA-MCA bypass and encephalo-duro-myo-synangiosis] in our institution. STA and DTA diameters were measured on axial magnetic resonance angiography images at 1 day and 3 months after surgery. RESULTS: DTA diameter increased in 64 hemispheres (82.1%). DTA diameter increase in association with STA diameter decrease was found in 39 hemispheres (50%). The proportion of hemispheres with a reduction in STA diameter was significantly higher in hemispheres with DTA enlargement than in hemispheres with DTA reduction (P = 0.0088). Among the 64 hemispheres with DTA enlargement, 51 (79.7%) showed cerebrovascular reserve (CVR) impairment in the anterior cerebral artery (ACA) territory before surgery. CVR impairment in the ACA territory was the only clinical factor related to DTA enlargement (P < 0.001). CONCLUSION: The DTA frequently enlarges after combined revascularization surgery, even in adult patients with moyamoya disease. In patients with impaired CVR in the ACA territory, blood supply from the DTA to the ACA territory can be expected after combined revascularization surgery.

Nontraumatic Internal Carotid Aneurysms in the Paranasal Sinuses Presenting with Epistaxis: A Case Report.

Epistaxis due to rupture of a nontraumatic internal carotid artery (ICA) aneurysm in the paranasal sinus has rarely been reported. Here, we report a case of double ICA aneurysms located within both the sphenoid and ethmoid sinuses. A 78-year-old woman presented with recurrent massive epistaxis. Magnetic resonance angiogram (MRA) and cerebral angiogram showed two ICA aneurysms: one protruded into the sphenoid sinus and the other protruded into the ethmoid sinus. Intra-aneurysmal coil embolization was performed for both aneurysms. The patient recovered completely, and a follow-up MRA 3 years later showed no recurrence of the aneurysms. Intra-aneurysmal coil embolization is an option of treatment for an ICA aneurysm filling the paranasal sinus.

Posterior Fossa Chronic Subdural Hematoma Associated with Supratentorial Chronic Subdural Hematoma.

OBJECTIVE: Chronic subdural hematoma (CSDH) in the posterior fossa has until now been reported in only 16 patients. This study clarified the frequency and characteristics of the posterior fossa CSDH through the use of magnetic resonance imaging (MRI) in patients with supratentorial CSDH. METHODS: We retrospectively examined presurgical MRI findings in patients with supratentorial CSDH who underwent surgery between 2006 and 2020. RESULTS: MRI revealed posterior fossa CSDH in 24 (7.3%) of 329 patients. Multivariable analyses demonstrated that anticoagulant treatment (P = 0.033, odds ratio [OR] 3.53), cerebrospinal fluid leak (P = 0.001, OR 18.5), and lack of previous trauma 3 weeks or more before admission (P = 0.027, OR 3.03) were risk factors of posterior fossa CSDH. Computed tomography could not show the hematomas in 20 patients (83.3%). All the posterior fossa CSDHs improved after supratentorial CSDH drainage. CONCLUSIONS: Posterior fossa CSDH was observed on MRI in a minority of patients with supratentorial CSDH. Although most patients with posterior fossa CSDH had good outcomes, large posterior fossa CSDH sometimes must be treated surgically, according to previous reports.

New-generation tyrosine kinase inhibitor-associated asymptomatic cerebrovascular stenosis: two illustrative cases.

New-generation tyrosine kinase inhibitors (TKIs), nilotinib and ponatinib, for chronic myelogenous leukemia (CML) have been reported to cause symptomatic cerebral ischemia. Herein, we report two patients with asymptomatic cerebral artery stenosis associated with these TKIs, as a previously unreported finding. Both patients were in their 40 s and administered new-generation TKIs without vascular risk factors. New-generation TKIs for CML can cause major cerebrovascular stenosis without any symptoms. Examining the neck and intracranial arteries using magnetic resonance angiography and carotid ultrasonography may prevent future cerebral infarctions associated with these TKIs.

Differentiation between ICA and ECA Feeder Distributions in Meningioma Using MR Perfusion Original Image.

OBJECTIVE: Preoperative information regarding tumor feeder distribution is important in meningioma surgery. We aimed to examine the relationship between the contrast-enhancement pattern in meningioma on magnetic resonance (MR) perfusion images and the feeder pattern. METHODS: The subjects were 21 patients diagnosed with meningioma who underwent MR perfusion imaging between 2017 and 2020. RESULTS: The distribution of feeders from the internal carotid artery (ICA) system or external carotid artery (ECA) system within the tumor based on angiograms was compared with that in areas of enhancement on original MR perfusion images in seven of 21 patients who underwent cerebral angiography. The aspect ratios of tumors, which was defined as the ratio of the area of contrast enhancement to the length of the enhanced area in contact with the tumor margin on the early-phase MR perfusion images, supplied by the ICA (pial feeder pattern) and ECA (dural feeder pattern) systems were 0.12 ± 0.11 and 7.21 ± 4.99 (mean ± standard deviation), respectively (p < 0.0001). MR perfusion imaging in all 21 patients revealed higher frequency of the pial feeder pattern in patients with peritumoral edema (p = 0.0009). CONCLUSION: The distribution of pial and dural feeders within a meningioma could be distinguished by the aspect ratio based on original MR perfusion images.

Real-world treatment results for ruptured blood-blister aneurysm of the internal carotid artery: analysis of a Japanese nationwide multicenter study.

Ruptured blood-blister aneurysm (BBA) of the internal carotid artery (ICA) remains a challenging lesion, even in the age of modern neurosurgery and endovascular treatment. This retrospective multicenter study aimed to investigate the real-world treatment choice and treatment results. We included 182 ruptured BBAs of the ICA treated at 51 neurosurgical centers in Japan between 2013 and 2017. The baseline patient characteristics, radiological features of the aneurysm, treatment modality, details of treatment, complications of treatment, and treatment results were retrospectively collected. The treatment strategy was divided into deconstructive and reconstructive procedures. Primary clinical outcomes were evaluated using the modified Rankin scale (mRS) at final follow-up. Direct surgery was performed in 144 (79%) cases, and the remaining 38 (21%) cases received endovascular treatment. The majority of treatment selections were deconstructive and reconstructive procedures in the direct surgery group and endovascular treatment group, respectively. Overall, favorable clinical outcomes (mRS 0 to 2) were achieved in 66% of cases, and the mortality rate was 15% at the final follow-up (mean 23 months). There was no significant difference in clinical outcome between direct and endovascular treatment groups. Our large nationwide study compared the real-world treatment options for ruptured BBAs and their results. Our findings may offer beneficial information for treatment decision and for future studies investigating ruptured BBAs.

Screening for idiopathic normal pressure hydrocephalus in the elderly after falls.

OBJECTIVE: Many patients with idiopathic normal pressure hydrocephalus (iNPH) have reportedly fallen prior to diagnosis. However, there are no previous reports on the iNPH prevalence among the elderly with history of falls. This study investigated the effectiveness of screening for iNPH in elderly patients presenting after a fall. METHODS: We retrospectively assessed the Evans' index (EI) of 235 consecutive patients aged 60-89 who presented after falls between May and October 2020. We also assessed the presence of the iNPH triad (gait disturbance, cognitive impairment, and urinary incontinence). Patients with EI > 0.3 and with all 3 triad were defined as having possible iNPH; those with clinical improvement after a cerebrospinal fluid (CSF) tap test as having probable iNPH; and those with clinical improvement after a shunt surgery as having definite iNPH. We also examined the 235 patients' EI, and performed a case-control study of EI using sex- and age-matched control patients. RESULTS: Among the included 235 cases presenting after falls, 44 (18.7%) were diagnosed with possible iNPH, 29 (12.3%) with probable iNPH, and 25 (10.6%) with definite iNPH. The mean EI of these 235 patients was significantly larger than that of controls (0.30 ± 0.04 vs 0.26 ± 0.02, p < 0.0001). The proportion of possible iNPH in the cases was 44 out of 235 (18.7%), significantly higher than that of the controls (0%, p < 0.0001). CONCLUSION: Screening for iNPH in the elderly presenting after falls can possibly identify iNPH patients in the earlier stage who may benefit more from surgical treatments.

Microcatheter Re-Shaping Using Fusion Image in Coil Embolization: A Technical Note.

Objective: We report the utility of microcatheter reshaping by referring to fusion images with 3D-DSA and microcatheter 3D images made using non-subtraction and non-contrast (non-SC) rotational images. Case Presentations: Case 1: The patient was a 74-year-old man who had an internal carotid-anterior choroidal artery bifurcation aneurysm with a tortuous proximal parent artery. The initial attempt to introduce the microcatheter into the aneurysm was unsuccessful. During this unsuccessful microcatheter introduction, we created fusion images with 3D-DSA and microcatheter 3D images by acquiring positional information of the microcatheter using the non-SC method. By reshaping the microcatheter with reference to the fusion images, the direction of the distal end of the microcatheter was reshaped to be in accordance with the long axis of the aneurysm, a shape more suitable for coiling. Case 2: The patient was a 47-year-old man who had an anterior communicating (A-com) artery aneurysm with two daughter sacs. We successfully placed two microcatheters in the direction of each sac to make more stable framing by referring to 3D fusion images after the first microcatheter was positioned. In both cases, microcatheter reshaping was necessary because of the vessel and aneurysm anatomy. We have used this technique successfully in 15 patients, for both ruptured and unruptured aneurysms. The average number of microcatheter reshaping was 1.3 times. Conclusion: This method provides effective microcatheter reshaping for coil embolization of aneurysms, particularly those with differences between the axis of the parent artery and the vertical axis of aneurysm, or with a tortuous proximal artery.

Diagnostic Tests for COVID-19 and Their Accuracy: Important Information for Physicians Caring for Patients with Stroke.

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SAR-CoV-2), which appeared at the end of 2019 and has spread rapidly worldwide. In Japan, the increasing number of people infected with SAR-CoV-2 is also a cause of concern for physicians managing stroke patients. From the perspective of viral transmission in the hospital, stroke physicians must determine whether patients who have been transported by emergency have confirmed or suspected COVID-19. For this reason, stroke physicians must also understand about the characteristics and accuracy of the test for COVID-19 diagnosis. This article describes the sensitivity of the clinical symptoms, imaging investigations such as chest radiography and chest CT, and accuracy of nucleic-acid amplification tests and antigen tests used in the diagnosis of COVID-19. However, it should be noted that the accuracy of specimen tests may change depending on the collection site, timing, and method, because positive results in these tested specimens depend on the viral loads. In performing medical treatment for stroke, high accuracy and rapid inspection for COVID-19 is desired, but this is not currently available. For acute stroke treatment, such as thrombectomy, we recommend that these emergency patients, who are suspected of COVID-19 by clinical symptoms and image investigations, should be treated with implementation of strict infection control against droplets, contact, and airborne transmission until the most sensitive polymerase chain reaction test result is confirmed as negative.

Author Correction: Insufficient production of IL-10 from M2 macrophages impairs in vitro endothelial progenitor cell differentiation in patients with Moyamoya disease.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

A Protocol of Infection Control for Mechanical Thrombectomy in Possible COVID-19 Patients: Tokai University COVID-19 Manual.

The crisis of the coronavirus disease (COVID-19) is causing damage to the social and medical community. However, extreme emergency neuro-interventions such as mechanical thrombectomy still require the healthcare workers to offer the appropriate treatment while preventing further spread of the infection. This article outlines the necessary steps in managing a possible COVID-19 patient starting from patient screening to personnel infection and environmental contamination measures.