The Stroke-Prone State
Rapid Assessment of Transient Ischemic Attacks
There is no doubt that transient ischemic attack (TIA) heralds stroke and that urgent assessment and management are essential. Recent evidence has emphasized the brief time window available for stroke prevention in many patients. In one study of ischemic stroke with a preceding TIA, the warning event had occurred in 26% of cases within a day.1 The key issues are the identification of high-risk patients and optimizing management in individual centers. Challenges include accuracy of diagnosis and rapid access to appropriate resources, necessitating both expert clinical opinion and modern imaging facilities. Both of our protagonists agree that urgent assessment is essential, but on our request, they have taken divergent views concerning the need for hospitalization, which reflect the range of current clinical practice.
Interestingly, in recent years, because of increasing pressures on hospital systems worldwide, there has been a reallocation of hospital resources with a greater emphasis on emergency care and shorter length of stay. One approach has been the development of rapid assessment, short-stay units, often attached to emergency departments. This model eliminates the inpatient/outpatient dichotomy alluded to by our protagonists and provides an efficient system for TIA management. Emergency department algorithms for TIA patients must involve expert stroke opinion because accurate diagnosis is often difficult, as emphasized by Lindley. We have all had the experience of being called to see a TIA patient who has clearly had an event caused by migraine, epilepsy, and numerous other pathologies, or indeed has had an established stroke.
Although we encourage the specialized assessment of patients with TIA, we fear that the establishment of “TIA outpatient clinics” de-emphasizes the urgency required for their assessment. Specialized areas of assessment need to be established, which are appropriately badged to underscore the urgency of the problem of TIA management.
The diagnosis of high-risk TIA patients remains a challenge. It has been suggested that diffusion-weighted imaging might predict those at highest risk, although an alternative explanation is that a positive diffusion-weighted imaging scan merely rules out the many patients with other causes of transient neurological events.2 A number of investigators identified clinical predictors of high-risk patients for subsequent stroke as indicated by Hill.
It is worth remembering that the high-risk nature of the TIA patient is not a new concept.3 However, more recent studies have highlighted the urgency of the problem in the context of modern imaging techniques and evolving management options. Whether TIA patients are managed as inpatients or outpatients is probably immaterial as long as the patient who is in this high-risk stroke-prone state is quickly recognized and managed urgently.