What influenced the lesion patterns and hemodynamic characteristics in patients with internal carotid artery stenosis? A retrospective study

•Blood perfusion influences ischemic lesions in patients with of ICAS.•Communicating arteries influence intracranial blood flow.•TCD was a convenient and rapid tool to assess cerebral blood flow

MOYA MOYA DISEASE- A REVIEW

Moya moya syndrome is a specific chronic cerebrovascular occlusive disease first reported by Japanese surgeons in 1957. The disease moya moya, which is a Japanese mimetic word, gets its characteristic name due to the appearance of puff of smoke on relevant angiographs resultant from the tangle of tiny vessels in response to stenosis. This makes the blood to leak out of the arteries, causing pressure to the brain. It may cause ischemic attacks or cerebal infarction, which is more frequent in children than in adults. The highest peak is in childhood at less than 10 years of age. The disease causes constrictions primarily in the internal carotid artery, and often extends to the middle and anterior cerebral arteries, branches of the internal carotid artery inside the skull. When the internal carotid artery becomes completely blocked, the fine collateral circulation that it supplies is obliterated. The clinical features are strokes, recurrent transient ischemic attacks (TIAs), sensorimotor paralysis (numbness and paralysis of the extremities), convulsions and/or migraine -like headaches. Moreover, following a stroke, secondary bleeding may occur. Such bleeding, called hemorrhagic strokes.Treatment with perivascular sympathectomy and superior cervical ganglionectomy. Etiology of the disease is still unknown; however, multifactorial inheritance is considered possible because of a higher incidence of the disease in Japanese and Koreans and approximately 10% of familial occurrence among the Japanese. Recent genetic studies suggest some responsible genetic foci in chromosomes 3, 6 and 17.Keywords: Moyamoya disease, Intracranial hemorrhage, Proteomics, Stenosis

Carotid Stenosis, Endarterectomy, and the Brain : Brain microcirculation, diffusion, and cognitive function before and after carotid endarterectomy in patients with a high-grade carotid stenosis

Carotid atherosclerotic disease is a major cause of stroke, but it may remain clinically asymptomatic. The factors that turn the asymptomatic plaque into a symptomatic one are not fully understood, neither are the subtle effects that a high-grade carotid stenosis may have on the brain. The purpose of this study was to evaluate brain microcirculation, diffusion, and cognitive performance in patients with a high-grade stenosis in carotid artery, clinically either symptomatic or asymptomatic, undergoing carotid endarterectomy (CEA). We wanted to find out whether the stenoses are associated with diffusion or perfusion abnormalities of the brain or variation in the cognitive functioning of the patients, and to what extent the potential findings are affected by CEA, and compare the clinically symptomatic and asymptomatic subjects as well as strictly healthy controls. Coagulation and fibrinolytic parameters were compared with the rate microembolic signals (MES) in transcranial Doppler (TCD) and the macroscopic appearance of stenosing plaques in surgery. Patients (n=92) underwent CEA within the study. Blood samples pertaining to coagulation and fibrinolysis were collected before CEA, and the subjects underwent repeated TCD monitoring for MES. A subpopulation (n= 46) underwent MR imaging and repeated neuropsychological examination (preoperative, as well 4 and 100 days after CEA). In MRI, the average apparent diffusion coefficients were higher in the ipsilateral white matter (WM), and altough the interhemispheric difference was abolished by CEA, the levels remained higher than in controls. Symptomatic stenoses were associated with more sluggish perfusion especially in WM, and lower pulsatility of flow in TCD. All patients had poorer cognitive performance than healthy controls. Cognitive functions improved as expected by learning effect despite transient postoperative worsening in a few subjects. Improvement was greater in patients with deepest hypoperfusion, primarily in executive functions. Symptomatic stenoses were associated with higher hematocrit and tissue plasminogen activator antigen levels, as well as higher rate of MES and ulcerated plaques, and better postoperative improvement of vasoreactivity and pulsatility. In light of the findings, carotid stenosis is associated with differences in brain diffusion, perfusion, and cognition. The effect on diffusion in the ipsilateral WM, partially reversible by CEA, may be associated with WM degeneration. Asymptomatic and symptomatic subpopulations differ from each other in terms of hemodynamic adaptation and in their vascular physiological response to removal of stenosis. Although CEA may be associated with a transient cognitive decline, a true improvement of cognitive performance by CEA is possible in patients with the most pronounced perfusion deficits. Mediators of fibrinolysis and unfavourable hemorheology may contribute to the development of a symptomatic disease in patients with a high-grade stenosis.Kaulavaltimoiden ateroskleroottinen ahtautuminen on tärkeä aivohalvauksen syy, mutta enemmistö ahtaumista ei aiheuta halvausta. Syyt, jotka tekevät kaulavaltimoplakista vaarallisen, tunnetaan puutteellisesti, samoin kuin ne mahdolliset muut vaikutukset, joita tiukalla ahtaumalla voi aivojen kannalta olla. Työn tarkoituksena oli tutkia aivojen perfuusiota eli mikroverenkiertoa, solutason diffuusiota ja kognitiivista suoriutumista potilailla, joiden tiukka kaulavaltimoahtauma poistettiin leikkauksella. Tavoitteina oli selvittää, liittyykö kaulavaltimoita ahtauttavaan tautiin aivojen diffuusion, perfuusion tai kognitiivisten toimintojen muutoksia, ja miten leikkaushoito vaikuttaa näihin ja verisuonten reaktiviteettiin, sekä verrata oireisten ja oireettomien löydöksiä keskenään mukaan lukien veren hyytymiseen ja hyytymän liukenemiseen liittyviä tekijöitä. Potilaiden diffuusio- ja kognitiolöydöksiä verrattiin terveiden henkilöiden arvoihin. Potilaiden kognitiivinen suoriutuminen oli kauttaaltaan alempi kuin täysin terveillä ikätovereilla. Ahtauman puoleisessa aivopuoliskossa todettiin magneettikuvauksella toista puolta korkeammat ns. näennäiset diffuusiovakiot aivojen valkeassa aineessa sekä hitaampi aivoperfuusio, ja nämä poikkeamat korjautuivat leikkauksen jälkeen. Diffuusiovakiot jäivät kuitenkin korkeammiksi kuin terveillä ikätovereilla. Neuropsykologinen suoriutuminen parani potilailla toistomittauksissa kuten terveillä, mutta osalla todettiin väliaikainen kognitiivinen heikkenemä heti leikkauksen jälkeen. Kognitiiviset toiminnot kohenivat pit-källä tähtäimellä enemmän niillä, joilla oli näkyvä aivoperfuusion vajaus ennen leikkausta, ja ensisijaisesti muutos tapahtui toiminnanohjauksessa. Näkyvä perfuusiovajaus oli yleisempää oireita aiheuttaneissa ahtaumissa. Oireilleilla oli myös korkeampi punasolujen tilavuusosuus ja kudosplasminogeenin aktivaattorin antigeeni veressä sekä useammin mikroveritulppia kuvaavia ultraäänisignaaleja aivoverenkierrossa kuin oireettomilla. Tulosten valossa tiukka kaulavaltimoahtauma vaikuttaa aivojen diffuusioon, perfuusioon ja kognitiivisiin toimintoihin kliinisistä oireista riippumattakin. Aivojen valkeaan aineeseen aiheutuva diffuusio muutos on samansuuntainen kuin valkean aineen degeneraatiossa, ja muutos korjaantuu osittain ahtauman kirurgisella hoidolla. Oireiset potilaat eroavat oireettomista hemodynamiikaltaan, ja leikkaus hyödyttää heitä enemmän parantuneen hemodynamiikan ja verisuoniston reaktiivisuuden muodossa. Vaikka potilailla on yleisesti alempi kognitiivinen suoritustaso täysin terveisiin verrattuna ja kirurgiseen hoitoon liittyy pieni ohimenevän kognitiivisen haitan riski, jopa kognitiivinen koheneminen on mahdollista potilailla, joiden perfuusiovajaus on suurin. Veren epäedulliset virtausominaisuudet ja fibrinolyysiin liittyvät tekijät saattavat vaikuttaa oireiden ilmaantumiseen näillä potilailla

Angioplasty, Various Techniques and Challenges in Treatment of Congenital and Acquired Vascular Stenoses

The field of performing transcatheter interventions to treat vascular lesions has exploded over the past 20 years. Not only has the technology changed, especially in the arena of balloon/stent devices, but the techniques of approaching complex lesions has evolved over the past decade. Lesions that no one would have imagined treating back in the 1990's are now being done routinely in the catheterization suite. This book provides an update on the current techniques and devices used to treat a wide variety of lesions. Though, at first, the outward appearance of the topics appears to be varied, they are all related by the common thread of treating vascular lesions. We hope, by publishing this book, to accomplish two things: First, to offer insight from experts in their field to treat, both medically and procedurally, complex vascular lesions that we frequently encounter. Secondly, we hope to promote increased communication between areas of medicine that frequently don't communicate, between adult interventional cardiologists, pediatric interventional cardiologists, interventional radiologists, and neurosurgeons. Much can be learned from our respective colleagues in these areas which can further our own world of interventions

Comparison of extra cranial with intra cranial carotid artery disease in ischemic stroke

INTRODUCTION: Stroke is defined as developing symptoms or and signs of global or focal, loss of cerebral function with symptoms lasting for more than 24 hours or leading to death with no apparent cause other than vascular origin. Globally, the rate of occurrence of stroke is estimated as 400 - 800 per lakh of population. Around 57 lakh deaths occur due to stroke in a year. Approximately, 1.6 crore new acute strokes are reported yearly. Worldwide, stroke mortality is high in Eastern Europe and Asia. In India, the rate of occurrence of stroke is estimated as 90 - 222 per lakh of population. Approximately, 14 – 16 lakhs new acute strokes are reported yearly. 12% of them occur in the age group of less than 40 years. In fact, it is estimated that the incidence of stroke will reach one million annually by the year 2050. Stroke is a leading cause of long term disability in our society. As the longevity of the population increase, the incidence is on the rise. Adoption of western diet may further increase the prevalence and incidence of cardiovascular disease and stroke. Of the hundreds and thousands of stroke survivors each year, approximately 30% need support for day- to-day activities 20% need assistance with ambulation and 16% require institutional care. Hence the need for identifying stroke risk factors to the reduce morbidity and mortality due to stroke. AIM OF THE STUDY: To assess the following in patients with anterior circulation ischemic stroke: 1. Risk factors involved in carotid artery stroke. 2. Clinical profile, pattern of vascular involvement in carotid artery stroke. 3. Extra cranial internal carotid artery disease by carotid doppler. 4. Intracranial carotid artery disease by transcranial doppler in patients who showed extracranial internal carotid artery disease. 5. Comparing the concordance and discordance of carotid artery disease in extracranial and intracranial part of internal carotid artery. MATERIALS AND METHODS: This cross sectional study was conducted during Jan 2011 to Oct 2012 at Madras Institute of Neurology, Rajiv Gandhi Government General Hospital, and Chennai. Patients with clinical features suggestive of stroke were enrolled in this study; all were subjected to CT Brain, MRI Brain and Carotid Doppler. Inclusion Criteria: 1. All the patients with clinical feature suggestive of stroke, 2. Imaging showing ischemic infarct in the anterior circulation, 3. Carotid Doppler showing atherosclerotic carotid artery disease, 4. Patients with anterior circulation TIA. Exclusion Criteria: 1. All hemorrhagic strokes, 2. Posterior circulation stroke, 3. Patients without carotid artery disease on carotid doppler, 4. Patients with cardiac disease. RESULTS: Among the total 485 patients, 150 patients (30.9%) with posterior circulation stroke or venous infarcts, intra cerebral hemorrhage were excluded from the study. Remaining 335 patients were subjected to cardiac evaluation, of them 23 patients (6.8%) who showed cardiac abnormalities were excluded from the study. Out of the 312 patients only 70 patients who showed carotid artery disease in carotid doppler were enrolled in this study and subjected to transcranial doppler to study the intra cranial part of internal carotid artery involvement. CONCLUSION: 1. The common risk factors for carotid artery disease in our study are dyslipidemia, systemic hypertension, diabetes mellitus, smoking and alcohol consumption, in the order of occurrence. 2. Incidence of transient ischemic attack was high in patients with intracranial carotid artery disease indicating the need for intensive management of these patients to prevent morbidity and mortality 3. The most common radiological presentation is the territorial infarct involving the middle cerebral artery territory followed by watershed infarcts. 4. Most of the patients with extracranial internal carotid artery disease also had co-existing intracranial internal carotid artery disease which in turn may further lead to stroke. This emphasizes the need to search for intracranial disease in patients with extra cranial carotid artery disease. 5. Transcranial doppler can be used as a noninvasive initial screening tool for detecting intracranial internal carotid artery stenosis before considering any invasive investigation

New Insight into Cerebrovascular Diseases

“Brain circulation is a true road map that consists of large extended navigation territories and a number of unimagined and undiscovered routes.” Dr. Patricia Bozzetto Ambrosi This book combines an update on the review of cerebrovascular diseases in the form of textbook chapters, which has been carefully reviewed by Dr. Patricia Bozzetto Ambrosi, Drs. Rufai Ahmad and Auwal Abdullahi and Dr. Amit Agrawal, high-performance academic editors with extensive experience in neurodisciplines, including neurology, neurosurgery, neuroscience, and neuroradiology, covering the best standards of neurological practice involving basic and clinical aspects of cerebrovascular diseases. Each topic was carefully revised and prepared using smooth, structured vocabulary, plus superb graphics and scientific illustrations. In emphasizing the most common aspects of cerebrovascular diseases: stroke burden, pathophysiology, hemodynamics, diagnosis, management, repair, and healing, the book is comprehensive but concise and should become the standard reference guide for this neurological approach

Incorporating the Aortic Valve into Computational Fluid Dynamics Models using Phase-Contrast MRI and Valve Tracking

The American Heart Association states about 2% of the general population have a bicuspid aortic valve (BAV). BAVs exist in 80% of patients with aortic coarctation (CoA) and likely influences flow patterns that contribute to long-term morbidity post-surgically. BAV patients tend to have larger ascending aortic diameters, increased risk of aneurysm formation, and require surgical intervention earlier than patients with a normal aortic valve. Magnetic resonance imaging (MRI) has been used clinically to assess aortic arch morphology and blood flow in these patients. These MRI data have been used in computational fluid dynamics (CFD) studies to investigate potential adverse hemodynamics in these patients, yet few studies have attempted to characterize the impact of the aortic valve on ascending aortic hemodynamics. To address this issue, this research sought to identify the impact of aortic valve morphology on hemodynamics in the ascending aorta and determine the location where the influence is negligible. Novel tools were developed to implement aortic valve morphology into CFD models and compensate for heart motion in MRI flow measurements acquired through the aortic valve. Hemodynamic metrics such as blood flow velocity, time-averaged wall shear stress (TAWSS), and turbulent kinetic energy (TKE) induced by the valve were compared to values obtained using the current plug inflow approach. The influence of heart motion on these metrics was also investigated, resulting in the underestimation of TAWSS and TKE when heart motion was neglected. CFD simulations of CoA patients exhibiting bicuspid and tricuspid aortic valves were performed in models including the aortic sinuses and patient-specific valves. Results indicated the aortic valve impacted hemodynamics primarily in the ascending aorta, with the BAV having the greatest influence along the outer right wall of the vessel. A marked increase in TKE is present in aortic valve simulations, particularly in BAV patients. These findings suggest that future CFD studies investigating altered hemodynamics in the ascending aorta should accurately replicate aortic valve morphology. Further, aortic valve disease impacts hemodynamics in the ascending aorta that may be a predictor of the development or progression of ascending aortic dilation and possible aneurysm formation in this region