Sinais tomográficos precoces do AVC isquémico
Palavras-chave:
acidente vascular cerebral, tomografia axial computorizadaResumo
A utilidade da Tomografia Axial Computorizada (TAC)
nas primeiras horas de um Acidente Vascular Cerebral
(AVC) isquémico tem sido reforçada. Não só se demonstrou
a sua capacidade para encontrar alterações nessas circunstâncias, como essas alterações poderão determinar ou não
a indicação para a terapêutica fibrinolítica. Desta forma, é
importante que todos os médicos envolvidos na abordagem
de doentes com AVC estejam familiarizados com os sinais
tomográficos precoces de um AVC isquémico.
As alterações da densidade dos tecidos cerebrais resultantes de isquemia são teoricamente visíveis em exames
tomográficos realizados nas primeiras 4 horas após o seu
início. Na prática, tal foi também verificado em estudos, quer animais, quer no homem.
O edema isquémico, sinal da artéria hiperdensa e edema
cerebral são as alterações potencialmente visíveis numa TAC
realizada nas primeiras horas após um AVC isquémico. Cada
um tem um significado e implicações próprias que, nalguns
casos, poderão chegar à contraindicação para fibrinólise.
Os autores apresentam exemplos de cada um dos sinais
precoces anteriormente referidos.
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Referências
Bronner LL, Kanter DS, Manson JE. Primary prevention of stroke. N Engl J Med 1995; 333 (21): 1392-1400.
Bogousslavsky J, Kaste M, Olsen TS, Hacke W, Orgogozo JM. Risk factors and stroke prevention. Cerebrovasc Dis 2000; 10( 3): 12-21.
Kaste M, Olsen TS, Orgogozo JM, Bogousslavsky J, Hacke W. Organization of stroke care: education, stroke units and rehabilitation.
Cerebrovasc Dis 2000; 10( 3): 1-11.
Adams HP, Brott TG, Furlan AJ et al. Guidelines for thrombolytic therapy for acute stroke: a supplement to the guidelines for the management of patients with acute ischemic stroke. Circulation 1996; 94: 1167-1174.
Von Kummer R. Effect of training in reading CT scans on patient selection for ECASS II. Neurology 1998; 51 ( 3): S50-S52.
Von Kummer R, Bozzao L, Manelfe C. Early CT diagnosis of hemispheric brain infarction. Springer-Verlag, Berlin. 1995: 89-95.
The National Institute of Neurological Disorders and Stroke rt-PA Stroke Study Group. Tissue plasminogen activator for acute ischemic stroke. N Engl J Med 1995; 333: 1581-1587.
Hacke W, Kaste M, Fieschi C et al. Intravenous thrombolysis with recombinant tissue plasminogen activator for acute ischemic stroke: the
European Cooperative Acute Stroke Study (ECASS). JAMA 1995; 274: 1017-1025.
Von Kummer R, Weber J. Brain and vascular imaging in acute ischemic stroke: the potencial of computed tomography. Neurology 1997; 49 ( 4): S52-S55.
Marks MP, Holmgren EB, Fox AJ, Patel S, von Kummer R, Froehlich J. Evaluation of early computed tomographic findings in acute ischemic
stroke. Stroke 1999; 30: 389-392.
Moulin T, Cattin F, Crépin-Leblond T, et al. Early CT signs in acute middle cerebral artery infarction: predictive value for subsequent infarct
locations and outcome. Neurology 1996; 47: 366-375.
Von Kummer R, Allen KL, Holle R, et al. Acute stroke: usefulness of early CT findings before thrombolytic therapy. Radiology 1997; 205:
-333.
Von Kummer R. Computed tomography in acute stroke. Personal comunication. 4th EUSI Stroke Summer School, Rome, July 2000.
Schuier FJ, Hossmann KA. Experimental brain infarcts in cats. II. Ischemic brain edema. Stroke 1980; 11: 593-601.
Hossmann KA. Viability thresholds and the penumbra of focal ischemia. Ann Neurol 1994; 36: 557-565.
Unger E, Littlefield J, Gado M. Water content and water structure in CT and MR signal changes: possible influence in detection of early
stroke. AJNR 1988; 9: 687-691.
Truwit Cl et al. Loss of the insular ribbon: another early CT sign of acute middle cerebral artery infarction. Radiology 1990; 176: 801-806.
Horowitz SH, et al. Computed tomographic and angiographic findings within the first five hours of cerebral infarction. Stroke 1991; 22: 1245-1253.
Tomura N et al. Early CT finding in cerebral infarction: obscuration of the lentiform nucleus. Radiology 1988; 168: 463-467.
Bozzao L et al. Correlation of angiographic and sequential CT findings in patients with evolving cerebral infarction. Am J Neuroradiol 1989;
: 1215-1222.
Von Kummer R, Meyding-Lamadé U, Forsting M, et al. Sensitivity and prognostic value of early CT in occlusion of the middle cerebral
artery trunk. Am J Neuroradiol 1994; 15: 9-15.
Huk WJ. Invasive and non-invasive vascular imaging techniques and their role in clinical stroke trials. In Thrombolytic therapy in acute
ischemic stroke. Hacke W, del Zoppo G, Hirschberg M, eds. Springer Verlag, Berlin 1991;186-195.
Wolpert SM, Pessin MS. The relevance of CT scanning and angiography in patients with acute stroke treated with rt-PA. In Thrombolytic
therapy in acute ischemic stroke II. Del Zoppo G, Mori E, Hacke W, eds. Springer-Verlag, Berlin. 1993. 189-191.
Gàcs G, Fox AJ, Barnett HJM, Vinuela F. CT visualization of intracranial arterial thromboembolism. Stroke 1983; 14: 756- 762.
Pressman BD, Tourje EJ, Thompson JR. An early CT sign of ischemic infarction: increased density in a cerebral artery. Am J Neuroradiol
; 8: 645-648.
Schuierer G, Huk W. The unilateral hyperdense middle cerebral artery: an early CT-sign of embolism or thrombosis. Neuroradiology 1988;
: 120-122.
Tomsick TA. Commentary. Sensitivity and prognostic value of early CT in occlusion of the middle cerebral artery trunk. Am J Neuroradiol
; 15: 16-18.
Leys D et al. Prevalence and significance of hyperdense middle cerebral artery in acute stroke. Stroke 1992; 23: 317-324
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