Blood viscosity associated with stroke mechanism and early neurological deterioration in middle cerebral artery atherosclerosis

Blood viscosity may affect the mechanisms of stroke and early neurological deterioration (END). We aimed to investigate the relationship between blood viscosity, stroke mechanisms, and END in patients with middle cerebral artery (MCA) infarction. Patients with symptomatic MCA atherosclerosis (≥ 50% stenosis) were recruited. Blood viscosity was compared across patients with different mechanisms of symptomatic MCA disease: in situ thrombo-occlusion (sMCA-IST), artery-to-artery embolism (sMCA-AAE), and local branch occlusion (sMCA-LBO). END was defined as four points increase in the National Institutes of Health Stroke Scale score from baseline during the first week. The association between blood viscosity and END was also evaluated. A total of 360 patients (76 with sMCA-IST, 216 with sMCA-AAE, and 68 with sMCA-LBO) were investigated. Blood viscosity was highest in patients with sMCA-IST, followed by sMCA-AAE and sMCA-LBO (P < 0.001). Blood viscosity was associated with END in patients with MCA disease. Low shear viscosity was associated with END in patients with sMCA- LBO (adjusted odds ratio, aOR 1.524; 95% confidence interval, CI 1.035-2.246), sMCA- IST (aOR 1.365; 95% CI 1.013-1.839), and sMCA- AAE (aOR 1.285; 95% CI 1.010-1.634). Blood viscosity was related to END in patients with stroke caused by MCA disease.

Diagnosis and treatment of Watershed strokes: a narrative review

Watershed strokes have been described previously as ischemic strokes located in vulnerable border zones between brain tissue supplied by the anterior, posterior, and middle cerebral arteries in the distal junction between two non-anastomotic arterial territories. Ischemic strokes in border zones are well-recognized entities and well-described in terms of imaging features, but the pathophysiological mechanism of brain injury production is not fully defined. Border zone ischemia is caused by cerebral hypoperfusion through decreased cerebral blood flow and arterial embolism in unstable atheroma plaque. It is often difficult to say which mechanisms are fully responsible for producing cerebral ischemic lesions. This review aimed to highlight the imaging aspect of watershed strokes and to correlate the clinical characteristics of this type of stroke with the diagnostic algorithm for optimal therapeutic management. Neurologists should promptly recognize this type of stroke and investigate its etiology in the shortest possible time.

Predisposing factors for the deformation of parent artery of anterior circulation saccular aneurysm after stent-assisted embolization: A retrospective cohort study

BACKGROUND

It has been previously reported in several studies that deformation of parent artery (DPA) occurs after stent-assisted coil embolization (SACE) for intracranial aneurysms (IAs).

OBJECTIVE

To investigate the predisposing factors of stent-induced DPA, as well as its effect on the follow-up of aneurysm embolization.

METHODS

Clinical and imaging data were collected from 198 patients (201 aneurysms). Angles of the stent-covered parental artery were measured before treatment and during follow-up. Cases in which the angle had changed more than 5 degrees, were defined as DPA. The related factors of DPA were analyzed. The relation between DPA and follow-up results was also studied.

RESULTS

Univariate analysis revealed that sex (p = 0.014), age (p = 0.017), aneurysm location (p < 0.001), stent type (p < 0.001), aneurysm size (p = 0.019), and pretreatment angle (p = 0.002) correlated with DPA. On the other hand, multivariate analysis revealed that aneurysms located in the anterior communicating artery (ACOA) (OR = 4.559, p = 0.013) and middle cerebral artery (MCA) (OR = 9.474, p < 0.001) were independent predisposing factors for DPA after stent implantation, whereas a braided stent (OR = 0.221, p = 0.030), flow diverter (FD) device (OR = 0.100, p = 0.028) were negative factors to develop DPA. The complete occlusion rate in the DPA group was higher (p = 0.035) than in the non-DPA group.

CONCLUSIONS

Aneurysms located in ACOA and MCA are more prone to DPA after SACE than aneurysms at other locations in the anterior circulation, braided stents and FD devices do not predispose to induce vascular deformation. DPA may be beneficial for the long-term cure of IAs after SACE.

The diagnostic performance of artificial intelligence algorithms for identifying M2 segment middle cerebral artery occlusions: A systematic review and meta-analysis

BACKGROUND

Artificial intelligence (AI)-based algorithms have been developed to facilitate rapid and accurate computed tomography angiography (CTA) assessment in proximal large vessel occlusion (LVO) acute ischemic stroke, including internal carotid artery and M1 occlusions. In clinical practice, however, the detection of medium vessel occlusion (MeVO) represents an ongoing diagnostic challenge in which the added value of AI remains unclear.

PURPOSE

To assess the diagnostic performance of AI platforms for detecting M2 occlusions.

METHODS

Studies that report the diagnostic performance of AI-based detection of M2 occlusions were screened, and sensitivity and specificity data were extracted using the semi-automated AutoLit software (Nested Knowledge, MN) platform. STATA (version 16 IC; Stata Corporation, College Station, Texas, USA) was used to conduct all analyses.

RESULTS

Eight studies with a low risk of bias and significant heterogeneity were included in the quantitative and qualitative synthesis. The pooled estimates of sensitivity and specificity of AI platforms for M2 occlusion detection were 64% (95% CI, 53 to 74%) and 97% (95% CI, 84 to 100%), respectively. The area under the curve (AUC) in the SROC curve was 0.79 (95% CI, 0.74 to 0.83).

CONCLUSION

The current performance of the AI-based algorithm makes it more suitable as an adjunctive confirmatory tool rather than as an independent one for M2 occlusions. With the rapid development of such algorithms, it is anticipated that newer generations will likely perform much better.

Force sensor reduced measurement error compared with verbal command during sit-to-stand assessment of cerebral autoregulation

Current methods estimate the time delay (TD) before the onset of dynamic cerebral autoregulation (dCA) from verbal command to stand. A force sensor used during a sit-to-stand dCA measure provides an objective moment an individual stands (arise-and-off, AO). We hypothesized that the detection of AO would improve the accuracy of TD compared with estimation. We measured middle cerebral artery blood velocity (MCAv) and mean arterial pressure (MAP) for 60 s sitting followed by 2-min standing, three times separated by 20 min. TD was calculated as the time from: (1) verbal command and (2) AO, until an increase in cerebrovascular conductance index (CVCi = MCAv/MAP). Sixty-five participants were enrolled: young adults (n = 25), older adults (n = 20), and individuals post-stroke (n = 20). The TD calculated from AO (x ¯ $$ \overline{x} $$  = 2.98 ± 1.64 s) was shorter than TD estimated from verbal command (x ¯ $$ \overline{x} $$  = 3.35 ± 1.72 s, η2  = 0.49, p < 0.001), improving measurement error by ~17%. TD measurement error was not related to age or stroke. Therefore, the force sensor provided an objective method to improve the calculation of TD compared with current methods. Our data support using a force sensor during sit-to-stand dCA measures in adults across the lifespan and post-stroke.

A Unique Technique to Adjust Snare Position for Coil Retrieval in Tortuous Vessel During Aneurysm Coil Embolization: A Technical Case Report

OBJECTIVE

Although snares are useful devices to retrieve an intravascular foreign body, the control of snares is often difficult. We present a safe and effective technique to adjust snare position in the tortuous vessel for coil retrieval during endovascular coil embolization.

METHODS

We describe a case of a protruding coil during coil embolization that was successfully retrieved using a unique technique to adjust snare position and discuss additional intraprocedural bailout strategies for retrieving a coil during endovascular coil embolization.

RESULTS

The patient was a 44-year-old female with unruptured right internal carotid artery (ICA) aneurysm that had grown over a 1.5-year period. Coil embolization was performed. After detachment of final coil and microcatheter removal, the final coil protruded into the ICA and floated. Coil retrieval using a snare was attempted, but the snare could not be placed around the coil tail and coil retrieval could not be achieved. The following technique was used to allow adjustment of snare position. First, a microguidewire and a microcatheter were guided into the M2 and M1 segment of the middle cerebral artery as monorail guides of the snare, respectively. Next, the snare was advanced over the microcatheter. Around C2 segment of the ICA, the microcatheter and the snare were manipulated as a unit. Thus, the snare could be placed around the protruding coil tail and the coil was retrieved successfully.

CONCLUSIONS

This technique may be widely adapted for various situations when using a snare.

Culprit Plaques of Large Parent Arteries, Rather than Cerebral Small Vessel Disease, Contribute to Early Neurological Deterioration in Stroke Patients with Intracranial Branch Atheromatous Disease

INTRODUCTION

Intracranial branch atheromatous disease (BAD) has been applied to occlusions that occur at the origin of large caliber penetrating arteries due to the microatheromas or large parent artery plaques. This study aimed to explore the association between culprit plaques of large parent arteries, neuroimaging markers of cerebral small vessel disease (CSVD), and the risk of early neurological deterioration (END) in stroke patients with BAD.

METHODS

A total of 97 stroke patients with BAD in the vascular territories of the lenticulostriate arteries or paramedian pontine arteries, diagnosed using high-resolution magnetic resonance imaging, were prospectively recruited in this observational study. A culprit plaque in the middle cerebral artery was defined as the only arterial plaque on the ipsilateral side of an infarction visible on diffusion-weighted imaging. A culprit plaque in the basilar artery (BA) was identified when it was observed within the same axial slices of an infarction or on the adjacent upper or lower slice, whereas a plaque within the BA located in the ventral region was considered non-culprit. If more than one plaque was present in the same vascular territory, the most stenotic plaque was chosen for the analysis. Four CSVD neuroimaging markers, including white matter hyperintensity, lacunes, microbleeds, and enlarged perivascular spaces, were evaluated in accordance with the total CSVD score. The associations between neuroimaging features of lesions within large parent arteries, neuroimaging markers of CSVD, and the risk of END in stroke patients with BAD were investigated using logistic regression analysis.

RESULTS

END occurred in 41 stroke patients (42.27%) with BAD. The degree of large parent artery stenosis (p < 0.001), culprit plaques of large parent arteries (p < 0.001), and plaque burden (p < 0.001) were significantly different between the END and non-END groups in stroke patients with BAD. In logistic regression analysis, culprit plaques of large parent arteries (odds ratio, 32.258; 95% confidence interval, 4.140-251.346) were independently associated with the risk of END in stroke patients with BAD.

CONCLUSIONS

Culprit plaques of large parent arteries could predict the risk of END in stroke patients with BAD. These results suggest that lesions in the large parent arteries, rather than damage to the cerebral small vessels, contribute to END in stroke patients with BAD.

Acute subdural haematoma exacerbates cerebral blood flow disorder and promotes the development of intraoperative brain bulge in patients with severe traumatic brain injury

BACKGROUND

Decompressive craniectomy (DC) is a routine procedure used for the treatment of severe traumatic brain injury (TBI) with concomitant acute subdural haematoma (SDH). However, certain patients are prone to developing malignant brain bulge during DC, which prolongs the operative time and worsens patient outcomes. Previous studies have shown that malignant intraoperative brain bulge (IOBB) may be associated with excessive arterial hyperaemia caused by cerebrovascular system disorders. Through a clinical retrospective analysis and prospective observations, we found that the cerebral blood flow of patients who possessed risk factors manifested high resistance and low flow velocity, which severely affected brain tissue perfusion and resulted in the occurrence of malignant IOBB. In the current literature, rat models of severe brain injury-associated brain bulge have rarely been reported.

METHODS

To gain an in-depth understanding of cerebrovascular changes and the cascade of responses related to brain bulge, we introduced acute SDH into the Marmarou model for the preparation of a rat model of high intracranial pressure (ICP) to simulate the pathological conditions experienced by patients with severe brain injury.

RESULTS

With the introduction of a 400-µL haematoma, significant dynamic changes occurred in ICP, mean arterial pressure, and relative blood perfusion rate of the cerebral cortical vessels. ICP increased to 56.9 ± 2.3 mmHg, mean arterial pressure showed reactive decrease, and the blood flow of cerebral cortical arteries and veins on the non-SDH-affected side decreased to < 10%. These changes could not fully recover even after DC. This resulted in generalised damage to the neurovascular unit and a lag effect to the venous blood reflux, which triggered malignant IOBB formation during DC.

CONCLUSION

An excessive increase in ICP causes cerebrovascular dysfunction and brings about a cascade of damage to brain tissue, which forms the basis for the development of diffuse brain swelling. The subsequent heterogeneous responses of the cerebral arteries and veins during craniotomy may be the main cause of primary IOBB. Clinicians should pay particular attention to the redistribution of CBF to various vessels when performing DC in patients with severe TBI.

Lyme neuroborreliosis: An unusual case with extensive (peri)vasculitis of the middle cerebral artery

Lyme disease is a tick-borne infection caused by Borrelia burgdorferi sensu latu. Neuroborreliosis is reported in approximately 10% of patients with Lyme disease. We report a patient with central nervous system (CNS) large vessel vasculitis, ischemic stroke, and tumefactive contrast-enhancing brain lesions, an unusual complication of neuroborreliosis. A 56-year-old man presented with headache and disorientation for 1 month. Magnetic resonance imaging revealed basal meningitis with rapidly progressing frontotemporoinsular edema and (peri)vasculitis. Transcranial ultrasound confirmed stenosed medial cerebral arteries. [¹⁸ F]GE-180 microglia positron emission tomography (PET) showed frontotemporoinsular signal more pronounced on the right. [¹⁸ F]FET amino acid PET demonstrated low tracer uptake, suggesting an inflammatory process. Cerebrospinal fluid (CSF) showed lymphomonocytosis (243/μl), intrathecal anti-Borrelia IgM (CSF/serum index = 15.65, normal < 1.5) and anti-Borrelia IgG (CSF/serum index = 6.5, normal < 1.5), and elevated CXCL13 (29.2 pg/ml, normal < 10 pg/ml). Main differential diagnoses of neurotuberculosis and perivascular CNS lymphoma were ruled out by biopsy and Quantiferon enzyme-linked immunosorbent assay. Ceftriaxone (28 days), cortisone, and nimodipine (3 months) led to full recovery. Neuroborreliosis is an important differential diagnosis in patients with CNS large vessel vasculitis and tumefactive contrast-enhancing brain lesions, mimicking perivascular CNS lymphoma or neurotuberculosis as main neuroradiological differential diagnoses. Vasculopathy and cerebrovascular events are rare in neuroborreliosis but should be considered, especially in endemic areas.

Proximal hyperdense middle cerebral artery sign is associated with increased risk of asymptomatic hemorrhagic transformation after endovascular thrombectomy: a multicenter retrospective study

OBJECTIVE

To investigate whether hyperdense middle cerebral artery sign (HMCAS) on pretreatment no-contrast CT (NCCT) is associated with hemorrhagic transformation (HT) after endovascular thrombectomy (EVT).

METHODS

Patients with acute middle cerebral artery (MCA) occlusion who received EVT in three comprehensive hospitals were retrospectively evaluated. They were divided into four groups based on the presence or absence of HMCAS and corresponding CTA findings, among whom differences were compared. Univariate and multivariate logistic regression analyses were performed to investigate the association between HMCAS and HT and its subtypes.

RESULTS

318 patients were included, among whom 149 (46.9%) had HMCAS. Patients in the proximal positive HMCAS group had higher National Institute of Health Stroke Scale scores and lower Alberta Stroke Program Early CT Scores (ASPECTS) than those in the proximal negative HMCAS group. The rate of HT was higher in the proximal positive HMCAS group than that in the proximal negative HMCAS group. In multivariate logistic regression analysis, the proximal HMCAS were independently associated with HT (adjusted OR = 2.073, 95% CI 1.211-3.551, p = 0.008) and aHT (adjusted OR = 2.271, 95% CI 1.294-3.986, p = 0.004), but not with sHT. Patients who developed HT, including aHT and sHT, had a lower rate of good outcome.

CONCLUSION

Proximal HMCAS on initial NCCT was independently associated with aHT in patients who received EVT for acute MCA occlusion. Both aHT and sHT had a detrimental effect on clinical outcome.

An Analysis of Landmark Articles Regarding Aneurysms of the Middle Cerebral Artery

OBJECTIVE

Aneurysms located on the middle cerebral artery (MCA) range from 22% to 31.5% in prevalence of all aneurysms in the anterior cerebral circulation. This bibliometric analysis summarizes the most cited articles on MCA aneurysms and highlights the landmark publications that contributed to evidence-based practice.

METHODS

In the execution of this bibliometric-based review article, the Scopus database was used to perform a title-specific, keyword-based search for all publications until August 2022. The keyword "(middle cerebral artery OR MCA) AND aneurysm" was used. Our results were arranged in descending order based on the citation count of the article. The 100 most cited articles were selected for analysis. Parameters included the following: title, citation count, citations per year, authors, specialty of first author, institution, country of origin, publishing journal, Source Normalized Impact per Paper, and Hirsch index.

RESULTS

The keyword-based search showed that 1206 articles on MCA aneurysms were published up to August 2022. The top 100 articles were published between 1940 and 2019. The top 100 most cited articles collected a total of 6232 citations with an average of 62.3 citations per article. The rate of self-citations accounted for an average of 5.75% of the total number of citations.

CONCLUSIONS

The bibliometric analysis provides a quantitative overview of how medical literature and interventions are analyzed in academic medicine. In the present study, we evaluated the global trends in research regarding MCA aneurysms by finding the top 100 most cited articles.

Hypoglycemic Hemiplegia Associated with Reversible Narrowing of the Contralateral Middle Cerebral Artery in a Patient with Adrenal Insufficiency

A 56-year-old man with a 2.5-month history of anorexia developed sweating, weakness, and left hemiplegia and hemispatial neglect. Brain magnetic resonance imaging detected no abnormalities, but magnetic resonance angiography revealed narrowing of the right middle cerebral artery (MCA). The focal neurological signs and narrowing of the MCA resolved after detection and correction of hypoglycemia. Endocrinological examinations indicated adrenal insufficiency. Hemiplegia is a rare but important neurological manifestation of hypoglycemia, although the mechanisms involved remain unknown. Combined hypoglycemia and decreased MCA blood flow associated with vasospasm probably induced regionally severe neuroglycopenia with ischemia, which presented as focal neurological symptoms.

Association of Brain Arterial Elongation With Risk of Stroke and Death in Stroke-Free Individuals: Results From NOMAS

BACKGROUND

Brain arterial dilation and elongation characterize dolichoectasia, an arteriopathy associated with risk of stroke and death. We aim to determine whether brain arterial elongation increases the risk of stroke and death independent of brain arterial diameters.

METHODS

We analyzed 1210 stroke-free participants (mean age 71±9 years, 41% men, 65% Hispanic) with available time-of-flight magnetic resonance angiogram from the Northern Manhattan Study, a population-based cohort study across a multiethnic urban community. We obtained baseline middle cerebral artery M1-segment (MCA-M1) and basilar artery (BA) mean lengths and diameters using a semi-automated software. Cox proportional hazards models adjusted for brain arterial diameters and potential confounders yielded adjusted hazards ratios with 95% CIs for the primary outcomes of incident stroke and all-cause mortality, as well as secondary outcomes including noncardioembolic stroke, vascular death, and any vascular event.

RESULTS

Neither MCA-M1 nor BA lengths correlated with incident stroke or all-cause mortality. Both MCA-M1 and BA larger diameters correlated with all-cause mortality (MCA-M1 aHR, 1.52 [95% CI, 1.03-2.23], BA aHR, 1.28 [95% CI, 1.02-1.61]), as well as larger MCA-M1 diameters with vascular death (aHR, 1.84 [95% CI, 1.02-3.31]). Larger MCA-M1 and BA diameters did not correlate with incident stroke. However, larger BA diameters were associated with posterior circulation noncardioembolic stroke (aHR, 2.93 [95% CI, 1.07-8.04]). There were no statistical interactions between brain arterial lengths and diameters in relation to study outcomes.

CONCLUSIONS

In a multiethnic cohort of stroke-free adults, brain arterial elongation did not correlate with risk of stroke or death, nor influenced the significant association between brain arterial dilation and vascular risk.

Diagnostic role of optic nerve sheath diameter and brain blood flow in neonates with hypoxic-ischemic encephalopathy

PURPOSE

The primary aim was to study the optic nerve sheath diameter (ONSD) measurements and cerebral blood flows in neonates with hypoxic-ischemic encephalopathy (HIE) who were at risk of cerebral edema and to compare the measurements with healthy neonates.

METHODS

Neonates diagnosed as Stage II and III HIE patients were enrolled in the study group. ONSD measurements and blood flow Doppler studies in the first 24-48 h of life during hypothermia and following hypothermia treatment. Magnetic resonance imaging (MRI) and transfontanelle ultrasonography were performed within the first 4-7 days of life in all HIE patients. Saved US and MRI images were assessed by a blind pediatric radiologist later on.

RESULTS

Data from a total of 63 infants (42 in the HIE group and 21 in the control group) were analyzed. Both the right and left ONSD measurements were comparable between HIE and control groups. However, both resistive index (RI) and pulsatility index (PI) of the middle cerebral artery were found to be significantly lower in HIE (0.69 ± 0.09 and 1.14 (0.98-1.30)) group when compared with controls (0.75 ± 0.04 and 1.41 (1.25-1.52)) (p < 0.01). Ultrasonographic ONSD measurements were significant and strongly correlated with MRI ONSD measurements for both sides (r = 0.91 and r = 0.93, p < 0.01). Doppler studies during normothermia were comparable with the control group and significantly increased following therapeutic hypothermia.

CONCLUSION

Ultrasonographic ONSD measurements can be reliably performed in term neonates with high compatibility to MRI. No significant effect on ONSD measurements was found related to asphyxia and therapeutic hypothermia despite the significant alteration observed in Doppler studies.

Sex Difference in Capillary Reperfusion After Transient Middle Cerebral Artery Occlusion in Diabetic Mice

BACKGROUND

Type 2 diabetes (DM2) exacerbates stroke injury, reduces efficacy of endovascular therapy, and worsens long-term functional outcome. Sex differences exist in stroke incidence, response to therapy, poststroke microvascular dysfunction, and functional recovery. In this study, we tested the hypotheses that poor outcome after stroke in the setting of DM2 is linked to impaired microvascular tissue reperfusion and that male and female DM2 mice exhibit different microvascular reperfusion response after transient middle cerebral artery occlusion (MCAO).

METHODS

Transient MCAO was induced for 60 minutes using an intraluminal filament in young adult DM2 and nondiabetic control male and female mice. Capillary flux in deep cortical layers was assessed using optical coherence tomography-based optical microangiography (OMAG), and associated regional brain infarct size was evaluated by hematoxylin and eosin staining.

RESULTS

Compared to baseline, MCAO reduced absolute capillary red blood cell flux by 84% at 24 hours post-MCAO in male DM2 (P<0.001) but not male control mice. When normalized to pre-MCAO baseline, red blood cell flux 24 hours after stroke was 64% lower in male DM2 mice than male nondiabetic controls (P<0.01). In females, MCAO decreased capillary flux by 48% at 24 hours post-MCAO compared with baseline in DM2 (P<0.05) but not in control mice. Red blood cell flux of female DM2 mice did not differ from that of nondiabetic controls either before or 24 hours after MCAO. Furthermore, normalized capillary flux 24 hours after MCAO failed to differ between female DM2 mice and nondiabetic controls. Concomitantly, male but not female DM2 mice experienced 25% larger infarct in caudate-putamen versus respective nondiabetic controls (P<0.05).

CONCLUSIONS

DM2 impairs capillary perfusion and exacerbates ischemic deep brain injury in male but not female young adult mice. Premenopausal females appear to be protected against DM2-related capillary dysfunction and brain injury.

Comparing data from thrombectomy in m2 occlusion and proximal middle cerebral artery

INTRODUCTION

Mechanical thrombectomy for large vessel occlusion in the anterior circulation has been shown to be beneficial. The question of whether this technique is safe and effective in the distal vasculature remains unanswered. We wanted to compare outcome data from mechanical thrombectomy of M2 branches of the middle cerebral artery (MCA) with those of the M1 segment, and better understand the clinical predictors of these M2 occlusions.

METHODS

A retrospective analysis was performed of data prospectively collected between January 2017 and July 2021 from patients with acute ischemic stroke undergoing mechanical thrombectomy of isolated M1 or M2 branches of the MCA.

RESULTS

350 patients were identified, 287 with M1 and 63 with M2 occlusions. Mean age was 70.71 ± 12.55 and 75.21 ± 10.21 years, respectively (p = 0.0083). Baseline Alberta Stroke Program Computed Tomography (ASPECT) score was worse in the M1 cohort (7.68 ± 1.73 vs. 8.32 ± 1.54; p = 0.0079), while there was no significant difference in National Institutes of Health Stroke Scale (NIHSS) scores. No statistical disparity existed in mean procedure duration for each cohort; fewer thrombectomy attempts were required in the M2 cohort (2.01 vs. 1.63; p = 0.0478). There was no statistical difference in total time to recanalization (559.19 vs. 629.97, p = 0.2506). Similar rates of successful reperfusion were observed (Thrombolysis in Ischaemic Stroke score [TICI] ≥ 2b 80.84% vs. 71.43% p = 0.1221). Good outcome (modified Rankin scale ≤ 2) was 56.10 in M1 occlusions and 63.49% on M2 groups. Intracranial haemorrhage rates were similar.

CONCLUSIONS

M2 thrombectomy is safe and a significant proportion of patients achieve a good clinical outcome. Advanced age, atrial fibrillation and previous treatment with anticoagulants were predictors for poor outcome. Good outcome was achieved when effective recanalization was obtained.

Ruptured saccular aneurysm of the lenticulostriate artery embolized without parent artery occlusion in a case of moyamoya disease

In cases of moyamoya disease, an aneurysm of the lenticulostriate artery (LSA) is a rare finding. Preventive management of rebleeding from a ruptured aneurysm of the LSA is important to avoid poor outcomes. Endovascular embolization of a ruptured LSA aneurysm with parent artery occlusion has been reported in previous cases of moyamoya disease; however, to the best of our knowledge, a ruptured aneurysm treated only with coil embolization has not been described. A 42-year-old woman presented with sudden onset of dysarthria and right hemiparesis. Putaminal hemorrhage from a ruptured aneurysm in the left LSA was detected. Angiographically, moyamoya vessels were revealed. The aneurysm in the left LSA was saccular type and seemed to be related to moyamoya disease. As the aneurysm was successfully approached with a microcatheter, coil embolization without parent artery occlusion was performed. Rebleeding from the embolized aneurysm in the LSA did not occur. This is the first report of a ruptured LSA aneurysm embolized using coils through a flow-guiding microcatheter without parent artery occlusion in a case of moyamoya disease.

Clipping of a Rebleeding Ruptured Aneurysm After Woven EndoBridge Treatment

AIM

To present the clipping of a ruptured aneurysm in the M1 segment of the right middle cerebral artery after rebleeding, which was treated with Woven EndoBridge (WEB).

CASE REPORT

A 68-year-old male patient with known hypertension, coronary artery disease and benign prostatic hypertrophy was admitted to our clinic after a ruptured aneurysm of 4.5 mm in the right middle cerebral artery M1 segment and subarachnoid hemorrhage were detected in the emergency room imaging after syncope at home. WEB device was placed into the aneurysm in the patient who was planned for endovascular treatment. After 3 days of the procedure, neurologic examination showed regression. In the brain computed tomography imaging, it was observed that there was an intraparenchymal hematoma of 4,5 cm in the right temporoparietal region and the aneurysm, which had been treated with endovascular WEB, was ruptured. The aneurysm was clipped in the patient for whom emergency surgical treatment was planned.

CONCLUSION

As a conclusion, re-bleeding can be seen after aneurysm treatment with the Web device. If it is planned to re-close the aneurysm treated with the web device with a surgical clip, the pressure created by the device against the vessel can be reduced with the additional clip.

Detrimental effects of transient cerebral ischemia on middle cerebral artery mitochondria in female rats

Mitochondrial numbers and dynamics in brain blood vessels differ between young male and female rats under physiological conditions, but how these differences are affected by stroke is unclear. In males, we found that mitochondrial numbers, possibly due to mitochondrial fission, in large middle cerebral arteries (MCAs) increased following transient middle cerebral artery occlusion (tMCAO). However, mitochondrial effects of stroke on MCAs of female rats have not been studied. To address this disparity, we conducted morphological, biochemical, and functional studies using electron microscopy, Western blot, mitochondrial respiration, and Ca2+ sparks activity measurements in MCAs of female, naïve or sham Sprague-Dawley rats before and 48 h after 90 min of tMCAO. Adverse changes in mitochondrial characteristics and the relationship between mitochondria and sarcoplasmic reticulum (SR) in MCAs were present on both sides. However, mitochondria and mitochondrial/SR associations were often within the range of normal appearance. Mitochondrial protein levels were similar between ipsilateral (ipsi) and contralateral (contra) sides. Nonrespiratory oxygen consumption, maximal respiration, and spare respiratory capacity were similar between ipsi and contra but were reduced compared with sham. Basal respiration, proton leak, and ATP production were similar among MCAs. Ca2+ sparks activity increased in sham and ipsi MCAs exposed to a mitochondrial ATP-sensitive potassium channel opener: diazoxide. Our results show that tMCAO has effects on mitochondria in MCAs on both the ipsi and contra sides. Mitochondrial responses of cerebral arteries to tMCAO in females are substantially different from responses seen previously in male rats suggesting the need for specific sex-based therapies.NEW & NOTEWORTHY We propose that differences in mitochondrial characteristics of males and females, including mitochondrial morphology, respiration, and calcium sparks activity contribute to sex differences in protective and repair mechanisms in response to transient ischemia-reperfusion.

The role of nitric oxide in flow-induced and myogenic responses in 1A, 2A, and 3A branches of the porcine middle cerebral artery

Myogenic and flow-induced reactivity contribute to cerebral autoregulation, with potentially divergent roles for smaller versus larger arteries. The present study tested the hypotheses that compared with first-order (1A) branches of the middle cerebral artery, second- and third-order branches (2A and 3A, respectively) exhibit greater myogenic reactivity but reduced flow-induced constriction. Furthermore, nitric oxide synthase (NOS) inhibition may amplify myogenic reactivity and abolish instances of flow-induced dilation. Isolated porcine cerebral arteries mounted in a pressure myograph were exposed to incremental increases in intraluminal pressure (40-120 mmHg; n = 41) or flow (1-1,170 µL/min; n = 31). Intraluminal flows were adjusted to achieve 5, 10, 20, and 40 dyn/cm2 of wall shear stress at 60 mmHg. Myogenic tone was greater in 3A versus 1A arteries (P < 0.05). There was an inverse relationship between myogenic reactivity and passive arterial diameter (P < 0.01). NOS inhibition increased basal tone to a lesser extent in 3A versus 1A arteries (P < 0.01) but did not influence myogenic reactivity (P = 0.49). Increasing flow decreased luminal diameter (P ≤ 0.01), with increased vasoconstriction at 10-40 dyn/cm2 of shear stress (P < 0.01). However, relative responses were similar between 1A, 2A, and 3A arteries (P = 0.40) with and without NOS inhibition conditions (P ≥ 0.29). Whereas NOS inhibition increases basal myogenic tone, and myogenic reactivity was less in smaller versus larger arteries (range = ∼100-550 µM), neither NOS inhibition nor luminal diameter influences flow-induced constriction in porcine cerebral arteries.NEW & NOTEWORTHY This study demonstrated size-dependent heterogeneity in myogenic reactivity in porcine cerebral arteries. Smaller branches of the middle cerebral artery exhibited increased myogenic reactivity, but attenuated NOS-dependent increases in myogenic tone compared with larger branches. Flow-dependent regulation does not exhibit the same variation; diameter-independent flow-induced vasoconstrictions occur across all branch orders and are not affected by NOS inhibition. Conceptually, flow-induced vasoconstriction contributes to cerebral autoregulation, particularly in larger arteries with low myogenic tone.

Technical Nuance of Sub 2-mm Middle Cerebral Artery Angioplasty and Stenting

Intracranial stenosis is among the common causes of ischemic strokes, especially in the Asian, African, and Hispanic populations. The Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis trial showed that, by 30 days, 33 (14.7%) of 224 patients in the stenting group and 13 (5.8%) of 227 patients in the medical group had died or had a stroke.1 The WEAVE (Wingspan Stent System Post Market Surveillance) trial showed 2%-2.7% periprocedural complications.2 However, with technical advancements and more experience, angioplasty and stenting in high-risk cases are feasible and successful even in vessels <2 mm. We present the technical nuances of angioplasty and stenting of a sub-2-mm intracranial vessel by submaximal balloon inflation. Both patients had recurrent ischemic stroke symptoms on best medical management. Best medical management includes a dual antiplatelet regimen with a high-dose statin. Both patients were compliant and had therapeutic platelet reactive unit.

Evaluation of Occluded Distal Vessels with Variable Flip-Angle 3-Dimensional Turbo Spin-Echo Magnetic Resonance Imaging Before Acute Mechanical Thrombectomy

OBJECTIVE

The aim of this study was to evaluate the course of occluded distal vessels before mechanical thrombectomy (MT) for acute large vessel occlusion (LVO) with non-contrast magnetic resonance imaging (MRI). The variable flip-angle three-dimensional turbo spin-echo (VRFA-3D-TSE) method was used to evaluate the course of occluded distal vessels quickly and clearly in acute LVO cases before MT.

METHODS

Patients with acute LVO who were indicated for MT between April 2021 and March 2022 were examined by the VRFA-3D-TSE method to evaluate the distal course of occluded vessels. We included internal carotid artery (ICA) occlusion, M1 occlusion of the middle cerebral artery, and basilar artery (BA) occlusion. Preoperative images were compared to the angiographic findings after recanalization or with follow-up magnetic resonance angiography, and the results were assessed by 2 endovascular treatment specialists as excellent, good, or poor imaging.

RESULTS

MT was performed in a total of 27 patients. There were 17 patients with intracranial occlusion of the ICA, M1, and BA. Occlusion was found in the intracranial ICA in 6 patients, the M1 in 7, and the BA in 4. VRFA-3D-TSE MRI was performed in all patients, and the imaging was rated (by the 2assessors) as excellent in 12 of 17 and 14 of 17 cases, good in 5 of 17 and 3 of 17 cases, and poor in 0 of 17 cases.

CONCLUSIONS

In patients with acute LVO, VRFA-3D-TSE MRI enabled rapid and good depiction of the course of occluded distal vessels before MT without the use of contrast medium.

[Feasibility of Cerebrovascular Reserve Assessment Using Stretched Exponential Model in Major Cerebral Artery Steno-occlusive Disease: Comparison with SPECT]

PURPOSE

To clarify whether diffusion-weighted imaging using stretched exponential model can assess cerebrovascular reserve (CVR) in patients with major cerebral artery steno-occlusive disease, we compared stretched exponential parameters and single-photon emission computed tomography (SPECT).

METHODS

Twenty-nine patients with unilateral major cerebral artery steno-occlusive disease (25 men and 4 women; age, 69±11 years) were analyzed in this study. The patients were divided into three groups: normal CVR (CVR≥30%), moderate CVR (10%≤CVR<30%), and severe CVR (CVR<10%). The distributed diffusion coefficient (DDC) and heterogeneity index (α) from the stretched exponential model, apparent diffusion coefficient (ADC) from the monoexponential model, and CVR and resting cerebral blood flow (CBF) from SPECT were measured in the bilateral middle cerebral artery territories, and ipsilateral-to-contralateral ratios (rDDC, rα, rADC, and rCBF) were obtained.

RESULTS

The rDDC values in severe CVR were significantly higher than those in normal CVR (P=0.003). The rDDC values were significantly negatively correlated with ipsilateral CVR (rho=-0.31, P=0.009). The rDDC values were not significantly correlated with rCBF (P=0.34).

CONCLUSION

We have shown that elevated rDDC values are associated with impaired CVR. Our results suggest that diffusion-weighted imaging using stretched exponential model has a potential to evaluate hemodynamic impairment.

Clinical Significance and Correlation Decomposition of Cord Blood NO, Activin A Levels, and MCA/UA with Fetal Distress

The clinical significance and correlation of cord blood NO, activin A levels, and middle cerebral artery (MCA)/umbilical artery (UA) with fetal distress are explored. 120 puerperae who delivered in the obstetrics department of our hospital from January 2021 to January 2022 are selected as the examination subjects. According to the diagnostic criteria of fetal distress, they are divided into 70 cases of fetal distress and 50 cases of normal delivery. The parameters of umbilical cord blood NO, activin A, UA, and MCA are contrast between the two sets, then the diagnostic value of umbilical cord blood NO and activin A combined with UA and MCA in fetal distress is analyzed. The experimental results show cord blood NO and activin A combined with UA and MCA have a high diagnostic value for fetal distress, and there is an extensive correlation with the occurrence of fetal distress, which provides a reliable clinical diagnosis of fetal distress in a timely manner.