Classification of strokes

Classification of stroke. (Adapted from Fagan SC, Hess DC. Stroke. 

FIGURE 20-1. A classification of stroke by mechanism with estimates of the frequency of various categories of abnormalities. Approximately 30% of ischemic strokes are cryptogenic. 

Chawla M., Sharma S., Sivaswamy J., and Kishore L. T. (2009) A method for automatic detection and classification of stroke from brain CT images, Proc. Ann, hit. Conf. IEEE Eng. Med. Biol. Soc. (EMBC 09), 2009. 

Adams HP, Jr., Bendixen BH, Kappelle LJ, Biller J, Love BB, Gordon DL, Marsh EE, 3rd. Classification of subtype of acute ischemic stroke. Definitions for use in a multicenter clinical trial. TOAST. Trial of Org 10172 in Acute Stroke Treatment. Stroke. 1993 24 35 1. 

Using clinical and emergency CT findings, the TOAST investigators found that their initial designation of subtype of stroke matched the final diagnosis in only 62% of patients. No subtype of stroke was more accurately diagnosed than another by initial assessment. In a series of 100 consecutive stroke patients, the accuracy of the initial classification was reported as 1Q% ... 

Using only a few neurological findings the Oxfordshire Community Stroke Project (OCSP) classification allocates strokes to four subgroups, locating them either in the territory of the anterior (total anterior circulation infarct, TACI partial anterior circulation infarct, PACI lacunar infarct, LACI) and the posterior circulation, (posterior circulation infarct, POCI) (Bamford et al. 1991). The OCSP is a clinical syndromic classification, which... 

Compared with brain ischemia spinal cord strokes are caused by more diverse etiologies. Up-to-now there is no satisfactory and accepted classification of spinal infarcts. Etiologies include circulatory arterial and venous disorders. From a clinical and pathoanatomical point of view it seems reasonable to differentiate between acute ischemic myelomalacia and subacute to chronic vascular myelopathy (Table 17.1). In most cases MRI enables the differentiation of these two main etiologies. A deficient spinal arterial blood flow generally has various causes, ranging from the occlusion of intercostal or lumbar arteries to affection of the intrinsic arteries of the spinal cord. ... 

Woo J, Kay R, Yuen YK et al. (1992). Factors influencing long-term survival and disability among three-month stroke survivors. Neuroepidemiology 11 143-150 World Health Organization (1987). International Classification of Diseases,... 

Ischemic strokes account for around 80-85% of all strokes and are caused by arterial vascular occlusions rarely occlusion in the cerebral venous system may result in ischemic and/or hemorrhagic stroke. Arterial occlusions resulting from cerebral embolism are the most common causes of ischemic strokes, and by about one week after stroke as many as 70-90% of occlusions will have spontaneously recanalized. Emboli typically originate from atherosclerotic stenoses in the internal carotid artery or from sources in the heart such as clots in the left atrium or the left ventricle. Hypertension-induced vascular disease of the small perforating intracerebral arteries is a common cause of lacunar strokes. A classification of the major stroke subtypes is shown in Table 31.1. 

Although several approaches to stroke classification have been described, the most common mechanism-based classification in current use is the system described by the TOAST investigators." This classification describes five major subtypes of ischemic stroke based on the results of neuroimaging and other medical investigations, namely (1) LAA, (2) cardioembolism, (3) small-vessel occlusion, (4) stroke of other determined etiology, and (5) stroke of undetermined etiology. Inter-rater reliability of the TOAST scheme has been reported as moderate-to-substantial K 0.5-0.7). 

---