M1 Segment Research Articles

Management of patients with diffusion-weighted imaging-negative acute ischemic stroke: Retrospective analysis of 47 consecutive patients

BackgroundFew studies with a limited number of patients focused on the outcomes of patients with diffusion-weighted imaging (DWI)-negative acute ischemic stroke (AIS) after intravenous thrombolysis (IVT) and/or endovascular treatment (EVT). MethodsThis retrospective observational, single-center study included all consecutive patients admitted for AIS involving the anterior circulation and treated with IVT and/or EVT between January 1, 2015 and December 31, 2023. The collected data were used to identify the characteristics of patients with negative DWI and to compare outcomes in patients with negative and positive DWI. ResultsAmong the 1210 patients included, 47 (3.9 %) had negative (DWI-negative group) and 1163 had increased DWI signal (DWI-positive group). In the DWI-negative group, the mean age was 69 years (SD=19.4), 55.3 % were men, and 27 (57.4 %) had a large vessel occlusion. Thirty eight (80.9 %) were treated with IVT alone, 7 (14.9 %) with EVT alone, and 2 (4.3 %) with both. Fluid attenuated inversion recovery (FLAIR) sequences were the most sensitive to detect predictive factors of cerebral ischemia, such as vessel thrombosis and the spaghetti sign that were found in 68.1 % and 83 %, of patients, respectively. Oxyhemoglobin-sensitive (T2*) and susceptibility-weighted angiography (SWAN) sequences were less sensitive: vessel thrombosis and the brush sign were detected in 55.3 % and 19.1 % of patients, respectively. Comparison of the two DWI groups showed that M2 occlusion was more frequent (31.9 % vs 13 %, p<0.001) and M1 occlusion rarer (19.1 % vs 36 %, p<0.02) in the DWI-negative than DWI-positive group. At admission, the median National Institutes of Health Stroke Scale score was lower in the DWI-negative than DWI-positive group (2 vs 6, p=0.0001), but the median symptom onset-to-MRI time was similar in both groups (108 vs 111 min, p=0.88). ConclusionsIn patients with DWI-negative AIS, symptoms are less severe. Large vessel occlusions, notably in the M2 segment, are more distal at the expense of the M1 segment of MCA. The spaghetti sign remains the most predictive feature of AIS that should be specifically searched in the absence of DWI lesions.

Degree of subarachnoid hemorrhage affects clinical outcome after mechanical thrombectomy for M2 occlusion.

The prognostic relevance of post-mechanical thrombectomy (MT) subarachnoid hemorrhage (SAH) remains controversial. This study aimed to investigate whether the thickness of the SAH clot affects clinical outcomes following MT for M2 occlusion. A retrospective analysis was conducted on a prospective database of patients who underwent MT for isolated M2 occlusion. Patients were categorized into three groups based on the presence and thickness of SAH. Clinical and angiographical characteristics and outcomes were compared. Of the 36 patients included, SAH was observed in 15 (42%). When comparing patients with no SAH (grade 0) or thin SAH (grade 1) (N = 28) with those who had thick SAH (grade 2) (N = 8), patients with Grade 2 SAH required a higher number of passes and had a more severe angulation at M2. Patients with SAH Grade 2 had significantly worse NIHSS scores at 24 h (median, 4 vs. 14), but only one patient was identified as having a symptomatic intracranial hemorrhage. Patients with SAH Grade 2 were found to have a lower rate of favorable outcome (modified Rankin scale 0-2) (23% vs. 75%, P = 0.0026) and higher mortality (25% vs. 0%, P = 0.0499) at 90 days. The study found that thick SAH prevents clinical recovery after MT for M2 occlusion, even in cases of successful recanalization, and is associated with an unfavorable outcome. Thick SAH after MT is also linked to an increase in the number of passes and severe angulation at the M2 segment.

Microsurgical clipping of large MCA aneurysm in a 2-month-old child.

Cerebral aneurysms in children have a low incidence and accounts for less than 4% of all cerebral aneurysms. These aneurysms have been linked to various factors. Severe headache, seizures, and motor-sensory deficits are common presentations. We describe the case of a 2-month-old male patient who presented with generalized tonic-clonic seizures for 4days. At the hospital, he was stabilized with ventilatory support, sedation, and antiepileptic drugs. A NCCT (Head) showed intraparenchymal hemorrhage in the left fronto-parieto-temporal lobe and subarachnoid hemorrhage. Subsequently a CT angiogram revealed an aneurysm of the left M3 segment of MCA. Successfully, the patient underwent microsurgical clipping of aneurysm and evacuation of hematoma. Pediatric cerebral aneurysms differ from their adult counterparts, mainly in their etiology and evolution. As per literature, aneurysmal clipping and neurological endovascular therapy have shown similar results.

Flow reduction due to arterial catheterization during stroke treatment - A computational study using a distributed compartment model.

The effectiveness of various stroke treatments depends on the anatomical variability of the cerebral vasculature, particularly the collateral blood vessel network. Collaterals at the level of the Circle of Willis and distal collaterals, such as the leptomeningeal arteries, serve as alternative avenues of flow when the primary pathway is obstructed during an ischemic stroke. Stroke treatment typically involves catheterization of the primary pathway, and the potential risk of further flow reduction to the affected brain area during this treatment has not been previously investigated. To address this clinical question, we derived the lumped parameters for catheterized blood vessels and implemented a corresponding distributed compartment (0D) model. This 0D model was validated against an experimental model and benchmark test cases solved using a 1D model. Additionally, we compared various off-center catheter trajectories modeled using a 3D solver to this 0D model. The differences between them were minimal, validating the simplifying assumption of the central catheter placement in the 0D model. The 0D model was then used to simulate blood flows in realistic cerebral arterial networks with different collateralization characteristics. Ischemic strokes were modeled by occlusion of the M1 segment of the middle cerebral artery in these networks. Catheters of different diameters were inserted up to the obstructed segment and flow alterations in the network were calculated. Results showed up to 45% maximum blood flow reduction in the affected brain region. These findings suggest that catheterization during stroke treatment may have a further detrimental effect for some patients with poor collateralization.

Can Lesions in the Right Basal Ganglia Cause Aphasia? Crossed Aphasia in a Right-Handed Patient.

Aphasia is a common neurocognitive disorder caused by impaired speech and language, with stroke being the most frequent cause. The neuroanatomical mechanism underlying this condition is not yet fully understood. This case describes a 74-year-old Caucasian woman admitted with a clinical picture of right total anterior circulation infarct (TACI) and aphasia, scoring 17 on the National Institutes of Health Stroke Scale. Neuroimaging showed a large cortico-subcortical frontotemporoparietal and insular infarct involving the basal ganglia of the right hemisphere and bilateral focal atherosclerotic stenosis on the M1 segment of the middle cerebral artery. There was no left hemispheric lesion or abnormal electric activity on the electroencephalogram. A formal evaluation was compatible with transcortical motor aphasia. The aetiological study revealed atrial fibrillation, and the case was admitted as an ischaemic stroke of undetermined aetiology with two possible causes - intracranial atherosclerotic stenosis or atrial fibrillation. Our patient fulfilled all the formal criteria for crossed aphasia in dextral (CAD): aphasia, a lesion in the right hemisphere coupled with the structural integrity of the left hemisphere, an established preference for right-hand use without a familial history of left-handedness individuals, and an absence of brain damage in childhood. Our patient's case adds to the evidence that deep structures - alone or in combination with cortical structures - are primarily affected in CAD. The diagnostic criteria for crossed aphasia in dextral (CAD) are derived from clinical case studies and include aphasia, a lesion in the right hemisphere, a strong preference for using the right hand, the structural integrity of the left hemisphere and no history of brain damage during childhood.The right lentiform nucleus was found to be the most frequent anatomical substrate involved in CAD patients, consistent with our case description.Our patient experienced transcortical motor aphasia due to a stroke in the right hemisphere, adding to the evidence that in CAD patients, deep structures are primarily affected. In contrast, in left hemispheric lesions, cortical structures seem to be the main culprits.

Validation of a model for outcome prediction after endovascular treatment for ischemic stroke.

The recently developed MR-PREDICTS@24 h model showed excellent performance in the MR-CLEAN Registry cohort in patients presenting within 12 h from onset. However, its applicability to an U.S. population and to patients presenting beyond 12 h from last known normal are still undetermined. We aim to externally validate the MR-PREDICTS@24 h model in a new geographic setting and in the late window. In this retrospective analysis of a prospectively collected database from a comprehensive stroke center in the United States, we included patients with intracranial carotid artery or middle cerebral artery M1 or M2 segment occlusions who underwent endovascular therapy and applied the MR-PREDICTS@24 h formula to estimate the probabilities of functional outcome at day 90. The primary endpoint was the modified Rankin Scale (mRS) at 90 days. We included 1246 patients, 879 in the early (<12 h) and 367 in the late (≥12 h) cohort. For both cohorts, calibration and discrimination of the model were accurate throughout mRS levels, with absolute differences between estimated and predicted proportions ranging from 1% to 5%. Calibration metrics and curve inspections showed good performance for estimating the probabilities of mRS ≤ 1 to mRS ≤ 5 for the early cohort. For the late cohort, predictions were reliable for the probabilities of mRS ≤ 1 to mRS ≤ 4. The MR-PREDICTS@24 h was transferrable to a real-world U.S.-based cohort in the early window and showed consistently accurate predictions for patients presenting in the late window without need for updating.

Automated identification of thrombectomy amenable vessel occlusion on computed tomography angiography using deep learning.

We developed and externally validated a fully automated algorithm using deep learning to detect large vessel occlusion (LVO) in computed tomography angiography (CTA). A total of 2,045 patients with acute ischemic stroke who underwent CTA were included in the development of our model. We validated the algorithm using two separate external datasets: one with 64 patients (external 1) and another with 313 patients (external 2), with ischemic stroke. In the context of current clinical practice, thrombectomy amenable vessel occlusion (TAVO) was defined as an occlusion in the intracranial internal carotid artery (ICA), or in the M1 or M2 segment of the middle cerebral artery (MCA). We employed the U-Net for vessel segmentation on the maximum intensity projection images, followed by the application of the EfficientNetV2 to predict TAVO. The algorithm's diagnostic performance was evaluated by calculating the area under the receiver operating characteristics curve (AUC), sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). The mean age in the training and validation dataset was 68.7 ± 12.6; 56.3% of participants were men, and 18.0% had TAVO. The algorithm achieved AUC of 0.950 (95% CI, 0.915-0.971) in the internal test. For the external datasets 1 and 2, the AUCs were 0.970 (0.897-0.997) and 0.971 (0.924-0.990), respectively. With a fixed sensitivity of 0.900, the specificities and PPVs for the internal test, external test 1, and external test 2 were 0.891, 0.796, and 0.930, and 0.665, 0.583, and 0.667, respectively. The algorithm demonstrated a sensitivity and specificity of approximately 0.95 in both internal and external datasets, specifically for cases involving intracranial ICA or M1-MCA occlusion. However, the diagnostic performance was somewhat reduced for isolated M2-MCA occlusion; the AUC for the internal and combined external datasets were 0.903 (0.812-0.944) and 0.916 (0.816-0.963), respectively. We developed and externally validated a fully automated algorithm that identifies TAVO. Further research is needed to evaluate its effectiveness in real-world clinical settings. This validated algorithm has the potential to assist early-career physicians, thereby streamlining the treatment process for patients who can benefit from endovascular treatment.

Real-time monitoring of middle cerebral artery blood flow using intraoperative transcranial doppler during trans-carotid artery revascularization

ObjectiveTranscarotid artery revascularization (TCAR) has emerged as a safe and effective method for carotid revascularization, offering several key advantages over carotid endarterectomy (CEA) and carotid artery stenting (CAS). Intraoperative transcranial Doppler (TCD) monitoring plays a pivotal role in assessing cerebral hemodynamics and detecting embolic signals during TCAR at our institution. MethodsThis review synthesizes the current literature and provides guidance for TCD monitoring throughout the various phases of TCAR, from preoperative assessment to postoperative management. Key considerations include probe placement, waveform evaluation, interpreting monitoring parameters such as mean flow velocity (MFV), pulsatility index (PI), and percentage change in the MFV (Δ%). Techniques for maintaining the insonation of the middle cerebral artery (MCA) M1 segment and optimal parameter settings for intraoperative TCD monitoring are detailed. ResultsTCAR phases are highlighted, including transcarotid access and vessel control, sheath insertion, the establishment of flow reversal, pre-dilation, stent placement, post-dilation, and closure, while emphasizing the importance of real-time feedback provided by TCD monitoring in identifying embolic signals and assessing changes in cerebral perfusion. The review discusses limitations of TCD monitoring, such as inadequate temporal windows, incorrect vessel identification and reliability issues with automatic emboli detection counters. Furthermore, practical advice is provided on how to navigate common pitfalls encountered during intraoperative TCD monitoring. ConclusionBy understanding the nuances of TCD monitoring and its application in TCAR, intraoperative TCD monitoring may aid to minimize the low but potential risk of intraprocedural embolic events, periprocedural hypoperfusion and postoperative hyperperfusion. Finally, we suggest opportunities for further research in embolization quantification and additional strategies to optimize quality control in TCAR.

Endovascular therapy versus best medical management in distal medium middle cerebral artery acute ischaemic stroke: a multinational multicentre propensity score-matched study

BackgroundThe efficacy of endovascular treatment (EVT) in acute ischaemic stroke due to distal medium vessel occlusion (DMVO) remains uncertain. Our study aimed to evaluate the safety and efficacy of EVT...

Minimally Invasive Lateral Transorbital Approach for Clipping of Right Middle Cerebral Artery Aneurysm: 2-Dimensional Operative Video.

The lateral transorbital approach is a minimally invasive approach that was first described for accessing the cavernous sinus.1 Although other minimally invasive approaches have been broadly applied to aneurysm surgery,2 the use of transorbital keyholes for this is still quite rare.3,4 We present a 72-year-old man with an incidentally discovered 5-mm middle cerebral artery aneurysm. Despite a low rupture risk,5 the patient himself opted for treatment, and because of the complex shape of the aneurysm, he chose surgical clipping as the treatment of choice. Two unique aspects of the patient's anatomy brought forth transorbital approach for consideration. He had a wide fissure, which opened to the orbital wall, and a giant frontal sinus made its avoidance difficult with any anterolateral transcranial approach. The lateral transorbital approach was started with a transpalpebral incision.4,6,7 Both wings of the sphenoid bone were drilled until the frontal and temporal dura was exposed. Opening this through the orbit gained direct access to the large Sylvian fissure. Two specific challenges were specific to this opening: the aneurysm dome pointed straight at the surgeon, and the M1 segment, needed for proximal control, was directly behind the aneurysm. Despite these, the aneurysm was successfully eliminated through the transorbital approach with no residual or normal branch compromise. Given the specific anatomical provisions, the lateral transorbital approach was an effective and safety alternative to the pterional approach for middle cerebral artery aneurysms. No Institutional Review Board approval was sought or necessary as the patient provided consent for the procedure, publication of his image, and this submission.

Pipeline versus non-pipeline flow diverter treatment for M1 aneurysms: A systematic review and meta-analysis.

The flow diversion treatment of aneurysms located distal to the Circle of Willis has recently increased in frequency. We conducted a systematic review and meta-analysis of the clinical and radiological outcomes of flow diverter (FD) embolization in treating M1 aneurysms. PubMed, Web of Science, Ovid Medline, Ovid Embase, and Scopus were searched up to May 2024 using the Nested Knowledge platform. We included studies assessing the long-term clinical and radiological outcomes for M1 aneurysms. Results of FDs classified as Pipeline Embolization Devices (PED) versus other types of FDs. Angiographic occlusion rates, ischemic and hemorrhagic complications, and favorable clinic outcomes were included. All data were analyzed using R software version 4.2.2. Thirteen studies with 112 total patients (58 patients for PED and 54 patients for other FD devices) were included in our meta-analysis. The overall adequate (complete + near-complete) occlusion rates were 85.1%. The complete occlusion rate was higher with PED than with other FD devices (72.9% PED and 41.6% for non-PED FDs, respectively, p-value <.01). The ischemic complications were 9.9% and 9.0% for the PED and non-PED groups, respectively (p-value = .89). The overall modified Rankin Scale 0-2 was 100% for the non-PED and 97.1% for the PED group (p-value = .51). In-stent stenosis rate was 7.5% for PED devices compared to 2.6% in the non-PED group (p-value = .35). This relatively small meta-analysis showed high rates of adequate and complete occlusion in FD treatment of M1 segment aneurysms, with favorable safety profiles. PEDs were associated with higher rates of complete aneurysm occlusion compared to other types of FDs.

Using High-Resolution Vessel Wall Magnetic Resonance Images in a Patient of Intracranial Artery Dissection Related Acute Infarction.

Acute ischemic stroke in young adults typically carries significant implications for morbidity, mortality, and long-term disability. In this study, we describe the case of a 34-year-old male with no prior medical history who presented with symptoms of right-sided weakness and slurred speech, suggesting an acute ischemic stroke. Initial CT angiography revealed an occlusion in the left M2 segment middle cerebral artery (MCA). The occlusion was successfully recanalized through emergent endovascular thrombectomy, which also identified a dissection as the cause of the stroke. Follow-up assessments at 3 days and three months, which included advanced vessel wall MRI, highlighted the critical role of intracranial artery dissection in strokes among young adults and provided essential images for ongoing evaluation.

Endovascular Thrombectomy Versus Intravenous Alteplase For Distal Medium Vessel Occlusions: A Propensity Score‐Matched Analysis

Background The benefits of endovascular thrombectomy (EVT) for distal medium vessel occlusions (DMVOs) are not well established. This study aimed to determine the superiority of EVT over intravenous tissue‐type plasminogen activator (IV tPA) in the treatment of DMVOs. Methods This study analyzed data from the Kanagawa Intravenous and Endovascular Treatment of Acute Ischemic Stroke Registry, a prospective, multicenter, observational registry of acute ischemic stroke patients treated with EVT or IV tPA. The study evaluated patients with acute DMVOs who were treated with EVT and/or IV tPA. DMVOs was defined as occlusions in M2–M3 segment of the middle cerebral artery, anterior cerebral artery, or posterior cerebral artery. The analysis included primary DMVOs and excluded secondary DMVOs, such as distal embolism after recanalization of proximal vessel occlusion. Propensity score‐matched analysis was conducted to compare the outcomes between EVT and IV tPA alone. A good outcome was defined as a modified Rankin Scale score 0–2 or no worsening at 90 days. An excellent outcome was defined as an modified Rankin Scale score 0–1. Results The study included 1148 patients with DMVOs, of whom 816 were treated with EVT and 332 were IV tPA alone. Before propensity score matching, the incidence of good and excellent outcomes was significantly lower in EVT group (good outcomes: EVT 50.3% versus IV tPA 68.0%; P &lt; 0.01; excellent outcomes: 39.8% versus 59.8%; P &lt; 0.001). After propensity score matching, there were no significant differences between EVT and IV tPA groups in good outcomes (EVT 57.8% versus IV tPA 61.3%; P = 0.51), excellent outcomes (46.6% versus 55.0%; P = 0.17), all cerebral hemorrhage (11.6% versus 12.7%; P = 0.74), and symptomatic hemorrhage (2.9% versus 0.6%; P = 0.13). Subarachnoid hemorrhage was more frequent in EVT group (14.5% versus IV tPA 0%). Conclusion The benefits of EVT for acute DMVOs were similar to IV tPA alone. Randomized multicenter trials are warranted to establish the superiority of EVT over IV tPA alone for DMVOs.

Role of Endovascular Thrombectomy in Improving the Functional Outcome in Acute Stroke Patients Presenting 6-12 Hours after Stroke Onset

Abstract Background Based on the World Health Organization (WHO) statistics, there are 15 million strokes annually. The aim of the treatment in acute ischemic stroke is rapid restoration of perfusion to the ischemic area by minimizing the time between the occurrence of symptoms and the treatment. This is crucial for saving the salvageable brain tissue (penumbra) by restoration of flow and metabolism to normal Aim of Work The aim of work is to evaluate the safety and efficacy of endovascular thrombectomy (EVT) in patients presenting 6-12 hours from onset of stroke symptoms secondary to large vessel occlusion. Patients and Methods 50 Patients presenting with acute ischemic stroke with causative occlusion of major vessels in anterior circulation, underwent mechanical thrombectomy Results Two-thirds of the patients had their intracranial arterial occlusion at M1 segment of the middle cerebral artery. The median baseline NIHSS score, ASPECTS, and mRS score of the studied patients was 16 (IQR 11-20), 8 (IQR 7-9) and 0 (IQR 0-1), respectively. The median final infarct volume, NIHSS score, ASPECTS post-intervention and mRS score at 90 days of the studied patients was 40 ml (IQR 26.5-70) (P &amp;lt; 0.001), 9 (IQR 4-16) (P &amp;lt; 0.001), 8(IQR 5-9) (P &amp;lt; 0.01), and 2 (IQR1-4) (P &amp;lt; 0.001), respectively and (90 %) of them had revascularization type TICI 2b- 3. More than half of the studied patients (52%) had mRS score at 90 days of ≤ 2 and mortality rate was 12%. Conclusions The current study showed that endovascular thrombectomy techniques are safe and effective in the treatment of acute ischemic stroke.

Preliminary outcomes of endovascular treatment of moyamoya disease

PurposeThis study aimed to investigate the effectiveness and safety of endovascular revascularisation of intracranial artery occlusion and stenosis in moyamoya disease using stent angioplasty. Materials and methodsWe recruited 12 patients (8 women and 4 men) with occlusion and stenosis of intracranial arteries in the context of moyamoya disease who underwent endovascular stent angioplasty. Clinical data, baseline conditions, lesion location, treatment outcomes, periprocedural complications, and follow-up outcomes were analysed. ResultsThe occlusion was located at the M1 segment of the middle cerebral artery in 8 patients, at both the M1 and A2 segments in one patient, and at the C7 segment of the internal carotid artery in 3. Thirteen stents were deployed at the occlusion site, including the low-profile visualized intraluminal support (LVIS) device in 8 patients, an LVIS device and a Solitaire AB stent in one, and a Leo stent in 3, with a success rate of 100% and no intraprocedural complications. Plain CT imaging after stenting revealed leakage of contrast agent, which disappeared on the second day, resulting in no clinical symptoms or neurological sequelae. Follow-up angiography studies were performed in all patients for 6–12 months (mean, 8.8). Slight asymptomatic in-stent stenosis was observed in 2 patients (16.7%), and no neurological deficits were observed in the other patients. All preoperative ischaemic symptoms completely disappeared at follow-up. ConclusionStent angioplasty is a safe and effective treatment for occlusion and stenosis of intracranial arteries in moyamoya disease.

Agreement between CT-Angiography and Digital Subtraction Angiography in Predicting Angiographic Vasospasm in Patients with Subarachnoid Hemorrhage.

Background/Objectives: Digital subtraction angiography (DSA) is the gold standard in the diagnosis of cerebral vasospasm, frequently observed after subarachnoid hemorrhage (SAH). However, less-invasive methods, such as computed tomography angiography (CTA), may be equally accurate. To further clarify comparability, this study evaluated the reliability of CTA in detecting cerebral vasospasm. Methods: This retrospective study included 51 patients with SAH who underwent both CTA and DSA within 24 h. The smallest diameter of the proximal cerebral arterial segments was measured in both modalities at admission and during the vasospasm period. The mean difference in diameter, the intraclass correlation coefficient (ICC) of CTA and DSA, the difference in grade of vasospasm and sensitivity, the specificity and the positive predictive value (PPV) for CTA were calculated. Results: A total of 872 arterial segments were investigated. At time of admission, arterial diameters were significantly smaller on CTA compared to DSA in all segments (-0.26 ± 0.12 mm; p < 0.05). At time of suspected vasospasm (day 9 ± 5), these differences remained significant only for the M1 segment (-0.18 ± 0.37 mm, p = 0.02), the P1 segment (-0.13 ± 0.24 mm, p = 0.04) and the basilar artery (-0.20 ± 0.37 mm, p = 0.0.04). The ICC between CTA and DSA was good (0.5-0.8). The sensitivity of CTA for predicting angiographic vasospasm was 99%, the specificity was 50% and the PPV was 92%. Conclusions: Arterial diameters measured on CTA may underestimate the arterial caliber observed in DSA; however, these absolute differences were minor. Importantly, vessel diameter alone does not fully reflect malperfusion, requiring additional imaging techniques such as CT perfusion.

Predicting Occluded Middle Cerebral Artery Morphology for Endovascular Mechanical Thrombectomy: A Contralateral Shape Analysis Approach.

Introduction Predicting the shape of the occluded middle cerebral artery (MCA) from the contralateral MCA might help catheterization in endovascular mechanical thrombectomy (EMT). Materials and Methods We analyzed magnetic resonance (MR) angiography in 100 consecutive patients who had MR imaging for diseases other than acute ischemic stroke. To assess the symmetricity of MCA, the shape of M1, length of M1, number of M2, number of early branches (EBs), and distance from the top of the internal carotid artery to EB were investigated. Results The shape of M1 was upward in 42%, horizontal in 47%, and downward in 11%. The M1 shape was the same on both sides in 64%, which exceeded the probability assumed to be left-right independent. The number of M2 trunks and EBs matched left and right in 86 and 55% of patients, respectively; however, these agreement rates were not higher than those with independent left and right sides. No left-right correlation was found between the M1 length and the distance from the internal carotid artery to EB. Conclusion Based on our data, the symmetry of MCA was observed only in the shape of the M1 segment. This finding could be beneficial for EMT targeting MCA embolisms.

BIOM-08. CDKN2A --AN INDEPENDENT CYCLIN-DEPENDENT KINASE INHIBITOR VARIANT ASSOCIATED WITH MALIGNANCY AND WITH SMALL VESSEL STROKE, AS A POTENTIAL MARKER FOR RISK OF LARGE-VESSEL STROKE COMPLICATING BENIGN TERATOMA

Abstract BACKGROUND Cyclin-dependent kinase inhibitor variants, particularly those of CDKN2A are known to be associated with autosomal dominant Familial Atypical Multiple Mole/Melanoma Syndrome and pancreatic cancer predisposition. These variants are associated with risk of small vessel stroke in African/ African-American populations, and are risk factors for stroke in Nordic populations with hypertension, independent of cardiovascular risk factors. METHODS We performed a case review of a female presenting in late infancy with a central nervous system teratoma, that later was complicated by a right hemispheric middle cerebral artery (MCA)stroke, associated with a CDKN2A germline mutation. RESULTS This 14month old female presented with transient alterations of consciousness and apparent abdominal migraine events with pernicious vomiting. Neuroimaging revealed a right heterogeneous para- suprasellar mass and bilateral complex arachnoid adjacent cysts. She was observed closely for any progression, as the lesion was immediately adjacent to the optic chiasm. One year after presentation, she developed an acute ischemic right middle cerebral artery (MCA) stroke and had radiographic evidence of severe stenosis and decreased flow primarily within the right supra-clinoid internal carotid artery, the M1 segment and portion of the right A1 segment of cerebral vessels, with decreased enhancement and number of vessels in the distal right MCA territory. The vessels did not appear to be compressed by any mass effect. The radiologic appearance was consistent with vasospasm. The patient upon stoke recovery, underwent near- complete resection of the mass with no evidence of disruption of the capsule surrounding it and no vascular infiltration. Pathology revealed the expected teratoma with prominence of pancreatic acinar structures, and molecular evidence of a variant of CDKN2A, which was present in the patient and mother in the germline. CONCLUSION We propose that the imaging evidence of a vasculopathy was related to the genotype at the cyclin- dependent kinase site.

Stop Ischemic Event to the Brain: Screening Risk Factors of Cerebrovascular Stenosis in Coronary Artery Disease Patients.

In this study, we investigated the difference in risk factors between the 2 diseases, aiming to further clarify who needs to do ischemic cerebrovascular disease (ICVD)-related screening among coronary artery disease (CAD) patients. Clinical data of 326 patients with first-episode CAD from June 1, 2017, to July 31, 2020, in the Chinese PLA General Hospital were retrospectively reviewed. Outcomes, including clinical features and laboratory examination, were taken. Features related to ICVD including the extension of intracranial arterial (internal carotid artery intracranial segment, middle cerebral artery M1 segment, anterior cerebral A1 segment, vertebrobasilar artery intracranial segment, posterior cerebral artery P1 segment) and carotid arterial (internal carotid artery extracranial segment, common carotid artery, subclavian artery) stenosis were detected. Risk factors for the occurrence of ICVD in patients with CAD were analyzed. Among patients with the onset of CAD, in comparison of the nonstenosis and stenosis of intracranial artery subgroups, there were statistical differences in the onset age, hypertension, and duration of hypertension as well as the biochemical indicators, including high-density lipoprotein and glycosylated hemoglobin. In addition, statistical differences were detected in the onset age as well as the biochemical indicators, including glycosylated hemoglobin and blood glucose serum protein, along with the difference in the degree of cardiovascular stenosis. The onset age of CAD was shown to serve as a vital risk factor for ICVD. The primary prevention of ICVD in patients with CAD should lay more emphasis on the management of hypertension and diabetes.

Association between procedural time and outcome in unsuccessful mechanical thrombectomy for acute ischemic stroke: analysis from the Italian Registry of Endovascular Treatment in Acute Stroke.

We aim to assess the association between procedural time and outcomes in patients in unsuccessful mechanical thrombectomy (MT) for anterior circulation acute stroke. We conducted a cohort study on prospectively collected data from patients with M1 and/or M2 segment of middle cerebral artery occlusion with a thrombolysis in cerebral infarction 0-1 at the end of procedure. Primary outcome was 90-day poor outcome. Secondary outcomes were early neurological deterioration (END), symptomatic intracranial hemorrhage (sICH) according to ECASS II and sICH according to SITS-MOST. Among 852 patients, after comparing characteristics of favourable and poor outcome groups, logistic regression analysis showed age (OR: 1.04; 95%CI: 1.02-1.05; p < 0.001), previous TIA/stroke (OR: 0.23; 95%CI: 0.12-0.74; p = 0.009), M1 occlusion (OR: 1.69; 95%CI: 1.13-2.50; p = 0.01), baseline NIHSS (OR: 1.01; 95%CI: 1.06-1.13; p < 0.001) and procedural time (OR:1.00; 95% CI: 1.00-1.01; p = 0.003) as independent predictors poor outcome at 90days. Concerning secondary outcomes, logistic regression analysis showed NIHSS (OR:0.96; 95%CI: 0.93-0.99; p = 0.008), general anaesthesia (OR:2.59; 95%CI: 1.52-4.40; p < 0.001), procedural time (OR: 1.00; 95% CI: 1.00-1.01; p = 0.002) and intraprocedural complications (OR: 1.89; 95%CI: 1.02-3.52; p = 0.04) as independent predictors of END. Bridging therapy (OR:2.93; 95%CI: 1.21-7.09; p = 0.017) was associated with sICH per SITS-MOST criteria whereas M1 occlusion (OR: 0.35; 95%CI: 0.18-0.69; p = 0.002), bridging therapy (OR: 2.02; 95%CI: 1.07-3.82; p = 0.03) and intraprocedural complications (OR: 5.55; 95%CI: 2.72-11.31; p < 0.001) were independently associated with sICH per ECASS II criteria. No significant association was found between the number of MT attempts and analyzed outcomes. Regardless of the number of MT attempts and intraprocedural complications, procedural time was associated with poor outcome and END. We suggest a deeper consideration of procedural time when treating anterior circulation occlusions refractory to MT.