Large artery disease, cause

Aphasia and neglect can be found following respectively dominant and non-dominant anterior choroidal artery infarcts. Anterior choroidal artery infarcts usually cause the classical 3H syndrome hemiparesis, hemihypesthesia, hemianopia. Pure motor hemiparesis and isolated hemianopia can also occur (Han et al. 2000). Anterior choroidal artery territory infarcts are rarely caused by small vessel occlusion. In general they are caused by cardioembolism or large artery disease with occlusion or artery-to-artery embolism (Leys et al. 1994). 

Approximately 25% of ischemic strokes are caused by identifiable atherothromboem-bolism from large artery disease, 25% by small vessel disease, 20% by cardioembolism, approximately 5% by rarities, and the remainder are of undetermined etiology (Schulz and Rothwell 2003) (Table 6.2). 

Approximately 20% of ischemic stroke is cardioembolic. There are a large number of potential cardiac sources of embolism (Table 6.3) but it may be difficult to be certain whether an identified putative embolic source is the cause of a stroke, particularly if there are alternative causes such as coexistent large artery disease, or if the stroke is lacunar and unlikely to be caused by cardiac embolism. 

Ischemic stroke has numerous causes. Cerebral infarction may result from large artery atherosclerosis, cardiac embolism, small artery lipohyalinosis, cryptogenic embolism, or, more rarely, from other diverse conditions such as arterial dissection, infective endocarditis, and sickle cell disease. Arterial occlusion is the cause of at least 80% of acute cerebral infarctions. " ... 

Clinical effects A large number of randomized, doubleblind, placebo-controlled trials have shown that the longterm use of (3 blockers improves the clinical status in patients with HF (22-32) (Table 2) and the ACC/AHA guidelines (II) recommend that (3 blockers should be routinely prescribed to all patients with asymptomatic LV dysfunction or stable HF caused by LV systolic dysfunction (unless they have a contraindication or have been shown to be intolerant to treatment with these drugs). (3 blockers should also be used in patients with HF and preserved LV systolic function, particularly when those patients have hypertension, coronary artery disease (CAD) and/or atrial fibrillation. 

Cardiovascular effects include tachycardia, hypertension, and increased cardiac irritability large intravenous doses can cause cardiac failure. Cardiac dysrhythmias have been ascribed to a direct toxic effect of cocaine and a secondary sensitization of ventricular tissue to catecholamines (17), along with slowed cardiac conduction secondary to local anesthetic effects. Myocardial infarction has increased as a complication of cocaine abuse (7,8). Dilated cardiomyopathies, with subsequent recurrent myocardial infarction, have been associated with long-term use of cocaine, raising the possibility of chronic effects on the heart (18). Many victims have evidence of pre-existing fixed coronary artery disease precipitated by cocaine (SEDA-9, 35) (19-21). However, myocardial infarction has been noted even in young intranasal users with no evidence of coronary disease (22), defined by autopsy or angiography (23,24). If applied to mucous membranes, cocaine causes local vasoconstriction, and, with chronic use, necrosis. 

The study of cerebrovascular disease has advanced markedly in recent years with advances in non-invasive imaging methods such as MR angiography and CT angiography as well as an improved understanding of the immune system in the pathogenesis of atherosclerosis. Atherosclerotic cerebrovascular disease is a common cause of strokes and shows a predilection for sites such as the bifurcation of the common carotid artery into the internal and external carotid arteries and the aortic arch and the major intracranial arteries such as the basilar artery and the middle cerebral arteries. Occlusive atherosclerotic vascular disease of these large extracranial arteries is responsible for as many as 20-30% of ischemic strokes and intracranial steno-occlusive disease causes around 5-10% of ischemic strokes. 

Diabetes is linked to hypertension in several important ways. Obesity predisposes patients to hypertension as well as to type 2 diabetes, so many patients suffer from both diseases. Both diseases can damage the kidney and both predispose patients to coronary artery disease. A large clinical trial of patients with type 2 diabetes suggests that poorly controlled hypertension exacerbates the microvascular disease caused by long-standing diabetes. Because of these links, it is important to think about the treatment of hypertension in diabetic patients. 

---