Assessment of arterial pulsatility of cerebral perforating arteries using 7T high-resolution dual-VENC phase-contrast MRI.

PURPOSE: Directly imaging the function of cerebral perforating arteries could provide valuable insight into the pathology of cerebral small vessel diseases (cSVD). Arterial pulsatility has been identified as a useful biomarker for assessing vascular dysfunction. In this study, we investigate the feasibility and reliability of using dual velocity encoding (VENC) phase-contrast MRI (PC-MRI) to measure the pulsatility of cerebral perforating arteries at 7 T. METHODS: Twenty participants, including 12 young volunteers and 8 elder adults, underwent high-resolution 2D PC-MRI scans with VENCs of 20 cm/s and 40 cm/s at 7T. The sensitivity of perforator detection and the reliability of pulsatility measurement of cerebral perforating arteries using dual-VENC PC-MRI were evaluated by comparison with the single-VENC data. The effects of temporal resolution in the PC-MRI acquisition and aging on the pulsatility measurements were investigated. RESULTS: Compared to the single VENCs, dual-VENC PC-MRI provided improved sensitivity of perforator detection and more reliable pulsatility measurements. Temporal resolution impacted the pulsatility measurements, as decreasing temporal resolution led to an underestimation of pulsatility. Elderly adults had elevated pulsatility in cerebral perforating arteries compared to young adults, but there was no difference in the number of detected perforators between the two age groups. CONCLUSION: Dual-VENC PC-MRI is a reliable imaging method for the assessment of pulsatility of cerebral perforating arteries, which could be useful as a potential imaging biomarker of aging and cSVD.

MRI Assessment of Brain Frailty and Clinical Outcome in Patients With Acute Posterior Perforating Artery Infarction.

BACKGROUND: Global brain health has gained increasing attention recently. Imaging markers of brain frailty have been related to functional outcomes in previous studies on anterior circulation; however, little data are available on imaging markers and posterior circulation. PURPOSE: To investigate the impact of brain frailty on functional outcomes in patients with acute perforating artery infarction (PAI) of the posterior circulation. STUDY TYPE: Prospective. POPULATION: One hundred patients (60.78 ± 9.51 years, 72% men) with acute posterior circulation PAI (determined by diffusion-weighted magnetic resonance imaging (MRI)/time-of-flight MR angiography). FIELD STRENGTH/SEQUENCE: T1- and T2-weighted fast spin echo, T2-weighted fluid-attenuated inversion recovery, diffusion-weighted echo planar, gradient echo (susceptibility-weight imaging), and 3D time-of-flight MR angiography sequences at 3.0 T. ASSESSMENT: Periventricular and deep white matter hyperintensities (WMH), enlarged perivascular spaces (EPVS) in the basal ganglia and centrum semiovale area, lacunes, cerebral microbleeds (CMB), and total brain frailty score by calculating the above imaging characters were rated visually by three radiologists with 9, 10, and 11 years of experience and one neuroradiologist with 12. Infarction volume was assessed using baseline diffusion-weighted imaging (DWI) data obtained within 24 hours of symptom onset. A modified Rankin Scale (mRS) score >1 on day 90 defined an adverse functional outcome. Associations between the imaging markers of brain frailty and functional outcomes were assessed. STATISTICAL TESTS: Fisher's exact test, Mann-Whitney U test, and multivariable binary logistic regression. A P value <0.05 was considered statistically significant. RESULTS: Adverse prognoses (mRS > 1) were observed in 34 (34%) patients. Infarction volume, periventricular WMH, deep WMH, basal ganglia EPVS, CMB, and the brain frailty score were significantly associated with adverse functional outcomes. An increased brain frailty score was significantly associated with unfavorable mRS score on day 90 (odds ratio 1.773, 95% confidence interval 1.237-2.541). DATA CONCLUSION: Advanced MRI imaging markers of brain frailty, individually or combined as a total brain frailty score, were associated with worse functional outcomes after acute posterior circulation PAI. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: Stage 3.

Customized ventral bony and dural opening in the transplanum/transtuberculum and transclival variants of extended endoscopic endonasal approach to suprasellar craniopharyngiomas: an approach-based stepwise cadaveric dissection and clinical applicability.

BACKGROUND: Optimal initial exposure through an extended endoscopic endonasal approach (EEA) for suprasellar craniopharyngiomas ensures safe and unrestricted surgical access while avoiding overexposure, which may prolong the procedure and increase neurovascular adverse events. METHOD: Here, the authors outline the surgical nuances of a customized bony and dural opening through the transplanum/transtuberculum and transclival variants of the extended EEA to suprasellar craniopharyngiomas based on the tumor-pituitary stalk relationship. A stepwise cadaveric dissection and intraoperative photographs relevant to the approaches are also provided. CONCLUSION: Safe maximal resection of suprasellar craniopharyngiomas through extended EEAs can be feasibly and safely achieved by implementing of tailored ventral exposure.

Sequential Development of Putaminal Hemorrhage and Corona Radiata Infarction in the Same Lenticulostriate Arterial Territory.

Putaminal hemorrhage is a common type of spontaneous cerebral hemorrhage. However, to our knowledge, there have been no reports of sequential cerebral hemorrhage and infarction in the same perforating arterial territory. Herein, we present the first reported case of the sequential development of putaminal hemorrhage and corona radiata infarction in the same lenticulostriate arterial (LSA) territory. Early intensive blood pressure lowering treatment may have aggravated ischemic damage. If a patient presents with motor weakness that cannot be explained by putaminal hemorrhage, the sequential development of corona radiata infarction in the same LSA territory should be ruled out.

Delineability and anatomical variations of perforating arteries from normal vertebral artery on 3D DSA: implications for endovascular treatment of dissecting aneurysms.

BACKGROUND AND PURPOSE: Endovascular trapping of the vertebral artery dissecting aneurysms (VADAs) carries a risk of medullary infarction due to the occlusion of the perforating arteries. We evaluated the detectability and anatomical variations of perforating arteries arising from the vertebral artery (VA) using three-dimensional DSA. METHODS: In 120 patients without VA lesions who underwent rotational vertebral arteriography, the anatomical configurations of perforating arteries from the VA were retrospectively evaluated on the bi-plane DSA and reconstructed images to reach the consensus between two experienced reviewers. The images were interpreted by focusing on the numbers and types of perforating arteries, the relationships between the number of perforators and the anatomy of the VA and its branches. RESULTS: Zero, 1, 2, 3, 4, and 6 perforators were detected in 2, 51, 56, 9, 1, and 1 patient, respectively (median of 2 perforators per VA). The 200 perforators were classified into 146 terminal and 54 longitudinal course types and into 32 ventral, 151 lateral, and 17 dorsolateral distribution types. All ventral type perforators were also terminal type. In contrast, the longitudinal type was seen in 28.5% of lateral types and in 65% of dorsolateral types. Regarding the difference in the origin of the posterior inferior cerebellar artery (PICA), non-PICA type VAs gave off larger number of perforators than the other types of VAs. CONCLUSIONS: Non-PICA type VAs give off a significantly larger number of perforators than other types, indicating that the trapping of non-PICA type VAs is associated with a risk of ischemic complications.

Impact of subcallosal artery origin and A1 asymmetry on surgical outcomes of anterior communicating artery aneurysms.

BACKGROUND: Surgical clipping of anterior communicating artery (ACoA) aneurysms remains challenging due to their complex anatomy. Anatomical risk factors for ACoA aneurysm surgery require further elucidation. The aim of this study is to investigate whether proximity of the midline perforating artery, subcallosal artery (SubCA), and associated anomaly of the ACoA complex affect functional outcomes of ACoA aneurysm surgery. METHODS: A total of 92 patients with both unruptured and ruptured ACoA aneurysms, who underwent surgical clipping, were retrospectively analyzed from a multicenter, observational cohort database. Association of ACoA anatomy with SubCA origin at the aneurysmal neck under microsurgical observation was analyzed in the interhemispheric approach subgroup (n = 56). Then, we evaluated whether anatomical factors associated with SubCA neck origin affected surgical outcomes in the entire cohort (both interhemispheric and pterional approaches, n = 92). RESULTS: In the interhemispheric approach cohort, combination of A1 asymmetry and aneurysmal size ≥ 5.0 mm was stratified to have the highest probability of the SubCA neck origin by a decision tree analysis. Then, among the entire cohort using either interhemispheric or pterional approach, combination of A1 asymmetry and aneurysmal size ≥ 5.0 mm was significantly associated with poor functional outcomes by multivariable logistic regression analysis (OR 6.76; 95% CI 1.19-38.5; p = 0.03) as compared with A1 symmetry group in the acute subarachnoid hemorrhage settings. CONCLUSION: Combination of A1 asymmetry and larger aneurysmal size was significantly associated with SubCA aneurysmal neck origin and poor functional outcomes in ACoA aneurysm surgery. Interhemispheric approach may be proposed to provide a wider and unobstructed view of SubCA for ACoA aneurysms with this high-risk anatomical variant.

Thalamic perforating artery stroke on computed tomography perfusion in a patient with coronavirus disease 2019.

Emerging evidence suggests that patients with coronavirus disease 2019 (COVID-19) are at risk of thromboembolic complications, including ischemic strokes. We present a case illustrating the value of CT perfusion to identify acute small subcortical infarcts in a patient with COVID-19 admitted to an intensive care unit for bilateral pneumonia and pulmonary embolism presenting with sudden right limb weakness.

Higher Pulsatility in Cerebral Perforating Arteries in Patients With Small Vessel Disease Related Stroke, a 7T MRI Study.

Background and Purpose- Cerebral small vessel disease (SVD) is a major cause of stroke and dementia, but underlying disease mechanisms are still largely unknown, partly because of the difficulty in assessing small vessel function in vivo. We developed a method to measure blood flow velocity pulsatility in perforating arteries in the basal ganglia and semioval center. We aimed to determine whether this novel method could detect functional abnormalities at the level of the small vessels in patients with stroke attributable to SVD. Methods- We investigated 10 patients with lacunar infarction (mean age 61 years, 80% men), 11 patients with deep intracerebral hemorrhage (ICH) considered to be caused by SVD (ICH, mean age 58 years, 82% men) and 18 healthy controls that were age- and sex-matched. We performed 2-dimensional phase contrast magnetic resonance imaging at 7 T to measure time-resolved blood flow velocity in cerebral perforating arteries of the semioval center and the basal ganglia. We compared the number of detected arteries, pulsatility index and mean velocity between the patient groups and controls. Results- In the basal ganglia, the number of detected perforators was lower in lacunar infarction (26±9, P=0.01) and deep ICH patients (28±6, P=0.02) than in controls (35±7). The pulsatility index in the basal ganglia was higher in lacunar infarction (1.07±0.13, P=0.03), and deep ICH patients (1.02±0.11, P=0.11), than in controls (0.94±0.10). Observations in the semioval center were similar. Number of detected perforators was lower in lacunar infarction (32±18, P=0.06), and deep ICH patients (28±18, P=0.02), than in controls (45±16). The pulsatility index was higher in lacunar infarction (1.18±0.15, P=0.02), and deep ICH patients (1.17±0.14, P=0.045) than in controls (1.08±0.07). No velocity differences were detected. Conclusions- This exploratory study shows that SVD can be expressed in terms of functional measures, such as pulsatility index, which are derived directly from the small vessels themselves. Future studies may use this technique to further unravel the mechanisms underlying SVD.

Vascular reactivity in small cerebral perforating arteries with 7 T phase contrast MRI - A proof of concept study.

Existing cerebrovascular reactivity (CVR) techniques assess flow reactivity in either the largest cerebral vessels or at the level of the parenchyma. We examined the ability of 2D phase contrast MRI at 7 T to measure CVR in small cerebral perforating arteries. Blood flow velocity in perforators was measured in 10 healthy volunteers (mean age 26 years) using a 7 T MR scanner, using phase contrast acquisitions in the semioval center (CSO), the basal ganglia (BG) and the middle cerebral artery (MCA). Changes in flow velocity in response to a hypercapnic breathing challenge were assessed, and expressed as the percentual increase of flow velocity as a function of the increase in end tidal partial pressure of CO2. The hypercapnic challenge increased (fit ±â€¯standard error) flow velocity by 0.7 ±â€¯0.3%/mmHg in the CSO (P < 0.01). Moreover, the number of detected perforators (mean [range]) increased from 63 [27-88] to 108 [61-178] (P < 0.001). In the BG, the hypercapnic challenge increased flow velocity by 1.6 ±â€¯0.5%/mmHg (P < 0.001), and the number of detected perforators increased from 48 [24-66] to 63 [32-91] (P < 0.01). The flow in the MCA increased by 5.2 ±â€¯1.4%/mmHg (P < 0.01). Small vessel specific reactivity can now be measured in perforators of the CSO and BG, using 2D phase contrast at 7 T.

Is the Occlusion Site of the Lenticulostriate Artery Identified on Admission Related to Clinical Prognosis in Patients with Lacunar Stroke?

BACKGROUND: The mechanism of lacunar stroke (LS) is rather speculative due to the lack of neuropathological evidence in clinical practice. To explore the significance of the occlusion site of the lenticulostriate artery (LSA) to this mechanism, we investigated the characteristics and prognosis of patients with LS with proximal occlusions. MATERIALS AND METHODS: We studied 202 patients with acute LS in the region of the LSA. The presumed occlusion site of the LSA was assessed on coronal, diffusion-weighted magnetic resonance images. Based on the distance from the basal surface of the hemisphere to the proximal site of the lacunar infarct, patients were divided into 3 groups: proximal, middle, and distal site occlusions, and their characteristics and outcomes were compared. RESULTS: White blood cell counts, blood glucose, hemoglobin A1c, low-density lipoprotein cholesterol, triglyceride, and admission National Institutes of Health Stroke Scale score were statistically different among the 3 groups. In multivariate analysis, both high levels of white blood cells (odds ratio [OR], 1.16; 95% confidence interval [CI], 1.01-1.33) and triglyceride (OR, 1.31; 95% CI, 1.09-1.61) were positively related to the proximal occlusion site. Proximal occlusion (OR, 3.98; 95% CI, 1.06-16.11) was related to poor outcome at discharge. CONCLUSIONS: Proximal occlusion of the LSA was independently related to elevated triglyceride and white blood cell counts. Patients with LS with proximal LSA occlusion had severe neurological deficits both on admission and at discharge.

Characteristics and surgical strategies for posterior clinoid process meningioma: two case reports and review of the literature.

Clinical and radiological features or characteristics of posterior clinoid process (PCP) meningiomas have rarely been described because of their extreme scarcity and terminological confusion. Therefore, the strategies in the surgical intervention for PCP meningiomas have not been well established. Moreover, the presence of deep and critical neuroanatomical structures and relatively high morbidity, which can be difficult to predict preoperatively, make their surgical excision more challenging. We report two surgical cases of PCP meningioma and discuss the appropriate assessment of preoperative features and surgical strategies with review of the literature. Our study suggests that PCP meningioma may be characterized by the anterior displacement of internal carotid artery, and infero-laterally shifted posterior communicating arteries, and homonymous hemianopsia, a distinctive clinical feature. One of the key issues in PCP meningioma surgery is preservation of the optic nerve. Unlocking the optic nerve by anterior clinoidectomy and dissection, the falciform ligament is the important step to preserve vision for larger tumors. Complication with the perforators is also hazardous of these challenging surgeries than anterior clinoid meningiomas for their specific neuroanatomical structures and might not be feasible to avoid even with additional techniques and critical monitoring. A combination and multi-staged-surgical approach can be options of tailor-made surgical strategy in cases with tumor adhesion to the perforators.

The outcome of a surgical protocol based on ischemia overprotection in large and giant aneurysms of the anterior cerebral circulation.

Aiming to define the optimal treatment of large and giant aneurysms (LGAs) in the anterior circulation, we present our surgical protocol and patient outcome. A series of 42 patients with intracavernous LGAs (n = 16), paraclinoid (C2) LGAs (n = 17), and peripheral (middle cerebral artery-MCA or anterior cerebral artery-ACA) LGAs (n = 9) were treated after bypass under motor evoked potential (MEP) monitoring. Preoperatively, three categories of ischemic tolerance during internal carotid artery (ICA) occlusion were defined on conventional angiography: optimal, suboptimal, and insufficient collaterals. Accordingly, three types of bypass: low flow (LFB), middle flow (MFB) and high flow (HFB) were applied for the cases with optimal, suboptimal, and insufficient collaterals, respectively. Outcome was evaluated by the Glasgow Outcome Scale (GOS). All patients had excellent GOS score except one, who suffered a major ischemic stroke immediately after surgery for a paraclinoid lesion. Forty-one patients were followed up for 87.1 ± 40.1 months (range 13-144 months). Intracavernous LGAs were all treated by proximal occlusion with bypass surgery. Of paraclinoid LGA patients, 15 patients had direct clipping under suction decompression and other 2 patients with recurrent aneurysms had ICA (C2) proximal clipping with HFB. MEP monitoring guided for temporary clipping time and clip repositioning, observing significant MEP changes for up to 6 min duration. Of 9 peripheral LGAs patients 7 MCA LGAs had reconstructive clipping (n = 4) or trapping (n = 3) with bypass including LFB in 3 cases, MFB in 1 and HFB in 1. Two ACA LGAs had clipping (n = 1) or trapping (n = 1) with A3-A3 bypass. The applied protocol provided excellent results in intracavernous, paraclinoid, and peripheral thrombosed LGAs of the anterior circulation.

Lesion patterns of single small subcortical infarct and its association with early neurological deterioration.

Early neurological deterioration (END), happening in the acute phase of infarct, is not rare in patients with single small subcortical infarction (SSSI). The aim of this study was to investigate the lesion patterns of SSSI and its association with END as well as functional outcome at 90 days after onset. 227 patients with acute SSSI in the perforator territory of MCA were prospectively recruited from Yangzhou No.1 People's Hospital between May 2010 and Jan 2014 and divided into proximal SSSI (pSSSI) and distal SSSI (dSSSI) according to the lesion patterns. END was defined as a change in National Institutes of Health Stroke Scale score ≥2 points in the first 72 h after admission. Functional outcome at 90 days after onset was assessed using the modified Rankin Score (mRS) and dichotomized as good (0-2) and poor (≥3). Of them, 93 (40.97%) patients had pSSSI and 134 (59.03%) patients had dSSSI. Univariate analysis found that the risk factors profiles differ significantly between patients with pSSSI and those with dSSSI (P < 0.05). During hospitalization, 60 (26.43%) patients experienced END during the first 72 h after admission, and 46 (22.01%) patients had poor outcome at 90 days after onset. After adjusting for potential confounders, pSSSI pattern (OR 2.242, 95% CI 1.165-4.313, P = 0.016) was an independent predictor of END and that the END (OR 2.637, 95% CI 1.208-5.759, P = 0.015) independently predicted the poor outcome at 90 days after onset. The pSSSI patterns might predict END for patients with SSSI in the MCA perforating territory.

Prediction of early neurologic deterioration in patients with perforating artery territory infarction using machine learning: a retrospective study.

Background: Early neurological deterioration (END) is a frequent complication in patients with perforating artery territory infarction (PAI), leading to poorer outcomes. Therefore, we aimed to apply machine learning (ML) algorithms to predict the occurrence of END in PAI and investigate related risk factors. Methods: This retrospective study analyzed a cohort of PAI patients, excluding those with severe stenosis of the parent artery. We included demographic characteristics, clinical features, laboratory data, and imaging variables. Recursive feature elimination with cross-validation (RFECV) was performed to identify critical features. Seven ML algorithms, namely logistic regression, random forest, adaptive boosting, gradient boosting decision tree, histogram-based gradient boosting, extreme gradient boosting, and category boosting, were developed to predict END in PAI patients using these critical features. We compared the accuracy of these models in predicting outcomes. Additionally, SHapley Additive exPlanations (SHAP) values were introduced to interpret the optimal model and assess the significance of input features. Results: The study enrolled 1,020 PAI patients with a mean age of 60.46 (range 49.11-71.81) years. Of these, 30.39% were women, and 129 (12.65%) experienced END. RFECV selected 13 critical features, including blood urea nitrogen (BUN), total cholesterol (TC), low-density-lipoprotein cholesterol (LDL-C), apolipoprotein B (apoB), atrial fibrillation, loading dual antiplatelet therapy (DAPT), single antiplatelet therapy (SAPT), argatroban, the basal ganglia, the thalamus, the posterior choroidal arteries, maximal axial infarct diameter (measured at < 15 mm), and stroke subtype. The gradient-boosting decision tree had the highest area under the curve (0.914) among the seven ML algorithms. The SHAP analysis identified apoB as the most significant variable for END. Conclusion: Our results suggest that ML algorithms, especially the gradient-boosting decision tree, are effective in predicting the occurrence of END in PAI patients.

Predictive factors for early neurological deterioration after intravenous thrombolysis of single subcortical infarction in the territory of the middle cerebral artery.

INTRODUCTION: Patients with a single subcortical infarction (SSI) in the territory of the middle cerebral artery (MCA) often experience early neurological deterioration (END) despite receiving intravenous thrombolytic therapy (IVT). In this study, predictors of END were investigated in patients with SSI in the MCA after IVT. METHODS: Patients with SSI in the MCA territory who had received IVT between June 2020 and 2022 were included. END was defined as an increase in the total National Institutes of Health Stroke Scale (NIHSS) score by ≥2 or in the motor NIHSS score by ≥1 within the first 72 h of admission. Patients with proximal (pSSI) and distal SSI (dSSI) were analyzed to determine SSI type-specific predictors for END. RESULTS: We evaluated 174 patients with SSI in the MCA territory who underwent IVT. Multivariable logistic regression analysis showed that pSSI (odds ratio [OR] = 0.242; 95% confidence interval [CI], 0.104-0.564; p = .001), lower high-density lipoprotein cholesterol (HDL-C) (OR = 0.150; 95% CI, 0.033-0.682; p = .014), higher blood glucose (OR = 0.858; 95% CI, 0.752-0.979; p = .023), and higher red blood cells count (OR = 1.966; 95% CI, 1.154-3.349; p = .013) were risk factors for END. In patients with pSSI, HDL-C and blood glucose were associated with END. No variable related to END was found in the dSSI group. CONCLUSIONS: The proportion of END in patients with SSI in the MCA territory after IVT was not low; therefore, pSSI, HDL-C, blood glucose, and red blood cells should be monitored closely. The frequency and predictors of SSI in the MCA territory differed between pSSI and dSSI.

Reverse Suction Decompression Using the Superior Thyroid Artery During Clipping of a Complex Anterior Choroidal Artery Aneurysm.

Direct aneurysmal suction decompression was first described by Dr. Flamm in 1981 to improve safety and ease clipping of complex aneurysms by deflating their dome.1 This technique evolved over the following decade, from direct aneurysmal puncture to indirect-reverse-suction decompression (RSD).2,3 The conventional technique for RSD involves a cannulation of the internal (ICA) or common (CCA) carotid arteries.2-9 Direct puncture of either the CCA or ICA carry risk of arterial wall damage (e.g., dissection), which may result in significant morbidity.10,11 We routinely cannulate the superior thyroidal artery (SThA) as the vascular access to perform RSD. This subtle technical nuance prevents dissection of either the CCA or ICA while providing a reliable source for RSD.12 In this operative video, the SThA was cannulated to apply reverse suction decompression, which allowed releasing perforating arteries from the dome of an anterior choroidal artery aneurysm in a 68-year-old lady. The patient tolerated the procedure well, was discharged without neurologic deficits, and resumed normal life with no aneurysm remnant. The patient consented to the procedure and video/photography publication. RSD is an optimal technique to enhance efficiency and safety when dissecting around the dome of a complex intradural ICA aneurysm. The use of the SThA avoids the risk of ICA or CCA wall damage due to access, which defeats the protective purpose of RSD itself. Video 1 provides an educational example of the SThA cannulation technique for RSD during dissection and clipping of a complex anterior choroidal artery aneurysm.

Perfusion Status in Lacunar Stroke: A Pathophysiological Issue.

The pathophysiology of lacunar infarction is an evolving and debated field, where relevant information comes from histopathology, old anatomical studies and animal models. Only in the last years, have neuroimaging techniques allowed a sufficient resolution to directly or indirectly assess the dynamic evolution of small vessel occlusion and to formulate hypotheses about the tissue status and the mechanisms of damage. The core-penumbra concept was extensively explored in large vessel occlusions (LVOs) both from the experimental and clinical point of view. Then, the perfusion thresholds on one side and the neuroimaging techniques studying the perfusion of brain tissue were focused and optimized for LVOs. The presence of a perfusion deficit in the territory of a single small perforating artery was negated for years until the recent proposal of the existence of a perfusion defect in a subgroup of lacunar infarcts by using magnetic resonance imaging (MRI). This last finding opens pathophysiological hypotheses and triggers a neurovascular multidisciplinary reasoning about how to image this perfusion deficit in the acute phase in particular. The aim of this review is to summarize the pathophysiological issues and the application of the core-penumbra hypothesis to lacunar stroke.

The value of diffusion weighted imaging in predicting the clinical progression of perforator artery cerebral infarction.

OBJECTIVES: To investigate the value of diffusion weighted imaging (DWI) in predicting the clinical progression of perforator artery cerebral infarction. METHODS: The magnetic resonance imaging (MRI) data of patients with perforator artery cerebral infarction hospitalized in our hospital from October 2015 to February 2022 were analyzed retrospectively. Then we compared the differences of apparent diffusion coefficient (ADC) value, maximal size, location of cerebral infarction, clinical data and treatment plan between the two groups. RESULTS: A total of 81 patients with perforating artery cerebral infarction were included, with 33 patients in the progressive cerebral infarction (PCI) group and 48 patients in the non-progressive cerebral infarction (NPCI) group. The ADC value in the progressive group was lower than that in the non-progressive group (P < 0.001), and ADC value was an independent factor influencing the clinical progression (OR = 0.974, 95 %CI = 0.960-0.989, P = 0.001); The average area of cerebral infarction in the progressive group was larger than that in the non-progressive group (P = 0.004). There was no difference between the two groups (P > 0.05) in terms of clinical data and treatment plan. CONCLUSIONS: The ADC value and maximal size of infarction were correlated with the clinical Progression. ADC value was an independent factor influencing the clinical progression of perforating artery cerebral infarction, which could be used for the prediction of clinical progress and provide guidance for the development of individualized treatment.

Perforating artery flow velocity and pulsatility in patients with carotid occlusive disease. A 7 tesla MRI study.

Patients with carotid occlusive disease express altered hemodynamics in the post-occlusive vasculature and lesions commonly attributed to cerebral small vessel disease (SVD). We addressed the question if cerebral perforating artery flow measures, using a novel 7T MRI technique, are altered and related to SVD lesion burden in patients with carotid occlusive disease. 21 patients were included with a uni- (18) or bilateral (3) carotid occlusion (64±7 years) and 19 controls (65±10 years). Mean flow velocity and pulsatility in the perforating arteries in the semi-oval center (CSO) and basal ganglia (BG), measured with a 2D phase contrast 7T MRI sequence, were compared between patients and controls, and between hemispheres in patients with unilateral carotid occlusive disease. In patients, relations were assessed between perforating artery flow measures and SVD burden score and white matter hyperintensity (WMH) volume. CSO perforating artery flow velocity was lower in patients than controls, albeit non-significant (mean difference [95% confidence interval] 0.08 cm/s [0.00-0.16]; p = 0.053), but pulsatility was similar (0.07  [-0.04-0.18]; p = 0.23). BG flow velocity and pulsatility did not differ between patients and controls (velocity = 0.28 cm/s [-0.32-0.88]; p = 0.34; pulsatility = 0.00 [-0.10-0.11]; p = 0.97). Patients with unilateral carotid occlusive disease showed no significant interhemispheric flow differences. Though non-significant, within patients lower CSO (p = 0.06) and BG (p = 0.11) flow velocity related to larger WMH volume. Our findings suggest that carotid occlusive disease may be associated with abnormal cerebral perforating artery flow and that this relates to SVD lesion burden in these patients, although our observations need corroboration in larger study populations.