Middle Cerebral Artery Disease Research Articles

Twig-like middle cerebral artery as a variety of isolated middle cerebral artery disease with new vessel formation: illustrative case.

Twig-like middle cerebral artery (T-MCA) is reported as a rare vascular anomaly characterized by reconstitution of the M1 segment of the middle cerebral artery (MCA) by a plexiform network of small vessels. Although it is generally believed that the etiology of T-MCA is an embryological persistence, some investigators have suggested that T-MCA may be a secondary consequence. Here, the authors report a second case of de novo T-MCA formation and reconsider the concept of T-MCA in connection with isolated MCA disease. A 40-year-old man's brain magnetic resonance imaging (MRI) checkup showed moderate stenosis of the M1 segment of the left MCA. Annual MRI follow-up was planned, and when performed 1 year later, it showed occlusion of the M1 segment of the left MCA. Cerebral angiography revealed occlusion of that M1 segment with abnormal arterial networks. This case was diagnosed as de novo T-MCA. The patient has remained asymptomatic for 2 years. The reports of de novo T-MCA indicate that acquired factors may be involved in the pathogenesis of T-MCA. We suggest that T-MCA should be defined as a variety of isolated MCA disease with new vessel formation.

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

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

Biological Mechanism of Sex Difference in Stroke Manifestation and Outcomes.

Female patients tend to have greater disability and worse long-term outcomes after stroke than male patients. To date, the biological basis of sex difference in ischemic stroke remains unclear. We aimed to (1) assess sex differences in clinical manifestation and outcomes of acute ischemic stroke and (2) investigate whether the sex disparity is due to different infarct locations or different impacts of infarct in the same location. This MRI-based multicenter study included 6,464 consecutive patients with acute ischemic stroke (<7 days) from 11 centers in South Korea (May 2011-January 2013). Multivariable statistical and brain mapping methods were used to analyze clinical and imaging data collected prospectively: admission NIH Stroke Scale (NIHSS) score, early neurologic deterioration (END) within 3 weeks, modified Rankin Scale (mRS) score at 3 months, and culprit cerebrovascular lesion (symptomatic large artery steno-occlusion and cerebral infarction) locations. The mean (SD) age was 67.5 (12.6) years, and 2,641 (40.9%) were female patients. Percentage infarct volumes on diffusion-weighted MRI did not differ between female patients and male patients (median 0.14% vs 0.14%, p = 0.35). However, female patients showed higher stroke severity (NIHSS score, median 4 vs 3, p < 0.001) and had more frequent END (adjusted difference 3.5%; p = 0.002) than male patients. Female patients had more frequent striatocapsular lesions (43.6% vs 39.8%, p = 0.001) and less frequent cerebrocortical (48.2% vs. 50.7% in patients older than 52 years, p = 0.06) and cerebellar (9.1% vs. 11.1%, p = 0.009) lesions than male patients, which aligned with angiographic findings: female patients had more prevalent symptomatic steno-occlusion of the middle cerebral artery (MCA) (31.1% vs 25.3%; p < 0.001) compared with male patients, who had more frequent symptomatic steno-occlusion of the extracranial internal carotid artery (14.2% vs 9.3%; p < 0.001) and vertebral artery (6.5% vs 4.7%; p = 0.001). Cortical infarcts in female patients, specifically left-sided parieto-occipital regions, were associated with higher NIHSS scores than expected for similar infarct volumes in male patients. Consequently, female patients had a higher likelihood of unfavorable functional outcome (mRS score >2) than male patients (adjusted absolute difference 4.5%; 95% CI 2.0-7.0; p < 0.001). Female patients have more frequent MCA disease and striatocapsular motor pathway involvement with acute ischemic stroke, along with left parieto-occipital cortical infarcts showing greater severity for equivalent infarct volumes than in male patients. This leads to more severe initial neurologic symptoms, higher susceptibility to neurologic worsening, and less 3-month functional independence, when compared with male patients.

Clonal hematopoiesis due to mosaic chromosomal alterations: Impact on disease risk and mortality

Mosaic chromosomal alterations (mCAs) are the clonal expansion of large somatically acquired structural chromosomal changes present on the autosomes and sex chromosomes. Most studies of mCAs use existing genotype array intensity data from large populations to investigate potential risk factors and disease outcomes associated with mCAs. In this review, we perform a comprehensive examination of existing evidence for mCA disease and mortality associations and provide a framework for interpreting these associations in the context of important biases specific to mCA studies. Our goal is to motivate well-designed mCA studies to assist in unlocking the potential of mCAs to improve understanding of the effects of ageing and accelerate translational applications for improving public health.

Misery Perfusion and Tau Deposition in Atherosclerotic Major Cerebral Artery Disease: A 18F-Florzolotau Positron Emission Tomography Study.

Studies using animal models have shown that cerebral hypoperfusion causes hyperphosphorylation of tau protein, leading to neuronal damage. However, the relationship between hypoperfusion and tau deposition in humans is unclear. Hence, we aimed to determine whether cerebral hypoperfusion leading to decreased blood flow relative to metabolic demand [increased oxygen extraction fraction (OEF), misery perfusion] is associated with increased tau deposition in patients with atherosclerotic internal carotid artery or middle cerebral artery disease. We prospectively evaluated the distribution of tau aggregate deposition using positron emission tomography and 18F-florzolotau (PMPBB3 [1-fluoro-3-((2-((1E,3E)-4-(6-(methylamino)pyridine-3-yl)buta-1,3-dien-1-yl)benzo[d]thiazol-6-yl)oxy)propan-2-ol)]) in 8 patients with atherosclerotic disease of the internal carotid artery or middle cerebral artery. The standardized uptake value ratio of 18F-florzolotau at 100 to 110 minutes after injection was calculated using the cerebellar cortex as a reference region and was correlated with OEF obtained from 15O-gas positron emission tomography in the middle cerebral artery distributions. Significant decreases in cerebral blood flow and cerebral metabolic rate of oxygen and increases in OEF were found in the hemisphere ipsilateral to the arterial lesion. 18F-florzolotau standardized uptake value ratio in this region was also greater than that in the contralateral hemisphere. In the ipsilateral hemisphere, 18F-florzolotau standardized uptake value ratio positively correlated with OEF values. This pilot study with a small sample size suggests that increases in OEF-misery perfusion-may be associated with increased tau aggregates deposition in atherosclerotic internal carotid artery or middle cerebral artery disease.

Neck-brain integrated ultrasound as a noninvasive screening tool to identify morphological features of middle cerebral artery disease

Background and aimsEndovascular treatment is suitable for middle cerebral artery (MCA) with focal lesion. Therefore, accurate evaluation of the morphological features of MCA disease is critical. Ultrasonography is commonly used to screen for MCA lesions. However, there are few studies on lesion length. Using ultrasonography, we aimed to prospectively evaluate MCA disease with focal stenosis, long stenosis, focal occlusion, and long occlusion. MethodsPatients with symptomatic MCA disease scheduled for digital subtraction angiography were enrolled. The ultrasonic parameters recorded included mean flow velocity at MCA (VMCA) and extracranial internal carotid artery (VICA), bilateral VMCA ratio, bilateral VICA ratio, and MCA flow continuity. ResultsA total of 278 MCAs were included. Compared to normal vessels, the bilateral VMCA ratio increased in the focal stenosis group and decreased in the long lesion and focal occlusion groups (all p < 0.05); the VICA and bilateral VICA ratio decreased in the long lesion group (all p < 0.01), and there was no significant difference in the focal lesion group (all p > 0.05). The optimal cut-offs were bilateral VMCA ratio <0.80 to predict long lesions and focal occlusions (sensitivity: 0.898, specificity: 0.975), and bilateral VICA ratio <0.84 to predict long lesions (sensitivity: 0.704, specificity: 0.879). The sensitivity and specificity to predict long occlusions were 96.7% and 94.8%, respectively, in the absence of MCA flow continuity. ConclusionsNeck-brain integrated ultrasound is an appropriate screening method for identifying MCA lesions with different morphologies. Endovascular treatment might not be recommended when bilateral VICA ratio <0.84 in patients with MCA lesions.

Neuronal Alterations in Secondary Thalamic Degeneration Due to Cerebral Infarction: A 11C-Flumazenil Positron Emission Tomography Study.

Background:Studies using animal experiments have shown secondary neuronal degeneration in the thalamus after cerebral infarction. Neuroimaging studies in humans have revealed changes in imaging parameters in the thalamus, remote to the infarction. However, few studies have directly demonstrated neuronal changes in the thalamus in vivo. The purpose of this study was to determine whether secondary thalamic neuronal damage may manifest as a decrease in central benzodiazepine receptors in patients with cerebral infarction and internal carotid artery or middle cerebral artery disease.Methods:We retrospectively analyzed the data of 140 patients with unilateral cerebral infarction ipsilateral to internal carotid artery or middle cerebral artery disease. All patients had quantitative measurements of 11C-flumazenil binding potential (FMZ-BP), cerebral blood flow, and cerebral metabolic rate of oxygen using positron emission tomography in the chronic stage. Region of interest analysis was performed using NeuroFlexer—an automated region of interest analysis software using NEUROSTAT.Results:In the thalamus ipsilateral to the infarcts, the values of FMZ-BP, cerebral blood flow, and cerebral metabolic rate of oxygen were significantly lower than those in the contralateral thalamus. Significant correlations were found between the ipsilateral-to-contralateral ratio of FMZ-BP and the ipsilateral-to-contralateral ratio of cerebral blood flow or cerebral metabolic rate of oxygen in the thalamus. Patients with corona radiata infarcts and striatocapsular infarcts had significantly decreased ipsilateral-to-contralateral FMZ-BP ratio in the thalamus compared with those without. The ipsilateral-to-contralateral ratio of FMZ-BP in the thalamus was significantly correlated with the ipsilateral-to-contralateral cerebral metabolic rate of oxygen ratio in the frontal cortex and showed a significant negative correlation with the number of perseverative errors on the Wisconsin Card Sorting Test.Conclusions:Secondary thalamic neuronal damage may manifest as a decrease in central benzodiazepine receptors in patients with cerebral infarction and internal carotid artery or middle cerebral artery disease, which may be associated with frontal lobe dysfunction.

Characterization of Moyamoya and Middle Cerebral Artery Diseases by Carotid Canal Diameter and RNF213 p.R4810K Genotype

ObjectivesIt is sometimes difficult to differentiate middle cerebral artery disease from moyamoya disease because the two can present similarly yet have different treatment strategies. We investigated whether the presence of a narrow carotid canal and the RNF213 mutation can help differentiate between the two phenotypes. Population and MethodsWe analyzed 78 patients with moyamoya disease, 27 patients with middle cerebral artery disease, and 79 controls from 2 facilities. The carotid canal diameter was measured using computed tomography. The p.R4810K mutation was genotyped by TaqMan assay. A receiver operating characteristics analysis was performed to assess the significance of the carotid canal diameter for the accurate diagnosis of moyamoya disease. ResultsThe carotid canal diameter was significantly narrower in patients with moyamoya disease than in controls. The optimal cutoff values were 5.0 mm for adult males and 4.5 mm for adult females and children (sensitivity: 0.82; specificity: 0.92). Among the patients with middle cerebral artery disease, 18.5% and 25.0% of the affected hemispheres had the p.R4810K mutation and narrow canal (i.e., below the cutoff), respectively, whereas only 3.1% of those had both. Contrastingly, 68.8% of the affected hemispheres in patients with moyamoya disease had both these characteristics. Among the patients with moyamoya disease, those with the p.R4810K mutation tended to have narrower carotid canals. ConclusionsAlthough the presence of a narrow carotid canal or the p.R4810K mutation alone could not be used to distinguish those with moyamoya disease from those with middle cerebral artery disease, the combination of these factors could better characterize the two phenotypes.

The role of hypertension and diabetes mellitus on the etiology of middle cerebral artery disease.

BackgroundIschemic stroke (IS) caused by middle cerebral artery (MCA) disease is the most common type of IS caused by intracranial artery disease in the Chinese population. Hypertension and diabetes mellitus are the common risk factors of cerebral small vessel disease and large artery atherosclerosis (LAA). However, little is known about whether hypertension and diabetes mellitus had different correlations with the small artery occlusion (SAO) and LAA etiology of MCA disease. Therefore, our aim was to identify the predictors of the etiology of MCA disease.MethodsWe consecutively enrolled 967 patients with noncardiogenic IS in unilateral MCA territory. Vascular risk factors and the clinical–radiologic features of IS were analyzed. The etiology of IS were classified as SAO or LAA according to the Stop Stroke Study Trial of Org 10172 in Acute Stroke Treatment classification criteria. Multivariable logistic regression was used to identify the differences in the predictors between SAO and LAA etiology of MCA disease.ResultsMultivariable logistic regression identified male and hypertension as the predictors of the SAO etiology of MCA disease, however diabetes mellitus, repeated transient ischemic attack before the stroke, gaze palsy, aphasia, headache at admission, and disability at discharge as the predictors of the LAA etiology of MCA disease.ConclusionHypertension and diabetes mellitus are related with the different etiology of MCA disease.

High-resolution MR vessel wall imaging in determining the stroke aetiology and risk stratification in isolated middle cerebral artery disease

High-resolution MR vessel wall imaging (HRVWI) can characterise vessel wall pathology affecting intracranial circulation and helps in differentiating intracranial vasculopathies. The aim was to differentiate intracranial pathologies involving middle cerebral artery (MCA) in patients with ischemic stroke and characterise the high-risk plaques in intracranial atherosclerotic disease (ICAD) using HRVWI. Patients with ischemic stroke with isolated MCA disease with ≥ 50% luminal narrowing by vascular imaging were enrolled within 2weeks of onset and underwent high-resolution (3T) intracranial vessel wall imaging (VWI). The pattern of vessel wall thickening, high signal on T1-weighted images, juxtaluminal hyperintensity, pattern and grade of enhancement were studied. The TOAST classification before and after HRVWI and the correlation of the recurrence of ischemic events at 3months with imaging characteristics were analysed. Of the 36 patients, the mean age was 49.53 ± 15.61years. After luminal imaging, by TOAST classification, 12 of 36 patients had stroke of undetermined aetiology. After vessel wall imaging, lesions in MCA were analysed. Of them, 23 patients had ICAD, 8 had vasculitis, and 2 had partially occlusive thrombus in MCA. The ability of HRVWI to bring a change in diagnosis was significant (p = 0.031). Of the 23 patients with ICAD, 12 patients had recurrent strokes within 3months. The presence of grade 2 contrast enhancement (p = 0.02) and type 2 wall thickening (p = 0.03) showed a statistically significant association with recurrent ischemic events. High-resolution MRVWI can help in identifying the aetiology of stroke. The HRVWI characteristics in ICAD can help in risk stratification.

Visit-to-Visit Blood PressureVariations and Hemodynamic Deterioration in Atherosclerotic Major Cerebral ArteryDisease

ObjectiveVisit-to-visit variations in blood pressure (BP) in patients with atherosclerotic major cerebral artery disease could impair the function of cerebral collaterals, leading to hemodynamic deterioration at follow-up. However, few studies have investigated the relationship between visit-to-visit BP variability and changes in hemodynamic parameters at follow-up. Materials and methodsWe evaluated 35 medically treated patients with atherosclerotic internal carotid artery or middle cerebral artery disease with no ischemic episodes during follow-up (mean: 35 ± 20 months); these patients had a three-time visit for positron emission tomography examinations with 15O-gas. Differences in the mean hemispheric values of hemodynamic parameters in the cortical territory of the diseased artery between the first and third examinations (changes at follow-up) were correlated with the coefficient of variation (CoV) in three systolic BP (SBP) values at the three examinations (BP variability during follow-up). ResultsCoV values were negatively correlated with changes in oxygen metabolism or cerebral blood flow/cerebral blood volume (CBF/CBV) ratio. In 17 patients with higher CoV values (> group median, 0.072), decreases in CBF, cerebral metabolic rate of oxygen, and CBF/CBV ratio were observed at follow-up; CBV decreased in 18 patients without elevated CoV. A higher CoV was associated with a lack of statin use. ConclusionIn patients with atherosclerotic major cerebral artery disease, high visit-to-visit SBP variations during follow-up may be associated with deterioration in cerebral hemodynamics and metabolism.

Incident disease associations with mosaic chromosomal alterations on autosomes, X and Y chromosomes: insights from a phenome-wide association study in the UK Biobank

BackgroundMosaic chromosomal alterations (mCAs) are large chromosomal gains, losses and copy-neutral losses of heterozygosity (LOH) in peripheral leukocytes. While many individuals with detectable mCAs have no notable adverse outcomes, mCA-associated gene dosage alterations as well as clonal expansion of mutated leukocyte clones could increase susceptibility to disease.ResultsWe performed a phenome-wide association study (PheWAS) using existing data from 482,396 UK Biobank (UKBB) participants to investigate potential associations between mCAs and incident disease. Of the 1290 ICD codes we examined, our adjusted analysis identified a total of 50 incident disease outcomes associated with mCAs at PheWAS significance levels. We observed striking differences in the diseases associated with each type of alteration, with autosomal mCAs most associated with increased hematologic malignancies, incident infections and possibly cancer therapy-related conditions. Alterations of chromosome X were associated with increased lymphoid leukemia risk and, mCAs of chromosome Y were linked to potential reduced metabolic disease risk.ConclusionsOur findings demonstrate that a wide range of diseases are potential sequelae of mCAs and highlight the critical importance of careful covariate adjustment in mCA disease association studies.

Clinical Application of Transcranial Color Doppler Ultrasound in Carotid Endarterectomy

Ischemic cerebrovascular diseases are important duet to the high incidence, disability, mortality, and recurrence. Intracranial arterial stenosis caused by atherosclerosis is an important pathological basis of ischemic cerebrovascular disease. Therefore, convenient, non-invasive, cheap and accurate screening methods have become the goal of everyone's joint efforts. The purpose of this study was to investigate the value of transcranial Doppler in judging arterial stenosis, and to explore the best cut-off point for assessing the blood flow velocity of middle cerebral artery disease and the compensation of the posterior branch of middle cerebral artery disease. Using retrospective analysis, binomial logistic regression analysis was performed on risk factors related to ischemic cerebrovascular disease. The 60 patients with intracranial stenosis were selected for TCD (Transcranial Color Doppler) and CTA (Computed Tomography Angiography) examinations within one week of onset. CTA was used as the diagnostic criterion to analyze the accuracy of TCD in the diagnosis of intracranial arterial disease. ROC (Receiver Operating Characteristic) curve was used to determine the optimal cutoff point of blood flow velocity for MCA (Middle Cerebral Artery) lesions. TCD has high specificity and sensitivity in the diagnosis of intracranial arterial disease, and it can be widely used in clinic as a simple, convenient and cheap diagnostic method for screening intracranial arterial stenosis.

Significance of Carotid Canal Plasticity and the RNF213 p.R4810K Mutation in Distinguishing Moyamoya Disease From Middle Cerebral Artery Disease

Oichi, Yuki; Mineharu, Yohei; Morimoto, Takaaki; Agawa, Yuji; Funaki, Takeshi; Hitomi, Toshiaki; Kobayashi, Hatasu; Todo, Kenichi; Tani, Shoichi; Imamura, Hirotoshi; Koizumi, Akio; Sakai, Nobuyuki; Miyamoyo, Susumu Author Information

Mechanism of Stroke According to the Severity and Location of Atherosclerotic Middle Cerebral Artery Disease

Background and purposeStrategy for secondary prevention of ischemic stroke depends on the mechanism of stroke. The aim of this study was to compare the stroke mechanism according to the location and severity of middle cerebral artery (MCA) disease. MethodsWe analyzed acute ischemic stroke patients within 7 days of onset with symptomatic MCA disease. The location of MCA disease was classified into proximal MCA M1 (pMCA) and distal MCA M1/proximal M2 (dMCA). The mechanism of stroke was categorized according to the pattern of ischemic lesion: local branch occlusion, artery-to-artery embolism/hemodynamic infarction, in situ-thrombosis, or a combined mechanism. The mechanism and imaging characteristics of stroke were compared according to the location and severity. The factors associated with the stroke mechanism were also investigated. ResultsA symptomatic MCA disease was observed in 126 patients (74 pMCA and 52 dMCA). The mechanism of stroke differed according to the location (p < 0.001); the combined mechanism was most common in pMCA disease (54.1%), especially in those who presented with MCA occlusion and with a susceptible vessel sign. Artery-to-artery embolism/hemodynamic infarction was most common in dMCA disease (46.2%). A longer length of stenosis was observed in local branch occlusion than in other mechanisms (p = 0.04) and was an independent factor associated with local branch occlusion (OR=1.631, 95% CI=1.161–2.292; p = 0.005). ConclusionsThe mechanism of stroke differed according to the location of MCA disease: occlusion caused by plaque rupture with combined mechanism of stroke type was predominant in pMCA. Longer length of stenosis was associated with local branch occlusion.

Plaque Distribution Correlates With Morphology of Lenticulostriate Arteries in Single Subcortical Infarctions.

We aimed to use novel whole-brain vessel-wall magnetic resonance imaging (WB-VWI) to investigate the association between plaque distribution of middle cerebral artery (MCA) and morphological changes of the lenticulostriate arteries (LSAs) in single subcortical infarctions. Forty single subcortical infarction patients with no relevant MCA disease on magnetic resonance angiography were prospectively enrolled. Plaque location in the MCA was dichotomized as proximal (located adjacent to the LSA origin) or distal (located distal to the LSA origin) on whole-brain vessel-wall magnetic resonance imaging. The MCAs with proximal plaques were divided into the symptomatic and asymptomatic side, and asymptomatic side MCAs without proximal plaques were the control group. The morphological characteristics of the LSAs and features of proximal plaques were analyzed. A total of 71 MCAs in 40 patients were analyzed (31 on the symptomatic side, 22 on the asymptomatic side, and 18 in the control group). Superior-wall plaques of MCAs were observed more frequently on the symptomatic side than the asymptomatic side (45.2% versus 9.1%, P=0.005). The wall area index, plaque burden, and remodeling index did not differ significantly between the symptomatic and asymptomatic side. The number of LSA branches was smaller (P=0.011) in the symptomatic side (5.48±1.88) compared with the control group (6.83±1.92). The symptomatic side exhibited shorter average length of the LSAs (23.23±3.44 versus 25.75±3.76 mm, P=0.025) and shorter average distance of the LSAs (16.47±3.11 versus 21.53±4.76 mm, P<0.001) compared with the asymptomatic side. Superiorly distributed MCA plaques at the LSA origin are closely associated with morphological changes of the LSA in symptomatic MCAs, suggesting that the distribution, rather than the inherent features of plaques, determines the occurrence of single subcortical infarctions. Our findings provide insight into the etiologic mechanism of branch atheromatous disease in single subcortical infarctions.

Mismatch of cognition and neural networks in asymptomatic middle cerebral artery steno-occlusive disease.

The role of intracranial steno-occlusive disease in cognitive impairment and dementia is unclear and has not been well studied. A total of 32 consecutive patients (13 males, aged 54±12years) with asymptomatic steno-occlusive middle cerebral artery (MCA) disease, defined as >70% stenosis on maximum intensity projection images or a complete signal loss of MCA trunk on magnetic resonance angiography, and 20 age- and education-matched normal controls (12 males, 60±8years old) were compared for neuropsychological performance, gray matter volume and neural network analysis. The patient group did not show a significant decrease in gray matter volume or cognitive tests except for their performance on the grooved pegboard test. However, graph analysis of resting-state functional magnetic resonance imaging showed significant decreases in network strength, global efficiency and the clustering coefficient, as well as a longer characteristic path length (P<0.05). The diffusive decrease pattern was particularly located in interhemispheric connectivity and there was no compensatory hyperconnectivity in any brain regions. In asymptomatic steno-occlusive MCA disease, cognition and neural network changes are mismatched and have underlying pathophysiological mechanisms that are different from those of neurodegenerative disease.

Clinical, imaging features and outcome in internal carotid artery versus middle cerebral artery disease.

BackgroundOnly a very few studies had compared the differences in topographic patterns of cerebral infarcts between middle cerebral artery (MCA) and internal carotid artery (ICA) disease. Besides, the comparison of clinical features and outcomes between MCA and ICA disease had rarely been reported.ObjectivesTo compare the clinical, imaging features and outcome of MCA versus ICA disease.MethodsWe prospectively enrolled 1172 patients with noncardiogenic ischemic stroke in ipsilateral ICA or MCA territory. Clinical, neuroradiologic and outcome of the two groups were compared in this observational cohort study.ResultsThe ICA group more frequently presented with decreased alertness, gaze palsy, aphasia, and neglect than the MCA group at admission, and more often had higher National Institute of Health stroke scale score at admission and discharge. Meanwhile, the ICA group more frequently had multiple acute infarcts, watershed infarcts, territorial infarct, small cortical infarct, and responsible artery stenosis ≥70%. Whereas penetrating artery infarct and parent artery occluding penetrating artery was more often associated with MCA disease. The ICA group more frequently had inhospital complications of pneumonia and deep vein thrombosis, more often had disability at discharge, and had more recurrent ischemic stroke or transient ischemic attack in 1 Year. Multivariable logistic regression identified male (OR, 1.99; 95% CI, 1.30 to 3.05; P = 0.002), history of coronary heart disease (OR, 1.85; 95% CI, 1.03 to 3.32; P = 0.041), multiple acute infarcts (OR, 4.18; 95% CI, 2.07 to 8.45; P<0.0001), and territorial infarct (OR, 2.23; 95% CI, 1.52 to 3.27; P<0.0001) was more often associated with ICA territory disease.ConclusionsThe clinical, radiologic characteristics and outcome are distinctively different between ICA and MCA disease. Compared to MCA disease, ICA disease has more serious clinical and radiologic manifestation, and poorer outcome.

Selective neuronal damage and blood pressure in atherosclerotic major cerebral artery disease

ObjectiveIn patients with atherosclerotic major cerebral artery disease, low blood pressure might impair cerebral perfusion, thereby exacerbate the risk of selective neuronal damage. The purpose of this retrospective study was...

Misery perfusion and amyloid deposition in atherosclerotic major cerebral artery disease.

Although experimental studies have shown that global cerebral hypoperfusion leads to amyloid deposition in the hemisphere with carotid artery occlusion in rodents, the results of such occurrence are controversial in humans. Hence, we aim to determine whether global cerebral hypoperfusion leading to decreased blood flow relative to metabolic demand [increased oxygen extraction fraction (OEF), misery perfusion] is associated with increases in amyloid deposition in the hemisphere with atherosclerotic major cerebral artery disease in patients. We evaluated the distribution of β-amyloid plaques using positron emission tomography and a [18F]-pyridylbenzofuran derivative (18F-FPYBF-2) in 13 patients with unilateral atherosclerotic disease of the internal carotid artery (ICA) or middle cerebral artery (MCA) disease and no cortical infarction. The distribution volume ratio (DVR) of 18F- FPYBF-2 was calculated using dynamic data and Logan graphical analysis with reference tissue and was correlated with the cerebral blood flow (CBF), cerebral metabolic rate of oxygen (CMRO2), and OEF, obtained from 15O-gas PET. The mean cortical value was calculated as the mean value within the frontal, posterior cingulate, precuneus, parietal, and lateral temporal cortical regions. Significant reductions in CBF and CMRO2 and increases in OEF were found in the hemisphere ipsilateral to the arterial lesion compared with the contralateral hemisphere. There was no significant difference for 18F-FPYBF-2 DVR between hemispheres. The ipsilateral to contralateral ratio of the 18F- FPYBF-2 DVR was increased in 3 patients, while the ipsilateral to contralateral OEF ratio was increased in 4 patients. The incidence of an increased hemispheric DVR ratio was significantly higher in patients with an increased hemispheric OEF ratio (3/4) than in patients without (0/9) (p < 0.02). Although the 18F- FPYBF-2 DVR in the ipsilateral hemisphere was positively correlated with OEF after adjustment for the 18F- FPYBF-2 DVR in the contralateral hemisphere using multiple regression analysis (p < 0.05), the contribution rate of OEF was small (R2 = 5.5%). Only one of the 4 patients with an increased hemispheric OEF ratio showed amyloid positivity based on the DVR value. In atherosclerotic major cerebral artery disease, misery perfusion accompanied only small increases of amyloid deposition at best. Misery perfusion was not associated with amyloid positivity.