The capsular warning syndrome

Abstract

Transient ischemic attacks (TIAs) are not homogeneous and may consist of subsets with mechanisms as varied as their stroke counterparts. We describe a form of TIA in 50 patients where crescendo episodes of ischemia were restricted to the region of the internal capsule, usually causing symptoms affecting face, arm, and leg. These patients composed 4.5% of a consecutive series of patients admitted with TIAs over a 15-year period and 33% of all TIAs classified as subcortical. We believe that the ischemia was most often due to hemodynamic phenomena in diseases, single, small penetrating vessels. When cerebral infarction developed, it was usually lacunar and involved a single penetrating vessel, although occasionally striatocapsular or anterior choroidal artery territory infarction occurred. There was no evidence of artery-to-artery or heart-to-artery embolism. Resistance to various forms of therapy, including hemodiluting, anticoagulant, and thrombolytic agents, was common. Because of dramatic and easily recognizable clinical presentation, apparent specific pathophysiologic mechanism, and the development of early capsular stroke in a high proportion of cases (42%), we have termed this the "capsular warning syndrome."

Population-based study of capsular warning syndrome and prognosis after early recurrent TIA

“…Although capsular warning syndrome is rare (only 1.5% of TIA presentations in our study), the early risk of stroke in previous studies has been very high. 18,19 Our results show that this poor prognosis still applies today. In contrast to capsular warning syndrome, however, the risk of stroke after recurrent TIAs of other etiologies was much lower in our study.…”

“…10 Many guidelines also recommend urgent evaluation for patients with Ն2 TIAs within 7 days, [11][12][13][14][15][16][17] perhaps in recognition of the capsular warning syndrome. In the classic description of the capsular warning syndrome, multiple, stereotyped motor TIAs precede capsular infarction, 18,19 probably as a consequence of hemodynamic compromise or thrombosis within a small, single penetrating artery or proximal middle cerebral artery stenosis. 19 -21 It is not certain whether all patients with recurrent TIAs are at high early risk of stroke or whether the capsular warning syndrome mainly accounts for the overall increased risk.…”

“…19 -21 It is not certain whether all patients with recurrent TIAs are at high early risk of stroke or whether the capsular warning syndrome mainly accounts for the overall increased risk. Moreover, the prognosis of capsular warning syndrome itself may have changed since the original hospital-based studies of patients presenting in the 1980s and 1990s 18,19 and may also be systematically different in population-based studies. It is also not certain to what extent other treatable underlying pathologic conditions, such as carotid stenosis or atrial fibrillation, are overrepresented in patients with multiple TIAs.…”

Predictive Values of Lacunar Transient Ischemic Attacks

“…4 -6 It has already been shown that lacunar infarction may be preceded by stereotypically repeated clinical events of brief duration, also called lacunar transient ischemic attacks (TIAs), and by symptoms of stepwise, progressive, or abrupt onset. 1,[7][8][9][10] These heterogeneous presentations may account for specific underlying stroke mechanisms of small vessel occlusion such as thrombosis formed locally or vasospasm of the small artery, with transient or permanent distal hemodynamic failure. 9,11 MRI may also show hyperintensities of white matter (ie, leukoaraiosis on computed tomography [CT] scan) and état criblé in association with multiple lacunes.…”

“…1,[7][8][9][10] These heterogeneous presentations may account for specific underlying stroke mechanisms of small vessel occlusion such as thrombosis formed locally or vasospasm of the small artery, with transient or permanent distal hemodynamic failure. 9,11 MRI may also show hyperintensities of white matter (ie, leukoaraiosis on computed tomography [CT] scan) and état criblé in association with multiple lacunes. 12,13 Our hypotheses were that these clinical and radiological characteristics could improve identification of small artery disease (ie, the phenotype of lipohyalinosis) in cases of lacunar syndrome.…”