Various diagnostic modalities exist to demonstrate blood flow or absence thereof in the vertebral arteries. The gold standard is cerebral angiography (with or without digital subtraction angiography). This involves puncture of a large artery (usually the femoral artery) and advancing an intravascular catheter through the aorta towards the vertebral arteries. At that point, radiocontrast is injected and its downstream flow captured on fluoroscopy (continuous X-ray imaging). The vessel may appear stenotic (narrowed, 41–75%), occluded (blocked, 18–49%), or as an aneurysm (area of dilation, 5–13%). The narrowing may be described as "rat's tail" or "string sign". Cerebral angiography is an invasive procedure, and it requires large volumes of radiocontrast that can cause complications such as kidney damage. Angiography also does not directly demonstrate the blood in the vessel wall, as opposed to more modern modalities. The only remaining use of angiography is when endovascular treatment is contemplated (see below).

More modern methods involve computed tomography (CT angiography) and magnetic resonance imaging (MR angiography). They use smaller amounts of contrast and are not invasive. CT angiography and MR angiography are more or less equivalent when used to diagnose or exclude vertebral artery dissection. CTA has the advantage of showing certain abnormalities earlier, tends to be available outside office hours, and can be performed rapidly. When MR angiography is used, the best results are achieved in the "T" setting using a protocol known as "fat suppression". Doppler ultrasound is less useful as it provides little information about the part of the artery close to the skull base and in the vertebral foramina, and any abnormality detected on ultrasound would still require confirmation with CT or MRI.

The U.S. Preventive Services Task Force (USPSTF) recommends against screening for carotid artery stenosis in those without symptoms.

Once suspected, intracranial aneurysms can be diagnosed radiologically using magnetic resonance or CT angiography. But these methods have limited sensitivity for diagnosis of small aneurysms, and often cannot be used to specifically distinguish them from infundibular dilations without performing a formal angiogram. The determination of whether an aneurysm is ruptured is critical to diagnosis. Lumbar puncture (LP) is the gold standard technique for determining aneurysm rupture (subarachnoid hemorrhage). Once an LP is performed, the CSF is evaluated for RBC count, and presence or absence of xanthochromia.

Prognosis of spontaneous cervical arterial dissection involves neurological and arterial results. The overall functional prognosis of individuals with stroke due to cervical artery dissection does not appear to vary from that of young people with stroke due to other causes. The rate of survival with good outcome (a modified Rankin score of 0–2) is generally about 75%, or possibly slightly better (85.7%) if antiplatelet drugs are used. In studies of anticoagulants and aspirin, the combined mortality with either treatment is 1.8–2.1%.

After the initial episode, 2% may experience a further episode within the first month. After this, there is a 1% annual risk of recurrence. Those with high blood pressure and dissections in multiple arteries may have a higher risk of recurrence. Further episodes of cervical artery dissection are more common in those who are younger, have a family history of cervical artery dissection, or have a diagnosis of Ehlers-Danlos syndrome or fibromuscular dysplasia.

Carotid stenosis is usually diagnosed by color flow duplex ultrasound scan of the carotid arteries in the neck. This involves no radiation, no needles and no contrast agents that may cause allergic reactions. This test has moderate sensitivity and specificity, and yields many false-positive results.

Typically duplex ultrasound scan is the only investigation required for decision making in carotid stenosis as it is widely available and rapidly performed. However, further imaging can be required if the stenosis is not near the bifurcation of the carotid artery.

One of several different imaging modalities, such as angiogram, computed tomography angiogram (CTA) or magnetic resonance imaging angiogram (MRA) may be useful. Each imaging modality has its advantages and disadvantages - Magnetic resonance angiography and CT angiography with contrast is contraindicated in patients with renal insufficiency, catheter angioigraphy has a 0.5% to 1.0% risk of stroke, MI, arterial injury or retoperitoneal bleeding. The investigation chosen will depend on the clinical question and the imaging expertise, experience and equipment available.

Diagnosis of a ruptured cerebral aneurysm is commonly made by finding signs of subarachnoid hemorrhage on a computed tomography (CT) scan. If the CT scan is negative but a ruptured aneurysm is still suspected based on clinical findings, a lumbar puncture can be performed to detect blood in the cerebrospinal fluid. Computed tomography angiography (CTA) is an alternative to traditional angiography and can be performed without the need for arterial catheterization. This test combines a regular CT scan with a contrast dye injected into a vein. Once the dye is injected into a vein, it travels to the cerebral arteries, and images are created using a CT scan. These images show exactly how blood flows into the brain arteries.

70% of patients with carotid arterial dissection are between the ages of 35 and 50, with a mean age of 47 years.

The condition is difficult to detect and may go unnoticed, because many patients have no specific symptoms. Diagnosis is further complicated by the fact that many patients with the injury experienced multiple other serious injuries as well, so the attention of hospital staff may be distracted from the possibility of aortic rupture. In fact most cases occur along with other injuries.

A common symptom is unusually high blood pressure in the upper body and very low blood pressure in lower limbs. Another symptom is renal failure where the creatinine level shoots very high and urine output becomes negligible. In most cases, however, the doctors would misinterpret renal failure as due to issues with the kidney itself and may recommend dialysis.

Though not completely reliable, chest X-rays are the first-line treatment, initially used to diagnose this condition when the patient is unstable and cannot be sent to the CT bay. The preferred method of diagnosis used to be CT angiogram until it was found to cause complications in some people; now it is reserved for when CT scans are inconclusive.

The classical findings on a chest X-ray will be widened mediastinum, apical cap, and displacement of the trachea, left main bronchus, or nasogastric tube. A normal chest x-ray does not exclude transection, but will diagnose conditions such as pneumothorax or hydrothorax. The aorta may also be torn at the point where it is connected to the heart. The aorta may be completely torn away from the heart, but patients with such injuries rarely survive very long after the injury; thus it is much more common for hospital staff to treat patients with partially torn aortas. When the aorta is partially torn, it may form a "pseudoaneurysm". In patients who do live long enough to be seen in a hospital, a majority have only a partially torn blood vessel, with the outermost adventitial layer still intact. In some of these patients, the adventitia and nearby structures within the chest may serve to prevent severe bleeding. After trauma, the aorta can be assessed by a CT angiogram or a direct angiogram, in which contrast is introduced into the aorta via a catheter.

Computed tomography (CT) and MRI scanning will show damaged area in the brain, showing that the symptoms were not caused by a tumor, subdural hematoma or other brain disorder. The blockage will also appear on the angiogram.

Patients can lower their risk for vulnerable plaque rupture in the same ways that they can cut their heart attack risk: Optimize lipoprotein patterns, keep blood glucose levels low normal (see HbA1c), stay slender, eat a proper diet, quit smoking, and maintain a regular exercise program. Researchers also think that obesity and diabetes may be tied to high levels of C-reactive protein.

The evaluation for VBI starts with a history and physical exam, with great emphasis on the cardiovascular and neurologic exam. It also includes a work-up to exclude benign conditions (such as labyrinthitis, vestibular neuronitis, and benign paroxysmal positional vertigo) that have overlapping signs and symptoms. However, the exact work-up largely depends on the patient’s age and known risk factors. For middle-aged patients, a cardiovascular risk factor evaluation is important. This often includes a cholesterol level, lipid profile (see this to determine what your cholesterol level means), ECG, and echocardiogram. If a person with VBI is under age 45 and has no evidence for atherosclerosis, a work-up for hypercoagulable states (Lupus anticoagulant, anti-cardiolipin antibodies, is indicated. Screening for protein C, protein S, or antithrombin III deficiency is sometimes recommended but these are more usually responsible for venous thrombosis than arterial problems.

Imaging studies are rarely required to diagnose VBI, but sometimes computed tomography (CT) is performed first. The CT is extremely sensitive in detecting hemorrhage. However, magnetic resonance imaging (MRI) is superior to the CT in detecting ischemic changes in the vertebrobasilar distribution. Magnetic resonance angiography (MRA) also can be used to identify vertebrobasilar stenoses or occlusions, but it can often overestimate the degree of stenosis, or wrongly show stenosis as an occlusion. Intracranial MRA is mostly sufficient to evaluate vertebrobasilar arteries, while extracranial vertebral arteries are better diagnosed using contrast-enhanced MRA, which is less dependent on flow phenomena and more accurate in evaluating stenosis.

CT angiography is also highly accurate in evaluation vertebrobasilar vessels, but ionizing radiation and use of nephrotoxic contrast media make it less suitable both in elderly with renal insufficiency and young adults because of radiation exposure. Moreover, vessel wall calcification and beam-hardening artifacts due to dense bones or metal fillings sometimes cause strong CT-image degradation.

Outcomes depend on the size of the aneurysm. Small aneurysms (less than 7 mm) have a low risk of rupture and increase in size slowly. The risk of rupture is less than a percent for aneurysms of this size.

The prognosis for a ruptured cerebral aneurysm depends on the extent and location of the aneurysm, the person's age, general health, and neurological condition. Some individuals with a ruptured cerebral aneurysm die from the initial bleeding. Other individuals with cerebral aneurysm recover with little or no neurological deficit. The most significant factors in determining outcome are the Hunt and Hess grade, and age. Generally patients with Hunt and Hess grade I and II hemorrhage on admission to the emergency room and patients who are younger within the typical age range of vulnerability can anticipate a good outcome, without death or permanent disability. Older patients and those with poorer Hunt and Hess grades on admission have a poor prognosis. Generally, about two-thirds of patients have a poor outcome, death, or permanent disability.

Renal aneurysms are very rare consisting of only 0.1–0.09% while rupture is even more rare. Conservative treatment with control of concomitant hypertension being the primary option with aneurysms smaller than 3 cm. If symptoms occur, or enlargement of the aneurysm, then endovascular or open repair should be considered. Pregnant women (due to high rupture risk of up to 80%) should be treated surgically.

During carotid angioplasty, an angiography cather with a small deflated balloon attached on the tip is advanced to a carotid stenosis. The ballon is then inflated slowly, forcing the narrowed portion of the vessel to expand.

While a single ruptured plaque can be identified during autopsy as the cause of a coronary event, there is currently no way to identify a culprit lesion before it ruptures.

Because artery walls typically enlarge in response to enlarging plaques, these plaques do not usually produce much stenosis of the artery lumen. Therefore, they are not detected by cardiac stress tests or angiography, the tests most commonly performed clinically with the goal of predicting susceptibility to future heart attack. In contrast to conventional angiography, cardiac CT angiography does enable visualization of the vessel wall as well as plaque composition. Some of the CT derived plaque characteristics can help predict for acute coronary syndrome. In addition, because these lesions do not produce significant stenoses, they are typically not considered "critical" and/or interventionable by interventional cardiologists, even though research indicates that they are the more important lesions for producing heart attacks.

The tests most commonly performed clinically with the goal of testing susceptibility to future heart attack include several medical research efforts, starting in the early to mid-1990s, using intravascular ultrasound (IVUS), thermography, near-infrared spectroscopy, careful clinical follow-up, and other methods, to predict these lesions and the individuals most prone to future heart attacks. These efforts remain largely research with no useful clinical methods to date (2006). Furthermore, the usefulness of detecting individual vulnerable plaques by invasive methods has been questioned because many "vulnerable" plaques rupture without any associated symptoms and it remains unclear if the risk of invasive detection methods is outweighed by clinical benefit.

Another approach to detecting and understanding plaque behavior, used in research and by a few clinicians, is to use ultrasound to non-invasively measure wall thickness (usually abbreviated IMT) in portions of larger arteries closest to the skin, such as the carotid or femoral arteries. While stability vs. vulnerability cannot be readily distinguished in this way, quantitative baseline measurements of the thickest portions of the arterial wall (locations with the most plaque accumulation). Documenting the IMT, location of each measurement and plaque size, a basis for tracking and partially verifying the effects of medical treatments on the progression, stability, or potential regression of plaque, within a given individual over time, may be achieved.

Although the mechanism is not entirely understood, the likelihood of a watershed stroke increases after cardiac surgery. An experiment conducted in a five-year span studied the diagnosis, etiology, and outcome of these postoperative strokes. It was observed that intraoperative decrease in blood pressure may lead to these strokes and patients who have undergone aortic procedures are more likely to have bilateral watershed infarcts. Furthermore, bilateral watershed strokes are associated with poor short-term outcomes and are most reliably observed by diffusion-weighted imaging MRI. Thus future clinical research and practice should focus on the identification of bilateral stroke characteristics. This identification can help discover affected areas and increase correct diagnosis.

Death occurs immediately after traumatic rupture of the thoracic aorta 75%–90% of the time since bleeding is so severe, and 80–85% of patients die before arriving at a hospital. Of those who live to reach a hospital, 23% die at the time of or shortly after arrival. In the US, an estimated 7,500–8,000 cases occur yearly, of which 1,000–1,500 make it to a hospital alive; these low numbers make it difficult to estimate the efficacy of surgical options. However, if surgery is performed in time, it can offer a chance of survival.

Though there is a concern that a small, stable tear in the aorta could enlarge and cause complete rupture of the aorta and heavy bleeding, this may be less common than previously believed as long as the patient's blood pressure does not get too high.

The goal of treatment is to prevent the development or continuation of neurologic deficits. Treatments include observation, anticoagulation, stent implantation and carotid artery ligation.

After taking the patient’s history, a thorough neurologic exam is needed to identify focal neurologic deficits, paying attention to the cranial nerve, motor, sensory, and coordination components of the exam. After the history and physical exam, clinicians may move on to laboratory workup and imaging.

Laboratory workup

Laboratory tests should focus on ruling out metabolic conditions that may mimic TIA (e.g. hypoglycemia causing altered mental status), in addition to further evaluating a patient’s risk factors for ischemic events. All patients should receive a complete blood count with platelet count, blood glucose, basic metabolic panel, prothrombin time/international normalized ratio, and activated partial thromboplastin time as part of their initial workup. These tests help with screening for bleeding or hypercoagulable conditions. An electrocardiogram will also be necessary to rule out abnormal heart rhythms such as atrial fibrillation that can predispose patients to clot formation and embolic events. Other lab tests, such as a full hypercoagulable state workup or serum drug screening should be considered based on the clinical situation and factors such as age of the patient and family history. A fasting lipid panel is also appropriate to thoroughly evaluate the patient’s risk for atherosclerotic disease and ischemic events in the future.

Imaging:

According to guidelines from the American Heart Association and American Stroke Association Stroke Council, patients with TIA should have head imaging “within 24 hours of symptom onset, preferably with magnetic resonance imaging, including diffusion sequences”. MRI is a better imaging modality for TIA than computed tomography (CT), as it is better able to pick up both new and old ischemic lesions than CT. CT, however, is more widely available and can be used particularly to rule out intracranial hemorrhage. Diffusion sequences can help further localize the area of ischemia and can serve as prognostic indicators. Presence of ischemic lesions on diffusion weighted imaging has been correlated with a higher risk of stroke after a TIA.

Vessels in the head and neck may also be evaluated to look for atherosclerotic lesions that may benefit from interventions such as carotid endarterectomy. The vasculature can be evaluated through the following imaging modalities: magnetic resonance angiography (MRA), CT angiography (CTA), and carotid ultrasonography/transcranial doppler ultrasonography. Carotid ultrasonography is often used to screen for carotid artery stenosis, as it is more readily available. However, all of the above imaging methods have variable sensitivities and specificities, making it important to supplement one of the imaging methods with another to help confirm the diagnosis (for example: screen for the disease with ultrasonography, and confirm with CTA). Confirming a diagnosis of carotid artery stenosis is important because the treatment for this condition, carotid endarterectomy, can pose significant risk to the patient, including heart attacks and strokes after the procedure. For this reason, the U.S. Preventive Services Task Force (USPSTF) "recommends against screening for asymptomatic carotid artery stenosis in the general adult population". This recommendation is for asymptomatic patients, so it does not necessarily apply to patients with TIAs as these may in fact be a symptom of underlying carotid artery disease (see "Causes and Pathogenesis" above). Therefore, patients who have had a TIA may opt to have a discussion with their clinician about the risks and benefits of screening for carotid artery stenosis, including the risks of surgical treatment of this condition.

Cardiac imaging can be performed if head and neck imaging do not reveal a vascular cause for the patient’s TIA (such as atherosclerosis of the carotid artery or other major vessels of the head and neck). Echocardiography can be performed to identify patent foramen ovale (PFO), valvular stenosis, and atherosclerosis of the aortic arch that could be sources of clots causing TIAs, with transesophageal echocardiography being more sensitive than transthoracic echocardiography in identifying these lesions. Prolonged cardiac rhythm monitoring can be considered to rule out arrhythmias like paroxysmal atrial fibrillation that may lead to clot formation and TIAs, however this should be considered if other causes of TIA have not been found.

In last decade, similar to myocardial infarction treatment, thrombolytic drugs were introduced in the therapy of cerebral infarction. The use of intravenous rtPA therapy can be advocated in patients who arrive to stroke unit and can be fully evaluated within 3 h of the onset.

If cerebral infarction is caused by a thrombus occluding blood flow to an artery supplying the brain, definitive therapy is aimed at removing the blockage by breaking the clot down (thrombolysis), or by removing it mechanically (thrombectomy). The more rapidly blood flow is restored to the brain, the fewer brain cells die. In increasing numbers of primary stroke centers, pharmacologic thrombolysis with the drug tissue plasminogen activator (tPA), is used to dissolve the clot and unblock the artery.

Another intervention for acute cerebral ischaemia is removal of the offending thrombus directly. This is accomplished by inserting a catheter into the femoral artery, directing it into the cerebral circulation, and deploying a corkscrew-like device to ensnare the clot, which is then withdrawn from the body. Mechanical embolectomy devices have been demonstrated effective at restoring blood flow in patients who were unable to receive thrombolytic drugs or for whom the drugs were ineffective, though no differences have been found between newer and older versions of the devices. The devices have only been tested on patients treated with mechanical clot embolectomy within eight hours of the onset of symptoms.

Angioplasty and stenting have begun to be looked at as possible viable options in treatment of acute cerebral ischaemia. In a systematic review of six uncontrolled, single-center trials, involving a total of 300 patients, of intra-cranial stenting in symptomatic intracranial arterial stenosis, the rate of technical success (reduction to stenosis of <50%) ranged from 90-98%, and the rate of major peri-procedural complications ranged from 4-10%. The rates of restenosis and/or stroke following the treatment were also favorable. This data suggests that a large, randomized controlled trial is needed to more completely evaluate the possible therapeutic advantage of this treatment.

If studies show carotid stenosis, and the patient has residual function in the affected side, carotid endarterectomy (surgical removal of the stenosis) may decrease the risk of recurrence if performed rapidly after cerebral infarction. Carotid endarterectomy is also indicated to decrease the risk of cerebral infarction for symptomatic carotid stenosis (>70 to 80% reduction in diameter).

In tissue losses that are not immediately fatal, the best course of action is to make every effort to restore impairments through physical therapy, cognitive therapy, occupational therapy, speech therapy and exercise.

Smith (2015) conducted a study that looked into specific biological markers that correlate to Moyamoya disease. Some of the categories of these biomarkers include phenotypes - conditions commonly related to Moyamoya, radiographical markers for the diagnosis of Moyamoya, and proteins as well as cellular changes that occur in cases of Moyamoya.

Similar to Moyamoya Disease, there are conditions that are closely associated with Moyamoya Syndrome. Some of the more common medical conditions that are closely associated with Moyamoya Syndrome include trisomy 21 (Down's Syndrome), sickle cell disease, and neurofibromatosis type 1. There is also evidence that identifies hyperthyroidism and congenital dwarfing syndromes as two of the more loosely associated syndromes that correlate with the possibility of being diagnosed with Moyamoya Disease later in life.

There is also research that has shown that certain radiographic biomarkers that lead to the diagnosis of Moyamoya Disease have been identified. The specific radiographic markers are now considered an acceptable key component to Moyamoya Disease and have been added to the INternational Classification of Diseases (ICD). These biomarkers of Moyamoya are "stenosis of the distal ICA's up to and including the bifurcation, along with segments of the proximal ACA and MCA...dilated basal collateral vessels must be present" Some other common findings that have not been added to the classification index of those with Moyamoya Disease which are found using radiography involve very distinct changes in the vessels of the brain. These changes include newly formed vessels made to compensate for another change noted, ischemia and cerebrovascular reserve, both found on MRI. Functional changes include evidence of ischemia in vessels of the brain (ICA, ACA, MCA, specifically). It is important to also note that the radiographic biomarkers, in order to be classified as Moyamoya Disease, all findings must be bilateral. If this is not the case and the findings are unilateral, it is diagnosed as Moyamoya Syndrome.

There are also several protein biomarkers that have been linked to the Moyamoya Disease diagnosis. Although the sample size of the studies performed are small due to the rarity of the disease, the findings are indicative of a correlation between the disease and several specific protein biomarkers. Other studies have confirmed the correlation of Moyamoya and adhesion molecule 1 (ICAM-1) being increased as compared to normal vascular function counterparts Furthermore, it has been concluded that the localization of inflammatory cells suggests that the inflammation stimulus iteself may be responsible for the proliferation and occlusion in the ICA, ACA, and MCA found in those with Moyamoya Disease.

Because artery walls enlarge at locations with atheroma, detecting atheroma before death and autopsy has long been problematic at best. Most methods have focused on the openings of arteries; highly relevant, yet totally miss the atheroma within artery walls.

Historically, arterial wall fixation, staining and thin section has been the gold standard for detection and description of atheroma, after death and autopsy. With special stains and examination, micro calcifications can be detected, typically within smooth muscle cells of the arterial media near the fatty streaks within a year or two of fatty streaks forming.

Interventional and non-interventional methods to detect atherosclerosis, specifically vulnerable plaque (non-occlusive or soft plaque), are widely used in research and clinical practice today.

Carotid Intima-media thickness Scan (CIMT can be measured by B-mode ultrasonography) measurement has been recommended by the American Heart Association as the most useful method to identify atherosclerosis and may now very well be the gold standard for detection.

IVUS is the current most sensitive method detecting and measuring more advanced atheroma within living individuals, though it is typically not used until decades after atheroma begin forming due to cost and body invasiveness.

CT scans using state of the art higher resolution spiral, or the higher speed EBT, machines have been the most effective method for detecting calcification present in plaque. However, the atheroma have to be advanced enough to have relatively large areas of calcification within them to create large enough regions of ~130 Hounsfield units which a CT scanner's software can recognize as distinct from the other surrounding tissues. Typically, such regions start occurring within the heart arteries about 2–3 decades after atheroma start developing. Hence the detection of much smaller plaques than previously possible is being developed by some companies, such as Image Analysis. The presence of smaller, spotty plaques may actually be more dangerous for progressing to acute myocardial infarction.

Arterial ultrasound, especially of the carotid arteries, with measurement of the thickness of the artery wall, offers a way to partially track the disease progression. As of 2006, the thickness, commonly referred to as IMT for intimal-medial thickness, is not measured clinically though it has been used by some researchers since the mid-1990s to track changes in arterial walls. Traditionally, clinical carotid ultrasounds have only estimated the degree of blood lumen restriction, stenosis, a result of very advanced disease. The National Institute of Health did a five-year $5 million study, headed by medical researcher Kenneth Ouriel, to study intravascular ultrasound techniques regarding atherosclerotic plaque. More progressive clinicians have begun using IMT measurement as a way to quantify and track disease progression or stability within individual patients.

Angiography, since the 1960s, has been the traditional way of evaluating for atheroma. However, angiography is only motion or still images of dye mixed with the blood with the arterial lumen and never show atheroma; the wall of arteries, including atheroma with the arterial wall remain invisible. The limited exception to this rule is that with very advanced atheroma, with extensive calcification within the wall, a halo-like ring of radiodensity can be seen in most older humans, especially when arterial lumens are visualized end-on. On cine-floro, cardiologists and radiologists typically look for these calcification shadows to recognize arteries before they inject any contrast agent during angiograms.

In developed countries, with improved public health, infection control and increasing life spans, atheroma processes have become an increasingly important problem and burden for society.

Atheromata continue to be the primary underlying basis for disability and death, despite a trend for gradual improvement since the early 1960s (adjusted for patient age). Thus, increasing efforts towards better understanding, treating and preventing the problem are continuing to evolve.

According to United States data, 2004, for about 65% of men and 47% of women, the first symptom of cardiovascular disease is myocardial infarction (heart attack) or sudden death (death within one hour of symptom onset).

A significant proportion of artery flow-disrupting events occur at locations with less than 50% lumenal narrowing. Cardiac stress testing, traditionally the most commonly performed noninvasive testing method for blood flow limitations, generally only detects lumen narrowing of ~75% or greater, although some physicians advocate nuclear stress methods that can sometimes detect as little as 50%.

The sudden nature of the complications of pre-existing atheroma, vulnerable plaque (non-occlusive or soft plaque), have led, since the 1950s, to the development of intensive care units and complex medical and surgical interventions. Angiography and later cardiac stress testing was begun to either visualize or indirectly detect stenosis. Next came bypass surgery, to plumb transplanted veins, sometimes arteries, around the stenoses and more recently angioplasty, now including stents, most recently drug coated stents, to stretch the stenoses more open.

Yet despite these medical advances, with success in reducing the symptoms of angina and reduced blood flow, atheroma rupture events remain the major problem and still sometimes result in sudden disability and death despite even the most rapid, massive and skilled medical and surgical intervention available anywhere today. According to some clinical trials, bypass surgery and angioplasty procedures have had at best a minimal effect, if any, on improving overall survival. Typically mortality of bypass operations is between 1 and 4%, of angioplasty between 1 and 1.5%.

Additionally, these vascular interventions are often done only after an individual is symptomatic, often already partially disabled, as a result of the disease. It is also clear that both angioplasty and bypass interventions do not prevent future heart attack.

The older methods for understanding atheroma, dating to before World War II, relied on autopsy data. Autopsy data has long shown initiation of fatty streaks in later childhood with slow asymptomatic progression over decades.

One way to see atheroma is the very invasive and costly IVUS ultrasound technology; it gives us the precise volume of the inside intima plus the central media layers of about of artery length. Unfortunately, it gives no information about the structural strength of the artery. Angiography does not visualize atheroma; it only makes the blood flow within blood vessels visible. Alternative methods that are non or less physically invasive and less expensive per individual test have been used and are continuing to be developed, such as those using computed tomography (CT; led by the electron beam tomography form, given its greater speed) and magnetic resonance imaging (MRI). The most promising since the early 1990s has been EBT, detecting calcification within the atheroma before most individuals start having clinically recognized symptoms and debility. Interestingly, statin therapy (to lower cholesterol) does not slow the speed of calcification as determined by CT scan. MRI coronary vessel wall imaging, although currently limited to research studies, has demonstrated the ability to detect vessel wall thickening in asymptomatic high risk individuals. As a non-invasive, ionising radiation free technique, MRI based techniques could have future uses in monitoring disease progression and regression. Most visualization techniques are used in research, they are not widely available to most patients, have significant technical limitations, have not been widely accepted and generally are not covered by medical insurance carriers.

From human clinical trials, it has become increasingly evident that a more effective focus of treatment is slowing, stopping and even partially reversing the atheroma growth process. There are several prospective epidemiologic studies including the Atherosclerosis Risk in Communities (ARIC) Study and the Cardiovascular Health Study (CHS), which have supported a direct correlation of Carotid Intima-media thickness (CIMT) with myocardial infarction and stroke risk in patients without cardiovascular disease history. The ARIC Study was conducted in 15,792 individuals between 5 and 65 years of age in four different regions of the US between 1987 and 1989. The baseline CIMT was measured and measurements were repeated at 4- to 7-year intervals by carotid B mode ultrasonography in this study. An increase in CIMT was correlated with an increased risk for CAD. The CHS was initiated in 1988, and the relationship of CIMT with risk of myocardial infarction and stroke was investigated in 4,476 subjects ≤65 years of age. At the end of approximately six years of follow-up, CIMT measurements were correlated with cardiovascular events.

Paroi artérielle et Risque Cardiovasculaire in Asia Africa/Middle East and Latin America (PARC-AALA) is another important large-scale study, in which 79 centers from countries in Asia, Africa, the Middle East, and Latin America participated, and the distribution of CIMT according to different ethnic groups and its association with the Framingham cardiovascular score was investigated. Multi-linear regression analysis revealed that an increased Framingham cardiovascular score was associated with CIMT, and carotid plaque independent of geographic differences.

Cahn et al. prospectively followed-up 152 patients with coronary artery disease for 6–11 months by carotid artery ultrasonography and noted 22 vascular events (myocardial infarction, transient ischemic attack, stroke, and coronary angioplasty) within this time period. They concluded that carotid atherosclerosis measured by this non-interventional method has prognostic significance in coronary artery patients.

In the Rotterdam Study, Bots et al. followed 7,983 patients >55 years of age for a mean period of 4.6 years, and reported 194 incident myocardial infarctions within this period. CIMT was significantly higher in the myocardial infarction group compared to the other group. Demircan et al. found that the CIMT of patients with acute coronary syndrome were significantly increased compared to patients with stable angina pectoris.

It has been reported in another study that a maximal CIMT value of 0.956 mm had 85.7% sensitivity and 85.1% specificity to predict angiographic CAD. The study group consisted of patients admitted to the cardiology outpatient clinic with symptoms of stable angina pectoris. The study showed CIMT was higher in patients with significant CAD than in patients with non-critical coronary lesions. Regression analysis revealed that thickening of the mean intima-media complex more than 1.0 was predictive of significant CAD our patients. There was incremental significant increase in CIMT with the number coronary vessel involved. In accordance with the literature, it was found that CIMT was significantly higher in the presence of CAD. Furthermore, CIMT was increased as the number of involved vessels increased and the highest CIMT values were noted in patients with left main coronary involvement. However, human clinical trials have been slow to provide clinical & medical evidence, partly because the asymptomatic nature of atheromata make them especially difficult to study. Promising results are found using carotid intima-media thickness scanning (CIMT can be measured by B-mode ultrasonography), B-vitamins that reduce a protein corrosive, homocysteine and that reduce neck carotid artery plaque volume and thickness, and stroke, even in late-stage disease.

Additionally, understanding what drives atheroma development is complex with multiple factors involved, only some of which, such as lipoproteins, more importantly lipoprotein subclass analysis, blood sugar levels and hypertension are best known and researched. More recently, some of the complex immune system patterns that promote, or inhibit, the inherent inflammatory macrophage triggering processes involved in atheroma progression are slowly being better elucidated in animal models of atherosclerosis.

The natural history of this disorder is not well known. The long term outlook for patients with treated moyamoya seems to be good. While symptoms may seem to improve almost immediately after the in-direct EDAS, EMS, and multiple burr holes surgeries, it will take probably 6–12 months before new vessels can develop to give a sufficient blood supply. With the direct STA-MCA surgery, increased blood supply is immediate.

Once major stroke or bleeding take place, even with treatment, the patient may be left with permanent loss of function so it is very important to treat this condition promptly.

Dr. Michael Scott, MD discusses the success rate for Moyamoya surgery in

The differentiating presentations are suggestive of FMD being a unique syndrome in respect to the pediatric population. Experienced FMD clinicians warn against relying in the “string of beads” angiography for a diagnosis. In fact, it is suggested that FMD may be both under and over-diagnosed in children with stroke.