Anterior Cerebral Research Articles

Flow-diverter stents in intracranial aneurysm treatment: impact on covered cerebral artery branches.

Flow diverter stents (FDSs) have attracted interest for intracranial aneurysm (IA) treatment; however, occlusion of side branches and related complications have been reported. This study aimed to investigate the effects of FDSs in IA management when different branches of intracranial arteries are covered. A cross-sectional study was conducted using PUBMED, Embase, Web of Science, and Cochrane databases to include randomized or nonrandomized comparative-designed studies from January 2000 to August 2022 which reported outcomes of occlusion/narrowing of branches after IA treatment using FDSs. The PRISMA guidelines were used for our report. A random-effects meta-analysis was conducted to pool the outcomes, which included incidence rates of occlusion/narrowing of FDS-covered branches, branch occlusion-related symptoms, obliteration of IAs, and ideal clinical outcomes (modified Rankin Scale score ≤2). The authors identified 57 studies involving 3789 patients with IA managed by FDSs covering different branches. During the median imaging follow-up at 12 months, the IA obliteration rate was satisfactory (>70%) when covering the ophthalmic artery (OA), posterior communicating artery (PComA), anterior choroidal artery (AChoA) or anterior cerebral artery (ACA), but not the middle cerebral artery-M2 segment (MCA-M2; 69.5%; 95% CI: 60.8-77.5%) and posterior inferior cerebellar artery (PICA; 59.1%, 13/22). The overall ideal clinical outcome was observed in 97.4% of patients (95% CI: 95.5-98.9%). Higher rates of occlusion/narrowing of branches were identified when FDSs covered the ACA (66.6%; 95% CI: 45.1-85.3%), PComA (44.3%; 95% CI: 34.2-54.6%), or MCA-M2 (39.2%; 95% CI: 24.5-54.7%); the risks were lower when covering the OA (11.8%; 95% CI: 8.8-15.1%), PICA (6.8%; 95% CI: 1.5-14.5%), and AchoA (0.5%; 95% CI: 0.0-2.9%). The risk of branch occlusion-related complications was low (incidence rate <5%) for each of the six evaluated branches. Acceptable outcomes were identified following treatment of IAs when FDSs were placed across each of the six studied cerebral arteries. Treatment decisions regarding FDS placement across branch arteries should be made with the risk of complications from branch occlusion in mind.

Study of Cerebral Hemispheric Lateralization in Stroke and the Arterial Territories Involved in High-risk Patients

Introduction: According to WHO, Stroke is the 2nd leading cause of death and disability after Ischemic heart disease. Prevalence rate of stroke in India varies from 44.45 to 150 per lakh population. Studies have reported a higher frequency of stroke of the left hemisphere. The artery reported to be the most affected is Left Middle Cerebral artery(MCA) followed by Right Middle Cerebral artery. The aim of this study is to determine the side of cerebral hemisphere most affected by stroke and the arterial territories involved in high-risk patients aged above 35 years presenting to the tertiary healthcare centre, as well as to study the sex predilection of stroke. Materials and Methods: A cross-sectional prospective study of 50 high risk stroke patients with Diabetes Mellitus(DM) and /or Hypertension(HTN) presenting to General medicine OPD of a tertiary healthcare centre were investigated with CT/MRI for the side of the cerebral hemisphere affected and the arterial territories involved. The data was tabulated over the course of three months and statistical analysis was carried out. Results: The left cerebral hemisphere was affected in 50%, right in 40% and bilateral involvement was found in 10% patients. Slight predilection of stroke towards the left was seen, however it was not found to be statistically significant (P-value= 0.249). MCA territory was involved in 66% of the patients, Posterior Cerebral Artery(PCA) territory in 8%, Vertebrobasilar Artery(VB) territory in 8%, Anterior Cerebral Artery(ACA) territory in 6% and MCA+ACA in 4%, MCA+VB in 2% and MCA-PCA watershed in 6% patients. Conclusions: We found a slight predilection of stroke towards the left, which was however, not found to be statistically significant. We also found that Middle Cerebral Artery(MCA) territory is the most commonly involved in stroke.

Intracranial aneurysm rupture risk in northern China: a retrospective case-control study.

Rupture of intracranial aneurysms (IAs) can cause subarachnoid hemorrhage (SAH), which leads to severe neurological dysfunction and even death. Exploring the risk factors for IA rupture and taking preventive measures accordingly can reduce or prevent the occurrence of SAH. Currently, there is still no consensus on the detrimental factors for IA rupture. Thus, our study aimed to investigate the risk factors of IA rupture in a population of northern China. We systematically collected the demographic features, medical history, and imaging data of aneurysms from patients with ruptured and unruptured IAs (UIAs) who attended the Department of Neurosurgery at the Second Hospital of Hebei Medical University from 2014 to 2019. All cases had been diagnosed by digital subtraction angiography. We excluded patients with SAH resulting from injuries, as well as those with vascular dissection and incomplete data. Finally, 1,214 patients including 616 with ruptured IAs and 598 with UIAs were collected for further analysis. A case-control study was conducted, in which multivariable logistic regression was used to analyze the risk factors for IA rupture. Our multivariable logistic regression showed that anterior cerebral artery [odds ratio (OR) =2.413; 95% confidence interval (CI): 1.235-4.718], anterior communicating artery (OR =3.952; 95% CI: 2.601-6.006), posterior communicating artery (OR =2.385; 95% CI: 1.790-3.177), and anterior circulation branches (OR =3.493; 95% CI: 1.422-8.581) were risk factors for IA rupture, whereas patients with a history of cerebral infarction (OR =0.395; 95% CI: 0.247-0.631) and those with IAs located in the internal carotid artery (OR =0.403; 95% CI: 0.292-0.557) were less likely to have IA rupture. IAs at specific locations are prone to rupture. These IAs should be paid particular attention and preventive measures should be taken to reduce or prevent their rupture.

Effect of Sit-to-Stand Training on Balance, Muscle Strength, and Activities of Daily Living in Patients with Stroke: A Randomised Controlled Trial

Introduction: Patients who have had a stroke often experience issues with static balance while sitting and standing. Additionally, they may encounter problems with dynamic balance, particularly when transitioning between sitting and standing positions, leading to reduced postural stability in both static and dynamic standing. This also contributes to weakness in the affected lower limb and decreased engagement in Activities of Daily Living (ADL). Nevertheless, few studies have investigated the impact of sit-to-stand training on balance, muscle strength, and ADL in stroke patients. Aim: To assess the impact of sit-to-stand training on balance, muscle strength, and ADL in patients who have had a stroke. Materials and Methods: This trial was an experimental, parallel, and assessor-blinded allocation with a computer-generated randomisation sequence. Sixty-six stroke patients (33 in each group) were enrolled from the inpatient Department of Medicine and the neurosurgery ward of Justice KS Hegde Charitable Hospital in Deralakatte, Mangaluru, Karnataka, India based on specific selection criteria. The trial was conducted from March 2022 to March 2023. Inclusion criteria included patients who had experienced a stroke involving the Anterior Cerebral Artery (ACA) and Middle Cerebral Artery (MCA), encompassing both ischaemic and haemorrhagic types of stroke, aged between 35-60 years, and including both male and female stroke patients who were able to effectively communicate and comprehend instructions. Other criteria included a Mini-Mental State Examination (MMSE) score greater than or equal to 23, the ability to independently have a transition from a supine position to a seated position, and a minimum score on the trunk impairment scale. In the experimental group, participants received sit-to-stand training for 45 minutes over five days, while the control group received conventional physical therapy, including tandem walking, single leg stance, double leg stance, early mobilisation, position and balance training exercises for 45 minutes over five days. The primary outcomes used for balance assessment were the Berg Balance Scale (BBS), and for ADL, the Barthel Index (BI) Scale was used, with muscle strength being measured using a push and pull dynamometer. The independent sample t-test was used to compare between groups, and within-group comparisons were conducted using the paired t-test. A p-value &lt;0.05 was considered significant. Results: Significant differences (p-value=0.044) were observed in BBS score and muscle strength between the groups during both the pretest (Day-1) and post-test (Week-1). The BI exhibited a significant difference (p-value=0.016) during the post-test (Week-1) only. Additionally, a significant difference (p-value&lt;0.001) was found in muscle strength, specifically in the Hip Extensors (HE) between the groups. Conclusion: The results of the current study showed a statistically significant difference in muscle strength of the HE. However, no significant difference was observed in BI and BBS between the groups. No side-effects or harms were reported, indicating that the approach is safe and feasible for stroke patients.

Intellectual function and memory in children with moyamoya disease: relationship between Wechsler Intelligence Scale and Benton Visual Retention Test scores and regional cerebral blood flow.

Intellectual function declines in about 30% of children with moyamoya disease (MMD). Memory function underpins higher order brain function, but the relationship between intellectual function and memory in pediatric MMD patients has not been well studied. This study aimed to investigate correlations between scores on the Wechsler Intelligence Scale for Children (WISC) and the Benton Visual Retention Test (BVRT), a visual memory test that can be administered to children, in children with MMD. Relationships between intellectual function or memory and regional cerebral blood flow (rCBF) have also not been well clarified in pediatric MMD patients. The authors also investigated associations between WISC or BVRT scores and rCBF in various brain regions. WISC and BVRT scores and rCBF were assessed in 17 children with ischemic-onset MMD before revascularization. Single-photon emission CT with 123I-iodoamphetamine was used to measure rCBF. Relationships between WISC and BVRT scores were evaluated using Spearman's correlation coefficient and multivariate linear regression analysis. Cutoff values were identified for BVRT scores. Sensitivity and specificity were calculated to predict full-scale intelligence quotient (FSIQ) > 85 or ≤ 85. Associations between rCBF and WISC or BVRT scores were evaluated using linear regression analysis. BVRT scores were significantly correlated with FSIQ and scores on the Working Memory Index (WMI), Processing Speed Index, and Verbal Comprehension Index (VCI)/Verbal Intelligence Quotient (VIQ) of WISC. Multivariate linear regression revealed that number correct score and number of errors score of BVRT were associated with FSIQ. As cutoff values, a number correct score of 5 and a number of errors score of 8 offered the most reliable predictors of FSIQ > 85 and ≤ 85, respectively. FSIQ correlated positively with rCBF in the right and left hemispheres, right and left ganglia, right and left thalamus, right and left cerebellum, right middle cerebral artery (MCA) territory, pons, and vermis. WMI score was positively associated with rCBF in the right hemisphere, right anterior cerebral artery territory, right MCA territory, right basal ganglia, right and left thalamus, right and left cerebellum, pons, and vermis. BVRT score correlated well with WISC index scores, suggesting that BVRT may be helpful in screening for intellectual impairments in children with MMD. In the MCA territory, basal ganglia, thalamus, cerebellum, pons, and vermis, rCBF associated well with WISC index scores, suggesting that reduced rCBF in relevant brain regions may influence intellectual function.

Sexual Dysfunction after Clipping of Ruptured Intracranial Aneurysms.

Sexual dysfunction significantly affects interpersonal relationships and overall quality of life. It remains a matter of concern for risk assessment and counseling in patients with ruptured intracranial aneurysms. To assess the sexual dysfunctions in patients undergoing clipping for ruptured intracranial aneurysms and comparative evaluation among different anterior circulation aneurysms. We prospectively included 40 male patients of ruptured intracranial aneurysms of anterior circulation (age range: 20-60 years; sexually active preoperatively), managed with craniotomy and clipping. We evaluated the sexual outcome in patients with excellent Glasgow outcome score (GOS) five at a minimum one year of follow-up. Patients with GOS-5 status at follow-up were broadly classified into two groups: Anterior communicating artery aneurysm (Acom), and non-Acom) aneurysms. We valued sexual outcome with Subjective Sexual Arousal Scale for Men at follow-up, and compared in the two groups. Mean age of patients was 44.78 ± 9.51 years. Besides 20 Acom aneurysms, other groups included 11 middle cerebral artery aneurysms, five internal carotid artery aneurysms, three posterior communicating artery aneurysms, and one distal anterior cerebral artery aneurysm. The mean follow-up was 24.45 ± 13.58 months. Patients with non-Acom aneurysms had an overall better outcome in the sexual performance domain "P = 0.015," mental satisfaction domain "P = 0.009," and sexual assertiveness domain "P = 0.007." However, there was no statistical difference in partner communication domain "P = 0.593," and partner relationship domain "P = 0.378." Overall, the sexual outcome was inferior in patients treated for Acom aneurysms compared to other anterior circulation aneurysms. In cases of aneurysmal subarachnoid hemorrhage, sexual dysfunctions are common even after good clinical outcomes. The study revealed prominent differences in outcomes on the sexual quality of life in patients harboring Acom aneurysms as compared to anterior circulation aneurysms located off-midline.

Intra-aneurysmatic thrombectomy in a distal anterior cerebral artery aneurysm.

Thrombectomy procedures following intra-aneurysmatic lesions are extremely rare, and few cases have been reported. This article describes a microsurgical intra-aneurysmatic thrombectomy (MIaT) for a distal anterior cerebral artery (DACA) aneurysm. We present the case of a 48-year-old female that was admitted to the emergency room, showing neurologic deterioration with focal deficits. A computed tomography angiography (CTA) scan revealed an aneurysm located in the distal segment of the left anterior cerebral artery. During the surgical procedure, after clipping, a wellformed clot was visualized through the aneurysm's wall obstructing the left DACA flow. We proceeded to open the aneurysm's dome to remove the thrombus and clip the aneurysm neck, re-establishing the flow of the left DACA. Intra-aneurysmatic thrombosis can occur as a complication during clipping, obstructing the distal flow of vital arteries and causing fatal results in the patient's postoperative status. MIaT is a good technique for restoring the flow of the affected vessel and allows a secure aneurysm clipping after thrombus removal.

Atypical Manifestation of Zoster Meningitis Presented with Headache and Multiple Cerebral Vasoconstrictions

Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by headaches and multiple transient cerebral vasoconstrictions. Central nervous system (CNS) infections related to the varicella zoster virus (VZV) can complicate various neurological disorders, including cerebral vasculopathy. We present the case of a patient who complained of a severe headache without any other symptoms or focal neurological signs. Brain magnetic resonance angiography showed multiple focal stenoses, especially in the right middle cerebral artery (MCA), and transcranial Doppler sonography revealed increased velocities in the MCA and right anterior cerebral artery. Initially, the headache was attributed to RCVS, and nimodipine infusion was initiated; however, the headache worsened. A cerebrospinal fluid study showed pleocytosis, increased protein levels, and positive polymerase chain reaction markers for VZV. No skin lesions or fever were observed during treatment. Our case emphasizes considering VZV meningitis as a cause of cerebral vasoconstriction, even in the absence of typical signs of CNS infection.

The Lateral Supraorbital Approach: 2-Dimensional Operative Video.

The lateral supraorbital approach (LSO), a minimally invasive alternative to the pterional approach, can be used for anterior circulation aneurysms (except distal anterior cerebral artery), some posterior circulation aneurysms, and tumors located around the sellar and suprasellar regions. Performing one-layer myocutaneous flap that is retracted anteriorly, exposure of the superior temporal line, and zygomatic process of the frontal bone and the inferior limit of the craniotomy represent the upper edge of the Sylvian fissure, exposing the anterolateral skull base. Skin incision behind the hairline, one-layer myocutaneous flap retracted anteriorly, minimal detachment of the temporalis muscle, burr hole over the superior temporal line, and craniotomy of 4 cm in diameter (inferior limit of the craniotomy represents the Sylvian fissure). Potential risks include opening of the frontal sinus, entering the orbit and exposure of the orbital fat, wrong craniotomy location, and limited exposure. Inadequate craniotomy size limits instruments maneuverability. To avoid complication, identification of anatomic landmarks, sinus closure, preoperative evaluation of computed tomography scans, and use of neuronavigation are necessary. This requires surgical expertise and familiarity of minimal invasive craniotomies. Anatomic limitations of the LSO include temporomesial region, distal Sylvian +/-, posterior communicating artery aneurysms medial projection, retro carotid space, and carotid cave. For pathologies requiring an additional lateral trajectory, we use an extended LSO, drilling the sphenoid wing through the fronto-pterio-orbital window without drilling of the temporal bone. Additional variations include performing an intradural or extradural clinoidectomy. The patient consented to the procedure and to the publication of their image.

Exploring the impact of super-resolution deep learning on MR angiography image quality.

The aim of this study is to assess the effect of super-resolution deep learning-based reconstruction (SR-DLR), which uses k-space properties, on image quality of intracranial time-of-flight (TOF) magnetic resonance angiography (MRA) at 3 T. This retrospective study involved 35 patients who underwent intracranial TOF-MRA using a 3-T MRI system with SR-DLR based on k-space properties in October and November 2022. We reconstructed MRA with SR-DLR (matrix = 1008 × 1008) and MRA without SR-DLR (matrix = 336 × 336). We measured the signal-to-noise ratio (SNR), contrast, and contrast-to-noise ratio (CNR) in the basilar artery (BA) and the anterior cerebral artery (ACA) and the sharpness of the posterior cerebral artery (PCA) using the slope of the signal intensity profile curve at the half-peak points. Two radiologists evaluated image noise, artifacts, contrast, sharpness, and overall image quality of the two image types using a 4-point scale. We compared quantitative and qualitative scores between images with and without SR-DLR using the Wilcoxon signed-rank test. The SNRs, contrasts, and CNRs were all significantly higher in images with SR-DLR than those without SR-DLR (p < 0.001). The slope was significantly greater in images with SR-DLR than those without SR-DLR (p < 0.001). The qualitative scores in MRAs with SR-DLR were all significantly higher than MRAs without SR-DLR (p < 0.001). SR-DLR with k-space properties can offer the benefits of increased spatial resolution without the associated drawbacks of longer scan times and reduced SNR and CNR in intracranial MRA.

Circulus Willis Anomalies Diagnosed with CT Angiography and Evaluation of Their Relations with Ischemic Stroke

Our aim in this study is examining the frequency of posterior communicating artery (PCoM), Anterior Cerebral Artery A1 segment (ACA AI) and Fetal type posterior cerebral artery (FPCA) anomalies and their effects on ischemic stroke by retrospectively analyzing examinations of Computerized Tomography Angiography (CTA) taken in our hospital within 2017. 22 cases (26.5%) diagnosed with bilateral hypoplastic / aplastic PCoA anomaly, were diagnosed with anterior circulation infarct, 24 cases (28.9%) were diagnosed with posterior circulation infarct, but 37 cases (44.6%) were not diagnosed with ischemic stroke. 17 (37.8%) of the cases who have unilateral hypoplastic / aplastic PCoA anomaly, were diagnosed with anterior circulation infarct, 14 cases (31.1%) were diagnosed with posterior circulation infarct. 13 (26%) of 50 cases diagnosed with unilateral hypoplastic / aplastic ACA A1 segment, were diagnosed with anterior circulation infarct, 10 cases (20%) were diagnosed with posterior circulation infarct. 27 cases (54%) were not diagnosed with ischemic stroke. Both of 2 cases diagnosed with bilateral hypoplastic / aplastic ACA A1 segment, had anterior circulation infarct. 4 (30.8%) of 13 cases diagnosed with unilateral FPCA anomaly, were diagnosed with anterior circulation infarct, 3 cases (23.1%) were diagnosed with posterior circulation infarct, 6 cases (46.2%) did not have ischemic stroke symptoms. In conclusion, even though these variations’ role in optimum stroke prophylaxis in individuals having one or more stroke risk factors, has not determined yet, there is no doubt that clinical researcher will eliminate these uncertainties in future studies.

Improving the impact of different input arteries on cerebral CT perfusion parameters and ischemic penumbra

This study aims to examine the impact of different input arteries on cerebral perfusion parameters and the volume of core infarction, ischemic area, and penumbra automatically measured by software in post-processing 256-slice CT brain perfusion images. Retrospective analysis was conducted on brain perfusion images of 58 patients who underwent 256-slice multidetector CT examination for cerebral infarction. Various input arteries, including bilateral internal carotid artery (ICA), bilateral middle cerebral artery (MCA), anterior cerebral artery (ACA), and basilar artery (BA), were selected for image processing and measurements. The volumes of core infarction, ischemic area, and penumbra were automatically calculated using software. Additionally, manual measurements were per-formed by experienced doctors. Perfusion parameters including cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and time to peak (TTP) were evaluated. The change of input artery resulted in a significant difference in CBF and MTT in the penumbra and normal brain tissue areas. However, no significant difference was observed in CBV, TTP, and perfusion parameters in the core infarct area. The volumes of core infarction acquired from different input arteries showed no significant difference. Nonetheless, significant differences were found in the volume of the ischemic area and the mismatched area. The selection of different input arteries affects CT cerebral perfusion parameter values and the automatic measurement of the ischemic area and penumbra by software. Thus, when performing post-processing of CT cerebral perfusion images, it is advisable to choose the thicker internal carotid artery on the healthy side as the input artery.

Coil embolization for ruptured distal anterior cerebral artery aneurysm at the supracallosal portion: Two case reports

Background: Distal anterior cerebral artery (ACA) aneurysms occur more frequently in the genu portion and much less frequently in the supracallosal portion (A4–A5). This report describes two cases of ruptured cerebral aneurysms occurring at the supracallosal portion successfully treated with coil embolization. Case Description: Case 1 involved a 61-year-old female with sudden-onset headache and vomiting attributed to subarachnoid hemorrhage (SAH). Digital subtraction angiography (DSA) revealed a bihemispheric ACA and aneurysm in the supracallosal portion. Coil embolization was performed, and the patient was discharged without neurological deficit. Case 2 involved a 35-year-old man with severe headache and disturbance of consciousness caused by SAH. DSA showed an aneurysm in A4 of the accessory ACA, and coil embolization was performed. After rehabilitation, he was discharged with a modified Rankin scale score of 2. Conclusion: Coil embolization for a ruptured aneurysm at the supracallosal portion can yield good results if the patient is appropriately selected.

Efficacy of enhanced extracorporeal counterpulsation combined with atorvastatin in the treatment of cognitive impairment after stroke.

Cerebral apoplexy patients are prone to cognitive impairment, and it is very important to choose appropriate treatment methods to improve their cognitive impairment after stroke. To evaluate the effects of enhanced external counterpulsation (EECP) in conjunction with atorvastatin on cognitive function, neurotransmitter levels, and the repair of brain tissue damage in patients with cognitive impairment due to stroke. In this retrospective study, data from 60 patients with poststroke cognitive impairment due to stroke who were treated in our hospital from February 2021 to July 2022 were analyzed and divided into a treatment group (n = 30) and a control group (n = 30) according to the different nursing methods applied. Patients in the treatment group received EECP in addition to atorvastatin, while those in the control group received atorvastatin alone. Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA) and activities of daily living (ADL) scale scores were compared between the two groups. Additionally, the two groups were compared in terms of serum acetylcholine (ACh), acetylcholinesterase (AChE), nitric oxide (NO), endothelin-1 (ET-1), β2-microglobulin (β2-MG), glial fibrillary acidic protein (GFAP), and visinin-like protein 1 (VILIP-1) in the serum. Blood flow measurements from the anterior cerebral artery (ACA), middle cerebral artery (MCA) and posterior cerebral artery (PCA) were compared between the two groups before and after treatment, and the pulsatility index (PI) and resistance index (RI) of each artery were determined. MMSE, MoCA, and ADL scores all improved in both groups following treatment, with the study group showing more improvement than the control group (P < 0.05). After treatment, there were statistically significant increases in both ACh and NO levels, whereas decreases occurred in AChE, ET-1, β2-MG, VILIP-1, and GFAP, levels and the PI and RI of the left-ACA, right-ACA, left-MCA, right-MCA, left-PCA, and right-PCA. The study group showed greater gains in all metrics than the control group (P < 0.05). EECP combined with atorvastatin is effective in the treatment of cognitive impairment after stroke and can effectively improve the cognitive function, neurotransmitter levels, and brain tissue damage status of patients.

A data-driven computational methodology towards a pre-hospital Acute Ischaemic Stroke screening tool using haemodynamics waveforms

Background and ObjectiveAcute Ischaemic Stroke (AIS), a significant global health concern, results from occlusions in cerebral arteries, causing irreversible brain damage. Different type of treatments exist depending on the size and location of the occlusion. Challenges persist in achieving faster diagnosis and treatment, which needs to happen in the first hours after the onset of symptoms to maximize the chances of patient recovery. The current diagnostic pipeline, i.e. “drip and ship”, involves diagnostic via advanced imaging tools, only available in large clinical facilities, which poses important delays. This study investigates the feasibility of developing a machine learning model to diagnose and locate occluding blood clots from velocity waveforms, which can be easily be obtained with portable devices such as Doppler Ultrasound. The goal is to explore this approach as a cost-effective and time-efficient alternative to advanced imaging techniques typically available only in large hospitals. MethodsSimulated haemodynamic data is used to conduct blood flow simulations representing healthy and different AIS scenarios using a population-based database. A Machine Learning classification model is trained to solve the inverse problem, this is, detect and locate a potentially occluding thrombus from measured waveforms. The classification process involves two steps. First, the region where the thrombus is located is classified into nine groups, including healthy, left or right large vessel occlusion, left or right anterior cerebral artery, and left or right posterior cerebral artery. In a second step, the bifurcation generation of the thrombus location is classified as small, medium, or large vessel occlusion. ResultsThe proposed methodology is evaluated for data without noise, achieving a true prediction rate exceeding 95% for both classification steps mentioned above. The inclusion of up to 20% noise reduces the true prediction rate to 80% for region detection and 70% for bifurcation generation detection. ConclusionsThis study demonstrates the potential effectiveness and efficiency of using haemodynamic data and machine learning to detect and locate occluding thrombi in AIS patients. Although the geometric and topological data used in this study are idealized, the results suggest that this approach could be applicable in real-world situations with appropriate adjustments. Source code is available in https://github.com/ahmetsenemse/Acute-Ischaemic-Stroke-screening-tool-.

A rare anatomical variation of the circle of Willis in a patient with an ischemic stroke

Purpose &#x0D; The cerebral arterial circuit provides collateral circulation to the brain and protects the brain from ischemia, by sustaining tissue perfusion in case of reduced or impaired blood flow through its branches. Although many random anatomical variations in the circle of Willis (CoW) are of minor importance, some increase the risk of ischemic events, aneurysm, and atherosclerosis, and play an important role in endovascular and surgical treatment planning. &#x0D; Case presentation &#x0D; We report a rare arterial variation of the CoW diagnosed by computed tomography angiography in a patient with ischemic stroke. We found aplasia of the A1 segment of the left anterior cerebral artery and ipsilateral hypoplasia of the P1 segment of the left posterior cerebral artery. &#x0D; Conclusion &#x0D; For neurosurgeons, neurologists, and neuroradiologists, detailed knowledge of the numerous anatomical variations in the arterial supply to the brain is crucial to make a correct diagnosis and choose the appropriate treatment. The type of CoW variation influences stroke severity and outcome, with an incomplete CoW related to more severe conditions (higher National Institutes of Health Stroke Scale scores, more severe neurological deficits, and worse neurological outcomes) and poor prognosis.

Differential sensitivities to blood pressure variations in internal carotid and intracranial arteries: a numerical approach to stroke prediction

Stroke remains a global health concern, necessitating early prediction for effective management. Atherosclerosis-induced internal carotid and intra cranial stenosis contributes significantly to stroke risk. This study explores the relationship between blood pressure and stroke prediction, focusing on internal carotid artery (ICA) branches: middle cerebral artery (MCA), anterior cerebral artery (ACA), and their role in hemodynamics. Computational fluid dynamics (CFD) informed by the Windkessel model were employed to simulate patient-specific ICA models with introduced stenosis. Central to our investigation is the impact of stenosis on blood pressure, flow velocity, and flow rate across these branches, incorporating Fractional Flow Reserve (FFR) analysis. Results highlight differential sensitivities to blood pressure variations, with M1 branch showing high sensitivity, ACA moderate, and M2 minimal. Comparing blood pressure fluctuations between ICA and MCA revealed heightened sensitivity to potential reverse flow compared to ICA and ACA comparisons, emphasizing MCA's role. Blood flow adjustments due to stenosis demonstrated intricate compensatory mechanisms. FFR emerged as a robust predictor of stenosis severity, particularly in the M2 branch. In conclusion, this study provides comprehensive insights into hemodynamic complexities within major intracranial arteries, elucidating the significance of blood pressure variations, flow attributes, and FFR in stenosis contexts. Subject-specific data integration enhances model reliability, aiding stroke risk assessment and advancing cerebrovascular disease understanding.

Fusiform aneurysms of anterior cerebral artery: center experience and systematic literature review

Fusiform aneurysms of anterior cerebral artery: center experience and systematic literature review

Hemodynamic Failure Staging With Blood Oxygenation Level-Dependent Cerebrovascular Reactivity and Acetazolamide-Challenged (15O-)H2O-Positron Emission Tomography Across Individual Cerebrovascular Territories.

Staging of hemodynamic failure (HF) in symptomatic patients with cerebrovascular steno-occlusive disease is required to assess the risk of ischemic stroke. Since the gold standard positron emission tomography-based perfusion reserve is unsuitable as a routine clinical imaging tool, blood oxygenation level-dependent cerebrovascular reactivity (BOLD-CVR) with CO2 is a promising surrogate imaging approach. We investigated the accuracy of standardized BOLD-CVR to classify the extent of HF. Patients with symptomatic unilateral cerebrovascular steno-occlusive disease, who underwent both an acetazolamide challenge (15O-)H2O-positron emission tomography and BOLD-CVR examination, were included. HF staging of vascular territories was assessed using qualitative inspection of the positron emission tomography perfusion reserve images. The optimum BOLD-CVR cutoff points between HF stages 0-1-2 were determined by comparing the quantitative BOLD-CVR data to the qualitative (15O-)H2O-positron emission tomography classification using the 3-dimensional accuracy index to the randomly assigned training and test data sets with the following determination of a single cutoff for clinical application. In the 2-case scenario, classifying data points as HF 0 or 1-2 and HF 0-1 or 2, BOLD-CVR showed an accuracy of >0.7 for all vascular territories for HF 1 and HF 2 cutoff points. In particular, the middle cerebral artery territory had an accuracy of 0.79 for HF 1 and 0.83 for HF 2, whereas the anterior cerebral artery had an accuracy of 0.78 for HF 1 and 0.82 for HF 2. Standardized and clinically accessible BOLD-CVR examinations harbor sufficient data to provide specific cerebrovascular reactivity cutoff points for HF staging across individual vascular territories in symptomatic patients with unilateral cerebrovascular steno-occlusive disease.

Rupture Risk Factors and Strategies for Unruptured Distal Anterior Cerebral Artery Aneurysms

Distal anterior cerebral artery (dACA) aneurysms are rare. Ruptured dACA aneurysms typically present with subarachnoid hemorrhage in conjunction with intracerebral hematoma and cause neurological deterioration. This study aimed to determine their risk of rupture and examine associated factors. We retrospectively analyzed patients with dACA aneurysms to compare patient and aneurysm characteristics between ruptured and unruptured aneurysms. Clinical outcome was used the modified Rankin scale. Univariate analyses were performed to identify rupture risk factors. One hundred three patients with dACA aneurysms were examined (51 ruptured and 52 unruptured). The median aspect ratio of ruptured and unruptured aneurysms was 1.69 and 1.22, respectively (P<0.01). The median maximum diameter of ruptured and unruptured aneurysms was 5.2 and 3.1mm, respectively (P<0.01). The median size ratio of ruptured and unruptured aneurysms was 3.32 and 2.17, respectively (P<0.01). Maximum diameter was <5mm in 45.2% of ruptured dACA aneurysms. dACA aneurysm, showing size ratio >2.4 and aspect ratio >1.4, had ruptured in 71.4% and 78.6%, respectively. We suggested that these are the threshold of size ratio and aspect ratio for rupture of dACA aneurysms. A total percentatge of 78.1% of aneurysms with aspect ratio >1.4 and size ratio >2.4 had ruptured. Distal anterior cerebral artery (dACA) aneurysms may rupture, even when small. We found a significant difference between ruptured and unruptured aneurysms with respect to maximum diameter, aspect ratio, and size ratio. Treatment for small aneurysms should be considered based on size ratio and aspect ratio, not just size.