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Diagnosis of cerebrovascular disease is done by (among other diagnoses):
- clinical history
- physical exam
- neurological examination.
It is important to differentiate the symptoms caused by a stroke from those caused by syncope (fainting) which is also a reduction in cerebral blood flow, almost always generalized, but they are usually caused by systemic hypotension of various origins: cardiac arrhythmias, myocardial infarction, hemorrhagic shock, among others.
Prognostics factors:
Lower Glasgow coma scale score, higher pulse rate, higher respiratory rate and lower arterial oxygen saturation level is prognostic features of in-hospital mortality rate in acute ischemic stroke.
Therapeutic hypothermia has been attempted to improve results post brain ischemia . This procedure was suggested to be beneficial based on its effects post cardiac arrest. Evidence supporting the use of therapeutic hypothermia after brain ischemia, however, is limited.
A closely related disease to brain ischemia is brain hypoxia. Brain hypoxia is the condition in which there is a decrease in the oxygen supply to the brain even in the presence of adequate blood flow. If hypoxia lasts for long periods of time, coma, seizures, and even brain death may occur. Symptoms of brain hypoxia are similar to ischemia and include inattentiveness, poor judgment, memory loss, and a decrease in motor coordination. Potential causes of brain hypoxia are suffocation, carbon monoxide poisoning, severe anemia, and use of drugs such as cocaine and other amphetamines. Other causes associated with brain hypoxia include drowning, strangling, choking, cardiac arrest, head trauma, and complications during general anesthesia. Treatment strategies for brain hypoxia vary depending on the original cause of injury, primary and/or secondary.
Alteplase (tpa) is an effective medication for acute ischemic stroke. When given within 3 hours, treatment with tpa significantly improves the probability of a favourable outcome versus treatment with placebo.
The outcome of brain ischemia is influenced by the quality of subsequent supportive care. Systemic blood pressure (or slightly above) should be maintained so that cerebral blood flow is restored. Also, hypoxaemia and hypercapnia should be avoided. Seizures can induce more damage; accordingly, anticonvulsants should be prescribed and should a seizure occur, aggressive treatment should be undertaken. Hyperglycaemia should also be avoided during brain ischemia.
Upon suspicion of PAD, the first-line study is the ankle–brachial index (ABI). When the blood pressure readings in the ankles is lower than that in the arms, blockages in the arteries which provide blood from the heart to the ankle are suspected. Normal ABI range of 1.00 to 1.40.The patient is diagnosed with PAD when the ABI is ≤ 0.90 . ABI values of 0.91 to 0.99 are considered "borderline" and values >1.40 indicate noncompressible arteries. PAD is graded as mild to moderate if the ABI is between 0.41 and 0.90, and an ABI less than 0.40 is suggestive of severe PAD. These relative categories have prognostic value.
In people with suspected PAD but normal resting ABIs, exercise testing of ABI can be done. A base line ABI is obtained prior to exercise. The patient is then asked to exercise (usually patients are made to walk on a treadmill at a constant speed) until claudication pain occurs (or a maximum of 5 minutes), following which the ankle pressure is again measured. A decrease in ABI of 15%-20% would be diagnostic of PAD.
It is possible for conditions which stiffen the vessel walls (such as calcifications that occur in the setting of long term diabetes) to produce false negatives usually, but not always, indicated by abnormally high ABIs (> 1.40). Such results and suspicions merit further investigation and higher level studies.
If ABIs are abnormal the next step is generally a lower limb doppler ultrasound examination to look at site and extent of atherosclerosis. Other imaging can be performed by angiography, where a catheter is inserted into the common femoral artery and selectively guided to the artery in question. While injecting a radiodense contrast agent an X-ray is taken. Any flow limiting stenoses found in the x-ray can be identified and treated by atherectomy, angioplasty or stenting. Contrast angiography is the most readily available and widely used imaging technique.
Modern multislice computerized tomography (CT) scanners provide direct imaging of the arterial system as an alternative to angiography.
Magnetic resonance angiography (MRA) is a noninvasive diagnostic procedure that uses a combination of a large magnet, radio frequencies, and a computer to produce detailed images to provide pictures of blood vessels inside the body. The advantages of MRA include its safety and ability to provide high-resolution three-dimensional (3D) imaging of the entire abdomen, pelvis and lower extremities in one sitting.
It is not clear if screening for disease is useful as it has not been properly studied.
The U.S. Preventive Services Task Force (USPSTF) recommends against screening for carotid artery stenosis in those without symptoms.
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.
Several specific diagnostic criteria can be used to diagnose vascular dementia, including the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria, the International Classification of Diseases, Tenth Edition (ICD-10) criteria, the National Institute of Neurological Disorders and Stroke criteria, Association Internationale pour la Recherche et l'Enseignement en Neurosciences (NINDS-AIREN) criteria, the Alzheimer's Disease Diagnostic and Treatment Center criteria, and the Hachinski Ischemic Score (after Vladimir Hachinski).
The recommended investigations for cognitive impairment include: blood tests (for anemia, vitamin deficiency, thyrotoxicosis, infection, etc.), chest X-Ray, ECG, and neuroimaging, preferably a scan with a functional or metabolic sensitivity beyond a simple CT or MRI. When available as a diagnostic tool, single photon emission computed tomography (SPECT) and positron emission tomography (PET) neuroimaging may be used to confirm a diagnosis of multi-infarct dementia in conjunction with evaluations involving mental status examination. In a person already having dementia, SPECT appears to be superior in differentiating multi-infarct dementia from Alzheimer's disease, compared to the usual mental testing and medical history analysis. Advances have led to the proposal of new diagnostic criteria.
The screening blood tests typically include full blood count, liver function tests, thyroid function tests, lipid profile, erythrocyte sedimentation rate, C reactive protein, syphilis serology, calcium serum level, fasting glucose, urea, electrolytes, vitamin B-12, and folate. In selected patients, HIV serology and certain autoantibody testing may be done.
Mixed dementia is diagnosed when people have evidence of Alzheimer's disease and cerebrovascular disease, either clinically or based on neuro-imaging evidence of ischemic lesions.
Gross examination of the brain may reveal noticeable lesions and damage to blood vessels. Accumulation of various substances such as lipid deposits and clotted blood appear on microscopic views. The white matter is most affected, with noticeable atrophy (tissue loss), in addition to calcification of the arteries. Microinfarcts may also be present in the gray matter (cerebral cortex), sometimes in large numbers.
Although atheroma of the major cerebral arteries is typical in vascular dementia, smaller vessels and arterioles are mainly affected.
It can be difficult to make a Vascular disease diagnosis since there are a variety of symptoms that a person can have, also family history and a physical examination are important. The physical exam may be different depending on the type of vascular disease. In the case of a peripheral vascular disease the physical exam consists in checking the blood flow in the legs.
Treatment varies with the type of vascular disease; in the case of renal artery disease, information from a meta-analysis indicated that balloon angioplasty results in improvement of diastolic blood pressure and a reduction in antihypertensive drug requirements. In the case of peripheral artery disease, preventing complications is important; without treatment, sores or gangrene (tissue death) may occur. Among the treatments are:
- Quitting smoking
- Lowering cholesterol
- Lower blood pressure
- Lower blood glucose
- Physical activity
A study by McKhann et al. compared the neurocognitive outcome of people with coronary artery disease (CAD) to heart-healthy controls (people with no cardiac risk factors). People with CAD were subdivided into treatment with CABG, OPCAB and non-surgical medical management. The three groups with CAD all performed significantly lower at baseline than the heart-healthy controls. All groups improved by 3 months, and there were minimal intrasubject changes from 3 to 12 months. No consistent difference between the CABG and off-pump patients was observed. The authors concluded patients with long-standing coronary artery disease have some degree of cognitive dysfunction secondary to cerebrovascular disease before surgery; there is no evidence the cognitive test performance of bypass surgery patients differed from similar control groups with coronary artery disease over a 12-month follow-up period. A related study by Selnes et al. concluded patients with coronary artery bypass grafting did not differ from a comparable nonsurgical control group with coronary artery disease 1 or 3 years after baseline examination. This finding suggests that late cognitive decline after coronary artery bypass grafting previously reported by Newman et al. may not be specific to the use of cardiopulmonary bypass, but may also occur in patients with very similar risk factors for cardiovascular and cerebrovascular disease.
A study by Newman et al. at Duke University Medical Center published in the "New England Journal of Medicine" (NEJM) showed an increased incidence of cognitive decline after coronary artery bypass surgery (CABG), both immediately (53 percent at discharge from hospital) and over time (36 percent six weeks, 24 percent at six months, and 42 percent at five years). This study shows an association of neurocognitive decline with CABG, but does not show causation; the study lacks a control group and is considered level II-3 evidence. Also, the statistical calculation of cognitive decline has been demonstrated as the least reliable due to practice effects, measurement error and the regression to the mean phenomenon.
Subsequent studies have compared "on-pump" CABG to off-pump coronary artery bypass (OPCAB)—essentially establishing controls to compare the incidence of neurocognitive decline in CABG with and without the use of CPB. A small study (60 patients total, 30 in each treatment arm) by Zamvar et al. demonstrated neurocognitive impairment at both 1 week and 10 weeks postoperatively. A larger study (281 patients total) by Van Dijk et al. showed CABG surgery without cardiopulmonary bypass improved cognitive outcomes 3 months after the procedure, but the effects were limited and became negligible at 12 months. Furthermore, the Van Dijk study showed no difference between the on-pump and off-pump groups in quality of life, stroke rate, or all-cause mortality at 3 and 12 months. A study by Jenson et al. published in Circulation found no significant difference in the incidence of cognitive dysfunction 3 months after either OPCAB or conventional on-pump CABG.
Given the above evidence, there is high incidence of neurocognitive deficit post bypass surgery, but the deficits are transient with no permanent neurological impairment. Controlled "on-pump" versus "off-pump" cardiac surgery has only been studied in the setting of CABG and is not necessarily generalizable to other types of cardiac surgery. Recent advancements in transcatheter and percutaneous valve replacement may soon allow comparison of other types of cardiac surgery with and without CPB.
In cardiology, stunned myocardium is a state when some section of the myocardium (corresponding to area of a major coronary occlusion) shows a form of contractile abnormality. This is a segmental dysfunction which persists for a variable period of time, about two weeks, even after ischemia has been relieved (by for instance angioplasty or coronary artery bypass surgery). In this situation, while myocardial blood flow (MBF) returns to normal, function is still depressed for a variable period of time.
Myocardial stunning is the reversible reduction of function of heart contraction after reperfusion not accounted for by tissue damage or reduced blood flow.
After total ischemia occurs, the myocardium switches immediately from aerobic glycolysis to anaerobic glycolysis resulting in the reduced ability to produce high energy phosphates such as ATP and Creatinine Phosphate. At this point, the lack of the energy and lactate accumulation results in cessation of contraction within 60 seconds of ischemia (i.e. Vessel Occlusion). Subsequent to this is a period of "myocardial stunning," in which reversible ischemic damage is taking place. At approximately 30 minutes after the onset of total ischemia the damage becomes irreversible, thereby ending the phase of myocardial stunning.
Clinical situations of stunned myocardium are:
- acute myocardial infarction (AMI)
- after percutaneous transluminal coronary angioplasty (PTCA)
- after cardiac surgery
- 'neurogenic' stunned myocardium following an acute cerebrovascular event such as a subarachnoid hemorrhage
Several classes of antihypertensive agents are recommended, with the choice depending on the cause of the hypertensive crisis, the severity of the elevation in blood pressure, and the usual blood pressure of the person before the hypertensive crisis. In most cases, the administration of intravenous sodium nitroprusside injection which has an almost immediate antihypertensive effect, is suitable (but in many cases not readily available). Besides, nitroprusside runs a risk of cyanide poisoning. Other intravenous agents like nitroglycerine, nicardipine, labetalol, fenoldopam or phentolamine can also be used, but all have a delayed onset of action (by several minutes) compared to sodium nitroprusside.
In addition, non-pharmacological treatment could be considered in cases of resistant malignant hypertension due to end stage kidney failure, such as surgical nephrectomy, laparoscopic nephrectomy, and renal artery embolization in cases of anesthesia risk.
It is also important that the blood pressure is lowered smoothly, not too abruptly. The initial goal in hypertensive emergencies is to reduce the pressure by no more than 25% (within minutes to 1 or 2 hours), and then toward a level of 160/100 mm Hg within a total of 2–6 hours. Excessive reduction in blood pressure can precipitate coronary, cerebral, or renal ischemia and, possibly, infarction.
The diagnosis of a hypertensive emergency is not based solely on an absolute level of blood pressure, but also on the typical blood pressure level of the patient before the hypertensive crisis occurs. Individuals with a history of chronic hypertension may not tolerate a "normal" blood pressure.
Severe hypertension is a serious and potentially life-threatening medical condition. It is estimated that people who do not receive appropriate treatment only live an average of about three years after the event.
The morbidity and of hypertensive emergencies depend on the extent of end-organ dysfunction at the time of presentation and the degree to which blood pressure is controlled afterward. With good blood pressure control and medication compliance, the 10-year survival rate of patients with hypertensive crises approaches 70%.
The risks of developing a life-threatening disease affecting the heart or brain increase as the blood flow increases. Commonly, ischemic heart attack and stroke are the causes that lead to death in patients with severe hypertension. It is estimated that for every 20 mm Hg systolic or 10 mm Hg diastolic increase in blood pressures above 115/75 mm Hg, the mortality rate for both ischemic heart disease and stroke doubles.
Several studies have concluded that African Americans have a greater incidence of hypertension and a greater morbidity and mortality from hypertensive disease than non-Hispanic whites. It appears that hypertensive crisis is also more common in African Americans compared with other races.
Although severe hypertension is more common in the elderly, it may occur in children (though very rarely). Also, women have slightly increased risks of developing hypertension crises than do men. The lifetime risk for developing hypertension is 86-90% in females and 81-83% in males.
There are no diagnostic tests on which all Sneddon's patients will have abnormal results, although brain MRI and skin biopsy are often abnormal. The diagnosis is based on a detailed history and physical examination. About 40-60% of patients with the syndrome test positive for antiphospholipid antibodies.
Sneddon's patients are generally treated with warfarin, maintaining a high INR of 3-4. Because most will experience significant relief of symptoms after several months of consistent INR in this range, treatment with warfarin is often used as a diagnostic tool.
There is no FDA-approved treatment for agitation in dementia.
Medical treatment may begin with a cholinesterase inhibitor, which appears safer than other alternatives although evidence for its efficacy is mixed. If this does not improve the symptoms, atypical antipsychotics may offer an alternative, although they are effective against agitation only in the short-term while posing a well-documented risk of cerebrovascular events (e.g. stroke). Other possible interventions, such as traditional antipsychotics or antidepressants, are less well studied for this condition.
Diagnosis is confirmed with CT, or bedside ultrasound for less stable patients. Exploratory laparotomy is rarely used, though it may be of benefit in patients with particularly severe hemorrhage. A set of CT scan grading criteria was created to identify the need for intervention (surgery or embolization) in patients with splenic injury. The criteria were established using 20 CT scans from a database of hemodynamically stable patients with blunt splenic injury. These criteria were then validated in 56 consecutive patients retrospectively and appear to reliably predict the need for invasive management in patients with blunt injury to the spleen (sensitivity of 100%, specificity 88%, overall accuracy was 93%).
The study suggested that the following three CT findings correlate with the need for intervention:
1. Devascularization or laceration involving 50% or more of the splenic parenchyma
2. Contrast blush greater than one centimeter in diameter (from active extravasation of IV contrast or pseudoaneurysm formation)
3. A large hemoperitoneum.
Macrovascular disease is a disease of any large ("macro") blood vessels in the body. It is a disease of the large blood vessels, including the coronary arteries, the aorta, and the sizable arteries in the brain and in the limbs.
This sometimes occurs when a person has had diabetes for an extended period of time. Fat and blood clots build up in the large blood vessels and stick to the vessel walls.
Three common macrovascular diseases are coronary disease (in the heart), cerebrovascular disease (in the brain), and peripheral vascular disease (in the limbs)
Macrovascular disease (macroangiopathy) refers to atherosclerosis. Atherosclerosis is a form of arteriosclerosis (thickening and hardening of arterial walls), characterized by plaque deposits of lipids, fibrous connective tissue, calcium, and other blood substances. Atherosclerosis, by definition, affects only medium and large arteries (excluding arterioles).
Macrovascular disease is associated with the development of coronary artery disease, peripheral vascular disease, brain attack (stroke), and increased risk of infection. Type 2 diabetes is more closely associated with macrovascular diseases than type 1 diabetes. Peripheral vascular disease and increased risk of infection have important implications in the care of the acutely ill patient.
It is important to rule out infection and other environmental causes of agitation, such as disease or other bodily discomfort, before initiating any intervention. If no such explanation is found, it is important to support caregivers and educate them about simple strategies such as distraction that may delay the transfer to institutional care (which is often triggered by the onset of agitation).
Diagnosis can be made by EEG. In case of epileptic spasms, EEG shows typical patterns.
Based on these studies, treating to a systolic blood pressure of 140, as long as the diastolic blood pressure is 68 or more, seems safe. Corroborating this, a reanalysis of the SHEP data suggests allowing the diastolic to go below 70 may increase adverse effects.
A meta-analysis of individual patient data from randomized controlled trials found the lowest diastolic blood pressure for which cardiovascular outcomes improve is 85 mm Hg for untreated hypertensives and 80 mm Hg for treated hypertensives. The authors concluded "poor health conditions leading to low blood pressure and an increased risk for death probably explain the J-shaped curve". Interpreting the meta-analysis is difficult, but avoiding a diastolic blood pressure below 68–70 mm Hg seems reasonable because:
- The low value of 85 mm Hg for treated hypertensives in the meta-analysis is higher than the value of 68–70 mm Hg that is suggested by the two major randomized controlled trials of isolated systolic hypertension
- The two largest trials in the meta-analysis, Hypertension Detection and Follow-up Program (HDFP) and Medical Research Council trial in mild hypertension (MRC1) were predominantly middle-aged subjects, all of whom had diastolic hypertension before treatment.
- The independent contributions of diseases and factors other than hypertension versus effects of treatment are not clear in the meta-analysis.
A more contemporary meta-analysis by the Cochrane Hypertension group found no benefits in terms of reduced mortality or morbidity from treating patients to lower diastolic targets than 90–100 mmHg.