Moyamoya disease is a rare cerebrovascular disease.Its incidence is higher in the East Asia.The pathogenesis of MMD remains unclear at present,but the epidemiological research both at home and abroad suggests that the genetic factors play an important role in the onset of MMD.This article briefly reviews the recent progress in research on MMD related genes.

Moyamoya disease is an uncommon cerebral disease, but its morbidity is relatively high in East Asian populations. Ivy sign refers to the dot or linear high signal phenomenon in MRI T1 enhanced sequence in patients with moyamoya disease. It mainly distributes in the pial surface of cerebral cortex or within subarachnoid space. It has important significance for diagnosing moyamoya disease and assessing the staging and prognosis of moyamoya disease. This article briefly reviews this imaging finding and its significance.

Cerebral hemodynamic changes are an important pathophysiologic process for the occurrence and development of Moyamoya disease. Cerebral hemodynamic changes of Moyamoya disease have been a research focus. This article mainly reviews the cerebral hemodynamic parameters and detecting methods, characteristics of cerebral hemodynamic changes in patients with Moyamoya disease and their new progress.

Objective To investigate the related risk factors for small artery occlusion (SAO) and its 2 subtypes. Methods The clinical and imaging data in 291 patients with first-ever stroke who met the TOAST criteria of large artery atherosclerotic stroke (LAA) or SAO were collected from the Nanjing Stroke Registry Prog-am from December 2009 to November 2010. All the patients were divided into a LAA group (n = 120) and a SAO group (n = 171). The latter was redivided into either a lacunar infarction with ischemic leukoaraiosis (ILA) subgroup (n = 84)or an isolated lacunar infarction (ILI) subgroup (n = 87). The risk factors of the LAA group and SAO group and its subgroups were compared. Multivariate logistic regression analysis was conducted and the independent risk factors were screened. Results The mean age in the SAO group was larger than that in the LAA group. The proportion of the patients with hypertension and the serum homocysteine (Hcy) level were significantly higher than those in the LAA group (all P ＜0. 05). Multivariate logistic analysis showed that the advanced age (odds ratio, [OR] = 1.041,95% confidence interval [CI] 1.02-1.06, P = 0.045), hypertension (OR = 2. 912,95% CI 1. 11-6. 46, P =0. 031) and increased plasma Hcy (OR = 1. 109, 95% CI 1. 11-1. 32, P =0. 001) were the independent risk factors for SAO. The advanced age (OR = 1. 047,95% CI 1.00-1.09, P = 0.043), hypertension (OR = 2. 632, 95% CI 1.08-6.41, P= 0.033) and increased plasma Hcy (OR = 1. 211, 95% CI 1. 11-1. 32, P ＜0. 001) were the independent risk factors for ILA, while the hypercholesterolemia (OR =0. 136, 95% CI 0. 05-0. 37, P ＜0. 001) was the independent risk factor for ILI. Conclusions The advanced age, hypertension and increased plasma Hcy level may play important roles in the pathogenesis of SAO. The hypercholesterolemia is an independent risk factor for ILI, while advanced age, hypertension and increased plasma Hcy level are the independent risk factors for ILA.

Objective To investigate the value of hyperintense vessel signs (HVS) on fluidattenuated inversion recovery (FLAIR) sequence for assessing the patterns of collateral blood flow in adult moyamoya disease (MMD).Methods Forty-one adult patients with non-hemorrhagic MMD retrieved from Nanjing Stroke Registry Program between August 2008 and January 2011 were identified by digital cerebral angiography and performed the examination of FLAIR sequence in Jinling hospital.According to the different sites of HVS located in the territory of the middle cerebral artery,the patterns of HVS were classified into grades 0-3: Grade 0,absence of HVS ; Grade 1,HVS limited in the cerebral sulci of temporal lobe and Sylvian fissure ; Grade 2,HVS in the cerebral sulci of frontal and parietal lobe regions and Sylvian fissure;and Grade 3,HVS in the combined territories of Grade 1 and Grade 2.According to the intracerebral collateral blood flow,steno-occlusions of the arteries were classified into three types: Type 1,residual antegrade flow across steno-occlusive lesions; Type 2,retrograde flow via leptomeningeal vessels; Type 3,the combined collateral blood flow of Type 1 and Type 2.The relationship between the patterns of intracerebral collateral blood flow and the location of HVS was analyzed.Results Of 41 adult patients with non-hemorrhagic MMD,there were 3 patients presented with unilateral vascular lesions and 38 with bilateral vascular lesions,so the total number of vascular lesions of the cerebral hemispheres was 79.Because three patients showed the absence of HVS in bilateral hemispheres,the total number of the presence of HVS of the cerebral hemispheres was 73.Therefore,the percentage of the presence of HVS was 92.4％ (73/79) in vascular lesions of the cerebral hemispheres.Importantly,the patterns of slow collateral blood flow corresponding to Grade 1 HVS were all antegrade (7/7) ; the collateral patterns corresponding to Grade 2 HVS were mainly retrograde leptomeningeal flow (95.0％,19/20) ; and the patterns corresponding to Grade 3 HVS were mainly slow combined collateral blood flow(84.8％,39/46).Furthermore,with the changing sites of HVS from the cerebral sulci of temporal lobe to the cerebral sulci of frontal and parietal lobe regions,the directions of collateral flow changed with a shift from antegrade to retrograde,which was statistically significant.Conclusion The different locations of HVS can reflect the different patterns of collateral blood flow,and the locations of HVS may predict the directions of intracerebral collateral blood flow in adult MMD patients.

Objective To investigate the possible formation mechanism and imaging features of the hyperintense vessel sign (HVS) on fluid attenuated inversion recovery (FLAIR) in patients with ischemic stroke or transient ischemic attack (TIA).Methods The baseline data of the patients with middle cerebral artery (MCA) ischemic stroke or TIA with digital subtraction angiography (DSA) showing the lesions of MCA M1 segment in clinical practice were retrospectively retrieved from Nanjing Stroke Registry Program from January 2010 to July 2011.FLAIR was used to observe HVS,and DSA was used to evaluate the degree of vascular stenosis and cerebral collateral circulation.Results A total of 101 patients were enrolled,76 (75.2％) were males,and their mean age was 53.94 ± 13.47 years; 90 patients (89.1％) with ischemic stroke and 11 patients (10.9％) with TIA; 55 patients (54.5％) were HVS negative and 46 (45.5％) were HVS positive.Among the patients whose MCA stenosis ＜50％,50％-70％,70％-90％ and ≥90％,the positive rates were 0％ (0/8),25.0％ (3/12),17.6％ (3/17),and 62.5％ (40/64),respectively.There were significant differences (Z=-4.479,P＜ 0.001).The leptomeningeal collateral circulation of the HVS positive group was significantly more than that of the HVS negative group (Z =-6.196,P ＜ 0.001).Multivariate logistic regression analysis showed that the degree of MCA stenosis was an independent risk factor for influencing the formation of HVS (odds ratio 3.943,95％ confidence interval 2.03-7.659; P ＜0.001).Conclusions The formed intracranial leptomeningeal colhteral circulation after severe intracranial vascular stenosis or occlusion is a major pathophysiological basis of HVS formation on FLAIR sequences in patients with ischemic stroke or TIA.

Objective To investigated the effect of the risk factors for stroke on the development of leptomeningeal colateral circulation in patients with middle cerebral artery occlusion. Methods Patients with acute ischemic stroke confirmed as middle cerebral artery occlusion by imaging were extracted from the Nanjing Stroke Registry Program between June 2006 and December 2011. The baseline clinical data were colected. Leptomeningeal colateral circulation was assessed by angiography. Results A total of 137 patients were enroled, including 100 males and 37 females; mean age 55. 26 ± 11. 71 years. The colateral circulation of 65 patients (47. 4% ) was good. Univariate analysis showed that the ages (52. 3 ± 13. 2 years vs. 57. 9 ± 9. 5 years; t = 2. 866, P = 0. 005) and the proportion of hypertension (52. 3% vs. 70. 8% ; χ2 = 4. 978, P =0. 026) in the good colateral circulation group were significantly lower than those in the poor colateral circulation group. Multivariate logistic regression analysis showed that age was an independent risk factor for affecting the leptomeningeal colateral circulation in patients with acute middle cerebral artery occlusion (odds ratio, 0. 965, 95% confidence interval 0. 934-0. 997, P = 0. 034). Conclusions Age is an independent risk factor for affecting the leptomeningeal colateral circulation in patients with middle cerebral artery occlusion.

Objective To investigate the correlation of the lesion pattern of internal border zone infarction (IBZI) with atherosclerosis and outcome.Methods Eighty-one patients with IBZI were retrospectively divided into a simple IBZI group and a mixed IBZI group (combined with other infarct patterns) according to diffusion-weighted imaging (DWI).The clinical characteristics were compared between the 2 groups.And then,the mixed IBZI group was further divided into 3 subgroups:IBZI + pial infarct (PI),IBZI + perforating artery infarct (PAI),and IBZI + PI + PAI.They were compared with the simple IBZI group respectively.Results There were no significant differences in the dinical characteristics,such as age,hypertension,and the numbers of patients with stent implantation between the simple IBZI group and the mixed IBZI group.The proportions of severe stenosis and occlusion of internal carotid artery (ICA) and/or middle cerebral artery (MCA) (P =0.009) and MCA lesions (P =0.032) in the mixed IBZI group were significantly higher.Among the patients with MCA lesions,the severe stenosis in the simple IBZI group was significantly more than that in the mixed IBZI group (P =0.042),while the occlusive lesions in the mixed IBZI group were significantly more than those in the simple IBZI group (P =0.022).The short-term (within 7 days) exacerbation (P =0.039) and poor outcome at 90 days (modified Rankin Scale＞ 3) in the mixed IBZI group (P=0.030) were significantly higher than those in the simple IBZI group.The subgroup analysis showed that the proportions of the short-term exacerbation (P =0.001 ) and poor outcome in patients at 90 days (P =0.010) in the IBZI + PI +PAI subgroup were significantly higher than those in the simple IBZI group.Conclusions The IBZI patients combined with other infarct patterns often exist severe cerebrovascular stenosis and occlusion,and their clinical outcome was poorer.For patients with MCA lesions,the mixed IBZI occurred more in patients with MCA occlusion,and the simple IBZI occurred more in patients with severe MCA stenosis.

Objective To evaluate the prognostic value of hyperintense vessel (HV) in patients with acute middle cerebral artery (MCA) occlusion.Methods Seventy-four consecutive patients with first ever stroke(48 male and 26 female,the mean age was (60.7 ± 15.3) years) in the territory of MCA,retrieved from Nanjing Stroke Registry Program between May 2009 and February 2011,were enrolled assubjects.All subjects completed brain MRI,and MRA or DSA indicated proximal MCA occlusion.According to the location and extent of HV,all subjects were classified into 3 groups:without HV,proximal HV and distal HV.Clinical data were obtained and compared among patients with different grades of HV.Logistic regression analysis was employed to confirm the relevant factors of prognosis 90 days after index stroke.Results HV was observed in 49 (66.2％ ) of the 74 enrolled patients.Among patients with HV,7 (9.4％ ) were classified as proximal HV and 42 ( 56.8％ ) as distal HV.Initial NIHSS score ( 11 ( 1 -22) ),10-day NIHSS score ( 13.5(4-25) ),infarction size ( ＞2/3:5 cases(6.8％ ) ),and 90-day mRSscore (3-6 scores:12 cases( 16.2％ )) were significantly lower in patients with distal HV than those without (15(6-25),Z=-3.544;7(0-22),Z=-4.461;20 cases(27.0％),x2 =20.916;27 cases (36.5％),x2 =22.689;all P＜0.01).The NIHSS score decreased from baseline to that on 10 days and the mRS score decreased from 10 days to that on 90 days in patients with distal HV was more than that in patients without distal HV. Multivariate analysis revealed that patients with older age ( OR =1.111,95％ CI 1.036-1.191,P=0.003),high infarction size (OR=3.679,95％ CI 1.35-10.025,P=0.011) worsened outcome,whereas distal HV (P =0.012,OR =0.131,95％ CI 0.027-0.638)improved outcome.Conclusion Distal HV on FLAIR may predict a favorable outcome in patients with acute middle cerebral artery occlusion.

Objective To study the patterns of collateral circulation in adults moyamoya disease (MMD). Methods One hundred and nineteen consecutive adult patients with MMD (ischemic or hemorrhagic type) were identified by digital cerebral angiography in Nanjing Stroke Registry Program of Jinling Hospital between August 2004 and January 2010.The extracranial and (or) intracranial collateral circulations ipsilateral to stroke hemisphere were regarded as the research objects,and furthermore,these collateral circulations were divided into three different grades:Grade 1 collateral (anterior cerebral artery (ACA) → meningeal arteries (MLA) → middle cerebral artery (MCA) ),Grade 2 collateral ( dilating and extensing anterior choroidal artery beyond choroid fissure,patent posterior communicating artery → posterior cerebral artery→MLA→ ACA and(or) MCA,posterior cerebral artery→MLA→ACA and (or) MCA and posterior choroidal artery → posterior pericallosal arteries → ACA ) and Grade 3 collateral (collateral originating from the external carotid artery supplying to cerebral blood flow). The relationship between collateral distribution patterns in adult MMD and Suzuki' s classification was analyzed.Results In 117 assessed vessel units of the collateral circulation ipsilateral to stroke hemisphere,there were a total of 200 collateral circulations.The percentage of numbers in Grade 1,Grade 2 and Grade 3 collateral was 11.5％(23/200),52.0％ (104/200) and 36.5％ (73/200),respectively.The distribution percentage of Grade 1 was gradually decreased from Suzuki's Ⅰ to Ⅵ,mainly distributed in the early stage of MMD ( Suzuki's Ⅰ -Ⅱ ) and accounted for 91.3％ (21/23; Z =- 7.270,P ＜ 0.01 ).The distribution percentage of Grade 3 was gradually increased from Suzuki' s Ⅰ to Ⅵ,especially in the late stage of MMD ( Suzuki' s Ⅴ-Ⅵ) and accounted respectively for 37.0％ (27/73) and 63.0％ (46/73; Z =-7.270,P ＜0.01 ).Compared with the total distribution of Grade 1 and 3 collateral circulation,the distribution percentage of Grade 2 was 6.7％ (7/104),7.7％ (8/104),15.4％ ( 16/104),40.4％ (42/104),14.4％ (15/104)and 15.4％ (16/104) from Suzuki' s Ⅰ to Ⅶ.Although there was not significant difference,Grade 2 mainly distributed in the medium stage of MMD ( Suzuki' s Ⅲ-Ⅳ ).Conclusions The patterns of collateral distribution is various,changing with the progression of MMD. Grade 2 collateral circulation accounts for a higher proportion,especially in the medium stage of the disease,which suggests that these collaterals play an important compensatory role of blood flow.