Defining "progressive stroke".

To the EditorSlivka and Levy 1 have described the natural history of "progressive ischemic stroke" during treatment with heparin. 1 Included among their 69 patients are three in whom worsening of a focal ischemic deficit occurred prior to hospitalization, that is, presumably, unwitnessed by medical personnel.The inclusion of this small minority of patients could not have had significant effect on the overall findings of this retrospective study.However, it again raises questions about the definition of "progressive stroke" or "stroke in evolution" or perhaps about the utility of the concept.First, what elements have been important in the concept of progressive stroke?Worsening of deficit is implied.The worsening occurs relatively early after the onset of the original deficit and implies the action of ongoing pathological processes, especially ischemia.Medical action above and beyond that appropriate for a "stable" case is encouraged.Should deterioration prior to medical witness qualify?If so, all cases except for those with virtually instantaneous onset and those present upon awakening would be called progressive.It is logical to expect most instability near time of onset.Hence, I am surprised by the 66/3 inhospital/prehospital ratio of cases in the Slivka report unless 1) the average time interval from onset of symptoms until admission is unusually short in their series, 2) the authors chose not to use heparin in most cases that worsened before hospitalization (these would have been excluded by their case finding method), or 3) some other criterion has been applied in case selection.I would be interested in knowing which was the case.The semantic problem could be resolved by simply excluding all cases with prehospitalization instability from the definition.Gautier, 2 in discussing the clinical concept of stroke-in-progression, points out that some authoritarian sources would include only cases that deteriorate while under medical supervision.This author concludes, however, that exclusion of cases that worsened prior to hospitalization would make no more sense than discounting patients' reports of a transient ischemic attack or transient monocular blindness.Moreover, the semantic solution is limiting from the clinical point of view.It dictates a wait-and-see posture that may destin any intervention to failure.At the other extreme, we might expand the concept of "progressing" or "evolving" to embrace all early ischemic strokes by emphasizing the idea of continuing high risk, whether the deficit is changing before our eyes or not.Which cases would qualify?First, potential for worsening requires that there be something more to lose, hence the initial deficit must be less than total ("partial") for the vascular territory at risk.Second, the process must be relatively fresh, perhaps within 24 hours of onset for hemispheric lesions, longer for those in the vertebrobasilar distribution.Interventions could be applied expectantly in all such cases, without waiting for deterioration.This policy would encourage "all out" therapy for a large number of stroke patients although only an unpredictable fraction will actually worsen clinically.Such a policy would also maximize the chances that an effective therapy (yet to be discovered) will actually be so in any given case, but at the expense of treating some patients unnecessarily.