Arterial occlusion is a condition involving partial or complete blockage of blood flow through an artery. Arteries are blood vessels that carry oxygenated blood to body tissues. An occlusion of arteries disrupts oxygen and blood supply to tissues, leading to ischemia. Depending on the extent of ischemia, symptoms of arterial occlusion range from simple soreness and pain that can be relieved with rest, to a lack of sensation or paralysis that could require amputation.Arterial occlusion can be classified into three types based on etiology: embolism, thrombosis, and atherosclerosis. These three types of occlusion underlie various common conditions, including coronary artery disease, peripheral artery disease, and pulmonary embolism, which may be prevented by lowering risk factors. With improper prevention or management, these diseases can progress into life-threatening complications of myocardial infarction, gangrene, ischemic stroke, and in severe cases, terminate in brain death or cardiac arrest.Arterial occlusion is diagnosed by exercise testing, ultrasonic duplex testing, and multi-detector coronary tomography angiography. Meanwhile, treatment can vary from surgical interventions such as bypass, endarterectomy, and embolectomy, to blood-thinning medication. Signs and symptoms
Signs and symptoms of arterial occlusion depend on several factors, including the location, extent, and onset of blockage. Normally, the blockage should affect approximately 70% of the artery for symptoms to become noticeable. Symptoms can be less severe during gradual narrowing, as this allows time for the widening of existing vessels and the formation of new ones (collateral vessels), allowing blood to still reach the area. Symptoms in this case will simply be intermittent claudication.
has been used as a primary diagnostic technique for discerning how SD patients understand word meaning.Speech of SD patients is marked by word-finding pauses, reduced frequency of content words, semantic paraphasias, circumlocutions, increased ratios of verbs to nouns, increased numbers of adverbs, and multiple repeats.SD patients sometimes show symptoms of surface dyslexia, a relatively selective impairment in reading low-frequency words with exceptional or atypical spelling-to-sound correspondences.It is currently unknown why semantic memory is impaired and semantic knowledge deteriorates in SD patients, though the cause may be due to damage to an amodal semantic system. This theory is supported by the atrophy of the anterior temporal lobe, which is believed to contain a component of the semantic system that integrates conceptual information. Others hypothesize that the damage is predominantly to the ventral temporal cortex, since SD patients remember numbers and music, but have trouble associating visual cues to concrete words.Due to the variety of symptoms dementia patients present, it becomes more difficult to assess semantic memory capability especially with regard to musical elements. In order to circumvent the explicit verbal learning tests for dementia, semantic melodic matching is a useful technique for detecting the semantic memory of semantic dementia patients. Moreover, it is important to maintain that these tests must be compared to nonmusical domain tests, as music cognition is not often measured in semantic dementia patients (less data available).