Cerebral areas most susceptible to ischemic damage include the speech and motor cortices, leading to contralateral paralysis, speech, and comprehension loss. Severe or prolonged strokes may terminate in coma or brain death. Therefore, the diagnosis and treatment of ischemic stroke are time-dependent. Diagnosis
There are several methods of diagnosing arterial occlusion, ranging from straightforward setups like exercise testing, to advanced scanning equipment such as ultrasonic duplex scanning or Multi-Detector Coronary Tomography (MDCT) angiography. Exercise Testing
Exercise testing is a simplistic, non-invasive method of diagnosing intermittent claudication. Blood pressure measurements at the suspected area can be taken before and after exercise, as some symptoms only appear during strenuous activity. Commonly, a treadmill setting at 2 mph with a 12-degree slope is utilized. Subjects are asked to walk on the treadmill for a maximum of 5 minutes or until moderate pain is felt. The time to pain or maximal walking duration is recorded and compared with baselines. Healthy individuals maintain systolic blood pressures at a normal range. Once exercise becomes more intense, there may be a temporary fall in systolic pressure, which quickly returns to normal with rest. However, those with intermittent claudication struggle to maintain standard values of systolic pressure, while recovery back to baseline is prolonged. Ultrasonic Duplex Testing
Ultrasonic duplex scanning was developed to primarily determine the extent of atherosclerosis in carotid arteries. Since then, its application has widened to include arteries in the limbs. The technique utilizes high-frequency sound waves for visualization of flow direction and velocity within the arteries in an area of interest.
Hypertension can also be caused by endocrine conditions, such as Cushings syndrome, hyperthyroidism, hypothyroidism, acromegaly, Conns syndrome or hyperaldosteronism, renal artery stenosis (from atherosclerosis or fibromuscular dysplasia), hyperparathyroidism, and pheochromocytoma. Other causes of secondary hypertension include obesity, sleep apnea, pregnancy, coarctation of the aorta, excessive eating of liquorice, excessive drinking of alcohol, certain prescription medicines, herbal remedies, and stimulants such as coffee, cocaine and methamphetamine. Arsenic exposure through drinking water has been shown to correlate with elevated blood pressure. Depression was also linked to hypertension. Loneliness is also a risk factor.A 2018 review found that any alcohol increased blood pressure in males while over one or two drinks increased the risk in females. Pathophysiology
In most people with established essential hypertension, increased resistance to blood flow (total peripheral resistance) accounts for the high pressure while cardiac output remains normal. There is evidence that some younger people with prehypertension or borderline hypertension have high cardiac output, an elevated heart rate and normal peripheral resistance, termed hyperkinetic borderline hypertension. These individuals develop the typical features of established essential hypertension in later life as their cardiac output falls and peripheral resistance rises with age. Whether this pattern is typical of all people who ultimately develop hypertension is disputed. The increased peripheral resistance in established hypertension is mainly attributable to structural narrowing of small arteries and arterioles, although a reduction in the number or density of capillaries may also contribute.It is not clear whether or not vasoconstriction of arteriolar blood vessels plays a role in hypertension.